import inspect
import typing

import fastapi


def load(parameters_definition: dict[str, dict]) -> list[inspect.Parameter]:
    """
    Load a list python function parameters from their definitions.
    :param parameters_definition: the definitions of the parameters
    :return: the python function parameters

    Examples:
        >>> parameters_definition = {
        ...     "boolean": {"type": "bool", "default": False},
        ...     "list": {"type": "list", "default": [1, 2, 3]},
        ...     "file": {"type": "file"},
        ... }
        >>> parameters = load_parameters(parameters_definition)
    """

    parameters: list[inspect.Parameter] = []

    for name, definition in parameters_definition.items():
        # preprocess the type
        match definition["type"]:
            case "file":
                # shortcut for uploading a file
                definition["type"] = typing.Annotated[
                    fastapi.UploadFile,
                    fastapi.File()
                ]

        # deserialize the parameter
        parameter = inspect.Parameter(
            name,
            inspect.Parameter.POSITIONAL_OR_KEYWORD,
            default=definition.get("default", inspect.Parameter.empty),
            annotation=definition["type"],
        )
        parameters.append(parameter)

    # sort the parameters so that non-default arguments always end up before default ones
    parameters.sort(key=lambda parameter: parameter.default is inspect.Parameter.empty, reverse=True)

    return parameters