"""
事件响应器
==========

该模块实现事件响应器的创建与运行，并提供一些快捷方法来帮助用户更好的与机器人进行对话 。
"""

from types import ModuleType
from datetime import datetime
from contextvars import ContextVar
from collections import defaultdict
from contextlib import AsyncExitStack
from typing import (
    TYPE_CHECKING,
    Any,
    Dict,
    List,
    Type,
    Union,
    Callable,
    NoReturn,
    Optional,
)

from nonebot import params
from nonebot.rule import Rule
from nonebot.log import logger
from nonebot.handler import Handler
from nonebot.dependencies import DependsWrapper
from nonebot.permission import USER, Permission
from nonebot.adapters import (
    Bot,
    Event,
    Message,
    MessageSegment,
    MessageTemplate,
)
from nonebot.exception import (
    PausedException,
    StopPropagation,
    SkippedException,
    FinishedException,
    RejectedException,
)
from nonebot.typing import (
    T_State,
    T_Handler,
    T_ArgsParser,
    T_TypeUpdater,
    T_StateFactory,
    T_DependencyCache,
    T_PermissionUpdater,
)

if TYPE_CHECKING:
    from nonebot.plugin import Plugin

matchers: Dict[int, List[Type["Matcher"]]] = defaultdict(list)
"""
:类型: ``Dict[int, List[Type[Matcher]]]``
:说明: 用于存储当前所有的事件响应器
"""
current_bot: ContextVar[Bot] = ContextVar("current_bot")
current_event: ContextVar[Event] = ContextVar("current_event")
current_state: ContextVar[T_State] = ContextVar("current_state")


class MatcherMeta(type):
    if TYPE_CHECKING:
        module: Optional[str]
        plugin_name: Optional[str]
        module_name: Optional[str]
        module_prefix: Optional[str]
        type: str
        rule: Rule
        permission: Permission
        handlers: List[T_Handler]
        priority: int
        block: bool
        temp: bool
        expire_time: Optional[datetime]

    def __repr__(self) -> str:
        return (
            f"<Matcher from {self.module_name or 'unknown'}, "
            f"type={self.type}, priority={self.priority}, "
            f"temp={self.temp}>"
        )

    def __str__(self) -> str:
        return repr(self)


class Matcher(metaclass=MatcherMeta):
    """事件响应器类"""

    plugin: Optional["Plugin"] = None
    """
    :类型: ``Optional[Plugin]``
    :说明: 事件响应器所在插件
    """
    module: Optional[ModuleType] = None
    """
    :类型: ``Optional[ModuleType]``
    :说明: 事件响应器所在插件模块
    """
    plugin_name: Optional[str] = None
    """
    :类型: ``Optional[str]``
    :说明: 事件响应器所在插件名
    """
    module_name: Optional[str] = None
    """
    :类型: ``Optional[str]``
    :说明: 事件响应器所在点分割插件模块路径
    """

    type: str = ""
    """
    :类型: ``str``
    :说明: 事件响应器类型
    """
    rule: Rule = Rule()
    """
    :类型: ``Rule``
    :说明: 事件响应器匹配规则
    """
    permission: Permission = Permission()
    """
    :类型: ``Permission``
    :说明: 事件响应器触发权限
    """
    handlers: List[Handler] = []
    """
    :类型: ``List[Handler]``
    :说明: 事件响应器拥有的事件处理函数列表
    """
    priority: int = 1
    """
    :类型: ``int``
    :说明: 事件响应器优先级
    """
    block: bool = False
    """
    :类型: ``bool``
    :说明: 事件响应器是否阻止事件传播
    """
    temp: bool = False
    """
    :类型: ``bool``
    :说明: 事件响应器是否为临时
    """
    expire_time: Optional[datetime] = None
    """
    :类型: ``Optional[datetime]``
    :说明: 事件响应器过期时间点
    """

    _default_state: T_State = {}
    """
    :类型: ``T_State``
    :说明: 事件响应器默认状态
    """
    _default_state_factory: Optional[T_StateFactory] = None
    """
    :类型: ``Optional[T_State]``
    :说明: 事件响应器默认工厂函数
    """

    _default_parser: Optional[T_ArgsParser] = None
    """
    :类型: ``Optional[T_ArgsParser]``
    :说明: 事件响应器默认参数解析函数
    """
    _default_type_updater: Optional[T_TypeUpdater] = None
    """
    :类型: ``Optional[T_TypeUpdater]``
    :说明: 事件响应器类型更新函数
    """
    _default_permission_updater: Optional[T_PermissionUpdater] = None
    """
    :类型: ``Optional[T_PermissionUpdater]``
    :说明: 事件响应器权限更新函数
    """

    HANDLER_PARAM_TYPES = [
        params.BotParam,
        params.EventParam,
        params.StateParam,
        params.MatcherParam,
        params.DefaultParam,
    ]

    def __init__(self):
        """实例化 Matcher 以便运行"""
        self.handlers = self.handlers.copy()
        self.state = self._default_state.copy()

    def __repr__(self) -> str:
        return (
            f"<Matcher from {self.module_name or 'unknown'}, type={self.type}, "
            f"priority={self.priority}, temp={self.temp}>"
        )

    def __str__(self) -> str:
        return repr(self)

    @classmethod
    def new(
        cls,
        type_: str = "",
        rule: Optional[Rule] = None,
        permission: Optional[Permission] = None,
        handlers: Optional[
            Union[List[T_Handler], List[Handler], List[Union[T_Handler, Handler]]]
        ] = None,
        temp: bool = False,
        priority: int = 1,
        block: bool = False,
        *,
        plugin: Optional["Plugin"] = None,
        module: Optional[ModuleType] = None,
        expire_time: Optional[datetime] = None,
        default_state: Optional[T_State] = None,
        default_state_factory: Optional[T_StateFactory] = None,
        default_parser: Optional[T_ArgsParser] = None,
        default_type_updater: Optional[T_TypeUpdater] = None,
        default_permission_updater: Optional[T_PermissionUpdater] = None,
    ) -> Type["Matcher"]:
        """
        :说明:

          创建一个新的事件响应器，并存储至 `matchers <#matchers>`_

        :参数:

          * ``type_: str``: 事件响应器类型，与 ``event.get_type()`` 一致时触发，空字符串表示任意
          * ``rule: Optional[Rule]``: 匹配规则
          * ``permission: Optional[Permission]``: 权限
          * ``handlers: Optional[List[T_Handler]]``: 事件处理函数列表
          * ``temp: bool``: 是否为临时事件响应器，即触发一次后删除
          * ``priority: int``: 响应优先级
          * ``block: bool``: 是否阻止事件向更低优先级的响应器传播
          * ``plugin: Optional[Plugin]``: 事件响应器所在插件
          * ``module: Optional[ModuleType]``: 事件响应器所在模块
          * ``default_state: Optional[T_State]``: 默认状态 ``state``
          * ``default_state_factory: Optional[T_StateFactory]``: 默认状态 ``state`` 的工厂函数
          * ``expire_time: Optional[datetime]``: 事件响应器最终有效时间点，过时即被删除

        :返回:

          - ``Type[Matcher]``: 新的事件响应器类
        """

        NewMatcher = type(
            "Matcher",
            (Matcher,),
            {
                "plugin": plugin,
                "module": module,
                "plugin_name": plugin and plugin.name,
                "module_name": module and module.__name__,
                "type": type_,
                "rule": rule or Rule(),
                "permission": permission or Permission(),
                "handlers": [
                    handler
                    if isinstance(handler, Handler)
                    else Handler(handler, allow_types=cls.HANDLER_PARAM_TYPES)
                    for handler in handlers
                ]
                if handlers
                else [],
                "temp": temp,
                "expire_time": expire_time,
                "priority": priority,
                "block": block,
                "_default_state": default_state or {},
                "_default_state_factory": staticmethod(default_state_factory)
                if default_state_factory
                else None,
                "_default_parser": default_parser,
                "_default_type_updater": default_type_updater,
                "_default_permission_updater": default_permission_updater,
            },
        )

        matchers[priority].append(NewMatcher)

        return NewMatcher

    @classmethod
    async def check_perm(
        cls,
        bot: Bot,
        event: Event,
        stack: Optional[AsyncExitStack] = None,
        dependency_cache: Optional[Dict[Callable[..., Any], Any]] = None,
    ) -> bool:
        """
        :说明:

          检查是否满足触发权限

        :参数:

          * ``bot: Bot``: Bot 对象
          * ``event: Event``: 上报事件

        :返回:

          - ``bool``: 是否满足权限
        """
        event_type = event.get_type()
        return event_type == (cls.type or event_type) and await cls.permission(
            bot, event, stack, dependency_cache
        )

    @classmethod
    async def check_rule(
        cls,
        bot: Bot,
        event: Event,
        state: T_State,
        stack: Optional[AsyncExitStack] = None,
        dependency_cache: Optional[Dict[Callable[..., Any], Any]] = None,
    ) -> bool:
        """
        :说明:

          检查是否满足匹配规则

        :参数:

          * ``bot: Bot``: Bot 对象
          * ``event: Event``: 上报事件
          * ``state: T_State``: 当前状态

        :返回:

          - ``bool``: 是否满足匹配规则
        """
        event_type = event.get_type()
        return event_type == (cls.type or event_type) and await cls.rule(
            bot, event, state, stack, dependency_cache
        )

    @classmethod
    def args_parser(cls, func: T_ArgsParser) -> T_ArgsParser:
        """
        :说明:

          装饰一个函数来更改当前事件响应器的默认参数解析函数

        :参数:

          * ``func: T_ArgsParser``: 参数解析函数
        """
        cls._default_parser = func
        return func

    @classmethod
    def type_updater(cls, func: T_TypeUpdater) -> T_TypeUpdater:
        """
        :说明:

          装饰一个函数来更改当前事件响应器的默认响应事件类型更新函数

        :参数:

          * ``func: T_TypeUpdater``: 响应事件类型更新函数
        """
        cls._default_type_updater = func
        return func

    @classmethod
    def permission_updater(cls, func: T_PermissionUpdater) -> T_PermissionUpdater:
        """
        :说明:

          装饰一个函数来更改当前事件响应器的默认会话权限更新函数

        :参数:

          * ``func: T_PermissionUpdater``: 会话权限更新函数
        """
        cls._default_permission_updater = func
        return func

    @classmethod
    def append_handler(
        cls, handler: T_Handler, dependencies: Optional[List[DependsWrapper]] = None
    ) -> Handler:
        handler_ = Handler(
            handler, dependencies=dependencies, allow_types=cls.HANDLER_PARAM_TYPES
        )
        cls.handlers.append(handler_)
        return handler_

    @classmethod
    def handle(cls) -> Callable[[T_Handler], T_Handler]:
        """
        :说明:

          装饰一个函数来向事件响应器直接添加一个处理函数

        :参数:

          * 无
        """

        def _decorator(func: T_Handler) -> T_Handler:
            cls.append_handler(func)
            return func

        return _decorator

    @classmethod
    def receive(cls) -> Callable[[T_Handler], T_Handler]:
        """
        :说明:

          装饰一个函数来指示 NoneBot 在接收用户新的一条消息后继续运行该函数

        :参数:

          * 无
        """

        async def _receive(state: T_State) -> Union[None, NoReturn]:
            if state.get(_receive):
                return
            state[_receive] = True
            del state["_current_key"]
            raise RejectedException

        def _decorator(func: T_Handler) -> T_Handler:

            depend = DependsWrapper(_receive)

            if cls.handlers and cls.handlers[-1].func is func:
                func_handler = cls.handlers[-1]
                func_handler.prepend_dependency(depend)
            else:
                cls.append_handler(func, dependencies=[depend] if cls.handlers else [])

            return func

        return _decorator

    @classmethod
    def got(
        cls,
        key: str,
        prompt: Optional[Union[str, Message, MessageSegment, MessageTemplate]] = None,
        args_parser: Optional[T_ArgsParser] = None,
    ) -> Callable[[T_Handler], T_Handler]:
        """
        :说明:

          装饰一个函数来指示 NoneBot 当要获取的 ``key`` 不存在时接收用户新的一条消息并经过 ``ArgsParser`` 处理后再运行该函数，如果 ``key`` 已存在则直接继续运行

        :参数:

          * ``key: str``: 参数名
          * ``prompt: Optional[Union[str, Message, MessageSegment, MessageFormatter]]``: 在参数不存在时向用户发送的消息
          * ``args_parser: Optional[T_ArgsParser]``: 可选参数解析函数，空则使用默认解析函数
        """

        async def _key_getter(bot: Bot, event: Event, state: T_State):
            if state.get(f"_{key}_prompted"):
                return

            state["_current_key"] = key
            state[f"_{key}_prompted"] = True
            if key not in state:
                if prompt is not None:
                    if isinstance(prompt, MessageTemplate):
                        _prompt = prompt.format(**state)
                    else:
                        _prompt = prompt
                    await bot.send(event=event, message=_prompt)
                raise RejectedException
            else:
                state[f"_{key}_parsed"] = True

        async def _key_parser(bot: Bot, event: Event, state: T_State):
            if key in state and state.get(f"_{key}_parsed"):
                return

            parser = args_parser or cls._default_parser
            if parser:
                await parser(bot, event, state)
            else:
                state[key] = str(event.get_message())
            state[f"_{key}_parsed"] = True

        def _decorator(func: T_Handler) -> T_Handler:

            get_depend = DependsWrapper(_key_getter)
            parser_depend = DependsWrapper(_key_parser)

            if cls.handlers and cls.handlers[-1].func is func:
                func_handler = cls.handlers[-1]
                func_handler.prepend_dependency(parser_depend)
                func_handler.prepend_dependency(get_depend)
            else:
                cls.append_handler(func, dependencies=[get_depend, parser_depend])

            return func

        return _decorator

    @classmethod
    async def send(
        cls, message: Union[str, Message, MessageSegment, MessageTemplate], **kwargs
    ) -> Any:
        """
        :说明:

          发送一条消息给当前交互用户

        :参数:

          * ``message: Union[str, Message, MessageSegment]``: 消息内容
          * ``**kwargs``: 其他传递给 ``bot.send`` 的参数，请参考对应 adapter 的 bot 对象 api
        """
        bot = current_bot.get()
        event = current_event.get()
        state = current_state.get()
        if isinstance(message, MessageTemplate):
            _message = message.format(**state)
        else:
            _message = message
        return await bot.send(event=event, message=_message, **kwargs)

    @classmethod
    async def finish(
        cls,
        message: Optional[Union[str, Message, MessageSegment, MessageTemplate]] = None,
        **kwargs,
    ) -> NoReturn:
        """
        :说明:

          发送一条消息给当前交互用户并结束当前事件响应器

        :参数:

          * ``message: Union[str, Message, MessageSegment]``: 消息内容
          * ``**kwargs``: 其他传递给 ``bot.send`` 的参数，请参考对应 adapter 的 bot 对象 api
        """
        bot = current_bot.get()
        event = current_event.get()
        state = current_state.get()
        if isinstance(message, MessageTemplate):
            _message = message.format(**state)
        else:
            _message = message
        if _message is not None:
            await bot.send(event=event, message=_message, **kwargs)
        raise FinishedException

    @classmethod
    async def pause(
        cls,
        prompt: Optional[Union[str, Message, MessageSegment, MessageTemplate]] = None,
        **kwargs,
    ) -> NoReturn:
        """
        :说明:

          发送一条消息给当前交互用户并暂停事件响应器，在接收用户新的一条消息后继续下一个处理函数

        :参数:

          * ``prompt: Union[str, Message, MessageSegment]``: 消息内容
          * ``**kwargs``: 其他传递给 ``bot.send`` 的参数，请参考对应 adapter 的 bot 对象 api
        """
        bot = current_bot.get()
        event = current_event.get()
        state = current_state.get()
        if isinstance(prompt, MessageTemplate):
            _prompt = prompt.format(**state)
        else:
            _prompt = prompt
        if _prompt is not None:
            await bot.send(event=event, message=_prompt, **kwargs)
        raise PausedException

    @classmethod
    async def reject(
        cls, prompt: Optional[Union[str, Message, MessageSegment]] = None, **kwargs
    ) -> NoReturn:
        """
        :说明:

          发送一条消息给当前交互用户并暂停事件响应器，在接收用户新的一条消息后重新运行当前处理函数

        :参数:

          * ``prompt: Union[str, Message, MessageSegment]``: 消息内容
          * ``**kwargs``: 其他传递给 ``bot.send`` 的参数，请参考对应 adapter 的 bot 对象 api
        """
        bot = current_bot.get()
        event = current_event.get()
        state = current_state.get()
        if "_current_key" in state and f"_{state['_current_key']}_parsed" in state:
            del state[f"_{state['_current_key']}_parsed"]
        if isinstance(prompt, MessageTemplate):
            _prompt = prompt.format(**state)
        else:
            _prompt = prompt
        if _prompt is not None:
            await bot.send(event=event, message=_prompt, **kwargs)
        raise RejectedException

    def stop_propagation(self):
        """
        :说明:

          阻止事件传播
        """
        self.block = True

    # 运行handlers
    async def run(
        self,
        bot: Bot,
        event: Event,
        state: T_State,
        stack: Optional[AsyncExitStack] = None,
        dependency_cache: Optional[T_DependencyCache] = None,
    ):
        b_t = current_bot.set(bot)
        e_t = current_event.set(event)
        s_t = current_state.set(self.state)
        try:
            # Refresh preprocess state
            self.state = (
                await self._default_state_factory(bot, event)
                if self._default_state_factory
                else self.state
            )
            self.state.update(state)

            while self.handlers:
                handler = self.handlers.pop(0)
                logger.debug(f"Running handler {handler}")
                try:
                    await handler(
                        matcher=self,
                        bot=bot,
                        event=event,
                        state=self.state,
                        _stack=stack,
                        _dependency_cache=dependency_cache,
                    )
                except SkippedException:
                    pass

        except RejectedException:
            self.handlers.insert(0, handler)  # type: ignore
            updater = self.__class__._default_type_updater
            if updater:
                type_ = await updater(bot, event, self.state, self.type)  # type: ignore
            else:
                type_ = "message"

            updater = self.__class__._default_permission_updater
            if updater:
                permission = await updater(bot, event, self.state, self.permission)
            else:
                permission = USER(event.get_session_id(), perm=self.permission)

            Matcher.new(
                type_,
                Rule(),
                permission,
                self.handlers,
                temp=True,
                priority=0,
                block=True,
                plugin=self.plugin,
                module=self.module,
                expire_time=datetime.now() + bot.config.session_expire_timeout,
                default_state=self.state,
                default_parser=self.__class__._default_parser,
                default_type_updater=self.__class__._default_type_updater,
                default_permission_updater=self.__class__._default_permission_updater,
            )
        except PausedException:
            updater = self.__class__._default_type_updater
            if updater:
                type_ = await updater(bot, event, self.state, self.type)  # type: ignore
            else:
                type_ = "message"

            updater = self.__class__._default_permission_updater
            if updater:
                permission = await updater(bot, event, self.state, self.permission)
            else:
                permission = USER(event.get_session_id(), perm=self.permission)

            Matcher.new(
                type_,
                Rule(),
                permission,
                self.handlers,
                temp=True,
                priority=0,
                block=True,
                plugin=self.plugin,
                module=self.module,
                expire_time=datetime.now() + bot.config.session_expire_timeout,
                default_state=self.state,
                default_parser=self.__class__._default_parser,
                default_type_updater=self.__class__._default_type_updater,
                default_permission_updater=self.__class__._default_permission_updater,
            )
        except FinishedException:
            pass
        except StopPropagation:
            self.block = True
        finally:
            logger.info(f"Matcher {self} running complete")
            current_bot.reset(b_t)
            current_event.reset(e_t)
            current_state.reset(s_t)