from __future__ import annotations

import asyncio
import logging
from typing import Any, Awaitable, Callable

from .startup import StartupTaskRunner

logger = logging.getLogger(__name__)

StartupTask = Callable[[], Awaitable[Any]]


class BootManager:
    """启动管理器 — 协调系统启动阶段的任务执行顺序。"""

    def __init__(self):
        self._phases: dict[str, list[tuple[int, StartupTask]]] = {
            "early": [],
            "config": [],
            "plugins": [],
            "channels": [],
            "services": [],
            "late": [],
        }
        self._runner = StartupTaskRunner()

    def register(self, phase: str, task: StartupTask, *, priority: int = 0) -> None:
        """注册一个启动任务到指定阶段。

        priority 值越大优先级越高，同阶段内优先执行。
        """
        if phase not in self._phases:
            raise ValueError(f"Unknown boot phase: {phase}")
        self._phases[phase].append((priority, task))

    async def run_startup_tasks(self) -> None:
        """按阶段顺序执行所有启动任务，阶段内按 priority 降序执行。"""
        for phase, tasks in self._phases.items():
            if not tasks:
                continue
            ordered = sorted(tasks, key=lambda x: x[0], reverse=True)
            logger.info("Boot phase: %s (%d tasks)", phase, len(ordered))
            for _, task in ordered:
                try:
                    await self._runner.run(task)
                except Exception:
                    logger.exception("Boot task failed in phase '%s'", phase)
                    raise

    def get_phases(self) -> dict[str, list[StartupTask]]:
        return {k: [t for _, t in v] for k, v in self._phases.items()}

    def to_dict(self) -> dict[str, Any]:
        return {
            "phases": {
                phase: [getattr(t, "__name__", str(t)) for t in tasks]
                for phase, tasks in self.get_phases().items()
            },
            "total_tasks": sum(len(v) for v in self._phases.values()),
        }