click_extensions.py

from gettext import gettext as _
from gettext import ngettext
from typing import Any, Callable, Sequence

import click


class DeferredChoice(click.ParamType):
    """This class is basically a copy of click.types.Choice,
    but allows configuring the choice list value to be deferred until execution time,
    which is extremely handy when writing unit tests.

    The choice type allows a value to be checked against a fixed set
    of supported values. All of these values have to be strings.

    You should only pass a list or tuple of choices. Other iterables
    (like generators) may lead to surprising results.

    The resulting value will always be one of the originally passed choices
    regardless of ``case_sensitive`` or any ``ctx.token_normalize_func``
    being specified.

    See :ref:`choice-opts` for an example.

    :param case_sensitive: Set to false to make choices case
        insensitive. Defaults to true.
    """

    name = "choice_dynamic"

    def __init__(self, choices: Callable[[], Sequence[str]], case_sensitive: bool = True) -> None:  # noqa: FBT
        self._choices = choices
        self.case_sensitive = case_sensitive

    @property
    def choices(self) -> Sequence[str]:
        return self._choices()

    def to_info_dict(self) -> dict[str, Any]:
        info_dict = super().to_info_dict()
        info_dict["choices"] = self.choices
        info_dict["case_sensitive"] = self.case_sensitive
        return info_dict

    def get_metavar(self, param: click.Parameter) -> str:
        choices_str = "|".join(self.choices)

        # Use curly braces to indicate a required argument.
        if param.required and param.param_type_name == "argument":
            return f"{{{choices_str}}}"

        # Use square braces to indicate an option or optional argument.
        return f"[{choices_str}]"

    def get_missing_message(self, param: click.Parameter) -> str:
        return _("Choose from:\n\t{choices}").format(choices=",\n\t".join(self.choices))

    def convert(self, value: Any, param: click.Parameter | None, ctx: click.Context | None) -> Any:  # noqa: ANN401
        # Match through normalization and case sensitivity
        # first do token_normalize_func, then lowercase
        # preserve original `value` to produce an accurate message in
        # `self.fail`
        normed_value = value
        normed_choices = {choice: choice for choice in self.choices}

        if ctx is not None and ctx.token_normalize_func is not None:
            normed_value = ctx.token_normalize_func(value)
            normed_choices = {
                ctx.token_normalize_func(normed_choice): original for normed_choice, original in normed_choices.items()
            }

        if not self.case_sensitive:
            normed_value = normed_value.casefold()
            normed_choices = {normed_choice.casefold(): original for normed_choice, original in normed_choices.items()}

        if normed_value in normed_choices:
            return normed_choices[normed_value]

        choices_str = ", ".join(map(repr, self.choices))
        self.fail(
            ngettext(
                "{value!r} is not {choice}.",
                "{value!r} is not one of {choices}.",
                len(self.choices),
            ).format(value=value, choice=choices_str, choices=choices_str),
            param,
            ctx,
        )

    def __repr__(self) -> str:
        return f"Choice({list(self.choices)})"

    def shell_complete(
        self, ctx: click.Context, param: click.Parameter, incomplete: str
    ) -> list["click.shell_completion.CompletionItem"]:
        """Complete choices that start with the incomplete value.

        :param ctx: Invocation context for this command.
        :param param: The parameter that is requesting completion.
        :param incomplete: Value being completed. May be empty.

        .. versionadded:: 8.0
        """
        from click.shell_completion import CompletionItem

        str_choices = map(str, self.choices)

        if self.case_sensitive:
            matched = (c for c in str_choices if c.startswith(incomplete))
        else:
            incomplete = incomplete.lower()
            matched = (c for c in str_choices if c.lower().startswith(incomplete))

        return [CompletionItem(c) for c in matched]