import inspect
import warnings

from enum import Enum, auto
from typing import Any, Dict, List, Optional, Tuple, Type, Union

from .generator import Generator
from .providers import BaseProvider
from .proxy import Faker


class FakerEnum(Enum):
    """Required for faker.providers.enum"""

    A = auto
    B = auto


class Documentor:
    def __init__(self, generator: Union[Generator, Faker]) -> None:
        """
        :param generator: a localized Generator with providers filled,
                          for which to write the documentation
        :type generator: faker.Generator()
        """
        self.generator = generator
        self.max_name_len: int = 0
        self.already_generated: List[str] = []

    def get_formatters(
        self,
        locale: Optional[str] = None,
        excludes: Optional[List[str]] = None,
        **kwargs: Any,
    ) -> List[Tuple[BaseProvider, Dict[str, str]]]:
        self.max_name_len = 0
        self.already_generated = [] if excludes is None else excludes[:]
        formatters = []
        providers: List[BaseProvider] = self.generator.get_providers()
        for provider in providers[::-1]:  # reverse
            if locale and provider.__lang__ and provider.__lang__ != locale:
                continue
            formatters.append(
                (provider, self.get_provider_formatters(provider, **kwargs)),
            )
        return formatters

    def get_provider_formatters(
        self,
        provider: BaseProvider,
        prefix: str = "fake.",
        with_args: bool = True,
        with_defaults: bool = True,
    ) -> Dict[str, str]:
        formatters = {}

        for name, method in inspect.getmembers(provider, inspect.ismethod):
            # skip 'private' method and inherited methods
            if name.startswith("_") or name in self.already_generated:
                continue

            arguments = []
            faker_args: List[Union[str, Type[Enum]]] = []
            faker_kwargs = {}

            if name == "binary":
                faker_kwargs["length"] = 1024
            elif name in ["zip", "tar"]:
                faker_kwargs.update(
                    {
                        "uncompressed_size": 1024,
                        "min_file_size": 512,
                    }
                )

            if name == "enum":
                faker_args = [FakerEnum]

            if with_args:
                # retrieve all parameter
                argspec = inspect.getfullargspec(method)

                lst = [x for x in argspec.args if x not in ["self", "cls"]]
                for i, arg in enumerate(lst):
                    if argspec.defaults and with_defaults:
                        try:
                            default = argspec.defaults[i]
                            if isinstance(default, str):
                                default = repr(default)
                            else:
                                # TODO check default type
                                default = f"{default}"

                            arg = f"{arg}={default}"

                        except IndexError:
                            pass

                    arguments.append(arg)
                    if with_args == "first":
                        break

                if with_args != "first":
                    if argspec.varargs:
                        arguments.append("*" + argspec.varargs)
                    if argspec.varkw:
                        arguments.append("**" + argspec.varkw)

            # build fake method signature
            signature = f"{prefix}{name}({', '.join(arguments)})"

            try:
                # make a fake example
                example = self.generator.format(name, *faker_args, **faker_kwargs)
            except (AttributeError, ValueError) as e:
                warnings.warn(str(e))
                continue
            formatters[signature] = example

            self.max_name_len = max(self.max_name_len, *(len(part) for part in signature.split()))
            self.already_generated.append(name)

        return formatters

    @staticmethod
    def get_provider_name(provider_class: BaseProvider) -> str:
        return provider_class.__provider__