from __future__ import annotations

import asyncio
import time
from dataclasses import dataclass, field
from typing import Any


@dataclass
class AuthHealth:
    status: str
    message: str = ""
    expires_at: float | None = None
    last_checked_at: float = field(default_factory=time.monotonic)
    metadata: dict[str, Any] = field(default_factory=dict)

    @property
    def is_healthy(self) -> bool:
        return self.status == "healthy"


class AuthHealthMonitor:
    def __init__(self):
        self._health_states: dict[str, AuthHealth] = {}
        self._check_tasks: dict[str, asyncio.Task] = {}
        self._on_expiring_callbacks: list = []
        self._on_expired_callbacks: list = []
        self._on_revoked_callbacks: list = []
        self._on_failure_callbacks: list = []
        self._locks: dict[str, asyncio.Lock] = {}

    def _get_lock(self, channel_id: str) -> asyncio.Lock:
        if channel_id not in self._locks:
            self._locks[channel_id] = asyncio.Lock()
        return self._locks[channel_id]

    def update_health(self, channel_id: str, health: AuthHealth) -> None:
        old = self._health_states.get(channel_id)
        self._health_states[channel_id] = health

        if old and old.status == "healthy" and health.status != "healthy":
            try:
                asyncio.create_task(self._notify_failure(channel_id, health))
            except RuntimeError:
                pass

    def get_health(self, channel_id: str) -> AuthHealth | None:
        return self._health_states.get(channel_id)

    def get_all_health(self) -> dict[str, AuthHealth]:
        return dict(self._health_states)

    def on_token_expiring(self, callback) -> None:
        self._on_expiring_callbacks.append(callback)

    def on_token_expired(self, callback) -> None:
        self._on_expired_callbacks.append(callback)

    def on_auth_revoked(self, callback) -> None:
        self._on_revoked_callbacks.append(callback)

    def on_auth_failure(self, callback) -> None:
        self._on_failure_callbacks.append(callback)

    async def _notify_expiring(self, channel_id: str) -> None:
        for cb in self._on_expiring_callbacks:
            try:
                await cb(channel_id)
            except Exception:
                pass

    async def _notify_expired(self, channel_id: str) -> None:
        for cb in self._on_expired_callbacks:
            try:
                await cb(channel_id)
            except Exception:
                pass

    async def _notify_revoked(self, channel_id: str) -> None:
        for cb in self._on_revoked_callbacks:
            try:
                await cb(channel_id)
            except Exception:
                pass

    async def _notify_failure(self, channel_id: str, health: AuthHealth) -> None:
        for cb in self._on_failure_callbacks:
            try:
                await cb(channel_id, health)
            except Exception:
                pass

    def start_periodic_check(
        self,
        channel_id: str,
        check_func,
        interval_seconds: float = 60.0,
    ) -> None:
        if channel_id in self._check_tasks and not self._check_tasks[channel_id].done():
            return
        self._check_tasks[channel_id] = asyncio.create_task(
            self._periodic_check_loop(channel_id, check_func, interval_seconds)
        )

    def stop_periodic_check(self, channel_id: str) -> None:
        task = self._check_tasks.pop(channel_id, None)
        if task and not task.done():
            task.cancel()

    async def _periodic_check_loop(
        self,
        channel_id: str,
        check_func,
        interval_seconds: float,
    ) -> None:
        from yuxi.utils.logging_config import logger

        while True:
            try:
                await asyncio.sleep(interval_seconds)
                health = await check_func()
                self.update_health(channel_id, health)
            except asyncio.CancelledError:
                break
            except Exception as e:
                logger.warning(f"[AuthHealthMonitor] Health check failed for {channel_id}: {e}")
                self.update_health(
                    channel_id,
                    AuthHealth(status="unhealthy", message=str(e)),
                )


_health_monitor: AuthHealthMonitor | None = None


def get_health_monitor() -> AuthHealthMonitor:
    global _health_monitor
    if _health_monitor is None:
        _health_monitor = AuthHealthMonitor()
    return _health_monitor