"""cmd2 - quickly build feature-rich and user-friendly interactive command line applications in Python.

cmd2 is a tool for building interactive command line applications in Python. Its goal is to make it quick and easy for
developers to build feature-rich and user-friendly interactive command line applications. It provides a simple API which
is an extension of Python's built-in cmd module. cmd2 provides a wealth of features on top of cmd to make your life easier
and eliminates much of the boilerplate code which would be necessary when using cmd.

Extra features include:
- Searchable command history (commands: "history")
- Run commands from file, save to file, edit commands in file
- Multi-line commands
- Special-character shortcut commands (beyond cmd's "?" and "!")
- Settable environment parameters
- Parsing commands with `argparse` argument parsers (flags)
- Redirection to file or paste buffer (clipboard) with > or >>
- Bash-style ``select`` available

Note: cmd2 redirection only captures output directed to self.stdout (e.g., via self.poutput()).
Standard print() calls write directly to sys.stdout and are not captured. However, print() calls
within pyscripts and the interactive Python shell are treated as command output and sent to
self.stdout, allowing them to be captured.

GitHub: https://github.com/python-cmd2/cmd2
Documentation: https://cmd2.readthedocs.io/
"""

# This module has many imports, quite a few of which are only
# infrequently utilized. To reduce the initial overhead of
# import this module, many of these imports are lazy-loaded
# i.e. we only import the module when we use it.
import argparse
import contextlib
import copy
import dataclasses
import datetime
import functools
import glob
import inspect
import os
import pydoc
import re
import sys
import tempfile
import threading
import time
from code import InteractiveConsole
from collections import deque
from collections.abc import (
    Callable,
    Iterable,
    Mapping,
    Sequence,
)
from dataclasses import (
    dataclass,
    field,
)
from types import FrameType
from typing import (
    IO,
    TYPE_CHECKING,
    Any,
    ClassVar,
    NamedTuple,
    TextIO,
    TypeVar,
    cast,
)

from prompt_toolkit import (
    filters,
    print_formatted_text,
)
from prompt_toolkit.application import create_app_session, get_app
from prompt_toolkit.auto_suggest import AutoSuggestFromHistory
from prompt_toolkit.completion import Completer, DummyCompleter
from prompt_toolkit.formatted_text import ANSI, AnyFormattedText
from prompt_toolkit.history import InMemoryHistory
from prompt_toolkit.input import DummyInput, create_input
from prompt_toolkit.key_binding import KeyBindings
from prompt_toolkit.output import DummyOutput, create_output
from prompt_toolkit.patch_stdout import patch_stdout
from prompt_toolkit.shortcuts import CompleteStyle, PromptSession, choice, set_title
from prompt_toolkit.styles import DynamicStyle
from rich.console import (
    Group,
    JustifyMethod,
    RenderableType,
)
from rich.highlighter import ReprHighlighter
from rich.pretty import Pretty
from rich.rule import Rule
from rich.style import (
    Style,
    StyleType,
)
from rich.table import (
    Column,
    Table,
)
from rich.text import Text
from rich.traceback import Traceback

from . import (
    argparse_completer,
    argparse_utils,
    constants,
    plugin,
    utils,
)
from . import rich_utils as ru
from . import string_utils as su
from .argparse_utils import (
    ArgparseCommandSpec,
    Cmd2ArgumentParser,
    ParserSource,
    SubcommandRecord,
    SubcommandSpec,
)
from .clipboard import (
    get_paste_buffer,
    write_to_paste_buffer,
)
from .command_set import CommandSet
from .completion import (
    Choices,
    CompletionItem,
    Completions,
)
from .constants import (
    COMMAND_FUNC_PREFIX,
    COMPLETER_FUNC_PREFIX,
    HELP_FUNC_PREFIX,
)
from .decorators import (
    as_subcommand_to,
    with_argparser,
)
from .exceptions import (
    Cmd2ShlexError,
    CommandSetRegistrationError,
    CompletionError,
    EmbeddedConsoleExit,
    EmptyStatement,
    IncompleteStatement,
    MacroError,
    PassThroughException,
    RedirectionError,
    SkipPostcommandHooks,
)
from .history import (
    History,
    HistoryItem,
)
from .parsing import (
    Macro,
    MacroArg,
    Statement,
    StatementParser,
    shlex_split,
)
from .rich_utils import (
    Cmd2BaseConsole,
    Cmd2ExceptionConsole,
    Cmd2GeneralConsole,
    Cmd2SimpleTable,
    TextGroup,
)
from .styles import Cmd2Style
from .theme import get_pt_theme
from .types import (
    BoundCommandFunc,
    BoundCompleter,
    CmdOrSet,
    CmdOrSetT,
    UnboundChoicesProvider,
    UnboundCompleter,
)

try:
    if sys.platform == "win32":
        from prompt_toolkit.output.win32 import NoConsoleScreenBufferError  # type: ignore[attr-defined]
    else:
        # Trigger the except block for non-Windows platforms
        raise ImportError  # noqa: TRY301
except ImportError:

    class NoConsoleScreenBufferError(Exception):  # type: ignore[no-redef]
        """Dummy exception to use when prompt_toolkit.output.win32.NoConsoleScreenBufferError is not available."""

        def __init__(self, msg: str = "") -> None:
            """Initialize NoConsoleScreenBufferError custom exception instance."""
            super().__init__(msg)


from .pt_utils import (
    Cmd2Completer,
    Cmd2History,
    Cmd2Lexer,
    pt_filter_style,
    pt_resolve_color_depth,
)
from .utils import (
    Settable,
    get_defining_class,
    get_types,
    strip_doc_annotations,
    suggest_similar,
)

if TYPE_CHECKING:  # pragma: no cover
    from prompt_toolkit.buffer import Buffer


class _SavedCmd2Env:
    """cmd2 environment settings that are backed up when entering an interactive Python shell."""

    def __init__(self) -> None:
        self.history: list[str] = []
        self.completer: Callable[[str, int], str | None] | None = None


class DisabledCommand(NamedTuple):
    """Stores data about a disabled command.

    This data is used to restore its functions when the command is enabled.
    """

    command_func: BoundCommandFunc
    help_func: Callable[[], Any] | None
    completer_func: BoundCompleter | None


class CommandParsers:
    """Create and store all command method argument parsers for a given Cmd instance.

    Parser creation and retrieval are accomplished through the get() method.
    """

    def __init__(self, cmd_app: "Cmd") -> None:
        """Initialize CommandParsers.

        :param cmd_app: the Cmd instance whose parsers are being managed
        """
        self._cmd_app = cmd_app

        # Keyed by the fully qualified method names. This is more reliable than
        # the methods themselves, since wrapping a method will change its address.
        self._parsers: dict[str, Cmd2ArgumentParser] = {}

    @staticmethod
    def _fully_qualified_name(command_method: BoundCommandFunc) -> str:
        """Return the fully qualified name of a method or None if a method wasn't passed in."""
        try:
            return f"{command_method.__module__}.{command_method.__qualname__}"
        except AttributeError:
            return ""

    def __contains__(self, command_method: BoundCommandFunc) -> bool:
        """Return whether a given method's parser is in self.

        If the parser does not yet exist, it will be created if applicable.
        This is basically for checking if a method is argarse-based.
        """
        parser = self.get(command_method)
        return bool(parser)

    def get(self, command_method: BoundCommandFunc) -> Cmd2ArgumentParser | None:
        """Return a given method's parser or None if the method is not argparse-based.

        If the parser does not yet exist, it will be created.
        """
        full_method_name = self._fully_qualified_name(command_method)
        if not full_method_name:
            return None

        if full_method_name not in self._parsers:
            if not command_method.__name__.startswith(COMMAND_FUNC_PREFIX):
                return None
            command = command_method.__name__[len(COMMAND_FUNC_PREFIX) :]

            spec: ArgparseCommandSpec | None = getattr(command_method, constants.ARGPARSE_COMMAND_ATTR_SPEC, None)
            if spec is None:
                return None

            owner = self._cmd_app.find_commandset_for_command(command) or self._cmd_app
            parser = self._cmd_app._build_parser(owner, spec.parser_source)

            # To ensure accurate usage strings, recursively update 'prog' values
            # within the parser to match the command name.
            parser.update_prog(command)

            # If the description has not been set, then use the method docstring if one exists
            if parser.description is None and command_method.__doc__:
                parser.description = strip_doc_annotations(command_method.__doc__)

            self._parsers[full_method_name] = parser

        return self._parsers.get(full_method_name)

    def remove(self, command_method: BoundCommandFunc) -> None:
        """Remove a given method's parser if it exists."""
        full_method_name = self._fully_qualified_name(command_method)
        if full_method_name in self._parsers:
            del self._parsers[full_method_name]


@dataclass(kw_only=True)
class AsyncAlert:
    """Contents of an asynchronous alert which display while user is at prompt.

    :param msg: an optional printable object (including Rich renderables) to be
                printed above the prompt.
    :param soft_wrap: Enable soft wrap mode. This only applies with msg is not None.
                      Defaults to True. See print_to() docstring for more details on
                      this parameter.
    :param prompt: an optional string to dynamically replace the current prompt.

    :ivar timestamp: monotonic creation time of the alert. If an alert was created
                     before the current prompt was rendered, its prompt data is ignored
                     to avoid a stale display, but its msg data will still be displayed.
    """

    msg: Any | None = None
    soft_wrap: bool = True
    prompt: str | None = None
    timestamp: float = field(default_factory=time.monotonic, init=False)


@dataclass
class _ConsoleCache(threading.local):
    """Thread-local storage for cached Rich consoles used by core print methods."""

    stdout: Cmd2BaseConsole | None = None
    stderr: Cmd2BaseConsole | None = None


class Cmd:
    """An easy but powerful framework for writing line-oriented command interpreters.

    Extends the Python Standard Library's cmd package by adding a lot of useful features
    to the out of the box configuration.

    Line-oriented command interpreters are often useful for test harnesses, internal tools, and rapid prototypes.
    """

    DEFAULT_COMPLETEKEY: ClassVar[str] = "tab"
    DEFAULT_EDITOR: ClassVar[str | None] = utils.find_editor()
    DEFAULT_PROMPT: ClassVar[str] = "(Cmd) "

    # Default category for commands defined in this class which have
    # not been explicitly categorized with the @with_category decorator.
    # This value is inherited by subclasses but they can set their own
    # DEFAULT_CATEGORY to place their commands into a custom category.
    # Subclasses can also reassign cmd2.Cmd.DEFAULT_CATEGORY to rename
    # the category used for the framework's built-in commands.
    DEFAULT_CATEGORY: ClassVar[str] = "Cmd2 Commands"

    # Header for table listing help topics not related to a command.
    MISC_HEADER: ClassVar[str] = "Miscellaneous Help Topics"

    def __init__(
        self,
        completekey: str | None = None,
        stdin: TextIO | None = None,
        stdout: TextIO | None = None,
        *,
        allow_cli_args: bool = True,
        allow_clipboard: bool = True,
        allow_redirection: bool = True,
        auto_load_commands: bool = False,
        auto_suggest: bool = True,
        complete_in_thread: bool = True,
        command_sets: Iterable[CommandSet[Any]] | None = None,
        enable_bottom_toolbar: bool = False,
        enable_rprompt: bool = False,
        include_ipy: bool = False,
        include_py: bool = False,
        intro: RenderableType = "",
        multiline_commands: Iterable[str] | None = None,
        persistent_history_file: str = "",
        persistent_history_length: int = 1000,
        refresh_interval: float = 0.0,
        shortcuts: Mapping[str, str] | None = None,
        silence_startup_script: bool = False,
        startup_script: str = "",
        suggest_similar_command: bool = False,
        terminators: Iterable[str] | None = None,
    ) -> None:
        """Easy but powerful framework for writing line-oriented command interpreters, extends Python's cmd package.

        :param completekey: name of a completion key, default to 'tab'. (If None or an empty string, 'tab' is used)
        :param stdin: alternate input file object, if not specified, sys.stdin is used
        :param stdout: alternate output file object, if not specified, sys.stdout is used
        :param allow_cli_args: if ``True``, then [cmd2.Cmd.__init__][] will process command
                               line arguments as either commands to be run. This should be
                               set to ``False`` if your application parses its own command line
                               arguments.
        :param allow_clipboard: If False, cmd2 will disable clipboard interactions
        :param allow_redirection: If ``False``, prevent output redirection and piping to shell
                                  commands. This parameter prevents redirection and piping, but
                                  does not alter parsing behavior. A user can still type
                                  redirection and piping tokens, and they will be parsed as such
                                  but they won't do anything.
        :param auto_load_commands: If True, cmd2 will check for all subclasses of `CommandSet`
                                   that are currently loaded by Python and automatically
                                   instantiate and register all commands. If False, CommandSets
                                   must be manually installed with `register_command_set`.
        :param auto_suggest: If True, cmd2 will provide fish shell style auto-suggestions
                            based on history. User can press right-arrow key to accept the
                            provided suggestion.
        :param complete_in_thread: if ``True``, then completion will run in a separate thread.
        :param command_sets: Provide CommandSet instances to load during cmd2 initialization.
                             This allows CommandSets with custom constructor parameters to be
                             loaded.  This also allows the a set of CommandSets to be provided
                             when `auto_load_commands` is set to False
        :param enable_bottom_toolbar: if ``True``, enables a bottom toolbar while at the main prompt.
                                      Override ``get_bottom_toolbar()`` to define its content.
        :param enable_rprompt: if ``True``, enables a right prompt while at the main prompt.
                               Override ``get_rprompt()`` to define its content.
        :param include_ipy: should the "ipy" command be included for an embedded IPython shell
        :param include_py: should the "py" command be included for an embedded Python shell
        :param intro: introduction to display at startup
        :param multiline_commands: Iterable of commands allowed to accept multi-line input
        :param persistent_history_file: file path to load a persistent cmd2 command history from
        :param persistent_history_length: max number of history items to write
                                          to the persistent history file
        :param refresh_interval: How often, in seconds, to refresh the UI. Defaults to 0.0.
                                 prompt-toolkit already refreshes the UI every time a key is pressed.
                                 Set this value if you need the UI to update automatically without
                                 user input (e.g., for displaying a clock or background status
                                 updates in the bottom toolbar).
        :param shortcuts: Mapping containing shortcuts for commands. If not supplied,
                          then defaults to constants.DEFAULT_SHORTCUTS. If you do not want
                          any shortcuts, pass None and an empty dictionary will be created.
        :param silence_startup_script: if ``True``, then the startup script's output will be
                                       suppressed. Anything written to stderr will still display.
        :param startup_script: file path to a script to execute at startup
        :param suggest_similar_command: if ``True``, then when a command is not found,
                                        [cmd2.Cmd][] will look for similar commands and suggest them.
        :param terminators: Iterable of characters that terminate a command. These are mainly
                            intended for terminating multiline commands, but will also
                            terminate single-line commands. If not supplied, the default
                            is a semicolon. If your app only contains single-line commands
                            and you want terminators to be treated as literals by the parser,
                            then set this to None.
        """
        # Check if py or ipy need to be disabled in this instance
        if not include_py:
            setattr(self, "do_py", None)  # noqa: B010
        if not include_ipy:
            setattr(self, "do_ipy", None)  # noqa: B010

        # initialize plugin system
        # needs to be done before we most of the other stuff below
        self._initialize_plugin_system()

        # Configure a few defaults
        self.prompt: str = self.DEFAULT_PROMPT
        self.intro = intro

        if not completekey:
            completekey = self.DEFAULT_COMPLETEKEY

        # What to use for standard input
        if stdin is not None:
            self.stdin = stdin
        else:
            self.stdin = sys.stdin

        # Standard output stream. The interactive UI remains attached to this initial
        # stream even when self.stdout is temporarily swapped during command output
        # redirection.
        if stdout is not None:
            self.stdout = stdout
        else:
            self.stdout = sys.stdout

        # Attributes which should NOT be dynamically settable via the set command at runtime
        self.allow_redirection = allow_redirection  # Security setting to prevent redirection of stdout

        # If True, cmd2 treats redirected input (pipes/files) as an interactive session.
        # It will display the prompt before reading each line to synchronize with
        # automation tools (like Pexpect) and will skip echoing the input to prevent
        # duplicate prompts in the output.
        self.interactive_pipe = False

        # Attributes which ARE dynamically settable via the set command at runtime
        self.debug = False
        self.echo = False
        self.editor = self.DEFAULT_EDITOR
        self.quiet = False  # Do not suppress nonessential output
        self.scripts_add_to_history = True  # Scripts and pyscripts add commands to history
        self.timing = False  # Prints elapsed time for each command

        # Default settings for Rich tracebacks created by format_exception().
        # This dictionary can contain any parameter accepted by the
        # rich.traceback.Traceback class. You can modify it to adjust
        # the detail and layout of tracebacks.
        self.traceback_kwargs: dict[str, Any] = {
            "width": 100,
            "code_width": None,  # Show all code characters
            "show_locals": False,
            "max_frames": 100,
            "word_wrap": True,  # Wrap long lines of code instead of truncate
            "indent_guides": True,
        }

        # Cached Rich consoles used by core print methods.
        self._console_cache = _ConsoleCache()

        # The maximum number of items to display in a completion table. If the number of completion
        # suggestions exceeds this number, then no table will appear.
        self.max_completion_table_items: int = 50

        # The maximum number of completion results to display in a single column (CompleteStyle.COLUMN).
        # If the number of results exceeds this, CompleteStyle.MULTI_COLUMN will be used.
        self.max_column_completion_results: int = 7

        # A dictionary mapping settable names to their Settable instance
        self._settables: dict[str, Settable] = {}
        self._always_prefix_settables: bool = False

        # CommandSet containers
        self._installed_command_sets: set[CommandSet[Any]] = set()
        self._cmd_to_command_sets: dict[str, CommandSet[Any]] = {}

        self.build_settables()

        # Use as prompt for multiline commands on the 2nd+ line of input
        self.continuation_prompt: str = "> "

        # Allow access to your application in embedded Python shells and pyscripts via self
        self.self_in_py = False

        # Commands to exclude from the help menu and completion
        self.hidden_commands = ["_eof", "_relative_run_script"]

        # Initialize history from a persistent history file (if present)
        self.persistent_history_file = ""
        self._persistent_history_length = persistent_history_length
        self._initialize_history(persistent_history_file)

        # Create the main PromptSession
        self.main_session = self._create_main_session(
            auto_suggest=auto_suggest,
            complete_in_thread=complete_in_thread,
            completekey=completekey,
            enable_bottom_toolbar=enable_bottom_toolbar,
            enable_rprompt=enable_rprompt,
            refresh_interval=refresh_interval,
        )

        # The session currently holding focus (either the main REPL or a command's
        # custom prompt). Completion and UI logic should reference this variable
        # to ensure they modify the correct session state.
        self.active_session = self.main_session

        # Commands to exclude from the history command
        self.exclude_from_history = ["_eof", "history"]

        # Dictionary of macro names and their values
        self.macros: dict[str, Macro] = {}

        # Keeps track of typed command history in the Python shell
        self._py_history: list[str] = []

        # The name by which Python environments refer to the PyBridge to call app commands
        self.py_bridge_name = "app"

        # Defines app-specific variables/functions available in Python shells and pyscripts
        self.py_locals: dict[str, Any] = {}

        # True if running inside a Python shell or pyscript, False otherwise
        self._in_py = False

        self.statement_parser: StatementParser = StatementParser(
            terminators=terminators, multiline_commands=multiline_commands, shortcuts=shortcuts
        )

        # Stores results from the last command run to enable usage of results in Python shells and pyscripts
        self.last_result: Any = None

        # Used by run_script command to store current script dir as a LIFO queue to support _relative_run_script command
        self._script_dir: list[str] = []

        # Context manager used to protect critical sections in the main thread from stopping due to a KeyboardInterrupt
        self.sigint_protection: utils.ContextFlag = utils.ContextFlag()

        # If the current command created a process to pipe to, then this will be a ProcReader object.
        # Otherwise it will be None. It's used to know when a pipe process can be killed and/or waited upon.
        self._cur_pipe_proc_reader: utils.ProcReader | None = None

        # Used to keep track of whether we are redirecting or piping output
        self._redirecting = False

        # Set text which prints right before all of the help tables are listed.
        self.doc_leader = ""

        # The error that prints when no help information can be found
        self.help_error = "No help on {}"

        # The error that prints when a non-existent command is run
        self.default_error = "{} is not a recognized command, alias, or macro."

        # If non-empty, this string will be displayed if a broken pipe error occurs
        self.broken_pipe_warning = ""

        # Commands that will run at the beginning of the command loop
        self._startup_commands: list[str] = []

        # Store initial termios settings to restore after each command.
        # This is a faster way of accomplishing what "stty sane" does.
        self._initial_termios_settings = None
        if not sys.platform.startswith("win") and self.stdin.isatty():
            try:
                import io
                import termios

                self._initial_termios_settings = termios.tcgetattr(self.stdin.fileno())
            except (ImportError, io.UnsupportedOperation, termios.error):
                # This can happen if termios isn't available or stdin is a pseudo-TTY
                self._initial_termios_settings = None

        # If a startup script is provided and exists, then execute it in the startup commands
        if startup_script:
            startup_script = os.path.abspath(os.path.expanduser(startup_script))
            if os.path.exists(startup_script):
                script_cmd = f"run_script {su.quote(startup_script)}"
                if silence_startup_script:
                    script_cmd += f" {constants.REDIRECTION_OVERWRITE} {os.devnull}"
                self._startup_commands.append(script_cmd)

        # Check for command line args
        if allow_cli_args:
            parser = argparse_utils.DEFAULT_ARGUMENT_PARSER()
            _callopts, callargs = parser.parse_known_args()

            # If commands were supplied at invocation, then add them to the command queue
            if callargs:
                self._startup_commands.extend(callargs)

        # Set the pager(s) for use when displaying output using a pager
        if sys.platform.startswith("win"):
            self.pager = self.pager_chop = "more"
        else:
            # Here is the meaning of the various flags we are using with the less command:
            # -S causes lines longer than the screen width to be chopped (truncated) rather than wrapped
            # -R causes ANSI "style" escape sequences to be output in raw form (i.e. colors are displayed)
            # -X disables sending the termcap initialization and deinitialization strings to the terminal
            # -F causes less to automatically exit if the entire file can be displayed on the first screen
            self.pager = "less -RXF"
            self.pager_chop = "less -SRXF"

        # This boolean flag stores whether cmd2 will allow clipboard related features
        self.allow_clipboard = allow_clipboard

        # This determines the value returned by cmdloop() when exiting the application
        self.exit_code = 0

        # Commands disabled during specific application states
        # Key: Command name | Value: DisabledCommand object
        # NOTE: Use disable_command() and enable_command() to modify this dictionary.
        self.disabled_commands: dict[str, DisabledCommand] = {}

        # Categories of commands to be disabled
        # Key: Category name | Value: Message to display
        # NOTE: Use disable_category() and enable_category() to modify this dictionary.
        self.disabled_categories: dict[str, str] = {}

        # Command parsers for this Cmd instance.
        self.command_parsers: CommandParsers = CommandParsers(self)

        # Members related to printing asynchronous alerts
        self._alert_queue: deque[AsyncAlert] = deque()
        self._alert_condition = threading.Condition()
        self._alert_allowed = False
        self._alert_shutdown = False
        self._alert_thread: threading.Thread | None = None
        self._alert_prompt_timestamp: float = 0.0  # Uses time.monotonic()

        # Add functions decorated to be subcommands
        self._register_subcommands(self)

        ############################################################################################################
        # The following code block loads CommandSets, verifies command names, and registers subcommands.
        # This block should appear after all attributes have been created since the registration code
        # depends on them and it's possible a module's on_register() method may need to access some.
        ############################################################################################################
        # Load modular commands
        if command_sets:
            for command_set in command_sets:
                self.register_command_set(command_set)

        if auto_load_commands:
            self._autoload_commands()

        # Verify commands don't have invalid names (like starting with a shortcut)
        for cur_cmd in self.get_all_commands():
            valid, errmsg = self.statement_parser.is_valid_command(cur_cmd)
            if not valid:
                raise ValueError(f"Invalid command name '{cur_cmd}': {errmsg}")

        self.suggest_similar_command = suggest_similar_command
        self.default_suggestion_message = "Did you mean {}?"

        # the current command being executed
        self.current_command: Statement | None = None

    def _should_continue_multiline(self) -> bool:
        """Return whether prompt-toolkit should continue prompting the user for a multiline command."""
        buffer: Buffer = get_app().current_buffer
        line: str = buffer.text

        used_macros = []

        # Continue until all macros are resolved
        while True:
            try:
                statement = self._check_statement_complete(line)
            except IncompleteStatement:
                # The statement (or the resolved macro) is incomplete.
                # Keep prompting the user.
                return True

            except (Cmd2ShlexError, EmptyStatement):
                # These are "finished" states (even if they are errors).
                # Submit so the main loop can handle the exception.
                return False

            # Check if this command matches a macro and wasn't already processed to avoid an infinite loop
            if statement.command in self.macros and statement.command not in used_macros:
                used_macros.append(statement.command)
                try:
                    line = self._resolve_macro(statement)
                except MacroError:
                    # Resolve failed. Submit to let the main loop handle the error.
                    return False
            else:
                # No macro found or already processed. The statement is complete.
                return False

    def _create_main_session(
        self,
        *,
        auto_suggest: bool,
        complete_in_thread: bool,
        completekey: str,
        enable_bottom_toolbar: bool,
        enable_rprompt: bool,
        refresh_interval: float,
    ) -> PromptSession[str]:
        """Create and return the main PromptSession for the application.

        Builds an interactive session if self.stdin and self.stdout are TTYs.
        Otherwise, uses dummy drivers to support non-interactive streams like
        pipes or files.
        """
        # Configure custom key bindings
        key_bindings = KeyBindings()

        # Add a binding for 'enter' that triggers only when a completion is selected.
        # This allows accepting a completion without submitting the command.
        @key_bindings.add("enter", filter=filters.completion_is_selected)
        def _(event: Any) -> None:  # pragma: no cover
            event.current_buffer.complete_state = None

        if completekey != self.DEFAULT_COMPLETEKEY:
            # Configure prompt_toolkit `KeyBindings` with the custom key for completion
            @key_bindings.add(completekey)
            def _(event: Any) -> None:  # pragma: no cover
                """Trigger completion."""
                b = event.current_buffer
                if b.complete_state:
                    b.complete_next()
                else:
                    b.start_completion(select_first=False)

        # Base configuration
        kwargs: dict[str, Any] = {
            "auto_suggest": AutoSuggestFromHistory() if auto_suggest else None,
            "bottom_toolbar": self.get_bottom_toolbar if enable_bottom_toolbar else None,
            "color_depth": pt_resolve_color_depth(),
            "complete_style": CompleteStyle.MULTI_COLUMN,
            "complete_in_thread": complete_in_thread,
            "complete_while_typing": False,
            "completer": Cmd2Completer(self),
            "history": Cmd2History(item.raw for item in self.history),
            "key_bindings": key_bindings,
            "lexer": Cmd2Lexer(self),
            "multiline": filters.Condition(self._should_continue_multiline),
            "prompt_continuation": self.continuation_prompt,
            "refresh_interval": refresh_interval,
            "rprompt": self.get_rprompt if enable_rprompt else None,
            "style": DynamicStyle(get_pt_theme),
        }

        if self.stdin.isatty() and self.stdout.isatty():
            try:
                if self.stdin != sys.stdin:
                    kwargs["input"] = create_input(stdin=self.stdin)
                if self.stdout != sys.stdout:
                    kwargs["output"] = create_output(stdout=self.stdout)
                return PromptSession(**kwargs)

            except (NoConsoleScreenBufferError, AttributeError, ValueError):
                # Fallback to dummy input/output if PromptSession initialization fails.
                # This can happen in some CI environments (like GitHub Actions on Windows)
                # where isatty() is True but there is no real console.
                pass

        # Fallback to dummy drivers for non-interactive environments.
        kwargs.update(
            {
                "input": DummyInput(),
                "output": DummyOutput(),
            }
        )
        return PromptSession(**kwargs)

    def find_commandsets(
        self, commandset_type: type[CommandSet[Any]], *, subclass_match: bool = False
    ) -> list[CommandSet[Any]]:
        """Find all CommandSets that match the provided CommandSet type.

        By default, locates a CommandSet that is an exact type match but may optionally return all CommandSets that
        are sub-classes of the provided type
        :param commandset_type: CommandSet sub-class type to search for
        :param subclass_match: If True, return all sub-classes of provided type, otherwise only search for exact match
        :return: Matching CommandSets
        """
        return [
            cmdset
            for cmdset in self._installed_command_sets
            if type(cmdset) == commandset_type or (subclass_match and isinstance(cmdset, commandset_type))  # noqa: E721
        ]

    def find_commandset_for_command(self, command_name: str) -> CommandSet[Any] | None:
        """Find the CommandSet that registered the command name.

        :param command_name: command name to search
        :return: CommandSet that provided the command
        """
        return self._cmd_to_command_sets.get(command_name)

    def _autoload_commands(self) -> None:
        """Load modular command definitions."""
        # Search for all subclasses of CommandSet, instantiate them if they weren't already provided in the constructor
        all_commandset_defs = CommandSet.__subclasses__()
        existing_commandset_types = [type(command_set) for command_set in self._installed_command_sets]

        def load_commandset_by_type(commandset_types: list[type[CommandSet[Any]]]) -> None:
            for cmdset_type in commandset_types:
                # check if the type has sub-classes. We will only auto-load leaf class types.
                subclasses = cmdset_type.__subclasses__()
                if subclasses:
                    load_commandset_by_type(subclasses)
                else:
                    init_sig = inspect.signature(cmdset_type.__init__)
                    if not (
                        cmdset_type in existing_commandset_types
                        or len(init_sig.parameters) != 1
                        or "self" not in init_sig.parameters
                    ):
                        cmdset = cmdset_type()
                        self.register_command_set(cmdset)

        load_commandset_by_type(all_commandset_defs)

    def register_command_set(self, cmdset: CommandSet[Any]) -> None:
        """Installs a CommandSet, loading all commands defined in the CommandSet.

        :param cmdset: CommandSet to load
        """
        existing_commandset_types = [type(command_set) for command_set in self._installed_command_sets]
        if type(cmdset) in existing_commandset_types:
            raise CommandSetRegistrationError("CommandSet " + type(cmdset).__name__ + " is already installed")

        all_settables = self.settables
        if self.always_prefix_settables:
            if not cmdset.settable_prefix.strip():
                raise CommandSetRegistrationError("CommandSet settable prefix must not be empty")
            for key in cmdset.settables:
                prefixed_name = f"{cmdset.settable_prefix}.{key}"
                if prefixed_name in all_settables:
                    raise CommandSetRegistrationError(f"Duplicate settable: {key}")

        else:
            for key in cmdset.settables:
                if key in all_settables:
                    raise CommandSetRegistrationError(f"Duplicate settable {key} is already registered")

        cmdset.on_register(self)
        methods = cast(
            list[tuple[str, Callable[..., Any]]],
            inspect.getmembers(
                cmdset,
                predicate=lambda meth: (  # type: ignore[arg-type]
                    isinstance(meth, Callable)  # type: ignore[arg-type]
                    and hasattr(meth, "__name__")
                    and meth.__name__.startswith(COMMAND_FUNC_PREFIX)
                ),
            ),
        )

        installed_attributes = []
        try:
            for cmd_func_name, command_method in methods:
                command = cmd_func_name[len(COMMAND_FUNC_PREFIX) :]

                self._install_command_function(cmd_func_name, command_method, type(cmdset).__name__)
                installed_attributes.append(cmd_func_name)

                completer_func_name = COMPLETER_FUNC_PREFIX + command
                cmd_completer = getattr(cmdset, completer_func_name, None)
                if cmd_completer is not None:
                    self._install_completer_function(command, cmd_completer)
                    installed_attributes.append(completer_func_name)

                help_func_name = HELP_FUNC_PREFIX + command
                cmd_help = getattr(cmdset, help_func_name, None)
                if cmd_help is not None:
                    self._install_help_function(command, cmd_help)
                    installed_attributes.append(help_func_name)

                self._cmd_to_command_sets[command] = cmdset

                # If this command is in a disabled category, then disable it
                command_category = self._get_command_category(command_method)
                if command_category in self.disabled_categories:
                    message_to_print = self.disabled_categories[command_category]
                    self.disable_command(command, message_to_print)

            self._installed_command_sets.add(cmdset)

            self._register_subcommands(cmdset)
            cmdset.on_registered()
        except Exception:
            cmdset.on_unregister()
            for attrib in installed_attributes:
                delattr(self, attrib)
            if cmdset in self._installed_command_sets:
                self._installed_command_sets.remove(cmdset)
            if cmdset in self._cmd_to_command_sets.values():
                self._cmd_to_command_sets = {key: val for key, val in self._cmd_to_command_sets.items() if val is not cmdset}
            cmdset.on_unregistered()
            raise

    def _build_parser(
        self,
        owner: CmdOrSet,
        parser_source: ParserSource[Any],
    ) -> Cmd2ArgumentParser:
        """Build argument parser for a command/subcommand.

        :param owner: the object that owns the command. If parser_source requires
                      a class argument (like a classmethod), this object's class is passed.
        :param parser_source: an existing Cmd2ArgumentParser instance or a factory
                              (callable, staticmethod, or classmethod) that returns one.
        :return: new parser
        :raises TypeError: if parser_source is an invalid type or if the factory fails
                           to return a Cmd2ArgumentParser
        """
        # Handle existing parser
        if isinstance(parser_source, argparse.ArgumentParser):
            if not isinstance(parser_source, Cmd2ArgumentParser):
                raise TypeError(
                    f"The parser must be an instance of 'Cmd2ArgumentParser' (or subclass). "
                    f"Received: '{type(parser_source).__name__}'."
                )
            return copy.deepcopy(parser_source)

        # Handle factories
        if isinstance(parser_source, staticmethod):
            parser = parser_source.__func__()
        elif isinstance(parser_source, classmethod):
            parser = parser_source.__func__(owner.__class__)
        else:
            # Following the ParserSource definition, any function with parameters
            # is assumed to be a one-argument factory expecting the owner's class.
            builder_sig = inspect.signature(parser_source)

            if builder_sig.parameters:
                parser = cast(Callable[[Any], Cmd2ArgumentParser], parser_source)(owner.__class__)
            else:
                parser = cast(Callable[[], Cmd2ArgumentParser], parser_source)()

        # Verify the factory returned the required type
        if not isinstance(parser, Cmd2ArgumentParser):
            builder_name = getattr(parser_source, "__name__", str(parser_source))  # type: ignore[unreachable]
            raise TypeError(
                f"'{builder_name}' must return a 'Cmd2ArgumentParser' (or subclass). Received: '{type(parser).__name__}'."
            )

        return parser

    def _install_command_function(self, command_func_name: str, command_method: BoundCommandFunc, context: str = "") -> None:
        """Install a new command function into the CLI.

        :param command_func_name: name of command function to add
                                  This points to the command method and may differ from the method's
                                  name if it's being used as a synonym. (e.g. do_exit = do_quit)
        :param command_method: the actual command method which runs when the command function is called
        :param context: optional info to provide in error message. (e.g. class this function belongs to)
        :raises CommandSetRegistrationError: if the command function fails to install
        """
        # command_func_name must begin with COMMAND_FUNC_PREFIX to be identified as a command by cmd2.
        if not command_func_name.startswith(COMMAND_FUNC_PREFIX):
            raise CommandSetRegistrationError(f"{command_func_name} does not begin with '{COMMAND_FUNC_PREFIX}'")

        # command_method must start with COMMAND_FUNC_PREFIX for use in self.command_parsers.
        if not command_method.__name__.startswith(COMMAND_FUNC_PREFIX):
            raise CommandSetRegistrationError(f"{command_method.__name__} does not begin with '{COMMAND_FUNC_PREFIX}'")

        command = command_func_name[len(COMMAND_FUNC_PREFIX) :]

        # Make sure command function doesn't share name with existing attribute
        if hasattr(self, command_func_name):
            raise CommandSetRegistrationError(f"Attribute already exists: {command_func_name} ({context})")

        # Check if command has an invalid name
        valid, errmsg = self.statement_parser.is_valid_command(command)
        if not valid:
            raise CommandSetRegistrationError(f"Invalid command name '{command}': {errmsg}")

        # Check if command shares a name with an alias
        if command in self.aliases:
            self.pwarning(f"Deleting alias '{command}' because it shares its name with a new command")
            del self.aliases[command]

        # Check if command shares a name with a macro
        if command in self.macros:
            self.pwarning(f"Deleting macro '{command}' because it shares its name with a new command")
            del self.macros[command]

        setattr(self, command_func_name, command_method)

    def _install_completer_function(self, cmd_name: str, cmd_completer: BoundCompleter) -> None:
        completer_func_name = COMPLETER_FUNC_PREFIX + cmd_name

        if hasattr(self, completer_func_name):
            raise CommandSetRegistrationError(f"Attribute already exists: {completer_func_name}")
        setattr(self, completer_func_name, cmd_completer)

    def _install_help_function(self, cmd_name: str, cmd_help: Callable[..., None]) -> None:
        help_func_name = HELP_FUNC_PREFIX + cmd_name

        if hasattr(self, help_func_name):
            raise CommandSetRegistrationError(f"Attribute already exists: {help_func_name}")
        setattr(self, help_func_name, cmd_help)

    def unregister_command_set(self, cmdset: CommandSet[Any]) -> None:
        """Uninstalls a CommandSet and unloads all associated commands.

        :param cmdset: CommandSet to uninstall
        """
        if cmdset in self._installed_command_sets:
            self._check_uninstallable(cmdset)
            cmdset.on_unregister()
            self._unregister_subcommands(cmdset)

            methods: list[tuple[str, Callable[..., Any]]] = inspect.getmembers(
                cmdset,
                predicate=lambda meth: (  # type: ignore[arg-type]
                    isinstance(meth, Callable)  # type: ignore[arg-type]
                    and hasattr(meth, "__name__")
                    and meth.__name__.startswith(COMMAND_FUNC_PREFIX)
                ),
            )

            for cmd_func_name, command_method in methods:
                command = cmd_func_name[len(COMMAND_FUNC_PREFIX) :]

                # Enable the command before uninstalling it to make sure we remove both
                # the real functions and the ones used by the DisabledCommand object.
                if command in self.disabled_commands:
                    self.enable_command(command)

                if command in self._cmd_to_command_sets:
                    del self._cmd_to_command_sets[command]

                # Only remove the parser if this is the actual
                # command since command synonyms don't own it.
                if cmd_func_name == command_method.__name__:
                    self.command_parsers.remove(command_method)

                if hasattr(self, COMPLETER_FUNC_PREFIX + command):
                    delattr(self, COMPLETER_FUNC_PREFIX + command)
                if hasattr(self, HELP_FUNC_PREFIX + command):
                    delattr(self, HELP_FUNC_PREFIX + command)

                delattr(self, cmd_func_name)

            cmdset.on_unregistered()
            self._installed_command_sets.remove(cmdset)

    def _check_uninstallable(self, cmdset: CommandSet[Any]) -> None:
        """Verify if a CommandSet can be safely uninstalled from the application.

        This method acts as a safety guard before unregistration. It inspects all
        command parsers provided by the CommandSet and recursively checks their
        subcommand hierarchies to ensure no other CommandSet or Cmd instance has
        attached subcommands to them.

        :param cmdset: the CommandSet instance to check for uninstallation safety
        :raises CommandSetRegistrationError: if it is not safe to uninstall the CommandSet
        """
        cmdset_id = id(cmdset)

        def check_parser_uninstallable(parser: Cmd2ArgumentParser) -> None:
            # Recursively verify no subcommands belong to a different CommandSet or Cmd instance
            try:
                subparsers_action = parser.get_subparsers_action()
            except ValueError:
                # No subcommands to check
                return

            # Prevent redundant traversal of parser aliases
            checked_parsers: set[Cmd2ArgumentParser] = set()

            for subparser in subparsers_action.choices.values():
                if subparser in checked_parsers:
                    continue
                checked_parsers.add(subparser)

                owner_id = getattr(subparser, constants.PARSER_ATTR_OWNER_ID, None)
                if owner_id is not None and owner_id != cmdset_id:
                    raise CommandSetRegistrationError(
                        f"Cannot uninstall CommandSet '{type(cmdset).__name__}' because it is still "
                        f"required by subcommand '{subparser.prog}'"
                    )
                check_parser_uninstallable(subparser)

        methods: list[tuple[str, Callable[..., Any]]] = inspect.getmembers(
            cmdset,
            predicate=lambda meth: (  # type: ignore[arg-type]
                isinstance(meth, Callable)  # type: ignore[arg-type]
                and hasattr(meth, "__name__")
                and meth.__name__.startswith(COMMAND_FUNC_PREFIX)
            ),
        )

        for cmd_func_name, command_method in methods:
            # We only need to check if it's safe to remove the parser if this
            # is the actual command since command synonyms don't own it.
            if cmd_func_name == command_method.__name__:
                command_parser = self.command_parsers.get(command_method)
                if command_parser is not None:
                    check_parser_uninstallable(command_parser)

    def _register_subcommands(self, owner: CmdOrSet) -> None:
        """Register subcommands with their base command.

        :param owner: Cmd or CommandSet which owns the subcommand functions
        """
        if not (owner is self or owner in self._installed_command_sets):
            raise CommandSetRegistrationError("Cannot register subcommands with an unregistered CommandSet")

        # find methods that have the required attributes necessary to be recognized as a sub-command
        methods = inspect.getmembers(
            owner,
            predicate=lambda meth: (
                isinstance(meth, Callable)  # type: ignore[arg-type]
                and hasattr(meth, constants.SUBCOMMAND_ATTR_SPEC)
            ),
        )

        # iterate through all matching methods
        for _method_name, method in methods:
            spec: SubcommandSpec = getattr(method, constants.SUBCOMMAND_ATTR_SPEC)

            subcommand_valid, errmsg = self.statement_parser.is_valid_command(spec.name, is_subcommand=True)
            if not subcommand_valid:
                raise CommandSetRegistrationError(f"Subcommand {spec.name} is not valid: {errmsg}")

            # Create the subcommand parser and configure it
            subcmd_parser = self._build_parser(owner, spec.parser_source)
            if subcmd_parser.description is None and method.__doc__:
                subcmd_parser.description = strip_doc_annotations(method.__doc__)

            # Set the subcommand function
            defaults = {constants.NS_ATTR_SUBCOMMAND_FUNC: method}
            subcmd_parser.set_defaults(**defaults)

            # Record the ID of the instance that registered this subcommand parser
            setattr(subcmd_parser, constants.PARSER_ATTR_OWNER_ID, id(owner))

            # Attach this subcommand
            record = SubcommandRecord(
                name=spec.name,
                command=spec.command,
                help=spec.help,
                aliases=spec.aliases,
                deprecated=spec.deprecated,
                parser=subcmd_parser,
            )

            try:
                self.attach_subcommand(record)
            except ValueError as ex:
                raise CommandSetRegistrationError(str(ex)) from ex

    def _unregister_subcommands(self, owner: CmdOrSet) -> None:
        """Unregister subcommands from their base command.

        :param owner: Cmd or CommandSet which owns the subcommand functions
        """
        if not (owner is self or owner in self._installed_command_sets):
            raise CommandSetRegistrationError("Cannot unregister subcommands with an unregistered CommandSet")

        # find methods that have the required attributes necessary to be recognized as a sub-command
        methods = inspect.getmembers(
            owner,
            predicate=lambda meth: (
                isinstance(meth, Callable)  # type: ignore[arg-type]
                and hasattr(meth, constants.SUBCOMMAND_ATTR_SPEC)
            ),
        )

        # iterate through all matching methods
        for _method_name, method in methods:
            spec: SubcommandSpec = getattr(method, constants.SUBCOMMAND_ATTR_SPEC)

            with contextlib.suppress(ValueError):
                self.detach_subcommand(spec.command, spec.name)

    def get_root_parser_and_subcmd_path(self, command: str) -> tuple[Cmd2ArgumentParser, list[str]]:
        """Tokenize a command string and resolve the associated root parser and relative subcommand path.

        This helper handles the initial resolution of a command string (e.g., 'foo bar baz') by
        identifying 'foo' as the root command, retrieving its associated parser, and returning
        any remaining tokens (['bar', 'baz']) as a path relative to that parser for further traversal.

        :param command: full space-delimited command path leading to a parser (e.g. 'foo' or 'foo bar')
        :return: a tuple containing the Cmd2ArgumentParser for the root command and a list of
                 strings representing the relative path to the desired hosting parser.
        :raises ValueError: if the command is empty, the root command is not found, or
                            the root command does not use an argparse parser.
        """
        tokens = command.split()
        if not tokens:
            raise ValueError("Command path cannot be empty")

        root_command = tokens[0]
        subcommand_path = tokens[1:]

        # Search for the base command function and verify it has a parser defined
        command_func = self.get_command_func(root_command)
        if command_func is None:
            raise ValueError(f"Root command '{root_command}' does not exist")

        root_parser = self.command_parsers.get(command_func)
        if root_parser is None:
            raise ValueError(f"Command '{root_command}' does not use argparse")

        return root_parser, subcommand_path

    def attach_subcommand(self, record: SubcommandRecord) -> None:
        """Attach a parser as a subcommand to a command at the specified path.

        :param record: SubcommandRecord object describing the subcommand
        :raises TypeError: if record.parser is not an instance of Cmd2ArgumentParser (or subclass)
        :raises ValueError: if the command path is invalid, doesn't support subcommands, or the
                            subcommand already exists
        """
        root_parser, subcommand_path = self.get_root_parser_and_subcmd_path(record.command)
        root_parser.attach_subcommand(record, subcommand_path=subcommand_path)

    def detach_subcommand(self, command: str, subcommand: str) -> SubcommandRecord:
        """Detach a subcommand from a command at the specified path.

        :param command: full command path (space-delimited) leading to the parser hosting the
                        subcommand to be detached (e.g. 'foo bar')
        :param subcommand: name of the subcommand to detach
        :return: a SubcommandRecord object describing the detached subcommand
        :raises ValueError: if the command path is invalid or the subcommand doesn't exist
        """
        root_parser, subcommand_path = self.get_root_parser_and_subcmd_path(command)
        return root_parser.detach_subcommand(subcommand_path, subcommand)

    def detach_all_subcommands(self, command: str) -> list[SubcommandRecord]:
        """Detach all subcommands from a command at the specified path.

        :param command: full command path (space-delimited) leading to the parser hosting the
                        subcommands to be detached (e.g. 'foo bar')
        :return: a list of SubcommandRecord objects describing the detached subcommands
        :raises ValueError: if the command path is invalid or the command doesn't support subcommands
        """
        root_parser, subcommand_path = self.get_root_parser_and_subcmd_path(command)
        return root_parser.detach_all_subcommands(subcommand_path)

    @property
    def always_prefix_settables(self) -> bool:
        """Flags whether CommandSet settable values should always be prefixed.

        :return: True if CommandSet settable values will always be prefixed. False if not.
        """
        return self._always_prefix_settables

    @always_prefix_settables.setter
    def always_prefix_settables(self, value: bool) -> None:
        """Set whether CommandSet settable values should always be prefixed.

        :param value: True if CommandSet settable values should always be prefixed. False if not.
        :raises ValueError: If a registered CommandSet does not have a defined prefix
        """
        if not self._always_prefix_settables and value:
            for cmd_set in self._installed_command_sets:
                if not cmd_set.settable_prefix:
                    raise ValueError(
                        f"Cannot force settable prefixes. CommandSet {cmd_set.__class__.__name__} does "
                        f"not have a settable prefix defined."
                    )
        self._always_prefix_settables = value

    @property
    def settables(self) -> Mapping[str, Settable]:
        """Get all available user-settable attributes. This includes settables defined in installed CommandSets.

        :return: Mapping from attribute-name to Settable of all user-settable attributes from
        """
        all_settables = dict(self._settables)
        for cmd_set in self._installed_command_sets:
            cmdset_settables = cmd_set.settables
            for settable_name, settable in cmdset_settables.items():
                if self.always_prefix_settables:
                    all_settables[f"{cmd_set.settable_prefix}.{settable_name}"] = settable
                else:
                    all_settables[settable_name] = settable
        return all_settables

    def add_settable(self, settable: Settable) -> None:
        """Add a settable parameter to ``self.settables``.

        :param settable: Settable object being added
        """
        if not self.always_prefix_settables and settable.name in self.settables and settable.name not in self._settables:
            raise KeyError(f"Duplicate settable: {settable.name}")
        self._settables[settable.name] = settable

    def remove_settable(self, name: str) -> None:
        """Remove a settable parameter from ``self.settables``.

        :param name: name of the settable being removed
        :raises KeyError: if the Settable matches this name
        """
        try:
            del self._settables[name]
        except KeyError as exc:
            raise KeyError(name + " is not a settable parameter") from exc

    def build_settables(self) -> None:
        """Create the dictionary of user-settable parameters."""

        def get_allow_style_choices(_cli_self: Cmd) -> Choices:
            """Complete allow_style values."""
            styles = [val.name.lower() for val in ru.AllowStyle]
            return Choices.from_values(styles)

        def allow_style_type(value: str) -> ru.AllowStyle:
            """Convert a string value into an ru.AllowStyle."""
            try:
                return ru.AllowStyle[value.upper()]
            except KeyError as ex:
                raise ValueError(
                    f"must be {ru.AllowStyle.ALWAYS}, {ru.AllowStyle.NEVER}, or {ru.AllowStyle.TERMINAL} (case-insensitive)"
                ) from ex

        settable_description = Text.assemble(
            "Allow styled text in output (Options: ",
            (str(ru.AllowStyle.ALWAYS), Style(bold=True)),
            ", ",
            (str(ru.AllowStyle.NEVER), Style(bold=True)),
            ", ",
            (str(ru.AllowStyle.TERMINAL), Style(bold=True)),
            ")",
        )
        self.add_settable(
            Settable(
                "allow_style",
                allow_style_type,
                settable_description,
                self,
                choices_provider=get_allow_style_choices,
            )
        )
        self.add_settable(Settable("debug", bool, "Show full traceback on exception", self))
        self.add_settable(Settable("echo", bool, "Echo command issued into output", self))

        editor_description = Text.assemble(
            "Program used by ",
            ("'edit'", Style(bold=True)),
            " command",
        )
        self.add_settable(
            Settable(
                "editor",
                str,
                editor_description,
                self,
            )
        )

        self.add_settable(
            Settable(
                "max_completion_table_items",
                int,
                "Max results allowed to display a table",
                self,
            )
        )
        self.add_settable(
            Settable(
                "max_column_completion_results",
                int,
                "Max results to display in a single column",
                self,
            )
        )
        self.add_settable(Settable("quiet", bool, "Don't print nonessential feedback", self))
        self.add_settable(Settable("scripts_add_to_history", bool, "Scripts and pyscripts add commands to history", self))
        self.add_settable(Settable("timing", bool, "Report execution times", self))
        self.add_settable(Settable("traceback_show_locals", bool, "Display local variables in tracebacks", self))

        traceback_width_description = Text.assemble(
            "Maximum display width for tracebacks. Set to ",
            ("None", Style(bold=True)),
            " (case-insensitive) to fill entire terminal width.",
        )
        self.add_settable(
            Settable(
                "traceback_width",
                utils.optional_int,
                traceback_width_description,
                self,
            )
        )

    @property
    def allow_style(self) -> ru.AllowStyle:
        """Property needed to support do_set when it reads allow_style."""
        return ru.ALLOW_STYLE

    @allow_style.setter
    def allow_style(self, value: ru.AllowStyle) -> None:
        """Setter property needed to support do_set when it updates allow_style."""
        ru.ALLOW_STYLE = value
        self.main_session.color_depth = pt_resolve_color_depth()

    @property
    def traceback_show_locals(self) -> bool:
        """Property needed to support do_set when it reads traceback_show_locals."""
        if "show_locals" in self.traceback_kwargs:
            return cast(bool, self.traceback_kwargs["show_locals"])

        # If setting is not present, then return its default value.
        traceback_sig = inspect.signature(Traceback.__init__)
        show_locals = traceback_sig.parameters["show_locals"].default
        return cast(bool, show_locals)

    @traceback_show_locals.setter
    def traceback_show_locals(self, value: bool) -> None:
        """Setter property needed to support do_set when it updates traceback_show_locals."""
        self.traceback_kwargs["show_locals"] = value

    @property
    def traceback_width(self) -> int | None:
        """Property needed to support do_set when it reads traceback_width."""
        if "width" in self.traceback_kwargs:
            return cast(int | None, self.traceback_kwargs["width"])

        # If setting is not present, then return its default value.
        traceback_sig = inspect.signature(Traceback.__init__)
        width = traceback_sig.parameters["width"].default
        return cast(int | None, width)

    @traceback_width.setter
    def traceback_width(self, value: int | None) -> None:
        """Setter property needed to support do_set when it updates traceback_width."""
        self.traceback_kwargs["width"] = value

    @property
    def visible_prompt(self) -> str:
        """Read-only property to get the visible prompt with any ANSI style sequences stripped.

        Useful for test frameworks doing comparisons without having to worry about color/style.

        :return: the stripped prompt
        """
        return su.strip_style(self.prompt)

    def _get_core_print_console(
        self,
        *,
        file: IO[str],
        emoji: bool,
        markup: bool,
        highlight: bool,
    ) -> Cmd2BaseConsole:
        """Get a console configured for the specified stream and formatting settings.

        This method is intended for internal use by cmd2's core print methods.
        To avoid the overhead of repeated initialization, it manages a thread-local
        cache for consoles targeting ``self.stdout`` or ``sys.stderr``. It returns a cached
        instance if its configuration matches the request. For all other streams, or if
        the configuration has changed, a new console is created.

        Note: This implementation works around a bug in Rich where passing formatting settings
        (emoji, markup, and highlight) directly to console.print() or console.log() does not
        always work when printing certain Renderables. Passing them to the constructor instead
        ensures they are correctly propagated. Once this bug is fixed, these parameters can
        be removed from this method. For more details, see:
        https://github.com/Textualize/rich/issues/4028
        """
        # Dictionary of settings to check against cached consoles
        kwargs = {
            "emoji": emoji,
            "markup": markup,
            "highlight": highlight,
        }

        # Check if we should use or update a cached console
        if file is self.stdout:
            cached = self._console_cache.stdout
            if cached is not None and cached.matches_config(file=file, **kwargs):
                return cached

            # Create new console and update cache
            self._console_cache.stdout = Cmd2BaseConsole(file=file, **kwargs)
            return self._console_cache.stdout

        if file is sys.stderr:
            cached = self._console_cache.stderr
            if cached is not None and cached.matches_config(file=file, **kwargs):
                return cached

            # Create new console and update cache
            self._console_cache.stderr = Cmd2BaseConsole(file=file, **kwargs)
            return self._console_cache.stderr

        # For any other file, just create a new console
        return Cmd2BaseConsole(file=file, **kwargs)

    def print_to(
        self,
        file: IO[str],
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        style: StyleType | None = None,
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print objects to a given file stream.

        This method is configured for general-purpose printing. By default, it enables
        soft wrap and disables Rich's automatic detection for markup, emoji, and highlighting.
        These defaults can be overridden by passing explicit keyword arguments.

        :param file: file stream being written to
        :param objects: objects to print
        :param sep: string to write between printed text. Defaults to " ".
        :param end: string to write at end of printed text. Defaults to a newline.
        :param style: optional style to apply to output
        :param soft_wrap: Enable soft wrap mode. Defaults to True.
                          If True, text that doesn't fit will run on to the following line,
                          just like the built-in print() function. This is useful for raw text
                          and logs.
                          If False, Rich wraps text to fit the terminal width.
                          Set this to False when printing structured Renderables like
                          Tables, Panels, or Columns to ensure they render as expected.
                          For example, when soft_wrap is True, Panels truncate text
                          which is wider than the terminal.
        :param justify: justify method ("left", "center", "right", "full"). Defaults to None.
        :param emoji: If True, Rich will replace emoji codes (e.g., :smiley:) with their
                      corresponding Unicode characters. Defaults to False.
        :param markup: If True, Rich will interpret strings with tags (e.g., [bold]hello[/bold])
                       as styled output. Defaults to False.
        :param highlight: If True, Rich will automatically apply highlighting to elements within
                          strings, such as common Python data types like numbers, booleans, or None.
                          This is particularly useful when pretty printing objects like lists and
                          dictionaries to display them in color. Defaults to False.
        :param rich_print_kwargs: optional additional keyword arguments to pass to console.print().
        :param kwargs: Arbitrary keyword arguments. This allows subclasses to extend the signature of this
                       method and still call `super()` without encountering unexpected keyword argument errors.
                       These arguments are not passed to console.print().

        See the Rich documentation for more details on emoji codes, markup tags, and highlighting.
        """
        try:
            self._get_core_print_console(
                file=file,
                emoji=emoji,
                markup=markup,
                highlight=highlight,
            ).print(
                *objects,
                sep=sep,
                end=end,
                style=style,
                justify=justify,
                soft_wrap=soft_wrap,
                **(rich_print_kwargs if rich_print_kwargs is not None else {}),
            )
        except BrokenPipeError:
            # This occurs if a command's output is being piped to another
            # process which closes the pipe before the command is finished
            # writing. If you would like your application to print a
            # warning message, then set the broken_pipe_warning attribute
            # to the message you want printed.
            if self.broken_pipe_warning and file != sys.stderr:
                Cmd2GeneralConsole(file=sys.stderr).print(self.broken_pipe_warning)

    def poutput(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        style: StyleType | None = None,
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print objects to self.stdout.

        For details on the parameters, refer to the `print_to` method documentation.
        """
        self.print_to(
            self.stdout,
            *objects,
            sep=sep,
            end=end,
            style=style,
            soft_wrap=soft_wrap,
            justify=justify,
            emoji=emoji,
            markup=markup,
            highlight=highlight,
            rich_print_kwargs=rich_print_kwargs,
        )

    def perror(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        style: StyleType | None = Cmd2Style.ERROR,
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print objects to sys.stderr.

        :param style: optional style to apply to output. Defaults to Cmd2Style.ERROR.

        For details on the other parameters, refer to the `print_to` method documentation.
        """
        self.print_to(
            sys.stderr,
            *objects,
            sep=sep,
            end=end,
            style=style,
            soft_wrap=soft_wrap,
            justify=justify,
            emoji=emoji,
            markup=markup,
            highlight=highlight,
            rich_print_kwargs=rich_print_kwargs,
        )

    def psuccess(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Wrap poutput, but apply Cmd2Style.SUCCESS.

        For details on the parameters, refer to the `print_to` method documentation.
        """
        self.poutput(
            *objects,
            sep=sep,
            end=end,
            style=Cmd2Style.SUCCESS,
            soft_wrap=soft_wrap,
            justify=justify,
            emoji=emoji,
            markup=markup,
            highlight=highlight,
            rich_print_kwargs=rich_print_kwargs,
        )

    def pwarning(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Wrap perror, but apply Cmd2Style.WARNING.

        For details on the parameters, refer to the `print_to` method documentation.
        """
        self.perror(
            *objects,
            sep=sep,
            end=end,
            style=Cmd2Style.WARNING,
            soft_wrap=soft_wrap,
            justify=justify,
            emoji=emoji,
            markup=markup,
            highlight=highlight,
            rich_print_kwargs=rich_print_kwargs,
        )

    def format_exception(self, exception: BaseException) -> str:
        """Format an exception for printing.

        If `debug` is true, a full traceback is included, if one exists.

        :param exception: the exception to be printed.
        :return: a formatted exception string
        """
        console = Cmd2ExceptionConsole(file=sys.stderr)
        with console.capture() as capture:
            # Only print a traceback if we're in debug mode and one exists.
            if self.debug and sys.exc_info() != (None, None, None):
                traceback = Traceback(**self.traceback_kwargs)
                console.print(traceback, end="")

            else:
                # Print the exception in the same style Rich uses after a traceback.
                exception_str = str(exception)

                if exception_str:
                    highlighter = ReprHighlighter()

                    final_msg = Text.assemble(
                        (f"{type(exception).__name__}: ", "traceback.exc_type"),
                        highlighter(exception_str),
                    )
                else:
                    final_msg = Text(f"{type(exception).__name__}", style="traceback.exc_type")

                # If not in debug mode and the 'debug' setting is available,
                # inform the user how to enable full tracebacks.
                if not self.debug and "debug" in self.settables:
                    help_msg = Text.assemble(
                        "\n\n",
                        ("To enable full traceback, run the following command: ", Cmd2Style.WARNING),
                        ("set debug true", Cmd2Style.COMMAND_LINE),
                    )
                    final_msg.append(help_msg)

                console.print(final_msg)

        return capture.get()

    def pexcept(
        self,
        exception: BaseException,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print an exception to sys.stderr.

        If `debug` is true, a full traceback is also printed, if one exists.

        :param exception: the exception to be printed.
        :param kwargs: Arbitrary keyword arguments. This allows subclasses to extend the signature of this
                       method and still call `super()` without encountering unexpected keyword argument errors.
        """
        formatted_exception = self.format_exception(exception)
        self.print_to(sys.stderr, formatted_exception)

    def pfeedback(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        style: StyleType | None = None,
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print nonessential feedback where the output can be silenced with the `quiet` setting.

        For details on the parameters, refer to the `print_to` method documentation.
        """
        if not self.quiet:
            self.poutput(
                *objects,
                sep=sep,
                end=end,
                style=style,
                soft_wrap=soft_wrap,
                justify=justify,
                emoji=emoji,
                markup=markup,
                highlight=highlight,
                rich_print_kwargs=rich_print_kwargs,
            )

    def ppaged(
        self,
        *objects: Any,
        sep: str = " ",
        end: str = "\n",
        style: StyleType | None = None,
        chop: bool = False,
        soft_wrap: bool = True,
        justify: JustifyMethod | None = None,
        emoji: bool = False,
        markup: bool = False,
        highlight: bool = False,
        rich_print_kwargs: Mapping[str, Any] | None = None,
        **kwargs: Any,  # noqa: ARG002
    ) -> None:
        """Print output using a pager.

        A pager is used when the terminal is interactive and may exit immediately if the output
        fits on the screen. A pager is not used inside a script (Python or text) or when output is
        redirected or piped, and in these cases, output is sent to `poutput`.

        :param chop: True -> causes lines longer than the screen width to be chopped (truncated) rather than wrapped
                              - truncated text is still accessible by scrolling with the right & left arrow keys
                              - chopping is ideal for displaying wide tabular data as is done in utilities like pgcli
                     False -> causes lines longer than the screen width to wrap to the next line
                              - wrapping is ideal when you want to keep users from having to use horizontal scrolling
                     WARNING: On Windows, the text always wraps regardless of what the chop argument is set to
        :param soft_wrap: Enable soft wrap mode. If True, lines of text will not be word-wrapped or cropped to
                          fit the terminal width. Defaults to True.

                          Note: If chop is True and a pager is used, soft_wrap is automatically set to True to
                          prevent wrapping and allow for horizontal scrolling.

        For details on the other parameters, refer to the `print_to` method documentation.
        """
        # Detect if we are running within an interactive terminal.
        # Don't try to use the pager when being run by a continuous integration system like Jenkins + pexpect.
        functional_terminal = (
            self.stdin.isatty()
            and self.stdout.isatty()
            and (sys.platform.startswith("win") or os.environ.get("TERM") is not None)
        )

        # A pager application blocks, so only run one if not redirecting or running a script (either text or Python).
        can_block = not (self._redirecting or self.in_pyscript() or self.in_script())

        # Check if we are outputting to a pager.
        if functional_terminal and can_block:
            # Chopping overrides soft_wrap
            if chop:
                soft_wrap = True

            # Generate the bytes to send to the pager
            console = self._get_core_print_console(
                file=self.stdout,
                emoji=emoji,
                markup=markup,
                highlight=highlight,
            )
            with console.capture() as capture:
                console.print(
                    *objects,
                    sep=sep,
                    end=end,
                    style=style,
                    justify=justify,
                    soft_wrap=soft_wrap,
                    **(rich_print_kwargs if rich_print_kwargs is not None else {}),
                )
            output_bytes = capture.get().encode("utf-8", "replace")

            # Prevent KeyboardInterrupts while in the pager. The pager application will
            # still receive the SIGINT since it is in the same process group as us.
            with self.sigint_protection:
                import subprocess

                pipe_proc = subprocess.Popen(  # noqa: S602
                    self.pager_chop if chop else self.pager,
                    shell=True,
                    stdin=subprocess.PIPE,
                    stdout=self.stdout,
                )
                pipe_proc.communicate(output_bytes)

                # If the pager was killed (e.g. SIGKILL), the terminal might be in a bad state.
                # Attempt to restore terminal settings and foreground process group.
                if self._initial_termios_settings is not None and self.stdin.isatty():  # type: ignore[unreachable]
                    try:  # type: ignore[unreachable]
                        import signal
                        import termios

                        # Ensure we are in the foreground process group
                        if hasattr(os, "tcsetpgrp") and hasattr(os, "getpgrp"):
                            # Ignore SIGTTOU to avoid getting stopped when calling tcsetpgrp from background
                            old_handler = signal.signal(signal.SIGTTOU, signal.SIG_IGN)
                            try:
                                os.tcsetpgrp(self.stdin.fileno(), os.getpgrp())
                            finally:
                                signal.signal(signal.SIGTTOU, old_handler)

                        # Restore terminal attributes
                        if self._initial_termios_settings is not None:
                            termios.tcsetattr(self.stdin.fileno(), termios.TCSANOW, self._initial_termios_settings)

                    except (OSError, termios.error):
                        pass

        else:
            self.poutput(
                *objects,
                sep=sep,
                end=end,
                style=style,
                soft_wrap=soft_wrap,
                justify=justify,
                emoji=emoji,
                markup=markup,
                highlight=highlight,
                rich_print_kwargs=rich_print_kwargs,
            )

    def ppretty(
        self,
        obj: Any,
        *,
        file: IO[str] | None = None,
        indent_size: int = 4,
        indent_guides: bool = True,
        max_length: int | None = None,
        max_string: int | None = None,
        max_depth: int | None = None,
        expand_all: bool = False,
        end: str = "\n",
    ) -> None:
        """Pretty print an object.

        This is a cmd2-compatible replacement for rich.pretty.pprint().

        :param obj: object to pretty print
        :param file: file stream being written to or None for self.stdout.
                     Defaults to None.
        :param indent_size: number of spaces in indent. Defaults to 4.
        :param indent_guides: enable indentation guides. Defaults to True.
        :param max_length: maximum length of containers before abbreviating, or None for no abbreviation.
                           Defaults to None.
        :param max_string: maximum length of strings before truncating, or None to disable. Defaults to None.
        :param max_depth: maximum depth for nested data structures, or None for unlimited depth. Defaults to None.
        :param expand_all: Expand all containers. Defaults to False.
        :param end: string to write at end of printed text. Defaults to a newline.
        """
        # The overflow and soft_wrap values match those in rich.pretty.pprint().
        # This ensures long strings are neither truncated with ellipses nor broken
        # up by injected newlines.
        pretty_obj = Pretty(
            obj,
            indent_size=indent_size,
            indent_guides=indent_guides,
            max_length=max_length,
            max_string=max_string,
            max_depth=max_depth,
            expand_all=expand_all,
            overflow="ignore",
        )

        self.print_to(
            file or self.stdout,
            pretty_obj,
            soft_wrap=True,
            end=end,
        )

    def get_bottom_toolbar(self) -> AnyFormattedText:
        """Get the bottom toolbar content.

        This method is called by prompt-toolkit while at the main prompt if ``enable_bottom_toolbar``
        was set to ``True`` during initialization. Because prompt-toolkit executes this callback
        on every UI refresh (such as on every keypress or at scheduled refresh intervals), keeping
        this function highly optimized is critical to ensuring the CLI remains responsive.

        Override this if you want a bottom toolbar displaying contextual information useful for
        your application. This could be information like the application name, current state,
        or even a real-time clock.

        :return: Content to populate the bottom toolbar.
        """
        return None

    def get_rprompt(self) -> AnyFormattedText:
        """Provide text to populate the prompt-toolkit right prompt.

        This method is called by prompt-toolkit while at the main prompt if ``enable_rprompt``
        was set to ``True`` during initialization. Because prompt-toolkit executes this callback
        on every UI refresh (such as on every keypress or at scheduled refresh intervals), keeping
        this function highly optimized is critical to ensuring the CLI remains responsive.

        Override this if you want a right prompt displaying contextual information useful for
        your application. This could be information like the current Git branch, time, or current
        working directory that is displayed without cluttering the main input area.

        :return: Content to populate the right prompt.
        """
        return None

    def tokens_for_completion(self, line: str, begidx: int, endidx: int) -> tuple[list[str], list[str]]:
        """Get all tokens through the one being completed, used by completion functions.

        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :return: A 2 item tuple where the items are
                 **On Success**
                 - tokens: list of unquoted tokens - this is generally the list needed for completion functions
                 - raw_tokens: list of tokens with any quotes preserved = this can be used to know if a token was quoted
                 or is missing a closing quote
                 Both lists are guaranteed to have at least 1 item. The last item in both lists is the token being tab
                 completed
                 **On Failure**
                 - Two empty lists
        """
        unclosed_quote = ""
        quotes_to_try = [*constants.QUOTES]

        tmp_line = line[:endidx]
        tmp_endidx = endidx

        # Parse the line into tokens
        while True:
            try:
                initial_tokens = shlex_split(tmp_line[:tmp_endidx])

                # If the cursor is at an empty token outside of a quoted string,
                # then that is the token being completed. Add it to the list.
                if not unclosed_quote and begidx == tmp_endidx:
                    initial_tokens.append("")
                break
            except ValueError as ex:
                # Make sure the exception was due to an unclosed quote and
                # we haven't exhausted the closing quotes to try
                if str(ex) == "No closing quotation" and quotes_to_try:
                    # Add a closing quote and try to parse again
                    unclosed_quote = quotes_to_try[0]
                    quotes_to_try = quotes_to_try[1:]

                    tmp_line = line[:endidx]
                    tmp_line += unclosed_quote
                    tmp_endidx = endidx + 1
                else:  # pragma: no cover
                    # The parsing error is not caused by unclosed quotes.
                    # Return empty lists since this means the line is malformed.
                    return [], []

        # Further split tokens on punctuation characters
        raw_tokens = self.statement_parser.split_on_punctuation(initial_tokens)

        # Save the unquoted tokens
        tokens = [su.strip_quotes(cur_token) for cur_token in raw_tokens]

        # If the token being completed had an unclosed quote, we need
        # to remove the closing quote that was added in order for it
        # to match what was on the command line.
        if unclosed_quote:
            raw_tokens[-1] = raw_tokens[-1][:-1]

        return tokens, raw_tokens

    def basic_complete(
        self,
        text: str,
        line: str,  # noqa: ARG002
        begidx: int,  # noqa: ARG002
        endidx: int,  # noqa: ARG002
        match_against: Iterable[str | CompletionItem],
        *,
        sort: bool = True,
    ) -> Completions:
        """Perform completion without considering line contents or cursor position.

        Strings are matched directly while CompletionItems are matched against their 'text' member.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param match_against: the items being matched against
        :param sort: if True, then results will be sorted. If False, then items will
                     be in the same order they appeared in match_against.
        :return: a Completions object
        """
        matches: list[CompletionItem] = []

        for item in match_against:
            candidate = item.text if isinstance(item, CompletionItem) else item
            if candidate.startswith(text):
                matches.append(item if isinstance(item, CompletionItem) else CompletionItem(item))

        return Completions(items=matches, is_sorted=not sort)

    def delimiter_complete(
        self,
        text: str,
        line: str,
        begidx: int,
        endidx: int,
        match_against: Iterable[str],
        delimiter: str,
    ) -> Completions:
        """Perform completion against a list but each match is split on a delimiter.

        Only the portion of the match being completed is shown as the completion suggestions.
        This is useful if you match against strings that are hierarchical in nature and have a
        common delimiter.

        An easy way to illustrate this concept is path completion since paths are just directories/files
        delimited by a slash. If you are completing items in /home/user you don't get the following
        as suggestions:

        /home/user/file.txt     /home/user/program.c
        /home/user/maps/        /home/user/cmd2.py

        Instead you are shown:

        file.txt                program.c
        maps/                   cmd2.py

        For a large set of data, this can be visually more pleasing and easier to search.

        Another example would be strings formatted with the following syntax: company::department::name
        In this case the delimiter would be :: and the user could easily narrow down what they are looking
        for if they were only shown suggestions in the category they are at in the string.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param match_against: the list being matched against
        :param delimiter: what delimits each portion of the matches (ex: paths are delimited by a slash)
        :return: a Completions object
        """
        basic_completions = self.basic_complete(text, line, begidx, endidx, match_against)
        if not basic_completions:
            return Completions()

        match_strings = basic_completions.to_strings()

        # Calculate what portion of the match we are completing
        common_prefix = su.common_prefix(match_strings)
        prefix_tokens = common_prefix.split(delimiter)
        display_token_index = len(prefix_tokens) - 1

        # Remove from each match everything after where the user is completing.
        # This approach can result in duplicates so we will filter those out.
        unique_results: dict[str, str] = {}

        allow_finalization = True
        for cur_match in match_strings:
            match_tokens = cur_match.split(delimiter)

            full_value = delimiter.join(match_tokens[: display_token_index + 1])
            display_val = match_tokens[display_token_index]

            # If there are more tokens, then we aren't done completing a full item
            if len(match_tokens) > display_token_index + 1:
                full_value += delimiter
                display_val += delimiter
                allow_finalization = False

            if full_value not in unique_results:
                unique_results[full_value] = display_val

        items = [
            CompletionItem(
                value=value,
                display=display,
            )
            for value, display in unique_results.items()
        ]

        return Completions(items, allow_finalization=allow_finalization)

    @staticmethod
    def _complete_users(text: str, add_trailing_sep_if_dir: bool) -> Completions:
        """Complete ~ and ~user strings.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param add_trailing_sep_if_dir: whether a trailing separator should be appended to directory completions
        :return: a Completions object
        """
        items: list[CompletionItem] = []

        # Windows lacks the pwd module so we can't get a list of users.
        # Instead we will return a result once the user enters text that
        # resolves to an existing home directory.
        if sys.platform.startswith("win"):
            expanded_path = os.path.expanduser(text)
            if os.path.isdir(expanded_path):
                user = text
                if add_trailing_sep_if_dir:
                    user += os.path.sep
                items.append(CompletionItem(user))
        else:
            import pwd

            # Iterate through a list of users from the password database
            for cur_pw in pwd.getpwall():
                # Check if the user has an existing home dir
                if os.path.isdir(cur_pw.pw_dir):
                    # Add a ~ to the user to match against text
                    cur_user = "~" + cur_pw.pw_name
                    if cur_user.startswith(text):
                        if add_trailing_sep_if_dir:
                            cur_user += os.path.sep
                        items.append(CompletionItem(cur_user))

        # Since all ~user matches resolve to directories, set allow_finalization to False
        # so the user can continue into the subdirectory structure.
        return Completions(items=items, allow_finalization=False)

    def path_complete(
        self,
        text: str,
        line: str,
        begidx: int,  # noqa: ARG002
        endidx: int,
        *,
        path_filter: Callable[[str], bool] | None = None,
    ) -> Completions:
        """Perform completion of local file system paths.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param path_filter: optional filter function that determines if a path belongs in the results
                            this function takes a path as its argument and returns True if the path should
                            be kept in the results
        :return: a Completions object
        """
        # Determine if a trailing separator should be appended to directory completions
        add_trailing_sep_if_dir = False
        if endidx == len(line) or (endidx < len(line) and line[endidx] != os.path.sep):
            add_trailing_sep_if_dir = True

        # Used to replace cwd in the final results
        cwd = os.getcwd()
        cwd_added = False

        # Used to replace expanded user path in final result
        orig_tilde_path = ""
        expanded_tilde_path = ""

        # If the search text is blank, then search in the CWD for *
        if not text:
            search_str = os.path.join(os.getcwd(), "*")
            cwd_added = True
        else:
            # Purposely don't match any path containing wildcards
            wildcards = ["*", "?"]
            for wildcard in wildcards:
                if wildcard in text:
                    return Completions()

            # Start the search string
            search_str = text + "*"

            # Handle tilde expansion and completion
            if text.startswith("~"):
                sep_index = text.find(os.path.sep, 1)

                # If there is no slash, then the user is still completing the user after the tilde
                if sep_index == -1:
                    return self._complete_users(text, add_trailing_sep_if_dir)

                # Otherwise expand the user dir
                search_str = os.path.expanduser(search_str)

                # Get what we need to restore the original tilde path later
                orig_tilde_path = text[:sep_index]
                expanded_tilde_path = os.path.expanduser(orig_tilde_path)

            # If the search text does not have a directory, then use the cwd
            elif not os.path.dirname(text):
                search_str = os.path.join(os.getcwd(), search_str)
                cwd_added = True

        # Find all matching path completions
        matches = glob.glob(search_str)

        # Filter out results that don't belong
        if path_filter is not None:
            matches = [c for c in matches if path_filter(c)]

        if not matches:
            return Completions()

        # If we have a single match and it's a directory, then don't append a space or closing quote
        allow_finalization = not (len(matches) == 1 and os.path.isdir(matches[0]))

        # Build display_matches and add a slash to directories
        display_matches: list[str] = []
        for index, cur_match in enumerate(matches):
            # Display only the basename of this path in the completion suggestions
            display_matches.append(os.path.basename(cur_match))

            # Add a separator after directories if the next character isn't already a separator
            if os.path.isdir(cur_match) and add_trailing_sep_if_dir:
                matches[index] += os.path.sep
                display_matches[index] += os.path.sep

        # Remove cwd if it was added to match the text prompt-toolkit expects
        if cwd_added:
            to_replace = cwd if cwd == os.path.sep else cwd + os.path.sep
            matches = [cur_path.replace(to_replace, "", 1) for cur_path in matches]

        # Restore the tilde string if we expanded one to match the text prompt-toolkit expects
        if expanded_tilde_path:
            matches = [cur_path.replace(expanded_tilde_path, orig_tilde_path, 1) for cur_path in matches]

        items = [
            CompletionItem(
                value=match,
                display=display,
            )
            for match, display in zip(matches, display_matches, strict=True)
        ]

        return Completions(items=items, allow_finalization=allow_finalization)

    def shell_cmd_complete(
        self, text: str, line: str, begidx: int, endidx: int, *, complete_blank: bool = False
    ) -> Completions:
        """Perform completion of executables either in a user's path or a given path.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param complete_blank: If True, then a blank will complete all shell commands in a user's path. If False, then
                               no completion is performed. Defaults to False to match Bash shell behavior.
        :return: a Completions object
        """
        # Don't complete anything if no shell command has been started
        if not complete_blank and not text:
            return Completions()

        # If there are no path characters in the search text, then do shell command completion in the user's path
        if not text.startswith("~") and os.path.sep not in text:
            items = [CompletionItem(exe) for exe in utils.get_exes_in_path(text)]
            return Completions(items=items)

        # Otherwise look for executables in the given path
        return self.path_complete(
            text, line, begidx, endidx, path_filter=lambda path: os.path.isdir(path) or os.access(path, os.X_OK)
        )

    def _redirect_complete(self, text: str, line: str, begidx: int, endidx: int, compfunc: BoundCompleter) -> Completions:
        """First completion function for all commands, called by complete().

        It determines if it should complete for redirection (|, >, >>) or use the
        completer function for the current command.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param compfunc: the completer function for the current command
                         this will be called if we aren't completing for redirection
        :return: a Completions object
        """
        # Get all tokens through the one being completed. We want the raw tokens
        # so we can tell if redirection strings are quoted and ignore them.
        _, raw_tokens = self.tokens_for_completion(line, begidx, endidx)
        if not raw_tokens:  # pragma: no cover
            return Completions()

        # Must at least have the command
        if len(raw_tokens) > 1:
            # True when command line contains any redirection tokens
            has_redirection = False

            # Keep track of state while examining tokens
            in_pipe = False
            in_file_redir = False
            do_shell_completion = False
            do_path_completion = False
            prior_token = None

            for cur_token in raw_tokens:
                # Process redirection tokens
                if cur_token in constants.REDIRECTION_TOKENS:
                    has_redirection = True

                    # Check if we are at a pipe
                    if cur_token == constants.REDIRECTION_PIPE:
                        # Do not complete bad syntax (e.g cmd | |)
                        if prior_token == constants.REDIRECTION_PIPE:
                            return Completions()

                        in_pipe = True
                        in_file_redir = False

                    # Otherwise this is a file redirection token
                    else:
                        if prior_token in constants.REDIRECTION_TOKENS or in_file_redir:
                            # Do not complete bad syntax (e.g cmd | >) (e.g cmd > blah >)
                            return Completions()

                        in_pipe = False
                        in_file_redir = True

                # Only complete after redirection tokens if redirection is allowed
                elif self.allow_redirection:
                    do_shell_completion = False
                    do_path_completion = False

                    if prior_token == constants.REDIRECTION_PIPE:
                        do_shell_completion = True
                    elif in_pipe or prior_token in (constants.REDIRECTION_OVERWRITE, constants.REDIRECTION_APPEND):
                        do_path_completion = True

                prior_token = cur_token

            if do_shell_completion:
                return self.shell_cmd_complete(text, line, begidx, endidx)

            if do_path_completion:
                return self.path_complete(text, line, begidx, endidx)

            # If there were redirection strings anywhere on the command line, then we
            # are no longer completing for the current command
            if has_redirection:
                return Completions()

        # Call the command's completer function
        return compfunc(text, line, begidx, endidx)

    def _perform_completion(
        self, text: str, line: str, begidx: int, endidx: int, custom_settings: utils.CustomCompletionSettings | None = None
    ) -> Completions:
        """Perform the actual completion, helper function for complete().

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :param custom_settings: optional prepopulated completion settings
        :return: a Completions object
        """
        # If custom_settings is None, then we are completing a command's argument.
        # Parse the command line to get the command token.
        command = ""
        if custom_settings is None:
            partial_statement = self.statement_parser.parse_command_only(line)
            command = partial_statement.command

            # Malformed command line (e.g. quoted command token)
            if not command:
                return Completions()

            expanded_line = partial_statement.command_and_args

            if not expanded_line[-1:].isspace():
                # Unquoted trailing whitespace gets stripped by parse_command_only().
                # Restore it since line is only supposed to be lstripped when passed
                # to completer functions according to the Python cmd docs. Regardless
                # of what type of whitespace (' ', \n) was stripped, just append spaces
                # since shlex treats whitespace characters the same when splitting.
                rstripped_len = len(line) - len(line.rstrip())
                expanded_line += " " * rstripped_len

            # Fix the index values if expanded_line has a different size than line
            if len(expanded_line) != len(line):
                diff = len(expanded_line) - len(line)
                begidx += diff
                endidx += diff

            # Overwrite line to pass into completers
            line = expanded_line

        # Get all tokens through the one being completed
        tokens, raw_tokens = self.tokens_for_completion(line, begidx, endidx)
        if not tokens:  # pragma: no cover
            return Completions()

        # Determine the completer function to use for the command's argument
        completer_func: BoundCompleter
        if custom_settings is None:
            # Check if a macro was entered
            if command in self.macros:
                completer_func = self.macro_arg_complete

            # Check if a command was entered
            elif command in self.get_all_commands():
                # Get the completer function for this command
                func_attr = getattr(self, constants.COMPLETER_FUNC_PREFIX + command, None)

                if func_attr is not None:
                    completer_func = func_attr
                else:
                    # There's no completer function, next see if the command uses argparse
                    command_func = self.get_command_func(command)
                    parser = None if command_func is None else self.command_parsers.get(command_func)

                    if command_func is not None and parser is not None:
                        # Get arguments for complete()
                        spec: ArgparseCommandSpec = getattr(command_func, constants.ARGPARSE_COMMAND_ATTR_SPEC)
                        cmd_set = self.find_commandset_for_command(command)

                        # Create the argparse completer
                        completer = parser.completer_class(parser, self)

                        completer_func = functools.partial(
                            completer.complete, tokens=raw_tokens[1:] if spec.preserve_quotes else tokens[1:], cmd_set=cmd_set
                        )
                    else:
                        completer_func = self.completedefault  # type: ignore[assignment]

            # Not a recognized macro or command
            else:
                completer_func = self.completedefault  # type: ignore[assignment]

        # Otherwise we are completing the command token or performing custom completion
        else:
            # Create the argparse completer
            completer = custom_settings.parser.completer_class(custom_settings.parser, self)

            completer_func = functools.partial(
                completer.complete, tokens=raw_tokens if custom_settings.preserve_quotes else tokens, cmd_set=None
            )

        # Text we need to remove from completions later
        text_to_remove = ""

        # Get the token being completed with any opening quote preserved
        raw_completion_token = raw_tokens[-1]

        # Used for adding quotes to the completion token
        completion_token_quote = ""

        # Check if the token being completed has an opening quote
        if raw_completion_token and raw_completion_token[0] in constants.QUOTES:
            # Since the token is still being completed, we know the opening quote is unclosed.
            # Save the quote so we can add a matching closing quote later.
            completion_token_quote = raw_completion_token[0]

            # Cmd2Completer still performs word breaks after a quote. Therefore, something like quoted search
            # text with a space would have resulted in begidx pointing to the middle of the token we
            # we want to complete. Figure out where that token actually begins and save the beginning
            # portion of it that was not part of the text prompt-toolkit gave us. We will remove it from the
            # completions later since prompt-toolkit expects them to start with the original text.
            actual_begidx = line[:endidx].rfind(tokens[-1])

            if actual_begidx != begidx:
                text_to_remove = line[actual_begidx:begidx]

                # Adjust text and where it begins so the completer routines
                # get unbroken search text to complete on.
                text = text_to_remove + text
                begidx = actual_begidx

        # Attempt completion for redirection first, and if that isn't occurring,
        # call the completer function for the current command
        completions = self._redirect_complete(text, line, begidx, endidx, completer_func)
        if not completions:
            return Completions()

        _add_opening_quote = False
        _quote_char = completion_token_quote

        # Check if we need to add an opening quote
        if not completion_token_quote:
            matches = completions.to_strings()

            if any(" " in match for match in matches):
                _add_opening_quote = True

                # Determine best quote (single vs double) based on text content
                _quote_char = "'" if any('"' in t for t in matches) else '"'

        # Check if we need to remove text from the beginning of completions
        elif text_to_remove:
            new_items = [
                dataclasses.replace(
                    item,
                    text=item.text.replace(text_to_remove, "", 1),
                )
                for item in completions
            ]
            completions = dataclasses.replace(completions, items=new_items)

        return dataclasses.replace(completions, _add_opening_quote=_add_opening_quote, _quote_char=_quote_char)

    def complete(
        self,
        text: str,
        line: str,
        begidx: int,
        endidx: int,
        custom_settings: utils.CustomCompletionSettings | None = None,
    ) -> Completions:
        """Handle completion for an input line.

        :param text: the current word that user is typing
        :param line: current input line
        :param begidx: beginning index of text
        :param endidx: ending index of text
        :param custom_settings: used when not completing the main command line
        :return: a Completions object
        """
        try:
            # lstrip the original line
            orig_line = line
            line = orig_line.lstrip()
            num_stripped = len(orig_line) - len(line)

            # Calculate new indexes for the stripped line. If the cursor is at a position before the end of a
            # line of spaces, then the following math could result in negative indexes. Enforce a max of 0.
            begidx = max(begidx - num_stripped, 0)
            endidx = max(endidx - num_stripped, 0)

            # Shortcuts are not word break characters when completing. Therefore, shortcuts become part
            # of the text variable if there isn't a word break, like a space, after it. We need to remove it
            # from text and update the indexes. This only applies if we are at the beginning of the command line.
            shortcut_to_restore = ""
            if begidx == 0 and custom_settings is None:
                for shortcut, _ in self.statement_parser.shortcuts:
                    if text.startswith(shortcut):
                        # Save the shortcut to restore later
                        shortcut_to_restore = shortcut

                        # Adjust text and where it begins
                        text = text[len(shortcut_to_restore) :]
                        begidx += len(shortcut_to_restore)
                        break
                else:
                    # No shortcut was found. Complete the command token.
                    parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(add_help=False)
                    parser.add_argument(
                        "command",
                        metavar="COMMAND",
                        help="command, alias, or macro name",
                        choices=self._get_commands_aliases_and_macros_choices(),
                    )
                    custom_settings = utils.CustomCompletionSettings(parser)

            completions = self._perform_completion(text, line, begidx, endidx, custom_settings)

            # Check if we need to restore a shortcut in the completion text
            # so it doesn't get erased from the command line.
            if completions and shortcut_to_restore:
                new_items = [
                    dataclasses.replace(
                        item,
                        text=shortcut_to_restore + item.text,
                    )
                    for item in completions
                ]

                # Update items and set _quote_from_offset so that any auto-inserted
                # opening quote is placed after the shortcut.
                completions = dataclasses.replace(
                    completions,
                    items=new_items,
                    _search_text_offset=len(shortcut_to_restore),
                )

            # Swap between COLUMN and MULTI_COLUMN style based on the number of matches.
            if len(completions) > self.max_column_completion_results:
                self.active_session.complete_style = CompleteStyle.MULTI_COLUMN
            else:
                self.active_session.complete_style = CompleteStyle.COLUMN

            return completions  # noqa: TRY300

        except CompletionError as ex:
            error_msg = str(ex)
            formatted_error = ""

            # Don't display anything if the error is blank (e.g. _NoResultsError for an argument which suppresses hints)
            if error_msg:
                # _NoResultsError completion hints already include a trailing "\n".
                end = "" if isinstance(ex, argparse_completer._NoResultsError) else "\n"

                console = Cmd2GeneralConsole(file=self.stdout)
                with console.capture() as capture:
                    console.print(
                        error_msg,
                        style=Cmd2Style.ERROR if ex.apply_style else "",
                        end=end,
                    )
                formatted_error = capture.get()
            return Completions(error=formatted_error)
        except Exception as ex:  # noqa: BLE001
            formatted_exception = self.format_exception(ex)
            return Completions(error=formatted_exception)

    def in_script(self) -> bool:
        """Return whether a text script is running."""
        return self._current_script_dir is not None

    def in_pyscript(self) -> bool:
        """Return whether running inside a Python shell or pyscript."""
        return self._in_py

    @property
    def aliases(self) -> dict[str, str]:
        """Read-only property to access the aliases stored in the StatementParser."""
        return self.statement_parser.aliases

    def get_names(self) -> list[str]:
        """Return an alphabetized list of names comprising the attributes of the cmd2 class instance."""
        return dir(self)

    def get_all_commands(self) -> list[str]:
        """Return a list of all commands."""
        return [
            name[len(constants.COMMAND_FUNC_PREFIX) :]
            for name in self.get_names()
            if name.startswith(constants.COMMAND_FUNC_PREFIX) and callable(getattr(self, name))
        ]

    def get_visible_commands(self) -> list[str]:
        """Return a list of commands that have not been hidden or disabled."""
        return [
            command
            for command in self.get_all_commands()
            if command not in self.hidden_commands and command not in self.disabled_commands
        ]

    def _get_alias_choices(self) -> Choices:
        """Return list of alias names and values as Choices."""
        items: list[CompletionItem] = []

        for name, value in self.aliases.items():
            items.append(CompletionItem(name, display_meta=value, table_data=[value]))

        return Choices(items=items)

    def _get_macro_choices(self) -> Choices:
        """Return list of macro names and values as Choices."""
        items: list[CompletionItem] = []

        for name, macro in self.macros.items():
            items.append(CompletionItem(name, display_meta=macro.value, table_data=[macro.value]))

        return Choices(items=items)

    def _get_settable_choices(self) -> Choices:
        """Return list of Settable names, values, and descriptions as Choices."""
        items: list[CompletionItem] = []

        for name, settable in self.settables.items():
            value_str = str(settable.value)
            table_data = [
                value_str,
                settable.description,
            ]
            display_meta = f"[Current: {su.stylize(value_str, Style(bold=True))}] {settable.description}"
            items.append(CompletionItem(name, display_meta=display_meta, table_data=table_data))

        return Choices(items=items)

    def _get_commands_aliases_and_macros_choices(self) -> Choices:
        """Return a list of visible commands, aliases, and macros as Choices."""
        items: list[CompletionItem] = []

        # Add commands
        for command in self.get_visible_commands():
            command_func = cast(BoundCommandFunc, self.get_command_func(command))
            description = strip_doc_annotations(command_func.__doc__).splitlines()[0] if command_func.__doc__ else ""
            items.append(CompletionItem(command, display_meta=description))

        # Add aliases
        for name, value in self.aliases.items():
            items.append(CompletionItem(name, display_meta=f"Alias for: {value}"))

        # Add macros
        for name, macro in self.macros.items():
            items.append(CompletionItem(name, display_meta=f"Macro: {macro.value}"))

        return Choices(items=items)

    def get_help_topics(self) -> list[str]:
        """Return a list of help topics."""
        all_topics = [
            name[len(constants.HELP_FUNC_PREFIX) :]
            for name in self.get_names()
            if name.startswith(constants.HELP_FUNC_PREFIX) and callable(getattr(self, name))
        ]

        # Filter out hidden and disabled commands
        return [topic for topic in all_topics if topic not in self.hidden_commands and topic not in self.disabled_commands]

    def sigint_handler(
        self,
        signum: int,  # noqa: ARG002
        frame: FrameType | None,  # noqa: ARG002
    ) -> None:
        """Signal handler for SIGINTs which typically come from Ctrl-C events.

        If you need custom SIGINT behavior, then override this method.

        :param signum: signal number
        :param frame: the current stack frame or None
        """
        if self._cur_pipe_proc_reader is not None:
            # Pass the SIGINT to the current pipe process
            self._cur_pipe_proc_reader.send_sigint()

        # Check if we are allowed to re-raise the KeyboardInterrupt
        if not self.sigint_protection:
            raise_interrupt = True
            if self.current_command is not None:
                command_set = self.find_commandset_for_command(self.current_command.command)
                if command_set is not None:
                    raise_interrupt = not command_set.sigint_handler()
            if raise_interrupt:
                self._raise_keyboard_interrupt()

    def termination_signal_handler(self, signum: int, _: FrameType | None) -> None:
        """Signal handler for SIGHUP and SIGTERM. Only runs on Linux and Mac.

        SIGHUP - received when terminal window is closed
        SIGTERM - received when this app has been requested to terminate

        The basic purpose of this method is to call sys.exit() so our exit handler will run
        and save the persistent history file. If you need more complex behavior like killing
        threads and performing cleanup, then override this method.

        :param signum: signal number
        :param _: the current stack frame or None
        """
        # POSIX systems add 128 to signal numbers for the exit code
        sys.exit(128 + signum)

    def _raise_keyboard_interrupt(self) -> None:
        """Raise a KeyboardInterrupt."""
        self.poutput()  # Ensure new prompt is on a line by itself
        raise KeyboardInterrupt("Got a keyboard interrupt")

    def pre_prompt(self) -> None:
        """Ran just before the prompt is displayed (and after the event loop has started).

        This is the ideal location to update `self.prompt` or any other state that should
        be current when the prompt appears.
        """

    def precmd(self, statement: Statement | str) -> Statement:
        """Ran just before the command is executed by [cmd2.Cmd.onecmd][] and after adding it to history (cmd Hook method).

        :param statement: subclass of str which also contains the parsed input
        :return: a potentially modified version of the input Statement object

        See [cmd2.Cmd.register_postparsing_hook][] and [cmd2.Cmd.register_precmd_hook][] for more robust ways
        to run hooks before the command is executed. See [Hooks](../features/hooks.md) for more information.
        """
        return Statement(statement) if not isinstance(statement, Statement) else statement

    def postcmd(self, stop: bool, statement: Statement | str) -> bool:  # noqa: ARG002
        """Ran just after a command is executed by [cmd2.Cmd.onecmd][] (cmd inherited Hook method).

        :param stop: return `True` to request the command loop terminate
        :param statement: subclass of str which also contains the parsed input

        See [cmd2.Cmd.register_postcmd_hook][] and [cmd2.Cmd.register_cmdfinalization_hook][] for more robust ways
        to run hooks after the command is executed. See [Hooks](../features/hooks.md) for more information.
        """
        return stop

    def preloop(self) -> None:
        """Ran once when the [cmd2.Cmd.cmdloop][] method is called (cmd inherited Hook method).

        This method is a stub that does nothing and exists to be overridden by subclasses.

        See [cmd2.Cmd.register_preloop_hook][] for a more robust wayto run hooks before the command loop begins.
        See [Hooks](../features/hooks.md) for more information.
        """

    def postloop(self) -> None:
        """Ran once when the [cmd2.Cmd.cmdloop][] method is about to return (cmd inherited Hook Method).

        This method is a stub that does nothing and exists to be overridden by subclasses.

        See [cmd2.Cmd.register_postloop_hook][] for a more robust way to run hooks after the command loop completes.
        See [Hooks](../features/hooks.md) for more information.
        """

    def onecmd_plus_hooks(
        self,
        line: str,
        *,
        add_to_history: bool = True,
        raise_keyboard_interrupt: bool = False,
        py_bridge_call: bool = False,
    ) -> bool:
        """Top-level function called by cmdloop() to handle parsing a line and running the command and all of its hooks.

        :param line: command line to run
        :param add_to_history: If True, then add this command to history. Defaults to True.
        :param raise_keyboard_interrupt: if True, then KeyboardInterrupt exceptions will be raised if stop isn't already
                                         True. This is used when running commands in a loop to be able to stop the whole
                                         loop and not just the current command. Defaults to False.
        :param py_bridge_call: This should only ever be set to True by PyBridge to signify the beginning
                               of an app() call from Python. It is used to enable/disable the storage of the
                               command's stdout.
        :return: True if running of commands should stop
        """
        stop = False
        statement = None

        try:
            # Convert the line into a Statement
            statement = self._input_line_to_statement(line)

            # call the postparsing hooks
            postparsing_data = plugin.PostparsingData(False, statement)
            for postparsing_func in self._postparsing_hooks:
                postparsing_data = postparsing_func(postparsing_data)
                if postparsing_data.stop:
                    break

            # unpack the postparsing_data object
            statement = postparsing_data.statement
            stop = postparsing_data.stop
            if stop:
                # we should not run the command, but
                # we need to run the finalization hooks
                raise EmptyStatement  # noqa: TRY301

            redir_saved_state: utils.RedirectionSavedState | None = None

            try:
                # Get sigint protection while we set up redirection
                with self.sigint_protection:
                    if py_bridge_call:
                        # Start saving command's stdout at this point
                        self.stdout.pause_storage = False  # type: ignore[attr-defined]

                    redir_saved_state = self._redirect_output(statement)

                timestart = datetime.datetime.now(tz=datetime.timezone.utc)

                # precommand hooks
                precmd_data = plugin.PrecommandData(statement)
                for precmd_func in self._precmd_hooks:
                    precmd_data = precmd_func(precmd_data)
                statement = precmd_data.statement

                # call precmd() for compatibility with cmd.Cmd
                statement = self.precmd(statement)

                # go run the command function
                stop = self.onecmd(statement, add_to_history=add_to_history)

                # postcommand hooks
                postcmd_data = plugin.PostcommandData(stop, statement)
                for postcmd_func in self._postcmd_hooks:
                    postcmd_data = postcmd_func(postcmd_data)

                # retrieve the final value of stop, ignoring any statement modification from the hooks
                stop = postcmd_data.stop

                # call postcmd() for compatibility with cmd.Cmd
                stop = self.postcmd(stop, statement)

                if self.timing:
                    self.perror(f"Elapsed: {datetime.datetime.now(tz=datetime.timezone.utc) - timestart}", style=None)
            finally:
                # Get sigint protection while we restore stuff
                with self.sigint_protection:
                    if redir_saved_state is not None:
                        self._restore_output(statement, redir_saved_state)

                    if py_bridge_call:
                        # Stop saving command's stdout before command finalization hooks run
                        self.stdout.pause_storage = True  # type: ignore[attr-defined]
        except (SkipPostcommandHooks, EmptyStatement):
            # Don't do anything, but do allow command finalization hooks to run
            pass
        except Cmd2ShlexError as ex:
            self.perror(f"Invalid syntax: {ex}")
        except RedirectionError as ex:
            self.perror(ex)
        except KeyboardInterrupt:
            if raise_keyboard_interrupt and not stop:
                raise
        except SystemExit as ex:
            if isinstance(ex.code, int):
                self.exit_code = ex.code
            stop = True
        except PassThroughException as ex:
            raise ex.wrapped_ex from None
        except Exception as ex:  # noqa: BLE001
            self.pexcept(ex)
        finally:
            try:
                stop = self._run_cmdfinalization_hooks(stop, statement)
            except KeyboardInterrupt:
                if raise_keyboard_interrupt and not stop:
                    raise
            except SystemExit as ex:
                if isinstance(ex.code, int):
                    self.exit_code = ex.code
                stop = True
            except PassThroughException as ex:
                raise ex.wrapped_ex from None
            except Exception as ex:  # noqa: BLE001
                self.pexcept(ex)

        return stop

    def _run_cmdfinalization_hooks(self, stop: bool, statement: Statement | None) -> bool:
        """Run the command finalization hooks."""
        if self._initial_termios_settings is not None and self.stdin.isatty():  # type: ignore[unreachable]
            import io  # type: ignore[unreachable]
            import termios

            # Before the next command runs, fix any terminal problems like those
            # caused by certain binary characters having been printed to it.
            with self.sigint_protection, contextlib.suppress(io.UnsupportedOperation, termios.error):
                # This can fail if stdin is a pseudo-TTY, in which case we just ignore it
                termios.tcsetattr(self.stdin.fileno(), termios.TCSANOW, self._initial_termios_settings)

        data = plugin.CommandFinalizationData(stop, statement)
        for func in self._cmdfinalization_hooks:
            data = func(data)
        # retrieve the final value of stop, ignoring any
        # modifications to the statement
        return data.stop

    def runcmds_plus_hooks(
        self,
        cmds: Iterable[HistoryItem] | Iterable[str],
        *,
        add_to_history: bool = True,
        stop_on_keyboard_interrupt: bool = False,
    ) -> bool:
        """Run commands in an automated fashion from sources like text scripts or history replays.

        The prompt and command line for each command will be printed if echo is True.

        :param cmds: commands to run
        :param add_to_history: If True, then add these commands to history. Defaults to True.
        :param stop_on_keyboard_interrupt: if True, then stop running contents of cmds if Ctrl-C is pressed instead of moving
                                           to the next command in the list. This is used when the commands are part of a
                                           group, like a text script, which should stop upon Ctrl-C. Defaults to False.
        :return: True if running of commands should stop
        """
        for line in cmds:
            if isinstance(line, HistoryItem):
                line = line.raw  # noqa: PLW2901

            if self.echo:
                self.poutput(f"{self.prompt}{line}")

            try:
                if self.onecmd_plus_hooks(
                    line, add_to_history=add_to_history, raise_keyboard_interrupt=stop_on_keyboard_interrupt
                ):
                    return True
            except KeyboardInterrupt as ex:
                if stop_on_keyboard_interrupt:
                    self.perror(ex)
                    break

        return False

    def _check_statement_complete(self, line: str) -> Statement:
        """Check if the given line is a complete statement.

        :param line: the current input string to check
        :return: the completed Statement
        :raises Cmd2ShlexError: if a shlex error occurs on a non-multiline command
        :raises IncompleteStatement: if more input is needed for multiline
        :raises EmptyStatement: if the command is blank
        """
        try:
            statement = self.statement_parser.parse(line)

            # Check if we have a finished multiline command or a standard command
            if (statement.multiline_command and statement.terminator) or not statement.multiline_command:
                if not statement.command:
                    raise EmptyStatement
                return statement

        except Cmd2ShlexError:
            # Check if the error is occurring within a multiline command
            partial_statement = self.statement_parser.parse_command_only(line)
            if not partial_statement.multiline_command:
                # It's a standard command with a quoting error, raise it
                raise

        # If we reached here, the statement is incomplete:
        # - Multiline command missing a terminator
        # - Multiline command with an unclosed quotation mark
        raise IncompleteStatement

    def _complete_statement(self, line: str) -> Statement:
        """Keep accepting lines of input until the command is complete.

        :param line: the line being parsed
        :return: the completed Statement
        :raises Cmd2ShlexError: if a shlex error occurs (e.g. No closing quotation)
        :raises EmptyStatement: when the resulting Statement is blank
        """
        while True:
            try:
                return self._check_statement_complete(line)
            except IncompleteStatement:
                # If incomplete, we need to fetch the next line
                try:
                    try:
                        nextline = self._read_command_line(self.continuation_prompt)
                    except EOFError:
                        # Add a blank line, which serves as a command terminator.
                        nextline = "\n"
                        self.poutput(nextline)

                    line += f"\n{nextline}"

                except KeyboardInterrupt:
                    self.poutput("^C")
                    raise EmptyStatement from None

    def _input_line_to_statement(self, line: str) -> Statement:
        """Parse the user's input line and convert it to a Statement, ensuring that all macros are also resolved.

        :param line: the line being parsed
        :return: parsed command line as a Statement
        :raises Cmd2ShlexError: if a shlex error occurs (e.g. No closing quotation)
        :raises EmptyStatement: when the resulting Statement is blank
        """
        used_macros = []
        orig_line = None

        # Continue until all macros are resolved
        while True:
            # Get a complete statement (handling multiline input)
            statement = self._complete_statement(line)

            # If this is the first loop iteration, save the original line
            if orig_line is None:
                orig_line = statement.raw

            # Check if this command matches a macro and wasn't already processed to avoid an infinite loop
            if statement.command in self.macros and statement.command not in used_macros:
                used_macros.append(statement.command)
                try:
                    line = self._resolve_macro(statement)
                except MacroError as ex:
                    self.perror(ex)
                    raise EmptyStatement from None
            else:
                # No macro found or already processed. The statement is complete.
                break

        # Restore original 'raw' text if a macro was expanded
        if orig_line != statement.raw:
            statement_dict = statement.to_dict()
            statement_dict["raw"] = orig_line
            statement = Statement.from_dict(statement_dict)

        return statement

    def _resolve_macro(self, statement: Statement) -> str:
        """Resolve a macro and return the resulting string.

        :param statement: the parsed statement from the command line
        :return: the resolved macro string
        :raises KeyError: if its not a macro
        :raises MacroError: if the macro cannot be resolved (e.g. not enough args)
        """
        if statement.command not in self.macros:
            raise KeyError(f"{statement.command} is not a macro")

        macro = self.macros[statement.command]

        # Make sure enough arguments were passed in
        if len(statement.arg_list) < macro.minimum_arg_count:
            plural = "" if macro.minimum_arg_count == 1 else "s"
            raise MacroError(f"The macro '{statement.command}' expects at least {macro.minimum_arg_count} argument{plural}")

        # Resolve the arguments in reverse and read their values from statement.argv since those
        # are unquoted. Macro args should have been quoted when the macro was created.
        resolved = macro.value
        reverse_arg_list = sorted(macro.args, key=lambda ma: ma.start_index, reverse=True)

        for macro_arg in reverse_arg_list:
            if macro_arg.is_escaped:
                to_replace = "{{" + macro_arg.number_str + "}}"
                replacement = "{" + macro_arg.number_str + "}"
            else:
                to_replace = "{" + macro_arg.number_str + "}"
                replacement = statement.argv[int(macro_arg.number_str)]

            parts = resolved.rsplit(to_replace, maxsplit=1)
            resolved = parts[0] + replacement + parts[1]

        # Append extra arguments and use statement.arg_list since these arguments need their quotes preserved
        for stmt_arg in statement.arg_list[macro.minimum_arg_count :]:
            resolved += " " + stmt_arg

        # Restore any terminator, suffix, redirection, etc.
        return resolved + statement.post_command

    def _redirect_output(self, statement: Statement) -> utils.RedirectionSavedState:
        """Set up a command's output redirection for >, >>, and |.

        :param statement: a parsed statement from the user
        :return: A bool telling if an error occurred and a utils.RedirectionSavedState object
        :raises RedirectionError: if an error occurs trying to pipe or redirect
        """
        import subprocess

        # Initialize the redirection saved state
        redir_saved_state = utils.RedirectionSavedState(self.stdout, self._cur_pipe_proc_reader, self._redirecting)

        # The ProcReader for this command
        cmd_pipe_proc_reader: utils.ProcReader | None = None

        if not self.allow_redirection:
            # Don't return since we set some state variables at the end of the function
            pass

        elif statement.redirector == constants.REDIRECTION_PIPE:
            # Create a pipe with read and write sides
            read_fd, write_fd = os.pipe()

            # Open each side of the pipe
            subproc_stdin = open(read_fd)  # noqa: SIM115
            new_stdout: TextIO = cast(TextIO, open(write_fd, "w"))  # noqa: SIM115

            # Create pipe process in a separate group to isolate our signals from it. If a Ctrl-C event occurs,
            # our sigint handler will forward it only to the most recent pipe process. This makes sure pipe
            # processes close in the right order (most recent first).
            kwargs: dict[str, Any] = {}
            if sys.platform == "win32":
                kwargs["creationflags"] = subprocess.CREATE_NEW_PROCESS_GROUP
            else:
                kwargs["start_new_session"] = True

                # Attempt to run the pipe process in the user's preferred shell instead of the default behavior of using sh.
                shell = os.environ.get("SHELL")
                if shell:
                    kwargs["executable"] = shell

            # For any stream that is a StdSim, we will use a pipe so we can capture its output
            proc = subprocess.Popen(  # noqa: S602
                statement.redirect_to,
                stdin=subproc_stdin,
                stdout=subprocess.PIPE if isinstance(self.stdout, utils.StdSim) else self.stdout,  # type: ignore[unreachable]
                stderr=subprocess.PIPE if isinstance(sys.stderr, utils.StdSim) else sys.stderr,
                shell=True,
                **kwargs,
            )

            # Popen was called with shell=True so the user can chain pipe commands and redirect their output
            # like: !ls -l | grep user | wc -l > out.txt. But this makes it difficult to know if the pipe process
            # started OK, since the shell itself always starts. Therefore, we will wait a short time and check
            # if the pipe process is still running.
            with contextlib.suppress(subprocess.TimeoutExpired):
                proc.wait(0.2)

            # Check if the pipe process already exited
            if proc.returncode is not None:
                subproc_stdin.close()
                new_stdout.close()
                raise RedirectionError(f"Pipe process exited with code {proc.returncode} before command could run")
            redir_saved_state.redirecting = True
            cmd_pipe_proc_reader = utils.ProcReader(proc, self.stdout, sys.stderr)

            self.stdout = new_stdout

        elif statement.redirector in (constants.REDIRECTION_OVERWRITE, constants.REDIRECTION_APPEND):
            if statement.redirect_to:
                # redirecting to a file
                # statement.output can only contain REDIRECTION_APPEND or REDIRECTION_OUTPUT
                mode = "a" if statement.redirector == constants.REDIRECTION_APPEND else "w"
                try:
                    # Use line buffering
                    new_stdout = cast(TextIO, open(su.strip_quotes(statement.redirect_to), mode=mode, buffering=1))  # noqa: SIM115
                except OSError as ex:
                    raise RedirectionError("Failed to redirect output") from ex

                redir_saved_state.redirecting = True

                self.stdout = new_stdout

            else:
                # Redirecting to a paste buffer
                # we are going to direct output to a temporary file, then read it back in and
                # put it in the paste buffer later
                if not self.allow_clipboard:
                    raise RedirectionError("Clipboard access not allowed")

                # attempt to get the paste buffer, this forces pyperclip to go figure
                # out if it can actually interact with the paste buffer, and will throw exceptions
                # if it's not gonna work. That way we throw the exception before we go
                # run the command and queue up all the output. if this is going to fail,
                # no point opening up the temporary file
                current_paste_buffer = get_paste_buffer()
                # create a temporary file to store output
                new_stdout = cast(TextIO, tempfile.TemporaryFile(mode="w+"))  # noqa: SIM115
                redir_saved_state.redirecting = True

                self.stdout = new_stdout

                if statement.redirector == constants.REDIRECTION_APPEND:
                    self.stdout.write(current_paste_buffer)
                    self.stdout.flush()

        # These are updated regardless of whether the command redirected
        self._cur_pipe_proc_reader = cmd_pipe_proc_reader
        self._redirecting = redir_saved_state.redirecting

        return redir_saved_state

    def _restore_output(self, statement: Statement, saved_redir_state: utils.RedirectionSavedState) -> None:
        """Handle restoring state after output redirection.

        :param statement: Statement object which contains the parsed input from the user
        :param saved_redir_state: contains information needed to restore state data
        """
        if saved_redir_state.redirecting:
            # If we redirected output to the clipboard
            if (
                statement.redirector in (constants.REDIRECTION_OVERWRITE, constants.REDIRECTION_APPEND)
                and not statement.redirect_to
            ):
                self.stdout.seek(0)
                write_to_paste_buffer(self.stdout.read())

            with contextlib.suppress(BrokenPipeError):
                # Close the file or pipe that stdout was redirected to
                self.stdout.close()

            # Restore self.stdout
            self.stdout = cast(TextIO, saved_redir_state.saved_self_stdout)

            # Check if we need to wait for the process being piped to
            if self._cur_pipe_proc_reader is not None:
                self._cur_pipe_proc_reader.wait()

        # These are restored regardless of whether the command redirected
        self._cur_pipe_proc_reader = saved_redir_state.saved_pipe_proc_reader
        self._redirecting = saved_redir_state.saved_redirecting

    def get_command_func(self, command: str) -> BoundCommandFunc | None:
        """Get the bound command function for a command.

        :param command: the name of the command
        :return: the bound function implementing the command, or None if not found
        """
        command_func_name = constants.COMMAND_FUNC_PREFIX + command
        command_func = getattr(self, command_func_name, None)
        return cast(BoundCommandFunc, command_func) if callable(command_func) else None

    def _get_command_category(self, func: BoundCommandFunc) -> str:
        """Determine the category for a command.

        :param func: the do_* function implementing the command
        :return: category name
        """
        # Check if the command function has a category.
        if hasattr(func, constants.COMMAND_ATTR_HELP_CATEGORY):
            category: str = getattr(func, constants.COMMAND_ATTR_HELP_CATEGORY)

        # Otherwise get the category from its defining class.
        else:
            defining_cls = get_defining_class(func)
            category = getattr(defining_cls, "DEFAULT_CATEGORY", self.DEFAULT_CATEGORY)

        return category

    def onecmd(self, statement: Statement | str, *, add_to_history: bool = True) -> bool:
        """Execute the actual do_* method for a command.

        If the command provided doesn't exist, then it executes default() instead.

        :param statement: intended to be a Statement instance parsed command from the input stream, alternative
                          acceptance of a str is present only for backward compatibility with cmd
        :param add_to_history: If True, then add this command to history. Defaults to True.
        :return: a flag indicating whether the interpretation of commands should stop
        """
        # For backwards compatibility with cmd, allow a str to be passed in
        if not isinstance(statement, Statement):
            statement = self._input_line_to_statement(statement)

        command_func = self.get_command_func(statement.command)
        if command_func:
            # Check to see if this command should be stored in history
            if (
                statement.command not in self.exclude_from_history
                and statement.command not in self.disabled_commands
                and add_to_history
            ):
                self.history.append(statement)

            try:
                self.current_command = statement
                stop = command_func(statement)
            finally:
                self.current_command = None

        else:
            stop = self.default(statement)

        return stop if stop is not None else False

    def default(self, statement: Statement) -> bool | None:
        """Execute when the command given isn't a recognized command implemented by a do_* method.

        :param statement: Statement object with parsed input
        """
        err_msg = self.default_error.format(statement.command)
        if self.suggest_similar_command and (suggested_command := self._suggest_similar_command(statement.command)):
            err_msg += f"\n{self.default_suggestion_message.format(suggested_command)}"

        self.perror(err_msg, style=None)
        return None

    def completedefault(self, *_ignored: Sequence[str]) -> Completions:
        """Call to complete an input line when no command-specific complete_*() method is available.

        This method is only called for non-argparse-based commands.

        By default, it returns a Completions object with no matches.
        """
        return Completions()

    def _suggest_similar_command(self, command: str) -> str | None:
        return suggest_similar(command, self.get_visible_commands())

    @staticmethod
    def _is_tty_session(session: PromptSession[str]) -> bool:
        """Determine if the session supports full terminal interactions.

        Returns True if the session is attached to a real TTY or a virtual
        terminal (like PipeInput in tests). Returns False if the session is
        running in a headless environment (DummyInput).
        """
        # Validate against the session's assigned input driver rather than sys.stdin.
        # This respects the fallback logic in _create_main_session() and allows unit
        # tests to inject PipeInput for programmatic interaction even if paired with
        # a DummyOutput.
        return not isinstance(session.input, DummyInput)

    def _read_raw_input(
        self,
        prompt: Callable[[], ANSI | str] | ANSI | str,
        session: PromptSession[str],
        **prompt_kwargs: Any,
    ) -> str:
        """Execute the low-level input read from either a terminal or a redirected stream.

        If input is coming from a TTY, it uses `prompt_toolkit` to render a
        UI with completion and `patch_stdout` protection. Otherwise it performs
        a direct line read from `stdin`.

        :param prompt: the prompt text or a callable that returns the prompt.
        :param session: the PromptSession instance to use for reading.
        :param prompt_kwargs: additional arguments passed directly to session.prompt().
        :return: the stripped input string.
        :raises EOFError: if the input stream is closed or the user signals EOF (e.g., Ctrl+D)
        """
        # Check if the session is configured for interactive terminal use.
        if self._is_tty_session(session):
            if not callable(prompt):
                prompt = pt_filter_style(prompt)

            with patch_stdout():
                try:
                    # Set this session as the active one for UI/completion logic.
                    self.active_session = session
                    return session.prompt(prompt, **prompt_kwargs)
                finally:
                    # Revert back to the main session.
                    self.active_session = self.main_session

        # We're not at a terminal, so we're likely reading from a file or a pipe.
        prompt_obj = prompt() if callable(prompt) else prompt
        prompt_str = prompt_obj.value if isinstance(prompt_obj, ANSI) else prompt_obj

        # If this is an interactive pipe, then display the prompt first
        if self.interactive_pipe:
            self.poutput(prompt_str, end="")
            self.stdout.flush()

        # Wait for the next line of input
        line = self.stdin.readline()

        # If the stream is empty, we've reached the end of the input.
        if not line:
            raise EOFError

        # If not interactive and echo is on, we want the output to simulate a
        # live session. Print the prompt and the command so they appear in the
        # output stream before the results.
        if not self.interactive_pipe and self.echo:
            end = "" if line.endswith("\n") else "\n"

            self.poutput(f"{prompt_str}{line}", end=end)

        return line.rstrip("\r\n")

    def _resolve_completer(
        self,
        preserve_quotes: bool = False,
        choices: Iterable[Any] | None = None,
        choices_provider: UnboundChoicesProvider[CmdOrSetT] | None = None,
        completer: UnboundCompleter[CmdOrSetT] | None = None,
        parser: Cmd2ArgumentParser | None = None,
    ) -> Completer:
        """Determine the appropriate completer based on provided arguments."""
        if not any((parser, choices, choices_provider, completer)):
            return DummyCompleter()

        if parser and any((choices, choices_provider, completer)):
            err_msg = "None of the following parameters can be used alongside a parser:\nchoices, choices_provider, completer"
            raise ValueError(err_msg)

        if parser is None:
            parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(add_help=False)
            parser.add_argument(
                "arg",
                suppress_tab_hint=True,
                choices=choices,
                choices_provider=choices_provider,
                completer=completer,
            )

        settings = utils.CustomCompletionSettings(parser, preserve_quotes=preserve_quotes)
        return Cmd2Completer(self, custom_settings=settings)

    def read_input(
        self,
        prompt: str = "",
        *,
        history: Sequence[str] | None = None,
        preserve_quotes: bool = False,
        choices: Iterable[Any] | None = None,
        choices_provider: UnboundChoicesProvider[CmdOrSetT] | None = None,
        completer: UnboundCompleter[CmdOrSetT] | None = None,
        parser: Cmd2ArgumentParser | None = None,
    ) -> str:
        """Read a line of input with optional completion and history.

        :param prompt: prompt to display to user
        :param history: optional Sequence of strings to use for up-arrow history. The passed in history
                        will not be edited. It is the caller's responsibility to add the returned input
                        to history if desired. Defaults to None.
        :param preserve_quotes: if True, then quoted tokens will keep their quotes when processed by
                                ArgparseCompleter. This is helpful in cases when you're completing
                                flag-like tokens (e.g. -o, --option) and you don't want them to be
                                treated as argparse flags when quoted. Set this to True if you plan
                                on passing the string to argparse with the tokens still quoted.

        A maximum of one of these should be provided:
        :param choices: iterable of accepted values for single argument
        :param choices_provider: function that provides choices for single argument
        :param completer: completion function that provides choices for single argument
        :param parser: an argument parser which supports the completion of multiple arguments
        :return: the line read from stdin with all trailing new lines removed
        :raises EOFError: if the input stream is closed or the user signals EOF (e.g., Ctrl+D)
        :raises Exception: any other exceptions raised by prompt()
        """
        completer_to_use = self._resolve_completer(
            preserve_quotes=preserve_quotes,
            choices=choices,
            choices_provider=choices_provider,
            completer=completer,
            parser=parser,
        )

        temp_session: PromptSession[str] = PromptSession(
            auto_suggest=self.main_session.auto_suggest,
            color_depth=self.main_session.color_depth,
            complete_style=self.main_session.complete_style,
            complete_in_thread=self.main_session.complete_in_thread,
            complete_while_typing=self.main_session.complete_while_typing,
            completer=completer_to_use,
            history=InMemoryHistory(history) if history is not None else InMemoryHistory(),
            key_bindings=self.main_session.key_bindings,
            input=self.main_session.input,
            output=self.main_session.output,
            style=self.main_session.style,
        )

        return self._read_raw_input(prompt, temp_session)

    def read_secret(
        self,
        prompt: str = "",
    ) -> str:
        """Read a secret from stdin without displaying the value on the screen.

        :param prompt: prompt to display to user
        :return: the secret read from stdin with all trailing new lines removed
        :raises EOFError: if the input stream is closed or the user signals EOF (e.g., Ctrl+D)
        :raises Exception: any other exceptions raised by prompt()
        """
        temp_session: PromptSession[str] = PromptSession(
            color_depth=self.main_session.color_depth,
            input=self.main_session.input,
            output=self.main_session.output,
            style=self.main_session.style,
        )

        return self._read_raw_input(prompt, temp_session, is_password=True)

    def _process_alerts(self) -> None:
        """Background worker that processes queued alerts and dynamic prompt updates."""
        while True:
            with self._alert_condition:
                # Wait until we have alerts and are allowed to display them, or shutdown is signaled.
                self._alert_condition.wait_for(
                    lambda: (len(self._alert_queue) > 0 and self._alert_allowed) or self._alert_shutdown
                )

                # Shutdown immediately even if we have alerts.
                if self._alert_shutdown:
                    break

                # Hold the condition lock while printing to block command execution. This
                # prevents async alerts from printing once a command starts.

                # Print all alerts at once to reduce flicker.
                console = self._get_core_print_console(
                    file=self.stdout,
                    emoji=False,
                    markup=False,
                    highlight=False,
                )

                with console.capture() as capture:
                    for alert in self._alert_queue:
                        if alert.msg is not None:
                            console.print(alert.msg, soft_wrap=alert.soft_wrap)

                alert_text = capture.get()

                # Find the latest prompt update among all pending alerts.
                latest_prompt = None
                for alert in reversed(self._alert_queue):
                    if (
                        alert.prompt is not None
                        and alert.prompt != self.prompt
                        and alert.timestamp > self._alert_prompt_timestamp
                    ):
                        latest_prompt = alert.prompt
                        self._alert_prompt_timestamp = alert.timestamp
                        break

                # Clear the alerts
                self._alert_queue.clear()

                if latest_prompt is not None:
                    # Update prompt so patch_stdout() or get_app().invalidate() can redraw it.
                    self.prompt = latest_prompt

                if alert_text:
                    # Print the alert messages above the prompt.
                    with patch_stdout():
                        print_formatted_text(ANSI(alert_text), end="")

                elif latest_prompt is not None:
                    # Refresh UI immediately to show the new prompt
                    get_app().invalidate()

    def _read_command_line(self, prompt: str) -> str:
        """Read the next command line from the input stream.

        :param prompt: prompt to display to user
        :return: the line read from stdin with all trailing new lines removed
        :raises EOFError: if the input stream is closed or the user signals EOF (e.g., Ctrl+D)
        :raises Exception: any other exceptions raised by prompt()
        """

        # Use dynamic prompt if the prompt matches self.prompt
        def get_prompt() -> str | ANSI:
            return pt_filter_style(self.prompt)

        prompt_to_use: Callable[[], ANSI | str] | ANSI | str = ANSI(prompt)
        if prompt == self.prompt:
            prompt_to_use = get_prompt

        def _pre_prompt() -> None:
            """Run standard pre-prompt processing and activate the background alerter."""
            # Record prompt start time so any async prompt updates queued during
            # pre_prompt() are considered current.
            self._alert_prompt_timestamp = time.monotonic()
            self.pre_prompt()

            # Start alerter thread if it's not already running.
            if self._alert_thread is None or not self._alert_thread.is_alive():
                self._alert_allowed = False
                self._alert_shutdown = False
                self._alert_thread = threading.Thread(target=self._process_alerts, daemon=True)
                self._alert_thread.start()

            # Allow alerts to be printed now that we are at a prompt.
            with self._alert_condition:
                self._alert_allowed = True
                self._alert_condition.notify_all()

        try:
            return self._read_raw_input(
                prompt=prompt_to_use,
                session=self.main_session,
                pre_run=_pre_prompt,
            )
        finally:
            # Ensure no alerts print while not at a prompt.
            with self._alert_condition:
                self._alert_allowed = False

    def _cmdloop(self) -> None:
        """Repeatedly issue a prompt, accept input, parse it, and dispatch to appropriate commands.

        Parse an initial prefix off the received input and dispatch to action methods, passing them
        the remainder of the line as argument.

        This serves the same role as cmd.cmdloop().
        """
        try:
            # Run startup commands
            stop = self.runcmds_plus_hooks(self._startup_commands)
            self._startup_commands.clear()

            while not stop:
                # Get commands from user
                try:
                    line = self._read_command_line(self.prompt)
                except KeyboardInterrupt:
                    self.poutput("^C")
                    line = ""
                except EOFError:
                    line = "_eof"

                # Run the command along with all associated pre and post hooks
                stop = self.onecmd_plus_hooks(line)
        finally:
            with self.sigint_protection:
                # Shut down the alert thread.
                if self._alert_thread is not None:
                    with self._alert_condition:
                        self._alert_shutdown = True
                        self._alert_condition.notify_all()

                    # The thread is event-driven and stays suspended until notified.
                    # We join with a 1 second timeout as a safety measure. If it hangs,
                    # the daemon status allows the OS to reap it on exit.
                    self._alert_thread.join(timeout=1.0)
                    self._alert_thread = None

    #############################################################
    # Parsers and functions for alias command and subcommands
    #############################################################

    # Top-level parser for alias
    @staticmethod
    def _build_alias_parser() -> Cmd2ArgumentParser:
        alias_description = Text.assemble(
            "Manage aliases.",
            "\n\n",
            "An alias is a command that enables replacement of a word by another string.",
        )
        alias_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=alias_description)
        alias_parser.epilog = TextGroup(
            "See Also",
            "macro",
        )
        alias_parser.add_subparsers(title="subcommands", metavar="SUBCOMMAND", required=True)

        return alias_parser

    # Preserve quotes since we are passing strings to other commands
    @with_argparser(_build_alias_parser, preserve_quotes=True)
    def do_alias(self, args: argparse.Namespace) -> None:
        """Manage aliases."""
        # Call function for whatever subcommand was selected
        args.cmd2_subcommand_func(args)

    # alias -> create
    @classmethod
    def _build_alias_create_parser(cls) -> Cmd2ArgumentParser:
        alias_create_description = "Create or overwrite an alias."
        alias_create_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=alias_create_description)

        # Add Notes epilog
        alias_create_notes = Text.assemble(
            "If you want to use redirection, pipes, or terminators in the value of the alias, then quote them.",
            "\n\n",
            ('    alias create save_results print_results ">" out.txt\n', Cmd2Style.COMMAND_LINE),
            "\n\n",
            (
                "Since aliases are resolved during parsing, completion will function as it would "
                "for the actual command the alias resolves to."
            ),
        )
        alias_create_parser.epilog = TextGroup("Notes", alias_create_notes)

        # Add arguments
        alias_create_parser.add_argument("name", help="name of this alias")
        alias_create_parser.add_argument(
            "command",
            help="command, alias, or macro to run",
            choices_provider=cls._get_commands_aliases_and_macros_choices,
        )
        alias_create_parser.add_argument(
            "command_args",
            nargs=argparse.REMAINDER,
            help="arguments to pass to command",
            completer=cls.path_complete,
        )

        return alias_create_parser

    @as_subcommand_to("alias", "create", _build_alias_create_parser, help="create or overwrite an alias")
    def _alias_create(self, args: argparse.Namespace) -> None:
        """Create or overwrite an alias."""
        self.last_result = False

        # Validate the alias name
        valid, errmsg = self.statement_parser.is_valid_command(args.name)
        if not valid:
            self.perror(f"Invalid alias name: {errmsg}")
            return

        if args.name in self.get_all_commands():
            self.perror("Alias cannot have the same name as a command")
            return

        if args.name in self.macros:
            self.perror("Alias cannot have the same name as a macro")
            return

        # Unquote redirection and terminator tokens
        tokens_to_unquote = (*constants.REDIRECTION_TOKENS, *self.statement_parser.terminators)
        utils.unquote_specific_tokens(args.command_args, tokens_to_unquote)

        # Build the alias value string
        value = args.command
        if args.command_args:
            value += " " + " ".join(args.command_args)

        # Set the alias
        result = "overwritten" if args.name in self.aliases else "created"
        self.pfeedback(f"Alias '{args.name}' {result}")

        self.aliases[args.name] = value
        self.last_result = True

    # alias -> delete
    @classmethod
    def _build_alias_delete_parser(cls) -> Cmd2ArgumentParser:
        alias_delete_description = "Delete specified aliases or all aliases if --all is used."

        alias_delete_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=alias_delete_description)
        alias_delete_parser.add_argument("-a", "--all", action="store_true", help="delete all aliases")
        alias_delete_parser.add_argument(
            "names",
            nargs=argparse.ZERO_OR_MORE,
            help="alias(es) to delete",
            choices_provider=cls._get_alias_choices,
            table_columns=["Value"],
        )

        return alias_delete_parser

    @as_subcommand_to("alias", "delete", _build_alias_delete_parser, help="delete aliases")
    def _alias_delete(self, args: argparse.Namespace) -> None:
        """Delete aliases."""
        self.last_result = True

        if args.all:
            self.aliases.clear()
            self.pfeedback("All aliases deleted")
        elif not args.names:
            self.perror("Either --all or alias name(s) must be specified")
            self.last_result = False
        else:
            for cur_name in utils.remove_duplicates(args.names):
                if cur_name in self.aliases:
                    del self.aliases[cur_name]
                    self.pfeedback(f"Alias '{cur_name}' deleted")
                else:
                    self.perror(f"Alias '{cur_name}' does not exist")

    # alias -> list
    @classmethod
    def _build_alias_list_parser(cls) -> Cmd2ArgumentParser:
        alias_list_description = Text.assemble(
            (
                "List specified aliases in a reusable form that can be saved to a startup "
                "script to preserve aliases across sessions."
            ),
            "\n\n",
            "Without arguments, all aliases will be listed.",
        )

        alias_list_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=alias_list_description)
        alias_list_parser.add_argument(
            "names",
            nargs=argparse.ZERO_OR_MORE,
            help="alias(es) to list",
            choices_provider=cls._get_alias_choices,
            table_columns=["Value"],
        )

        return alias_list_parser

    @as_subcommand_to("alias", "list", _build_alias_list_parser, help="list aliases")
    def _alias_list(self, args: argparse.Namespace) -> None:
        """List some or all aliases as 'alias create' commands."""
        self.last_result = {}  # dict[alias_name, alias_value]

        tokens_to_quote = (*constants.REDIRECTION_TOKENS, *self.statement_parser.terminators)

        to_list = (
            utils.remove_duplicates(args.names)
            if args.names
            else sorted(
                self.aliases,
                key=utils.DEFAULT_STR_SORT_KEY,
            )
        )

        not_found: list[str] = []
        for name in to_list:
            if name not in self.aliases:
                not_found.append(name)
                continue

            # Quote redirection and terminator tokens for the 'alias create' command
            tokens = shlex_split(self.aliases[name])
            command = tokens[0]
            command_args = tokens[1:]
            utils.quote_specific_tokens(command_args, tokens_to_quote)

            val = command
            if command_args:
                val += " " + " ".join(command_args)

            self.poutput(f"alias create {name} {val}")
            self.last_result[name] = val

        for name in not_found:
            self.perror(f"Alias '{name}' not found")

    #############################################################
    # Parsers and functions for macro command and subcommands
    #############################################################

    def macro_arg_complete(
        self,
        text: str,
        line: str,
        begidx: int,
        endidx: int,
    ) -> Completions:
        """Completes arguments to a macro.

        Its default behavior is to call path_complete, but you can override this as needed.

        :param text: the string prefix we are attempting to match (all matches must begin with it)
        :param line: the current input line with leading whitespace removed
        :param begidx: the beginning index of the prefix text
        :param endidx: the ending index of the prefix text
        :return: a Completions object
        """
        return self.path_complete(text, line, begidx, endidx)

    # Top-level parser for macro
    @staticmethod
    def _build_macro_parser() -> Cmd2ArgumentParser:
        macro_description = Text.assemble(
            "Manage macros.",
            "\n\n",
            "A macro is similar to an alias, but it can contain argument placeholders.",
        )
        macro_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=macro_description)
        macro_parser.epilog = TextGroup(
            "See Also",
            "alias",
        )
        macro_parser.add_subparsers(title="subcommands", metavar="SUBCOMMAND", required=True)

        return macro_parser

    # Preserve quotes since we are passing strings to other commands
    @with_argparser(_build_macro_parser, preserve_quotes=True)
    def do_macro(self, args: argparse.Namespace) -> None:
        """Manage macros."""
        # Call function for whatever subcommand was selected
        args.cmd2_subcommand_func(args)

    # macro -> create
    @classmethod
    def _build_macro_create_parser(cls) -> Cmd2ArgumentParser:
        macro_create_description = Text.assemble(
            "Create or overwrite a macro.",
            "\n\n",
            "A macro is similar to an alias, but it can contain argument placeholders.",
            "\n\n",
            "Arguments are expressed when creating a macro using {#} notation where {1} means the first argument.",
            "\n\n",
            "The following creates a macro called my_macro that expects two arguments:",
            "\n\n",
            ("    macro create my_macro make_dinner --meat {1} --veggie {2}", Cmd2Style.COMMAND_LINE),
            "\n\n",
            "When the macro is called, the provided arguments are resolved and the assembled command is run. For example:",
            "\n\n",
            ("    my_macro beef broccoli", Cmd2Style.COMMAND_LINE),
            (" ─> ", Style(bold=True)),
            ("make_dinner --meat beef --veggie broccoli", Cmd2Style.COMMAND_LINE),
        )
        macro_create_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=macro_create_description)

        # Add Notes epilog
        macro_create_notes = Text.assemble(
            "To use the literal string {1} in your command, escape it this way: {{1}}.",
            "\n\n",
            "Extra arguments passed to a macro are appended to resolved command.",
            "\n\n",
            (
                "An argument number can be repeated in a macro. In the following example the "
                "first argument will populate both {1} instances."
            ),
            "\n\n",
            ("    macro create ft file_taxes -p {1} -q {2} -r {1}", Cmd2Style.COMMAND_LINE),
            "\n\n",
            "To quote an argument in the resolved command, quote it during creation.",
            "\n\n",
            ('    macro create backup !cp "{1}" "{1}.orig"', Cmd2Style.COMMAND_LINE),
            "\n\n",
            "If you want to use redirection, pipes, or terminators in the value of the macro, then quote them.",
            "\n\n",
            ('    macro create show_results print_results -type {1} "|" less', Cmd2Style.COMMAND_LINE),
            "\n\n",
            (
                "Since macros don't resolve until after you press Enter, their arguments complete as paths. "
                "This default behavior changes if custom completion for macro arguments has been implemented."
            ),
        )
        macro_create_parser.epilog = TextGroup("Notes", macro_create_notes)

        # Add arguments
        macro_create_parser.add_argument("name", help="name of this macro")
        macro_create_parser.add_argument(
            "command",
            help="command, alias, or macro to run",
            choices_provider=cls._get_commands_aliases_and_macros_choices,
        )
        macro_create_parser.add_argument(
            "command_args",
            nargs=argparse.REMAINDER,
            help="arguments to pass to command",
            completer=cls.path_complete,
        )

        return macro_create_parser

    @as_subcommand_to("macro", "create", _build_macro_create_parser, help="create or overwrite a macro")
    def _macro_create(self, args: argparse.Namespace) -> None:
        """Create or overwrite a macro."""
        self.last_result = False

        # Validate the macro name
        valid, errmsg = self.statement_parser.is_valid_command(args.name)
        if not valid:
            self.perror(f"Invalid macro name: {errmsg}")
            return

        if args.name in self.get_all_commands():
            self.perror("Macro cannot have the same name as a command")
            return

        if args.name in self.aliases:
            self.perror("Macro cannot have the same name as an alias")
            return

        # Unquote redirection and terminator tokens
        tokens_to_unquote = (*constants.REDIRECTION_TOKENS, *self.statement_parser.terminators)
        utils.unquote_specific_tokens(args.command_args, tokens_to_unquote)

        # Build the macro value string
        value = args.command
        if args.command_args:
            value += " " + " ".join(args.command_args)

        # Find all normal arguments
        macro_args = []
        normal_matches = re.finditer(MacroArg.macro_normal_arg_pattern, value)
        max_arg_num = 0
        arg_nums = set()

        try:
            while True:
                cur_match = normal_matches.__next__()

                # Get the number string between the braces
                cur_num_str = re.findall(MacroArg.digit_pattern, cur_match.group())[0]
                cur_num = int(cur_num_str)
                if cur_num < 1:
                    self.perror("Argument numbers must be greater than 0")
                    return

                arg_nums.add(cur_num)
                max_arg_num = max(max_arg_num, cur_num)

                macro_args.append(MacroArg(start_index=cur_match.start(), number_str=cur_num_str, is_escaped=False))
        except StopIteration:
            pass

        # Make sure the argument numbers are continuous
        if len(arg_nums) != max_arg_num:
            self.perror(f"Not all numbers between 1 and {max_arg_num} are present in the argument placeholders")
            return

        # Find all escaped arguments
        escaped_matches = re.finditer(MacroArg.macro_escaped_arg_pattern, value)

        try:
            while True:
                cur_match = escaped_matches.__next__()

                # Get the number string between the braces
                cur_num_str = re.findall(MacroArg.digit_pattern, cur_match.group())[0]

                macro_args.append(MacroArg(start_index=cur_match.start(), number_str=cur_num_str, is_escaped=True))
        except StopIteration:
            pass

        # Set the macro
        result = "overwritten" if args.name in self.macros else "created"
        self.pfeedback(f"Macro '{args.name}' {result}")

        self.macros[args.name] = Macro(name=args.name, value=value, minimum_arg_count=max_arg_num, args=macro_args)
        self.last_result = True

    # macro -> delete
    @classmethod
    def _build_macro_delete_parser(cls) -> Cmd2ArgumentParser:
        macro_delete_description = "Delete specified macros or all macros if --all is used."

        macro_delete_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=macro_delete_description)
        macro_delete_parser.add_argument("-a", "--all", action="store_true", help="delete all macros")
        macro_delete_parser.add_argument(
            "names",
            nargs=argparse.ZERO_OR_MORE,
            help="macro(s) to delete",
            choices_provider=cls._get_macro_choices,
            table_columns=["Value"],
        )

        return macro_delete_parser

    @as_subcommand_to("macro", "delete", _build_macro_delete_parser, help="delete macros")
    def _macro_delete(self, args: argparse.Namespace) -> None:
        """Delete macros."""
        self.last_result = True

        if args.all:
            self.macros.clear()
            self.pfeedback("All macros deleted")
        elif not args.names:
            self.perror("Either --all or macro name(s) must be specified")
            self.last_result = False
        else:
            for cur_name in utils.remove_duplicates(args.names):
                if cur_name in self.macros:
                    del self.macros[cur_name]
                    self.pfeedback(f"Macro '{cur_name}' deleted")
                else:
                    self.perror(f"Macro '{cur_name}' does not exist")

    # macro -> list
    @classmethod
    def _build_macro_list_parser(cls) -> Cmd2ArgumentParser:
        macro_list_description = Text.assemble(
            (
                "List specified macros in a reusable form that can be saved to a startup script "
                "to preserve macros across sessions."
            ),
            "\n\n",
            "Without arguments, all macros will be listed.",
        )

        macro_list_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=macro_list_description)
        macro_list_parser.add_argument(
            "names",
            nargs=argparse.ZERO_OR_MORE,
            help="macro(s) to list",
            choices_provider=cls._get_macro_choices,
            table_columns=["Value"],
        )

        return macro_list_parser

    @as_subcommand_to("macro", "list", _build_macro_list_parser, help="list macros")
    def _macro_list(self, args: argparse.Namespace) -> None:
        """List macros."""
        self.last_result = {}  # dict[macro_name, macro_value]

        tokens_to_quote = (*constants.REDIRECTION_TOKENS, *self.statement_parser.terminators)

        to_list = (
            utils.remove_duplicates(args.names)
            if args.names
            else sorted(
                self.macros,
                key=utils.DEFAULT_STR_SORT_KEY,
            )
        )

        not_found: list[str] = []
        for name in to_list:
            if name not in self.macros:
                not_found.append(name)
                continue

            # Quote redirection and terminator tokens for the 'macro create' command
            tokens = shlex_split(self.macros[name].value)
            command = tokens[0]
            command_args = tokens[1:]
            utils.quote_specific_tokens(command_args, tokens_to_quote)

            val = command
            if command_args:
                val += " " + " ".join(command_args)

            self.poutput(f"macro create {name} {val}")
            self.last_result[name] = val

        for name in not_found:
            self.perror(f"Macro '{name}' not found")

    def complete_help_command(self, text: str, line: str, begidx: int, endidx: int) -> Completions:
        """Completes the command argument of help."""
        # Complete token against topics and visible commands
        topics = set(self.get_help_topics())
        visible_commands = set(self.get_visible_commands())
        strs_to_match = list(topics | visible_commands)
        return self.basic_complete(text, line, begidx, endidx, strs_to_match)

    def complete_help_subcommands(
        self, text: str, line: str, begidx: int, endidx: int, arg_tokens: Mapping[str, Sequence[str]]
    ) -> Completions:
        """Completes the subcommands argument of help."""
        # Make sure we have a command whose subcommands we will complete
        command = arg_tokens["command"][0]
        if not command:
            return Completions()

        # Check if this command uses argparse
        if (command_func := self.get_command_func(command)) is None or (
            parser := self.command_parsers.get(command_func)
        ) is None:
            return Completions()

        completer = parser.completer_class(parser, self)
        return completer.complete_subcommand_help(text, line, begidx, endidx, arg_tokens["subcommands"])

    def _build_command_info(self) -> tuple[dict[str, list[str]], list[str]]:
        """Categorizes and sorts visible commands and help topics for display.

        :return: tuple containing:
                  - dictionary mapping category names to lists of command names
                  - list of help topic names that are not also commands
        """
        # Get a sorted list of help topics
        help_topics = sorted(self.get_help_topics(), key=utils.DEFAULT_STR_SORT_KEY)

        # Get a sorted list of visible command names
        visible_commands = sorted(self.get_visible_commands(), key=utils.DEFAULT_STR_SORT_KEY)
        cmds_cats: dict[str, list[str]] = {}

        for command in visible_commands:
            # Prevent the command from showing as both a command and help topic in the output
            if command in help_topics:
                help_topics.remove(command)

            # Store the command within its category
            command_func = cast(BoundCommandFunc, self.get_command_func(command))
            category = self._get_command_category(command_func)
            cmds_cats.setdefault(category, []).append(command)

        return cmds_cats, help_topics

    @classmethod
    def _build_help_parser(cls) -> Cmd2ArgumentParser:
        help_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(
            description="List available commands or provide detailed help for a specific command."
        )
        help_parser.add_argument(
            "-v",
            "--verbose",
            action="store_true",
            help="print a list of all commands with descriptions of each",
        )
        help_parser.add_argument(
            "command",
            nargs=argparse.OPTIONAL,
            help="command to retrieve help for",
            completer=cls.complete_help_command,
        )
        help_parser.add_argument(
            "subcommands",
            nargs=argparse.REMAINDER,
            help="subcommand(s) to retrieve help for",
            completer=cls.complete_help_subcommands,
        )
        return help_parser

    @with_argparser(_build_help_parser)
    def do_help(self, args: argparse.Namespace) -> None:
        """List available commands or provide detailed help for a specific command."""
        self.last_result = True

        if not args.command or args.verbose:
            cmds_cats, help_topics = self._build_command_info()

            if self.doc_leader:
                self.poutput()
                self.poutput(Text(self.doc_leader, style=Cmd2Style.HELP_LEADER))
            self.poutput()

            # Used to provide verbose table separation for better readability.
            previous_table_printed = False

            # Print commands grouped by category
            sorted_categories = sorted(cmds_cats.keys(), key=utils.DEFAULT_STR_SORT_KEY)
            all_cmds = {category: cmds_cats[category] for category in sorted_categories}

            for category, commands in all_cmds.items():
                if previous_table_printed:
                    self.poutput()

                self._print_documented_command_topics(category, commands, args.verbose)
                previous_table_printed = bool(commands) and args.verbose

            if previous_table_printed and help_topics:
                self.poutput()

            # Print help topics table
            self.print_topics(self.MISC_HEADER, help_topics, 15, 80)

        else:
            # Getting help for a specific command
            disabled = args.command in self.disabled_commands
            help_func = getattr(self, constants.HELP_FUNC_PREFIX + args.command, None)

            # If the command is disabled, then call the help function which was
            # overwritten by disable_command() to print the disabled message.
            if disabled:
                if help_func is not None:
                    help_func()
                else:
                    # Handle potential case where command is disabled by manually editing
                    # self.disabled_commands instead of using disable_command().
                    self._report_disabled_command_usage(message_to_print=f"{args.command} is currently disabled.")
                return

            command_func = self.get_command_func(args.command)
            parser = None if command_func is None else self.command_parsers.get(command_func)

            # If the command function uses argparse, then use argparse's help
            if command_func is not None and parser is not None:
                completer = parser.completer_class(parser, self)
                completer.print_help(args.subcommands, self.stdout)

            # If the command has a custom help function, then call it
            elif help_func is not None:
                help_func()

            # If the command function has a docstring, then print it
            elif command_func is not None and command_func.__doc__ is not None:
                self.poutput(pydoc.getdoc(command_func))

            # If there is no help information then print an error
            else:
                err_msg = self.help_error.format(args.command)
                self.perror(err_msg, style=None)
                self.last_result = False

    def _create_help_grid(self, title: str, *content: RenderableType) -> Table:
        """Create a titled grid for help headers with a ruler and optional content."""
        grid = Table.grid()
        grid.add_row(Text(title, style=Cmd2Style.HELP_HEADER))
        grid.add_row(Rule(style=Cmd2Style.TABLE_BORDER))
        for item in content:
            grid.add_row(item)
        return grid

    def print_topics(self, header: str, cmds: Sequence[str] | None, cmdlen: int, maxcol: int) -> None:  # noqa: ARG002
        """Print groups of commands and topics in columns and an optional header.

        Override of cmd's print_topics() to use Rich.

        :param header: string to print above commands being printed
        :param cmds: Sequence of topics to print
        :param cmdlen: unused, even by cmd's version
        :param maxcol: max number of display columns to fit into
        """
        if not cmds:
            return

        if header:
            self.poutput(
                self._create_help_grid(header),
                soft_wrap=False,
            )

        # Subtract 1 from maxcol to account for a one-space right margin.
        maxcol = min(maxcol, ru.console_width()) - 1
        self.columnize(cmds, maxcol)
        self.poutput()

    def _print_documented_command_topics(self, header: str, commands: Sequence[str], verbose: bool) -> None:
        """Print topics which are documented commands, switching between verbose or traditional output."""
        if not commands:
            return

        if not verbose:
            self.print_topics(header, commands, 15, 80)
            return

        topic_table = Cmd2SimpleTable(
            Column("Name", no_wrap=True),
            Column("Description", overflow="fold"),
        )

        # Try to get the documentation string for each command
        for command in commands:
            if (command_func := self.get_command_func(command)) is None:
                continue

            doc = command_func.__doc__

            # Attempt to locate the first documentation block
            cmd_desc = strip_doc_annotations(doc) if doc else ""

            # Add this command to the table
            topic_table.add_row(command, cmd_desc)

        self.poutput(
            self._create_help_grid(header, topic_table),
            soft_wrap=False,
        )
        self.poutput()

    def render_columns(self, str_list: Sequence[str] | None, display_width: int = 80) -> str:
        """Render a list of single-line strings as a compact set of columns.

        This method correctly handles strings containing ANSI style sequences and
        full-width characters (like those used in CJK languages). Each column is
        only as wide as necessary and columns are separated by two spaces.

        :param str_list: Sequence of single-line strings to display
        :param display_width: max number of display columns to fit into
        :return: a string containing the columnized output
        """
        if not str_list:
            return ""

        size = len(str_list)
        if size == 1:
            return str_list[0]

        rows: list[str] = []

        # Try every row count from 1 upwards
        for nrows in range(1, len(str_list)):
            ncols = (size + nrows - 1) // nrows
            colwidths = []
            totwidth = -2
            for col in range(ncols):
                colwidth = 0
                for row in range(nrows):
                    i = row + nrows * col
                    if i >= size:
                        break
                    x = str_list[i]
                    colwidth = max(colwidth, su.str_width(x))
                colwidths.append(colwidth)
                totwidth += colwidth + 2
                if totwidth > display_width:
                    break
            if totwidth <= display_width:
                break
        else:
            # The output is wider than display_width. Print 1 column with each string on its own row.
            nrows = len(str_list)
            ncols = 1
            max_width = max(su.str_width(s) for s in str_list)
            colwidths = [max_width]
        for row in range(nrows):
            texts = []
            for col in range(ncols):
                i = row + nrows * col
                x = "" if i >= size else str_list[i]
                texts.append(x)
            while texts and not texts[-1]:
                del texts[-1]
            for col in range(len(texts)):
                texts[col] = su.align_left(texts[col], width=colwidths[col])
            rows.append("  ".join(texts))

        return "\n".join(rows)

    def columnize(self, str_list: Sequence[str] | None, display_width: int = 80) -> None:
        """Display a list of single-line strings as a compact set of columns.

        Override of cmd's columnize() that uses the render_columns() method.
        The method correctly handles strings with ANSI style sequences and
        full-width characters (like those used in CJK languages).

        :param str_list: Sequence of single-line strings to display
        :param display_width: max number of display columns to fit into
        """
        columnized_strs = self.render_columns(str_list, display_width)
        self.poutput(columnized_strs)

    @staticmethod
    def _build_shortcuts_parser() -> Cmd2ArgumentParser:
        return argparse_utils.DEFAULT_ARGUMENT_PARSER(description="List available shortcuts.")

    @with_argparser(_build_shortcuts_parser)
    def do_shortcuts(self, _: argparse.Namespace) -> None:
        """List available shortcuts."""
        # Sort the shortcut tuples by name
        sorted_shortcuts = sorted(self.statement_parser.shortcuts, key=lambda x: utils.DEFAULT_STR_SORT_KEY(x[0]))
        result = "\n".join(f"{sc[0]}: {sc[1]}" for sc in sorted_shortcuts)
        self.poutput(f"Shortcuts for other commands:\n{result}")
        self.last_result = True

    @staticmethod
    def _build__eof_parser() -> Cmd2ArgumentParser:
        _eof_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Called when Ctrl-D is pressed.")
        _eof_parser.epilog = TextGroup(
            "Note",
            "This command is for internal use and is not intended to be called from the command line.",
        )

        return _eof_parser

    @with_argparser(_build__eof_parser)
    def do__eof(self, _: argparse.Namespace) -> bool | None:
        """Quit with no arguments, called when Ctrl-D is pressed.

        This can be overridden if quit should be called differently.
        """
        self.poutput()

        # self.last_result will be set by do_quit()
        return self.do_quit("")

    @staticmethod
    def _build_quit_parser() -> Cmd2ArgumentParser:
        return argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Exit this application.")

    @with_argparser(_build_quit_parser)
    def do_quit(self, _: argparse.Namespace) -> bool | None:
        """Exit this application."""
        # Return True to stop the command loop
        self.last_result = True
        return True

    def select(self, opts: str | Iterable[str] | Iterable[tuple[Any, str | None]], prompt: str = "Your choice? ") -> Any:
        """Present a menu to the user.

        Modeled after the bash shell's SELECT.  Returns the item chosen.

        Argument ``opts`` can be:

          | a single string -> will be split into one-word options
          | a list of strings -> will be offered as options
          | a list of tuples -> interpreted as (value, text), so
                                that the return value can differ from
                                the text advertised to the user
        """
        local_opts: Iterable[str] | Iterable[tuple[Any, str | None]]
        if isinstance(opts, str):
            local_opts = cast(list[tuple[Any, str | None]], list(zip(opts.split(), opts.split(), strict=False)))
        else:
            local_opts = opts
        fulloptions: list[tuple[Any, str]] = []
        for opt in local_opts:
            if isinstance(opt, str):
                fulloptions.append((opt, opt))
            else:
                try:
                    val = opt[0]
                    text = str(opt[1]) if len(opt) > 1 and opt[1] is not None else str(val)
                    fulloptions.append((val, text))
                except (IndexError, TypeError):
                    fulloptions.append((opt[0], str(opt[0])))

        if self._is_tty_session(self.main_session):
            try:
                while True:
                    with create_app_session(input=self.main_session.input, output=self.main_session.output):
                        result = choice(message=prompt, options=fulloptions)
                    if result is not None:
                        return result
            except KeyboardInterrupt:
                self.poutput("^C")
                raise

        # Non-interactive fallback
        for idx, (_, text) in enumerate(fulloptions):
            self.poutput("  %2d. %s" % (idx + 1, text))  # noqa: UP031

        while True:
            try:
                response = self.read_input(prompt)
            except EOFError:
                response = ""
                self.poutput()
            except KeyboardInterrupt:
                self.poutput("^C")
                raise

            if not response:
                continue

            try:
                choice_idx = int(response)
                if choice_idx < 1:
                    raise IndexError  # noqa: TRY301
                return fulloptions[choice_idx - 1][0]
            except (ValueError, IndexError):
                self.poutput(f"'{response}' isn't a valid choice. Pick a number between 1 and {len(fulloptions)}:")

    @classmethod
    def _build_base_set_parser(cls) -> Cmd2ArgumentParser:
        # When completing value, we recreate the set command parser with a value argument specific to
        # the settable being edited. To make this easier, define a base parser with all the common elements.
        set_description = Text.assemble(
            "Set a settable parameter or show current settings of parameters.",
            "\n\n",
            (
                "Call without arguments for a list of all settable parameters with their values. "
                "Call with just param to view that parameter's value."
            ),
        )
        base_set_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=set_description)
        base_set_parser.add_argument(
            "param",
            nargs=argparse.OPTIONAL,
            help="parameter to set or view",
            choices_provider=cls._get_settable_choices,
            table_columns=["Value", "Description"],
        )

        return base_set_parser

    def complete_set_value(
        self, text: str, line: str, begidx: int, endidx: int, arg_tokens: Mapping[str, Sequence[str]]
    ) -> Completions:
        """Completes the value argument of set."""
        param = arg_tokens["param"][0]
        try:
            settable = self.settables[param]
        except KeyError as ex:
            raise CompletionError(param + " is not a settable parameter") from ex

        # Create a parser with a value field based on this settable
        settable_parser = self._build_base_set_parser()

        # Settables with choices list the values of those choices instead of the arg name
        # in help text and this shows in completion hints. Set metavar to avoid this.
        arg_name = "value"
        settable_parser.add_argument(
            arg_name,
            metavar=arg_name,
            help=settable.description,
            choices=settable.choices,
            choices_provider=settable.choices_provider,
            completer=settable.completer,
        )

        completer = settable_parser.completer_class(settable_parser, self)

        # Use raw_tokens since quotes have been preserved
        _, raw_tokens = self.tokens_for_completion(line, begidx, endidx)
        return completer.complete(text, line, begidx, endidx, raw_tokens[1:])

    @classmethod
    def _build_set_parser(cls) -> Cmd2ArgumentParser:
        # Create the parser for the set command
        set_parser = cls._build_base_set_parser()
        set_parser.add_argument(
            "value",
            nargs=argparse.OPTIONAL,
            help="new value for settable",
            completer=cls.complete_set_value,
            suppress_tab_hint=True,
        )

        return set_parser

    # Preserve quotes so users can pass in quoted empty strings and flags (e.g. -h) as the value
    @with_argparser(_build_set_parser, preserve_quotes=True)
    def do_set(self, args: argparse.Namespace) -> None:
        """Set a settable parameter or show current settings of parameters."""
        self.last_result = False

        if not self.settables:
            self.pwarning("There are no settable parameters")
            return

        if args.param:
            try:
                settable = self.settables[args.param]
            except KeyError:
                self.perror(f"Parameter '{args.param}' not supported (type 'set' for list of parameters).")
                return

            if args.value:
                # Try to update the settable's value
                try:
                    settable.value = su.strip_quotes(args.value)
                except ValueError as ex:
                    self.perror(f"Error setting {args.param}: {ex}")
                else:
                    # Create the feedback message using Rich Text for color
                    feedback_msg = Text.assemble(
                        f"{args.param} ─> ",
                        (f"{settable.value!r}", Cmd2Style.SUCCESS),
                    )
                    self.pfeedback(feedback_msg)

                    self.last_result = True
                return

            # Show one settable
            to_show: list[str] = [args.param]
        else:
            # Show all settables
            to_show = list(self.settables.keys())

        settable_table = Cmd2SimpleTable(
            Column("Name", no_wrap=True),
            Column("Value", overflow="fold"),
            Column("Description", overflow="fold"),
        )

        # Build the table and populate self.last_result
        self.last_result = {}  # dict[settable_name, settable_value]

        for param in sorted(to_show, key=utils.DEFAULT_STR_SORT_KEY):
            settable = self.settables[param]
            settable_table.add_row(
                param,
                str(settable.value),
                Text.from_ansi(settable.description),
            )
            self.last_result[param] = settable.value

        self.poutput()
        self.poutput(settable_table, soft_wrap=False)
        self.poutput()

    @classmethod
    def _build_shell_parser(cls) -> Cmd2ArgumentParser:
        shell_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Execute a command as if at the OS prompt.")
        shell_parser.add_argument("command", help="the command to run", completer=cls.shell_cmd_complete)
        shell_parser.add_argument(
            "command_args", nargs=argparse.REMAINDER, help="arguments to pass to command", completer=cls.path_complete
        )

        return shell_parser

    # Preserve quotes since we are passing these strings to the shell
    @with_argparser(_build_shell_parser, preserve_quotes=True)
    def do_shell(self, args: argparse.Namespace) -> None:
        """Execute a command as if at the OS prompt."""
        import signal
        import subprocess

        kwargs: dict[str, Any] = {}

        # Set OS-specific parameters
        if sys.platform.startswith("win"):
            # Windows returns STATUS_CONTROL_C_EXIT when application stopped by Ctrl-C
            ctrl_c_ret_code = 0xC000013A
        else:
            # On POSIX, Popen() returns -SIGINT when application stopped by Ctrl-C
            ctrl_c_ret_code = signal.SIGINT.value * -1

            # On POSIX with shell=True, Popen() defaults to /bin/sh as the shell.
            # sh reports an incorrect return code for some applications when Ctrl-C is pressed within that
            # application (e.g. less). Since sh received the SIGINT, it sets the return code to reflect being
            # closed by SIGINT even though less did not exit upon a Ctrl-C press. In the same situation, other
            # shells like bash and zsh report the actual return code of less. Therefore, we will try to run the
            # user's preferred shell which most likely will be something other than sh. This also allows the user
            # to run builtin commands of their preferred shell.
            shell = os.environ.get("SHELL")
            if shell:
                kwargs["executable"] = shell

        # Create a list of arguments to shell
        tokens = [args.command, *args.command_args]

        # Expand ~ where needed
        utils.expand_user_in_tokens(tokens)
        expanded_command = " ".join(tokens)

        # Prevent KeyboardInterrupts while in the shell process. The shell process will
        # still receive the SIGINT since it is in the same process group as us.
        with self.sigint_protection:
            # For any stream that is a StdSim, we will use a pipe so we can capture its output
            proc = subprocess.Popen(  # noqa: S602
                expanded_command,
                stdout=subprocess.PIPE if isinstance(self.stdout, utils.StdSim) else self.stdout,  # type: ignore[unreachable]
                stderr=subprocess.PIPE if isinstance(sys.stderr, utils.StdSim) else sys.stderr,
                shell=True,
                **kwargs,
            )

            proc_reader = utils.ProcReader(proc, self.stdout, sys.stderr)
            proc_reader.wait()

            # Save the return code of the application for use in a pyscript
            self.last_result = proc.returncode

            # If the process was stopped by Ctrl-C, then inform the caller by raising a KeyboardInterrupt.
            # This is to support things like stop_on_keyboard_interrupt in runcmds_plus_hooks().
            if proc.returncode == ctrl_c_ret_code:
                self._raise_keyboard_interrupt()

    @staticmethod
    def _reset_py_display() -> None:
        """Reset the dynamic objects in the sys module that the py and ipy consoles fight over.

        When a Python console starts it adopts certain display settings if they've already been set.
        If an ipy console has previously been run, then py uses its settings and ends up looking
        like an ipy console in terms of prompt and exception text. This method forces the Python
        console to create its own display settings since they won't exist.

        IPython does not have this problem since it always overwrites the display settings when it
        is run. Therefore, this method only needs to be called before creating a Python console.
        """
        # Delete any prompts that have been set
        attributes = ["ps1", "ps2", "ps3"]
        for cur_attr in attributes:
            with contextlib.suppress(KeyError):
                del sys.__dict__[cur_attr]

        # Reset functions
        sys.displayhook = sys.__displayhook__
        sys.excepthook = sys.__excepthook__

    def _set_up_py_shell_env(self, interp: InteractiveConsole) -> _SavedCmd2Env:
        """Set up interactive Python shell environment.

        :return: Class containing saved up cmd2 environment.
        """
        cmd2_env = _SavedCmd2Env()

        # Set up sys module for the Python console
        self._reset_py_display()

        # Enable completion if readline is available
        if not sys.platform.startswith("win"):
            import readline
            import rlcompleter

            # Save the current completer
            cmd2_env.completer = readline.get_completer()

            # Set the completer to use the interpreter's locals
            readline.set_completer(rlcompleter.Completer(interp.locals).complete)  # type: ignore[arg-type]

            # Use the correct binding based on whether LibEdit or Readline is being used
            if "libedit" in (readline.__doc__ or ""):
                readline.parse_and_bind("bind ^I rl_complete")
            else:
                readline.parse_and_bind("tab: complete")

        return cmd2_env

    def _restore_cmd2_env(self, cmd2_env: _SavedCmd2Env) -> None:
        """Restore cmd2 environment after exiting an interactive Python shell.

        :param cmd2_env: the environment settings to restore
        """
        # Restore the readline completer
        if not sys.platform.startswith("win"):
            import readline

            readline.set_completer(cmd2_env.completer)

    def _run_python(self, *, pyscript: str | None = None) -> bool | None:
        """Run an interactive Python shell or execute a pyscript file.

        Called by do_py() and do_run_pyscript().

        If pyscript is None, then this function runs an interactive Python shell.
        Otherwise, it runs the pyscript file.

        :param pyscript: optional path to a pyscript file to run. This is intended only to be used by do_run_pyscript()
                         after it sets up sys.argv for the script. (Defaults to None)
        :return: True if running of commands should stop
        """
        self.last_result = False

        # Replace print() in the embedded Python environment. Standard print() writes to
        # sys.stdout, which bypasses cmd2 redirection (e.g., run_pyscript script.py > out.txt).
        # Using self.print_to(self.stdout) ensures output is capturable and respects 'allow_style'
        # without requiring the user to have access to 'self'.
        def py_print(
            *objects: Any,
            sep: str = " ",
            end: str = "\n",
            file: IO[str] | None = None,
            flush: bool = False,  # noqa: ARG001
        ) -> None:
            """Print objects to a stream, defaulting to self.stdout.

            This is used as the print() function within interactive Python shells and pyscripts.
            It wraps cmd2's print_to() method to honor output redirection and style settings.

            :param objects: objects to print (including Rich objects)
            :param sep: string to write between printed text. Defaults to " ".
            :param end: string to write at end of printed text. Defaults to a newline.
            :param file: file stream being written to. Defaults to self.stdout.
            :param flush: ignored as Rich-based output is flushed automatically. Defaults to False.
            """
            if file is None:
                file = self.stdout

            self.print_to(file, *objects, sep=sep, end=end)

        # Replace quit/exit in the embedded Python environment. Standard sys.exit()
        # would kill the entire application process; raising EmbeddedConsoleExit
        # allows the interpreter to return gracefully to the cmd2 prompt.
        def py_quit() -> None:
            """Exit an interactive Python shell or pyscript."""
            raise EmbeddedConsoleExit

        from .py_bridge import PyBridge

        add_to_history = self.scripts_add_to_history if pyscript else True
        py_bridge = PyBridge(self, add_to_history=add_to_history)
        saved_sys_path = None

        if self.in_pyscript():
            self.perror("Recursively entering interactive Python shells is not allowed")
            return None

        try:
            self._in_py = True
            py_code_to_run = ""

            # Make a copy of self.py_locals for the locals dictionary in the Python environment we are creating.
            # This is to prevent pyscripts from editing it. (e.g. locals().clear()). It also ensures a pyscript's
            # environment won't be filled with data from a previously run pyscript. Only make a shallow copy since
            # it's OK for py_locals to contain objects which are editable in a pyscript.
            local_vars = self.py_locals.copy()
            local_vars[self.py_bridge_name] = py_bridge
            local_vars["print"] = py_print
            local_vars["quit"] = py_quit
            local_vars["exit"] = py_quit

            if self.self_in_py:
                local_vars["self"] = self

            # Handle case where we were called by do_run_pyscript()
            if pyscript is not None:
                # Read the script file
                expanded_filename = os.path.expanduser(pyscript)

                try:
                    with open(expanded_filename) as f:
                        py_code_to_run = f.read()
                except OSError as ex:
                    self.perror(f"Error reading script file '{expanded_filename}': {ex}")
                    return None

                local_vars["__name__"] = "__main__"
                local_vars["__file__"] = expanded_filename

                # Place the script's directory at sys.path[0] just as Python does when executing a script
                saved_sys_path = list(sys.path)
                sys.path.insert(0, os.path.dirname(os.path.abspath(expanded_filename)))

            else:
                # This is the default name chosen by InteractiveConsole when no locals are passed in
                local_vars["__name__"] = "__console__"

            # Create the Python interpreter
            self.last_result = True
            interp = InteractiveConsole(locals=local_vars)

            # Check if we are running Python code
            if py_code_to_run:
                try:  # noqa: SIM105
                    interp.runcode(py_code_to_run)  # type: ignore[arg-type]
                except BaseException:  # noqa: BLE001, S110
                    # We don't care about any exception that happened in the Python code
                    pass

            # Otherwise we will open an interactive Python shell
            else:
                cprt = 'Type "help", "copyright", "credits" or "license" for more information.'
                instructions = (
                    "Use `Ctrl-D` (Unix) / `Ctrl-Z` (Windows), `quit()`, `exit()` to exit.\n"
                    f'Run CLI commands with: {self.py_bridge_name}("command ...")'
                )
                banner = f"Python {sys.version} on {sys.platform}\n{cprt}\n\n{instructions}\n"

                saved_cmd2_env = None

                try:
                    # Get sigint protection while we set up the Python shell environment
                    with self.sigint_protection:
                        saved_cmd2_env = self._set_up_py_shell_env(interp)

                    # Since quit() or exit() raise an EmbeddedConsoleExit, interact() exits before printing
                    # the exitmsg. Therefore, we will not provide it one and print it manually later.
                    interp.interact(banner=banner, exitmsg="")
                except BaseException:  # noqa: BLE001, S110
                    # We don't care about any exception that happened in the interactive console
                    pass
                finally:
                    # Get sigint protection while we restore cmd2 environment settings
                    with self.sigint_protection:
                        if saved_cmd2_env is not None:
                            self._restore_cmd2_env(saved_cmd2_env)
                    self.poutput("Now exiting Python shell...")

        finally:
            with self.sigint_protection:
                if saved_sys_path is not None:
                    sys.path = saved_sys_path
                self._in_py = False

        return py_bridge.stop

    @staticmethod
    def _build_py_parser() -> Cmd2ArgumentParser:
        return argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Run an interactive Python shell.")

    @with_argparser(_build_py_parser)
    def do_py(self, _: argparse.Namespace) -> bool | None:
        """Run an interactive Python shell.

        :return: True if running of commands should stop.
        """
        # self.last_result will be set by _run_python()
        return self._run_python()

    @classmethod
    def _build_run_pyscript_parser(cls) -> Cmd2ArgumentParser:
        run_pyscript_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(
            description="Run Python script within this application's environment."
        )
        run_pyscript_parser.add_argument("script_path", help="path to the script file", completer=cls.path_complete)
        run_pyscript_parser.add_argument(
            "script_arguments", nargs=argparse.REMAINDER, help="arguments to pass to script", completer=cls.path_complete
        )

        return run_pyscript_parser

    @with_argparser(_build_run_pyscript_parser)
    def do_run_pyscript(self, args: argparse.Namespace) -> bool | None:
        """Run Python script within this application's environment.

        :return: True if running of commands should stop
        """
        self.last_result = False

        # Expand ~ before placing this path in sys.argv just as a shell would
        args.script_path = os.path.expanduser(args.script_path)

        # Add some protection against accidentally running a non-Python file. The happens when users
        # mix up run_script and run_pyscript.
        if not args.script_path.endswith(".py"):
            self.pwarning(f"'{args.script_path}' does not have a .py extension")
            selection = self.select("Yes No", "Continue to try to run it as a Python script? ")
            if selection != "Yes":
                return None

        # Save current command line arguments
        orig_args = sys.argv

        try:
            # Overwrite sys.argv to allow the script to take command line arguments
            sys.argv = [args.script_path, *args.script_arguments]

            # self.last_result will be set by _run_python()
            py_return = self._run_python(pyscript=args.script_path)
        finally:
            # Restore command line arguments to original state
            sys.argv = orig_args

        return py_return

    @staticmethod
    def _build_ipython_parser() -> Cmd2ArgumentParser:
        return argparse_utils.DEFAULT_ARGUMENT_PARSER(description="Run an interactive IPython shell.")

    @with_argparser(_build_ipython_parser)
    def do_ipy(self, _: argparse.Namespace) -> bool | None:  # pragma: no cover
        """Run an interactive IPython shell.

        :return: True if running of commands should stop
        """
        self.last_result = False

        # Detect whether IPython is installed
        try:
            import traitlets.config.loader as traitlets_loader
            from IPython import start_ipython
            from IPython.terminal.interactiveshell import TerminalInteractiveShell
            from IPython.terminal.ipapp import TerminalIPythonApp
        except ImportError:
            self.perror("IPython package is not installed")
            return None

        from .py_bridge import PyBridge

        if self.in_pyscript():
            self.perror("Recursively entering interactive Python shells is not allowed")
            return None

        self.last_result = True

        try:
            self._in_py = True
            py_bridge = PyBridge(self)

            # Make a copy of self.py_locals for the locals dictionary in the IPython environment we are creating.
            # This is to prevent ipy from editing it. (e.g. locals().clear()). Only make a shallow copy since
            # it's OK for py_locals to contain objects which are editable in ipy.
            local_vars = self.py_locals.copy()
            local_vars[self.py_bridge_name] = py_bridge
            if self.self_in_py:
                local_vars["self"] = self

            # Configure IPython
            config = traitlets_loader.Config()
            config.InteractiveShell.banner2 = (
                "Entering an IPython shell. Type exit, quit, or Ctrl-D to exit.\n"
                f'Run CLI commands with: {self.py_bridge_name}("command ...")\n'
            )

            # Start IPython
            start_ipython(config=config, argv=[], user_ns=local_vars)  # type: ignore[no-untyped-call]
            self.poutput("Now exiting IPython shell...")

            # The IPython application is a singleton and won't be recreated next time
            # this function runs. That's a problem since the contents of local_vars
            # may need to be changed. Therefore, we must destroy all instances of the
            # relevant classes.
            TerminalIPythonApp.clear_instance()
            TerminalInteractiveShell.clear_instance()

            return py_bridge.stop
        finally:
            self._in_py = False

    @classmethod
    def _build_history_parser(cls) -> Cmd2ArgumentParser:
        history_description = "View, run, edit, save, or clear previously entered commands."

        history_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(
            description=history_description, formatter_class=ru.RawTextCmd2HelpFormatter
        )
        history_action_group = history_parser.add_mutually_exclusive_group()
        history_action_group.add_argument("-r", "--run", action="store_true", help="run selected history items")
        history_action_group.add_argument("-e", "--edit", action="store_true", help="edit and then run selected history items")
        history_action_group.add_argument(
            "-o",
            "--output-file",
            metavar="FILE",
            help="output commands to a script file, implies -s",
            completer=cls.path_complete,
        )
        history_action_group.add_argument("-c", "--clear", action="store_true", help="clear all history")

        history_format_group = history_parser.add_argument_group(title="formatting")
        history_format_group.add_argument(
            "-s",
            "--script",
            action="store_true",
            help="output commands in script format, i.e. without command numbers",
        )
        history_format_group.add_argument(
            "-x",
            "--expanded",
            action="store_true",
            help="output fully parsed commands with shortcuts, aliases, and macros expanded",
        )
        history_format_group.add_argument(
            "-v",
            "--verbose",
            action="store_true",
            help="display history and include expanded commands if they differ from the typed command",
        )
        history_format_group.add_argument(
            "-a",
            "--all",
            action="store_true",
            help="display all commands, including ones persisted from previous sessions",
        )

        history_arg_help = (
            "empty               all history items\n"
            "a                   one history item by number\n"
            "a..b, a:b, a:, ..b  items by indices (inclusive)\n"
            "string              items containing string\n"
            "/regex/             items matching regular expression"
        )
        history_parser.add_argument("arg", nargs=argparse.OPTIONAL, help=history_arg_help)

        return history_parser

    @with_argparser(_build_history_parser)
    def do_history(self, args: argparse.Namespace) -> bool | None:
        """View, run, edit, save, or clear previously entered commands.

        :return: True if running of commands should stop
        """
        self.last_result = False

        # -v must be used alone with no other options
        if args.verbose:  # noqa: SIM102
            if args.clear or args.edit or args.output_file or args.run or args.expanded or args.script:
                self.poutput("-v cannot be used with any other options")
                return None

        # -s and -x can only be used if none of these options are present: [-c -r -e -o -t]
        if (args.script or args.expanded) and (args.clear or args.edit or args.output_file or args.run):
            self.poutput("-s and -x cannot be used with -c, -r, -e, or -o")
            return None

        if args.clear:
            self.last_result = True

            # Clear command and prompt-toolkit history
            self.history.clear()
            cast(Cmd2History, self.main_session.history).clear()

            if self.persistent_history_file:
                try:
                    os.remove(self.persistent_history_file)
                except FileNotFoundError:
                    pass
                except OSError as ex:
                    self.perror(f"Error removing history file '{self.persistent_history_file}': {ex}")
                    self.last_result = False
                    return None

            return None

        # If an argument was supplied, then retrieve partial contents of the history, otherwise retrieve it all
        history = self._get_history(args)

        if args.run:
            if not args.arg:
                self.perror("Cowardly refusing to run all previously entered commands.")
                self.perror("If this is what you want to do, specify '1:' as the range of history.")
            else:
                stop = self.runcmds_plus_hooks(list(history.values()))
                self.last_result = True
                return stop
        elif args.edit:
            fd, fname = tempfile.mkstemp(suffix=".txt", text=True)
            fobj: TextIO
            with os.fdopen(fd, "w") as fobj:
                for command in history.values():
                    if command.statement.multiline_command:
                        fobj.write(f"{command.expanded}\n")
                    else:
                        fobj.write(f"{command.raw}\n")
            try:
                self.run_editor(fname)

                # self.last_result will be set by do_run_script()
                return self.do_run_script(su.quote(fname))
            finally:
                os.remove(fname)
        elif args.output_file:
            full_path = os.path.abspath(os.path.expanduser(args.output_file))
            try:
                with open(full_path, "w") as fobj:
                    for item in history.values():
                        if item.statement.multiline_command:
                            fobj.write(f"{item.expanded}\n")
                        else:
                            fobj.write(f"{item.raw}\n")
                plural = "" if len(history) == 1 else "s"
            except OSError as ex:
                self.perror(f"Error saving history file '{full_path}': {ex}")
            else:
                self.pfeedback(f"{len(history)} command{plural} saved to {full_path}")
                self.last_result = True
        else:
            # Display the history items retrieved
            for idx, hi in history.items():
                self.poutput(hi.pr(idx, script=args.script, expanded=args.expanded, verbose=args.verbose))
            self.last_result = history
        return None

    def _get_history(self, args: argparse.Namespace) -> dict[int, HistoryItem]:
        """If an argument was supplied, then retrieve partial contents of the history; otherwise retrieve entire history.

        This function returns a dictionary with history items keyed by their 1-based index in ascending order.
        """
        if args.arg:
            try:
                int_arg = int(args.arg)
                return {int_arg: self.history.get(int_arg)}
            except ValueError:
                pass

            if ".." in args.arg or ":" in args.arg:
                # Get a slice of history
                history = self.history.span(args.arg, args.all)
            elif args.arg.startswith(r"/") and args.arg.endswith(r"/"):
                history = self.history.regex_search(args.arg, args.all)
            else:
                history = self.history.str_search(args.arg, args.all)
        else:
            # Get a copy of the history so it doesn't get mutated while we are using it
            history = self.history.span(":", args.all)
        return history

    def _initialize_history(self, hist_file: str) -> None:
        """Initialize history using history related attributes.

        :param hist_file: optional path to persistent history file. If specified, then history from
                          previous sessions will be included. Additionally, all history will be written
                          to this file when the application exits.
        """
        self.history = History()

        # With no persistent history, nothing else in this method is relevant
        if not hist_file:
            self.persistent_history_file = hist_file
            return

        hist_file = os.path.abspath(os.path.expanduser(hist_file))

        # On Windows, trying to open a directory throws a permission
        # error, not a `IsADirectoryError`. So we'll check it ourselves.
        if os.path.isdir(hist_file):
            self.perror(f"Persistent history file '{hist_file}' is a directory")
            return

        # Create the directory for the history file if it doesn't already exist
        hist_file_dir = os.path.dirname(hist_file)
        try:
            os.makedirs(hist_file_dir, exist_ok=True)
        except OSError as ex:
            self.perror(f"Error creating persistent history file directory '{hist_file_dir}': {ex}")
            return

        # Read history file
        try:
            with open(hist_file, "rb") as fobj:
                compressed_bytes = fobj.read()
        except FileNotFoundError:
            compressed_bytes = b""
        except OSError as ex:
            self.perror(f"Cannot read persistent history file '{hist_file}': {ex}")
            return

        # Register a function to write history at save
        import atexit

        self.persistent_history_file = hist_file
        atexit.register(self._persist_history)

        # Empty or nonexistent history file. Nothing more to do.
        if not compressed_bytes:
            return

        # Decompress history data
        try:
            import lzma as decompress_lib

            decompress_exceptions: tuple[type[Exception]] = (decompress_lib.LZMAError,)
        except ModuleNotFoundError:  # pragma: no cover
            import bz2 as decompress_lib  # type: ignore[no-redef]

            decompress_exceptions: tuple[type[Exception]] = (OSError, ValueError)  # type: ignore[no-redef]

        try:
            history_json = decompress_lib.decompress(compressed_bytes).decode(encoding="utf-8")
        except decompress_exceptions as ex:
            self.perror(
                f"Error decompressing persistent history data '{hist_file}': {ex}\n"
                f"The history file will be recreated when this application exits."
            )
            return

        # Decode history json
        import json

        try:
            self.history = History.from_json(history_json)
        except (json.JSONDecodeError, KeyError, ValueError) as ex:
            self.perror(
                f"Error processing persistent history data '{hist_file}': {ex}\n"
                f"The history file will be recreated when this application exits."
            )
            return

        self.history.start_session()

    def _persist_history(self) -> None:
        """Write history out to the persistent history file as compressed JSON."""
        if not self.persistent_history_file:
            return

        try:
            import lzma as compress_lib
        except ModuleNotFoundError:  # pragma: no cover
            import bz2 as compress_lib  # type: ignore[no-redef]

        self.history.truncate(self._persistent_history_length)
        history_json = self.history.to_json()
        compressed_bytes = compress_lib.compress(history_json.encode(encoding="utf-8"))

        try:
            with open(self.persistent_history_file, "wb") as fobj:
                fobj.write(compressed_bytes)
        except OSError as ex:
            self.perror(f"Cannot write persistent history file '{self.persistent_history_file}': {ex}")

    @classmethod
    def _build_edit_parser(cls) -> Cmd2ArgumentParser:
        edit_description = "Run a text editor and optionally open a file with it."
        edit_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=edit_description)
        edit_parser.epilog = TextGroup(
            "Note",
            Text.assemble(
                "To set a new editor, run: ",
                ("set editor <program>", Cmd2Style.COMMAND_LINE),
            ),
        )

        edit_parser.add_argument(
            "file_path",
            nargs=argparse.OPTIONAL,
            help="optional path to a file to open in editor",
            completer=cls.path_complete,
        )
        return edit_parser

    @with_argparser(_build_edit_parser)
    def do_edit(self, args: argparse.Namespace) -> None:
        """Run a text editor and optionally open a file with it."""
        # self.last_result will be set by do_shell() which is called by run_editor()
        self.run_editor(args.file_path)

    def run_editor(self, file_path: str | None = None) -> None:
        """Run a text editor and optionally open a file with it.

        :param file_path: optional path of the file to edit. Defaults to None.
        :raises ValueError: if self.editor is not set
        """
        if not self.editor:
            raise ValueError("Please use 'set editor' to specify your text editing program of choice.")

        command = su.quote(os.path.expanduser(self.editor))
        if file_path:
            command += " " + su.quote(os.path.expanduser(file_path))

        self.do_shell(command)

    @property
    def _current_script_dir(self) -> str | None:
        """Accessor to get the current script directory from the _script_dir LIFO queue."""
        if self._script_dir:
            return self._script_dir[-1]
        return None

    @classmethod
    def _build_base_run_script_parser(cls) -> Cmd2ArgumentParser:
        run_script_description = Text.assemble(
            "Run text script.",
            "\n\n",
            "Scripts should contain one command per line, entered as you would in the console.",
        )

        run_script_parser = argparse_utils.DEFAULT_ARGUMENT_PARSER(description=run_script_description)
        run_script_parser.add_argument(
            "script_path",
            help="path to the script file",
            completer=cls.path_complete,
        )

        return run_script_parser

    @classmethod
    def _build_run_script_parser(cls) -> Cmd2ArgumentParser:
        return cls._build_base_run_script_parser()

    @with_argparser(_build_run_script_parser)
    def do_run_script(self, args: argparse.Namespace) -> bool | None:
        """Run text script.

        :return: True if running of commands should stop
        """
        self.last_result = False
        expanded_path = os.path.abspath(os.path.expanduser(args.script_path))

        # Add some protection against accidentally running a Python file. The happens when users
        # mix up run_script and run_pyscript.
        if expanded_path.endswith(".py"):
            self.pwarning(f"'{expanded_path}' appears to be a Python file")
            selection = self.select("Yes No", "Continue to try to run it as a text script? ")
            if selection != "Yes":
                return None

        try:
            # An empty file is not an error, so just return
            if os.path.getsize(expanded_path) == 0:
                self.last_result = True
                return None

            # Make sure the file is ASCII or UTF-8 encoded text
            if not utils.is_text_file(expanded_path):
                self.perror(f"'{expanded_path}' is not an ASCII or UTF-8 encoded text file")
                return None

            # Read all lines of the script
            with open(expanded_path, encoding="utf-8") as target:
                script_commands = target.read().splitlines()
        except OSError as ex:
            self.perror(f"Problem accessing script from '{expanded_path}': {ex}")
            return None

        orig_script_dir_count = len(self._script_dir)

        try:
            self._script_dir.append(os.path.dirname(expanded_path))
            stop = self.runcmds_plus_hooks(
                script_commands,
                add_to_history=self.scripts_add_to_history,
                stop_on_keyboard_interrupt=True,
            )
            self.last_result = True
            return stop
        finally:
            with self.sigint_protection:
                # Check if a script dir was added before an exception occurred
                if orig_script_dir_count != len(self._script_dir):
                    self._script_dir.pop()

    @classmethod
    def _build__relative_run_script_parser(cls) -> Cmd2ArgumentParser:
        _relative_run_script_parser = cls._build_base_run_script_parser()

        # Append to existing description
        _relative_run_script_parser.description = Group(
            cast(Group, _relative_run_script_parser.description),
            "\n",
            (
                "If this is called from within an already-running script, the filename will be "
                "interpreted relative to the already-running script's directory."
            ),
        )

        _relative_run_script_parser.epilog = TextGroup(
            "Note",
            "This command is intended to be used from within a text script.",
        )

        return _relative_run_script_parser

    @with_argparser(_build__relative_run_script_parser)
    def do__relative_run_script(self, args: argparse.Namespace) -> bool | None:
        """Run text script.

        This command is intended to be used from within a text script.

        :return: True if running of commands should stop
        """
        script_path = args.script_path
        # NOTE: Relative path is an absolute path, it is just relative to the current script directory
        relative_path = os.path.join(self._current_script_dir or "", script_path)

        # self.last_result will be set by do_run_script()
        return self.do_run_script(su.quote(relative_path))

    def add_alert(
        self,
        *,
        msg: Any | None = None,
        soft_wrap: bool = True,
        prompt: str | None = None,
    ) -> None:
        """Queue an asynchronous alert to be displayed when the prompt is active.

        Examples:
            add_alert(msg="System error!")        # Print message only
            add_alert(prompt="user@host> ")       # Update prompt only
            add_alert(msg="Done", prompt="> ")    # Update both

        :param msg: an optional printable object (including Rich renderables) to be
                    printed above the prompt.
        :param soft_wrap: Enable soft wrap mode. This only applies with msg is not None.
                          Defaults to True. See print_to() docstring for more details on
                          this parameter.
        :param prompt: an optional string to dynamically replace the current prompt.

        """
        if msg is None and prompt is None:
            return

        with self._alert_condition:
            alert = AsyncAlert(msg=msg, soft_wrap=soft_wrap, prompt=prompt)
            self._alert_queue.append(alert)
            self._alert_condition.notify_all()

    @staticmethod
    def set_window_title(title: str) -> None:  # pragma: no cover
        """Set the terminal window title.

        :param title: the new window title
        """
        set_title(title)

    def enable_command(self, command: str) -> None:
        """Enable a command by restoring its functions.

        :param command: the command being enabled
        """
        # If the command is already enabled, then return
        if command not in self.disabled_commands:
            return

        command_func_name = constants.COMMAND_FUNC_PREFIX + command
        help_func_name = constants.HELP_FUNC_PREFIX + command
        completer_func_name = constants.COMPLETER_FUNC_PREFIX + command

        # Restore the command function to its original value
        dc = self.disabled_commands[command]
        setattr(self, command_func_name, dc.command_func)

        # Restore the help function to its original value
        if dc.help_func is None:
            delattr(self, help_func_name)
        else:
            setattr(self, help_func_name, dc.help_func)

        # Restore the completer function to its original value
        if dc.completer_func is None:
            delattr(self, completer_func_name)
        else:
            setattr(self, completer_func_name, dc.completer_func)

        # Remove the disabled command entry
        del self.disabled_commands[command]

    def enable_category(self, category: str) -> None:
        """Enable an entire category of commands.

        :param category: the category to enable
        """
        # If the category is already enabled, then return
        if category not in self.disabled_categories:
            return

        for command in list(self.disabled_commands):
            command_func = self.disabled_commands[command].command_func
            if self._get_command_category(command_func) == category:
                self.enable_command(command)

        del self.disabled_categories[category]

    def disable_command(self, command: str, message_to_print: str) -> None:
        """Disable a command and replace its functions with disabled versions.

        :param command: the command being disabled
        :param message_to_print: what to print when this command is run or help is called on it while disabled

                                 The variable cmd2.COMMAND_NAME can be used as a placeholder for the name of the
                                 command being disabled.
                                 ex: message_to_print = f"{cmd2.COMMAND_NAME} is currently disabled"
        """
        # If the command is already disabled, then return
        if command in self.disabled_commands:
            return

        # Make sure this is an actual command
        command_func = self.get_command_func(command)
        if command_func is None:
            raise AttributeError(f"'{command}' does not refer to a command")

        command_func_name = constants.COMMAND_FUNC_PREFIX + command

        help_func_name = constants.HELP_FUNC_PREFIX + command
        help_func = getattr(self, help_func_name, None)

        completer_func_name = constants.COMPLETER_FUNC_PREFIX + command
        completer_func = getattr(self, completer_func_name, None)

        # Add the disabled command record
        self.disabled_commands[command] = DisabledCommand(
            command_func=command_func,
            help_func=help_func,
            completer_func=completer_func,
        )

        # Replace command and help functions to report the disabled message
        message_to_print = message_to_print.replace(constants.COMMAND_NAME, command)
        new_cmd_func = functools.partial(
            self._report_disabled_command_usage,
            message_to_print=message_to_print,
        )

        # Ensure the replacement function identifies as the original for introspection
        functools.update_wrapper(new_cmd_func, command_func)
        setattr(self, command_func_name, new_cmd_func)

        new_help_func = functools.partial(
            self._report_disabled_command_usage,
            message_to_print=message_to_print,
        )
        if help_func is not None:
            functools.update_wrapper(new_help_func, help_func)
        setattr(self, help_func_name, new_help_func)

        # Replace completer with a function that returns nothing
        new_completer_func = functools.partial(self._disabled_completer)
        if completer_func is not None:
            functools.update_wrapper(new_completer_func, completer_func)
        setattr(self, completer_func_name, new_completer_func)

    def disable_category(self, category: str, message_to_print: str) -> None:
        """Disable an entire category of commands.

        :param category: the category to disable
        :param message_to_print: what to print when anything in this category is run or help is called on it
                                 while disabled. The variable cmd2.COMMAND_NAME can be used as a placeholder for the name
                                 of the command being disabled.
                                 ex: message_to_print = f"{cmd2.COMMAND_NAME} is currently disabled"
        """
        # If the category is already disabled, then return
        if category in self.disabled_categories:
            return

        all_commands = self.get_all_commands()

        for command in all_commands:
            command_func = cast(BoundCommandFunc, self.get_command_func(command))
            if self._get_command_category(command_func) == category:
                self.disable_command(command, message_to_print)

        self.disabled_categories[category] = message_to_print

    def _report_disabled_command_usage(self, *_args: Any, message_to_print: str, **_kwargs: Any) -> None:
        """Report when a disabled command or its help function is run.

        :param _args: not used
        :param message_to_print: the message reporting that the command is disabled
        :param _kwargs: not used
        """
        self.perror(message_to_print, style=None)

    def _disabled_completer(self, *_args: Any, **_kwargs: Any) -> Completions:
        """Completer function for a disabled command.

        :param _args: not used
        :param _kwargs: not used
        :return: an empty Completions object
        """
        return Completions()

    def cmdloop(self, intro: RenderableType = "") -> int:
        """Deal with extra features provided by cmd2, this is an outer wrapper around _cmdloop().

        _cmdloop() provides the main loop.  This provides the following extra features provided by cmd2:
        - intro banner
        - exit code

        :param intro: if provided this overrides self.intro and serves as the intro banner printed once at start
        :return: exit code
        """
        # cmdloop() expects to be run in the main thread to support extensive use of KeyboardInterrupts throughout the
        # other built-in functions. You are free to override cmdloop, but much of cmd2's features will be limited.
        if threading.current_thread() is not threading.main_thread():
            raise RuntimeError("cmdloop must be run in the main thread")

        # Register signal handlers
        import signal

        original_sigint_handler = signal.getsignal(signal.SIGINT)
        signal.signal(signal.SIGINT, self.sigint_handler)

        if not sys.platform.startswith("win"):
            original_sighup_handler = signal.getsignal(signal.SIGHUP)
            signal.signal(signal.SIGHUP, self.termination_signal_handler)

            original_sigterm_handler = signal.getsignal(signal.SIGTERM)
            signal.signal(signal.SIGTERM, self.termination_signal_handler)

        # Always run the preloop first
        for func in self._preloop_hooks:
            func()
        self.preloop()

        # If an intro was supplied in the method call, allow it to override the default
        if intro:
            self.intro = intro

        # Print the intro, if there is one, right after the preloop
        if self.intro:
            self.poutput(self.intro)

        # And then call _cmdloop() to enter the main loop
        self._cmdloop()

        # Run the postloop() no matter what
        for func in self._postloop_hooks:
            func()
        self.postloop()

        # Restore original signal handlers
        signal.signal(signal.SIGINT, original_sigint_handler)

        if not sys.platform.startswith("win"):
            signal.signal(signal.SIGHUP, original_sighup_handler)
            signal.signal(signal.SIGTERM, original_sigterm_handler)

        return self.exit_code

    ###
    #
    # plugin related functions
    #
    ###
    def _initialize_plugin_system(self) -> None:
        """Initialize the plugin system."""
        self._preloop_hooks: list[Callable[[], None]] = []
        self._postloop_hooks: list[Callable[[], None]] = []
        self._postparsing_hooks: list[Callable[[plugin.PostparsingData], plugin.PostparsingData]] = []
        self._precmd_hooks: list[Callable[[plugin.PrecommandData], plugin.PrecommandData]] = []
        self._postcmd_hooks: list[Callable[[plugin.PostcommandData], plugin.PostcommandData]] = []
        self._cmdfinalization_hooks: list[Callable[[plugin.CommandFinalizationData], plugin.CommandFinalizationData]] = []

    @classmethod
    def _validate_callable_param_count(cls, func: Callable[..., Any], count: int) -> None:
        """Ensure a function has the given number of parameters."""
        signature = inspect.signature(func)
        # validate that the callable has the right number of parameters
        nparam = len(signature.parameters)
        if nparam != count:
            plural = "" if nparam == 1 else "s"
            raise TypeError(f"{func.__name__} has {nparam} positional argument{plural}, expected {count}")

    @classmethod
    def _validate_prepostloop_callable(cls, func: Callable[[], None]) -> None:
        """Check parameter and return types for preloop and postloop hooks."""
        cls._validate_callable_param_count(func, 0)
        # make sure there is no return annotation or the return is specified as None
        _, ret_ann = get_types(func)
        if ret_ann is not None:
            raise TypeError(f"{func.__name__} must have a return type of 'None', got: {ret_ann}")

    def register_preloop_hook(self, func: Callable[[], None]) -> None:
        """Register a function to be called at the beginning of the command loop."""
        self._validate_prepostloop_callable(func)
        self._preloop_hooks.append(func)

    def register_postloop_hook(self, func: Callable[[], None]) -> None:
        """Register a function to be called at the end of the command loop."""
        self._validate_prepostloop_callable(func)
        self._postloop_hooks.append(func)

    @classmethod
    def _validate_postparsing_callable(cls, func: Callable[[plugin.PostparsingData], plugin.PostparsingData]) -> None:
        """Check parameter and return types for postparsing hooks."""
        cls._validate_callable_param_count(cast(Callable[..., Any], func), 1)
        type_hints, ret_ann = get_types(func)
        if not type_hints:
            raise TypeError(f"{func.__name__} parameter is missing a type hint, expected: 'cmd2.plugin.PostparsingData'")
        par_ann = next(iter(type_hints.values()))
        if par_ann != plugin.PostparsingData:
            raise TypeError(f"{func.__name__} must have one parameter declared with type 'cmd2.plugin.PostparsingData'")
        if ret_ann != plugin.PostparsingData:
            raise TypeError(f"{func.__name__} must declare return a return type of 'cmd2.plugin.PostparsingData'")

    def register_postparsing_hook(self, func: Callable[[plugin.PostparsingData], plugin.PostparsingData]) -> None:
        """Register a function to be called after parsing user input but before running the command."""
        self._validate_postparsing_callable(func)
        self._postparsing_hooks.append(func)

    CommandDataType = TypeVar("CommandDataType")

    @classmethod
    def _validate_prepostcmd_hook(
        cls, func: Callable[[CommandDataType], CommandDataType], data_type: type[CommandDataType]
    ) -> None:
        """Check parameter and return types for pre and post command hooks."""
        # validate that the callable has the right number of parameters
        cls._validate_callable_param_count(cast(Callable[..., Any], func), 1)

        type_hints, ret_ann = get_types(func)
        if not type_hints:
            raise TypeError(f"{func.__name__} parameter is missing a type hint, expected: {data_type}")
        _param_name, par_ann = next(iter(type_hints.items()))
        # validate the parameter has the right annotation
        if par_ann != data_type:
            raise TypeError(f"argument 1 of {func.__name__} has incompatible type {par_ann}, expected {data_type}")
        # validate the return value has the right annotation
        if ret_ann is None:
            raise TypeError(f"{func.__name__} does not have a declared return type, expected {data_type}")
        if ret_ann != data_type:
            raise TypeError(f"{func.__name__} has incompatible return type {ret_ann}, expected {data_type}")

    def register_precmd_hook(self, func: Callable[[plugin.PrecommandData], plugin.PrecommandData]) -> None:
        """Register a hook to be called before the command function."""
        self._validate_prepostcmd_hook(func, plugin.PrecommandData)
        self._precmd_hooks.append(func)

    def register_postcmd_hook(self, func: Callable[[plugin.PostcommandData], plugin.PostcommandData]) -> None:
        """Register a hook to be called after the command function."""
        self._validate_prepostcmd_hook(func, plugin.PostcommandData)
        self._postcmd_hooks.append(func)

    @classmethod
    def _validate_cmdfinalization_callable(
        cls, func: Callable[[plugin.CommandFinalizationData], plugin.CommandFinalizationData]
    ) -> None:
        """Check parameter and return types for command finalization hooks."""
        cls._validate_callable_param_count(func, 1)
        type_hints, ret_ann = get_types(func)
        if not type_hints:
            raise TypeError(f"{func.__name__} parameter is missing a type hint, expected: {plugin.CommandFinalizationData}")
        _, par_ann = next(iter(type_hints.items()))
        if par_ann != plugin.CommandFinalizationData:
            raise TypeError(
                f"{func.__name__} must have one parameter declared with type {plugin.CommandFinalizationData}, got: {par_ann}"
            )
        if ret_ann != plugin.CommandFinalizationData:
            raise TypeError(f"{func.__name__} must declare return a return type of {plugin.CommandFinalizationData}")

    def register_cmdfinalization_hook(
        self, func: Callable[[plugin.CommandFinalizationData], plugin.CommandFinalizationData]
    ) -> None:
        """Register a hook to be called after a command is completed, whether it completes successfully or not."""
        self._validate_cmdfinalization_callable(func)
        self._cmdfinalization_hooks.append(func)

    def _resolve_func_self(
        self,
        cmd_support_func: Callable[..., Any],
        cmd_self: CmdOrSet | None,
    ) -> object | None:
        """Attempt to resolve a candidate instance to pass as 'self'.

        Used for an unbound class method that was used when defining command's argparse object.

        Since we restrict registration to only a single CommandSet
        instance of each type, using type is a reasonably safe way to resolve the correct object instance.

        :param cmd_support_func: command support function. This could be a completer or namespace provider
        :param cmd_self: The `self` associated with the command or subcommand
        """
        # figure out what class the command support function was defined in
        func_class: type[Any] | None = get_defining_class(cmd_support_func)

        # Was there a defining class identified? If so, is it a sub-class of CommandSet?
        if func_class is not None and issubclass(func_class, CommandSet):
            # Since the support function is provided as an unbound function, we need to locate the instance
            # of the CommandSet to pass in as `self` to emulate a bound method call.
            # We're searching for candidates that match the support function's defining class type in this order:
            #   1. Is the command's CommandSet a sub-class of the support function's class?
            #   2. Do any of the registered CommandSets in the Cmd2 application exactly match the type?
            #   3. Is there a registered CommandSet that is is the only matching subclass?

            func_self: CmdOrSet | None

            # check if the command's CommandSet is a sub-class of the support function's defining class
            if isinstance(cmd_self, func_class):
                # Case 1: Command's CommandSet is a sub-class of the support function's CommandSet
                func_self = cmd_self
            else:
                # Search all registered CommandSets
                func_self = None
                candidate_sets: list[CommandSet[Any]] = []
                for installed_cmd_set in self._installed_command_sets:
                    if type(installed_cmd_set) == func_class:  # noqa: E721
                        # Case 2: CommandSet is an exact type match for the function's CommandSet
                        func_self = installed_cmd_set
                        break

                    # Add candidate for Case 3:
                    if isinstance(installed_cmd_set, func_class):
                        candidate_sets.append(installed_cmd_set)
                if func_self is None and len(candidate_sets) == 1:
                    # Case 3: There exists exactly 1 CommandSet that is a sub-class match of the function's CommandSet
                    func_self = candidate_sets[0]
            return func_self
        return self
