nonebot2/nonebot/processor/handler.py

"""
事件处理函数
============

该模块实现事件处理函数的封装，以实现动态参数等功能。
"""

import asyncio
from contextlib import AsyncExitStack
from typing import TYPE_CHECKING, Any, Dict, List, Tuple, Callable, Optional

from .models import Depends, Dependent
from nonebot.utils import get_name, run_sync
from nonebot.typing import T_State, T_Handler
from . import get_dependent, solve_dependencies, get_parameterless_sub_dependant

if TYPE_CHECKING:
    from .matcher import Matcher
    from .params import ParamTypes
    from nonebot.adapters import Bot, Event


class Handler:
    """事件处理函数类"""

    def __init__(self,
                 func: T_Handler,
                 *,
                 name: Optional[str] = None,
                 dependencies: Optional[List[Depends]] = None,
                 allow_types: Optional[List["ParamTypes"]] = None,
                 dependency_overrides_provider: Optional[Any] = None):
        """装饰事件处理函数以便根据动态参数运行"""
        self.func: T_Handler = func
        """
        :类型: ``T_Handler``
        :说明: 事件处理函数
        """
        self.name = get_name(func) if name is None else name
        self.allow_types = allow_types

        self.dependencies = dependencies or []
        self.sub_dependents: Dict[Callable[..., Any], Dependent] = {}
        if dependencies:
            for depends in dependencies:
                if not depends.dependency:
                    raise ValueError(f"{depends} has no dependency")
                if depends.dependency in self.sub_dependents:
                    raise ValueError(f"{depends} is already in dependencies")
                sub_dependant = get_parameterless_sub_dependant(
                    depends=depends, allow_types=self.allow_types)
                self.sub_dependents[depends.dependency] = sub_dependant
        self.dependency_overrides_provider = dependency_overrides_provider
        self.dependent = get_dependent(func=func, allow_types=self.allow_types)

    def __repr__(self) -> str:
        return (
            f"<Handler {self.func}({', '.join(map(str, self.dependent.params))})>"
        )

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

    async def __call__(
        self,
        matcher: "Matcher",
        bot: "Bot",
        event: "Event",
        state: T_State,
        *,
        stack: Optional[AsyncExitStack] = None,
        dependency_cache: Optional[Dict[Callable[..., Any],
                                        Any]] = None) -> Any:
        values, _, ignored = await solve_dependencies(
            dependent=self.dependent,
            bot=bot,
            event=event,
            state=state,
            matcher=matcher,
            stack=stack,
            sub_dependents=[
                self.sub_dependents[dependency.dependency]  # type: ignore
                for dependency in self.dependencies
            ],
            dependency_overrides_provider=self.dependency_overrides_provider,
            dependency_cache=dependency_cache)

        if ignored:
            return

        if asyncio.iscoroutinefunction(self.func):
            await self.func(**values)
        else:
            await run_sync(self.func)(**values)

    def cache_dependent(self, dependency: Depends):
        if not dependency.dependency:
            raise ValueError(f"{dependency} has no dependency")
        if (dependency.dependency,) in self.sub_dependents:
            raise ValueError(f"{dependency} is already in dependencies")
        sub_dependant = get_parameterless_sub_dependant(
            depends=dependency, allow_types=self.allow_types)
        self.sub_dependents[dependency.dependency] = sub_dependant

    def prepend_dependency(self, dependency: Depends):
        self.cache_dependent(dependency)
        self.dependencies.insert(0, dependency)

    def append_dependency(self, dependency: Depends):
        self.cache_dependent(dependency)
        self.dependencies.append(dependency)

    def remove_dependency(self, dependency: Depends):
        if not dependency.dependency:
            raise ValueError(f"{dependency} has no dependency")
        if dependency.dependency in self.sub_dependents:
            del self.sub_dependents[dependency.dependency]
        if dependency in self.dependencies:
            self.dependencies.remove(dependency)