#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from functools import wraps
from datetime import datetime
from collections import defaultdict
from typing import Type, List, Dict, Optional, Callable

from nonebot.event import Event
from nonebot.typing import Handler
from nonebot.rule import Rule, user
from nonebot.exception import PausedException, RejectedException, FinishedException

matchers: Dict[int, List[Type["Matcher"]]] = defaultdict(list)


class Matcher:
    """`Matcher`类
    """

    rule: Rule = Rule()
    handlers: List[Handler] = []
    temp: bool = False
    expire_time: Optional[datetime] = None
    priority: int = 1

    _default_state: dict = {}

    # _default_parser: Optional[Callable[[Event, dict], None]] = None
    # _args_parser: Optional[Callable[[Event, dict], None]] = None

    def __init__(self):
        """实例化 Matcher 以便运行
        """
        self.handlers = self.handlers.copy()
        self.state = self._default_state.copy()
        # self.parser = self._args_parser or self._default_parser

    @classmethod
    def new(cls,
            rule: Rule = Rule(),
            handlers: list = [],
            temp: bool = False,
            priority: int = 1,
            *,
            default_state: dict = {},
            expire_time: Optional[datetime] = None) -> Type["Matcher"]:
        """创建新的 Matcher

        Returns:
            Type["Matcher"]: 新的 Matcher 类
        """

        NewMatcher = type(
            "Matcher", (Matcher,), {
                "rule": rule,
                "handlers": handlers,
                "temp": temp,
                "expire_time": expire_time,
                "priority": priority,
                "_default_state": default_state
            })

        matchers[priority].append(NewMatcher)

        return NewMatcher

    @classmethod
    def check_rule(cls, bot, event: Event) -> bool:
        """检查 Matcher 的 Rule 是否成立

        Args:
            event (Event): 消息事件

        Returns:
            bool: 条件成立与否
        """
        return cls.rule(bot, event)

    # @classmethod
    # def args_parser(cls, func: Callable[[Event, dict], None]):
    #     cls._default_parser = func
    #     return func

    @classmethod
    def handle(cls):
        """直接处理消息事件"""

        def _decorator(func: Handler) -> Handler:
            cls.handlers.append(func)
            return func

        return _decorator

    @classmethod
    def receive(cls):
        """接收一条新消息并处理"""

        def _decorator(func: Handler) -> Handler:

            async def _handler(bot, event: Event, state: dict):
                raise PausedException

            cls.handlers.append(_handler)
            cls.handlers.append(func)

            return func

        return _decorator

    # @classmethod
    # def got(cls,
    #         key: str,
    #         prompt: Optional[str] = None,
    #         args_parser: Optional[Callable[[Event, dict], None]] = None):

    #     def _decorator(func: Handler) -> Handler:

    #         @wraps(func)
    #         def _handler(event: Event, state: dict):
    #             if key not in state:
    #                 if state.get("__current_arg__", None) == key:
    #                     state[key] = event.message
    #                     del state["__current_arg__"]
    #                     return func(event, state)
    #                 state["__current_arg__"] = key
    #                 cls._args_parser = args_parser
    #                 raise RejectedException

    #             return func(event, state)

    #         cls.handlers.append(_handler)

    #         return func

    #     return _decorator

    # @classmethod
    # def finish(cls, prompt: Optional[str] = None):
    #     raise FinishedException

    # @classmethod
    # def reject(cls, prompt: Optional[str] = None):
    #     raise RejectedException

    # 运行handlers
    async def run(self, bot, event):
        try:
            # if self.parser:
            #     await self.parser(event, state)  # type: ignore

            for _ in range(len(self.handlers)):
                handler = self.handlers.pop(0)
                await handler(bot, event, self.state)
        except RejectedException:
            self.handlers.insert(0, handler)  # type: ignore
            matcher = Matcher.new(user(event.user_id) & self.rule,
                                  self.handlers,
                                  temp=True,
                                  priority=0,
                                  default_state=self.state,
                                  expire_time=datetime.now() +
                                  bot.config.session_expire_timeout)
            matchers[0].append(matcher)
            return
        except PausedException:
            matcher = Matcher.new(user(event.user_id) & self.rule,
                                  self.handlers,
                                  temp=True,
                                  priority=0,
                                  default_state=self.state,
                                  expire_time=datetime.now() +
                                  bot.config.session_expire_timeout)
            matchers[0].append(matcher)
            return
        except FinishedException:
            return