from abc import abstractmethod
from dataclasses import dataclass, field
from functools import reduce
from typing import Optional

from nonebot.adapters.onebot.v11.message import Message, MessageSegment

from ..plugin_config import plugin_config


@dataclass
class BasePost:
    @abstractmethod
    async def generate_text_messages(self) -> list[MessageSegment]:
        "Generate Message list from this instance"
        ...

    @abstractmethod
    async def generate_pic_messages(self) -> list[MessageSegment]:
        "Generate Message list from this instance with `use_pic`"
        ...


@dataclass
class OptionalMixin:
    # Because of https://stackoverflow.com/questions/51575931/class-inheritance-in-python-3-7-dataclasses

    override_use_pic: Optional[bool] = None
    compress: bool = False
    extra_msg: list[Message] = field(default_factory=list)

    def _use_pic(self):
        if not self.override_use_pic is None:
            return self.override_use_pic
        return plugin_config.bison_use_pic


@dataclass
class AbstractPost(OptionalMixin, BasePost):
    async def generate_messages(self) -> list[Message]:
        if self._use_pic():
            msg_segments = await self.generate_pic_messages()
        else:
            msg_segments = await self.generate_text_messages()
        if msg_segments:
            if self.compress:
                msgs = [reduce(lambda x, y: x.append(y), msg_segments, Message())]
            else:
                msgs = list(
                    map(lambda msg_segment: Message([msg_segment]), msg_segments)
                )
        else:
            msgs = []
        msgs.extend(self.extra_msg)
        return msgs