from __future__ import annotations

import asyncio
import json
from collections.abc import Callable, Coroutine
from typing import Any

from yuxi.utils.logging_config import logger

try:
    import websockets
except ImportError:
    websockets = None


class YuanbaoMonitor:
    def __init__(
        self,
        ws_url: str,
        token_provider: Callable[[], Coroutine[Any, Any, str]],
        on_event: Callable[[dict[str, Any]], Coroutine[Any, Any, None]],
        max_reconnect: int = 10,
        ping_interval: float = 30,
        ping_timeout: float = 10,
        close_timeout: float = 5,
        auth_timeout: float = 10,
    ):
        self._ws_url = ws_url
        self._token_provider = token_provider
        self._on_event = on_event
        self._max_reconnect = max_reconnect
        self._ping_interval = ping_interval
        self._ping_timeout = ping_timeout
        self._close_timeout = close_timeout
        self._auth_timeout = auth_timeout
        self._ws = None
        self._running = False
        self._reconnect_delay = 1.0
        self._max_reconnect_delay = 60.0
        self._task: asyncio.Task | None = None
        self._reconnect_count = 0
        self._auth_failed = False
        self._last_event_timestamp: float | None = None

    async def start(self) -> None:
        if websockets is None:
            logger.warning("[Yuanbao] websockets library not installed, skipping WebSocket")
            return
        self._running = True
        self._reconnect_delay = 1.0
        self._reconnect_count = 0
        self._auth_failed = False
        self._task = asyncio.create_task(self._listen_loop())
        logger.info("[Yuanbao] WebSocket monitor started")

    async def stop(self) -> None:
        self._running = False
        if self._task and not self._task.done():
            self._task.cancel()
            try:
                await self._task
            except asyncio.CancelledError:
                pass
            self._task = None
        if self._ws:
            await self._ws.close()
            self._ws = None
        logger.info("[Yuanbao] WebSocket monitor stopped")

    @property
    def is_connected(self) -> bool:
        return self._ws is not None and self._running

    @property
    def reconnect_count(self) -> int:
        return self._reconnect_count

    @property
    def healthy(self) -> bool:
        if not self.is_connected:
            return False
        if self._last_event_timestamp is None:
            return True
        import time

        idle_seconds = time.monotonic() - self._last_event_timestamp
        return idle_seconds < self._ping_interval * 3

    @property
    def last_event_timestamp(self) -> float | None:
        return self._last_event_timestamp

    async def _listen_loop(self) -> None:
        while self._running:
            try:
                token = await self._token_provider()
                headers = {"Authorization": f"Bearer {token}"}
                async for ws in websockets.connect(
                    self._ws_url,
                    additional_headers=headers,
                    ping_interval=self._ping_interval,
                    ping_timeout=self._ping_timeout,
                    close_timeout=self._close_timeout,
                ):
                    self._ws = ws
                    self._reconnect_delay = 1.0
                    self._reconnect_count = 0
                    logger.info(f"[Yuanbao] WebSocket connected: {self._ws_url}")

                    auth_frame = json.dumps(
                        {
                            "type": "auth",
                            "access_token": token,
                        }
                    )
                    await ws.send(auth_frame)

                    try:
                        auth_raw = await asyncio.wait_for(ws.recv(), timeout=self._auth_timeout)
                        auth_data = json.loads(auth_raw)
                        if auth_data.get("type") != "auth_ok":
                            logger.warning(f"[Yuanbao] WS auth failed: {auth_data}")
                            self._auth_failed = True
                            break
                    except TimeoutError:
                        logger.warning("[Yuanbao] WS auth timeout")
                        break

                    await self._handle_messages(ws)
            except Exception as e:
                if not self._running:
                    break
                if self._auth_failed:
                    logger.error(f"[Yuanbao] WebSocket auth permanently failed, stopping")
                    break
                self._reconnect_count += 1
                if self._reconnect_count > self._max_reconnect:
                    logger.error(f"[Yuanbao] Max reconnect attempts ({self._max_reconnect}) exceeded")
                    break
                logger.warning(
                    f"[Yuanbao] WebSocket disconnected, reconnecting in {self._reconnect_delay}s "
                    f"(attempt {self._reconnect_count}/{self._max_reconnect}): {e}"
                )
                await asyncio.sleep(self._reconnect_delay)
                self._reconnect_delay = min(
                    self._reconnect_delay * 2,
                    self._max_reconnect_delay,
                )

    async def _handle_messages(self, ws) -> None:
        try:
            async for raw in ws:
                if not self._running:
                    break
                try:
                    event = json.loads(raw)
                    event_type = event.get("type", "")

                    if event.get("timestamp"):
                        try:
                            self._last_event_timestamp = float(event["timestamp"])
                        except (ValueError, TypeError):
                            pass

                    if event_type == "pong":
                        continue

                    await self._on_event(event)
                except Exception as e:
                    logger.error(f"[Yuanbao] Failed to handle WS event: {e}", exc_info=True)
        except asyncio.CancelledError:
            raise
        except Exception:
            raise  # connection closed or other transport error, triggers reconnect in _listen_loop