"""
WebSocket Router - WebSocket 实时推送接口
Real-time data push via WebSocket with topic subscriptions.
"""

import logging
import secrets

from fastapi import APIRouter, Query, WebSocket, WebSocketDisconnect

from app.config import settings
from app.websocket_manager import ws_manager, VALID_TOPICS

logger = logging.getLogger(__name__)

router = APIRouter(tags=["WebSocket / 实时推送"])


@router.websocket("/ws")
async def websocket_endpoint(
    websocket: WebSocket,
    api_key: str | None = Query(default=None, alias="api_key"),
    topics: str | None = Query(default=None, description="Comma-separated topics"),
):
    """
    WebSocket endpoint for real-time data push.

    Connect: ws://host/ws?api_key=xxx&topics=location,alarm
    Topics: location, alarm, device_status, attendance, bluetooth
    If no topics specified, subscribes to all.
    """
    # Authenticate
    if settings.API_KEY is not None:
        if api_key is None or not secrets.compare_digest(api_key, settings.API_KEY):
            # For DB keys, do a simple hash check
            if api_key is not None:
                from app.dependencies import _hash_key
                from app.database import async_session
                from sqlalchemy import select
                from app.models import ApiKey

                try:
                    async with async_session() as session:
                        key_hash = _hash_key(api_key)
                        result = await session.execute(
                            select(ApiKey.id).where(
                                ApiKey.key_hash == key_hash,
                                ApiKey.is_active == True,  # noqa: E712
                            )
                        )
                        if result.scalar_one_or_none() is None:
                            await websocket.close(code=4001, reason="Invalid API key")
                            return
                except Exception:
                    await websocket.close(code=4001, reason="Auth error")
                    return
            else:
                await websocket.close(code=4001, reason="Missing API key")
                return

    # Parse topics
    requested_topics = set()
    if topics:
        requested_topics = {t.strip() for t in topics.split(",") if t.strip() in VALID_TOPICS}

    if not await ws_manager.connect(websocket, requested_topics):
        return

    try:
        # Keep connection alive, handle pings
        while True:
            data = await websocket.receive_text()
            # Client can send "ping" to keep alive
            if data.strip().lower() == "ping":
                await websocket.send_text("pong")
    except WebSocketDisconnect:
        pass
    except Exception:
        logger.debug("WebSocket connection error", exc_info=True)
    finally:
        ws_manager.disconnect(websocket)