"""Agent 专属 Protocol 端口。"""
from __future__ import annotations

from typing import Any, Protocol, runtime_checkable

import pluggy

from core.agent.types import LoopResult, Step

hookspec = pluggy.HookspecMarker("agent_loop")
hookimpl = pluggy.HookimplMarker("agent_loop")


@runtime_checkable
class ToolDispatcher(Protocol):
    """Agent 工具调度端口。无效工具名抛 ValueError。"""

    async def dispatch(
        self, tool_name: str, args: dict[str, Any], *, context: dict[str, Any]
    ) -> str: ...


class AgentLoopSpec:
    """AgentLoop 生命周期扩展点。

    每个 hookimpl 可选择观察（返回 None）或变换（返回值）。
    """

    @hookspec
    async def before_step(
        self, iteration: int, messages: list[dict[str, Any]]
    ) -> None: ...

    @hookspec
    async def after_tool(
        self, iteration: int, step: Step
    ) -> str | None: ...

    @hookspec
    async def after_step(
        self, iteration: int, messages: list[dict[str, Any]]
    ) -> None: ...

    @hookspec
    async def on_finish(self, result: LoopResult) -> None: ...