nonebot2/nonebot/permission.py

r"""
权限
====

每个 ``Matcher`` 拥有一个 ``Permission`` ，其中是 ``PermissionChecker`` 的集合，只要有一个 ``PermissionChecker`` 检查结果为 ``True`` 时就会继续运行。

\:\:\:tip 提示
``PermissionChecker`` 既可以是 async function 也可以是 sync function
\:\:\:
"""

import asyncio
from contextlib import AsyncExitStack
from typing import (
    Any,
    Set,
    Dict,
    Tuple,
    Union,
    Callable,
    NoReturn,
    Optional,
    Coroutine,
)

from nonebot import params
from nonebot.adapters import Bot, Event
from nonebot.dependencies import Dependent
from nonebot.exception import SkippedException
from nonebot.typing import T_Handler, T_DependencyCache, T_PermissionChecker


async def _run_coro_with_catch(coro: Coroutine[Any, Any, Any]):
    try:
        return await coro
    except SkippedException:
        return False


class Permission:
    """
    :说明:

      ``Matcher`` 规则类，当事件传递时，在 ``Matcher`` 运行前进行检查。

    :示例:

    .. code-block:: python

        Permission(async_function) | sync_function
        # 等价于
        from nonebot.utils import run_sync
        Permission(async_function, run_sync(sync_function))
    """

    __slots__ = ("checkers",)

    HANDLER_PARAM_TYPES = [
        params.DependParam,
        params.BotParam,
        params.EventParam,
        params.DefaultParam,
    ]

    def __init__(self, *checkers: Union[T_PermissionChecker, Dependent[bool]]) -> None:
        """
        :参数:

          * ``*checkers: Union[T_PermissionChecker, Dependent[bool]``: PermissionChecker
        """

        self.checkers: Set[Dependent[bool]] = set(
            checker
            if isinstance(checker, Dependent)
            else Dependent[bool].parse(
                call=checker, allow_types=self.HANDLER_PARAM_TYPES
            )
            for checker in checkers
        )
        """
        :说明:

          存储 ``PermissionChecker``

        :类型:

          * ``Set[Dependent[bool]]``
        """

    async def __call__(
        self,
        bot: Bot,
        event: Event,
        stack: Optional[AsyncExitStack] = None,
        dependency_cache: Optional[T_DependencyCache] = None,
    ) -> bool:
        """
        :说明:

          检查是否满足某个权限

        :参数:

          * ``bot: Bot``: Bot 对象
          * ``event: Event``: Event 对象
          * ``stack: Optional[AsyncExitStack]``: 异步上下文栈
          * ``dependency_cache: Optional[CacheDict[T_Handler, Any]]``: 依赖缓存

        :返回:

          - ``bool``
        """
        if not self.checkers:
            return True
        results = await asyncio.gather(
            *(
                _run_coro_with_catch(
                    checker(
                        bot=bot,
                        event=event,
                        stack=stack,
                        dependency_cache=dependency_cache,
                    )
                )
                for checker in self.checkers
            ),
        )
        return any(results)

    def __and__(self, other) -> NoReturn:
        raise RuntimeError("And operation between Permissions is not allowed.")

    def __or__(
        self, other: Optional[Union["Permission", T_PermissionChecker]]
    ) -> "Permission":
        if other is None:
            return self
        elif isinstance(other, Permission):
            return Permission(*self.checkers, *other.checkers)
        else:
            return Permission(*self.checkers, other)


class Message:
    async def __call__(self, event: Event) -> bool:
        return event.get_type() == "message"


class Notice:
    async def __call__(self, event: Event) -> bool:
        return event.get_type() == "notice"


class Request:
    async def __call__(self, event: Event) -> bool:
        return event.get_type() == "request"


class MetaEvent:
    async def __call__(self, event: Event) -> bool:
        return event.get_type() == "meta_event"


MESSAGE = Permission(Message())
"""
- **说明**: 匹配任意 ``message`` 类型事件，仅在需要同时捕获不同类型事件时使用。优先使用 message type 的 Matcher。
"""
NOTICE = Permission(Notice())
"""
- **说明**: 匹配任意 ``notice`` 类型事件，仅在需要同时捕获不同类型事件时使用。优先使用 notice type 的 Matcher。
"""
REQUEST = Permission(Request())
"""
- **说明**: 匹配任意 ``request`` 类型事件，仅在需要同时捕获不同类型事件时使用。优先使用 request type 的 Matcher。
"""
METAEVENT = Permission(MetaEvent())
"""
- **说明**: 匹配任意 ``meta_event`` 类型事件，仅在需要同时捕获不同类型事件时使用。优先使用 meta_event type 的 Matcher。
"""


class User:
    def __init__(
        self, users: Tuple[str, ...], perm: Optional[Permission] = None
    ) -> None:
        self.users = users
        self.perm = perm

    async def __call__(self, bot: Bot, event: Event) -> bool:
        return bool(
            event.get_session_id() in self.users
            and (self.perm is None or await self.perm(bot, event))
        )


def USER(*users: str, perm: Optional[Permission] = None):
    """
    :说明:

      ``event`` 的 ``session_id`` 在白名单内且满足 perm

    :参数:

      * ``*user: str``: 白名单
      * ``perm: Optional[Permission]``: 需要同时满足的权限
    """

    return Permission(User(users, perm))


class SuperUser:
    async def __call__(self, bot: Bot, event: Event) -> bool:
        return (
            event.get_type() == "message"
            and event.get_user_id() in bot.config.superusers
        )


SUPERUSER = Permission(SuperUser())
"""
- **说明**: 匹配任意超级用户消息类型事件
"""