from typing import Type, Union, Mapping, Iterable, Optional

from pydantic import create_model

from nonebot.adapters import Event, Message, MessageSegment


def escape_text(s: str, *, escape_comma: bool = True) -> str:
    s = s.replace("&", "&").replace("[", "[").replace("]", "]")
    if escape_comma:
        s = s.replace(",", ",")
    return s


def make_fake_message():
    class FakeMessageSegment(MessageSegment):
        @classmethod
        def get_message_class(cls):
            return FakeMessage

        def __str__(self) -> str:
            return self.data["text"] if self.type == "text" else f"[fake:{self.type}]"

        @classmethod
        def text(cls, text: str):
            return cls("text", {"text": text})

        @staticmethod
        def image(url: str):
            return FakeMessageSegment("image", {"url": url})

        @staticmethod
        def nested(content: "FakeMessage"):
            return FakeMessageSegment("node", {"content": content})

        def is_text(self) -> bool:
            return self.type == "text"

    class FakeMessage(Message):
        @classmethod
        def get_segment_class(cls):
            return FakeMessageSegment

        @staticmethod
        def _construct(msg: Union[str, Iterable[Mapping]]):
            if isinstance(msg, str):
                yield FakeMessageSegment.text(msg)
            else:
                for seg in msg:
                    yield FakeMessageSegment(**seg)
            return

        def __add__(self, other):
            other = escape_text(other) if isinstance(other, str) else other
            return super().__add__(other)

    return FakeMessage


def make_fake_event(
    _base: Optional[Type[Event]] = None,
    _type: str = "message",
    _name: str = "test",
    _description: str = "test",
    _user_id: Optional[str] = "test",
    _session_id: Optional[str] = "test",
    _message: Optional[Message] = None,
    _to_me: bool = True,
    **fields,
) -> Type[Event]:
    _Fake = create_model("_Fake", __base__=_base or Event, **fields)

    class FakeEvent(_Fake):
        def get_type(self) -> str:
            return _type

        def get_event_name(self) -> str:
            return _name

        def get_event_description(self) -> str:
            return _description

        def get_user_id(self) -> str:
            if _user_id is not None:
                return _user_id
            raise NotImplementedError

        def get_session_id(self) -> str:
            if _session_id is not None:
                return _session_id
            raise NotImplementedError

        def get_message(self) -> "Message":
            if _message is not None:
                return _message
            raise NotImplementedError

        def is_tome(self) -> bool:
            return _to_me

        class Config:
            extra = "forbid"

    return FakeEvent