"""
WebSocket endpoint – connessione real-time per aggiornamenti inbox.

URL: ws://<host>/api/v1/ws?token=<jwt_access_token>

Protocollo messaggi (dal server al client):
  {
    "type": "mailbox:new_message",
    "mailbox_id": "<uuid>",
    "message_id": "<uuid>",
    "subject": "...",
    "from_address": "...",
    "received_at": "2026-03-18T14:00:00Z"
  }

  {
    "type": "mailbox:sync_error",
    "mailbox_id": "<uuid>",
    "error": "...",
    "status": "error"
  }

  { "type": "ping" }   ← heartbeat ogni 30s per mantenere connessione viva
"""

import asyncio
import uuid

from fastapi import APIRouter, Query, WebSocket, WebSocketDisconnect
from jose import JWTError

from app.core.security import decode_token
from app.core.logging import get_logger
from app.websocket.manager import manager

router = APIRouter(tags=["WebSocket"])
logger = get_logger(__name__)


@router.websocket("/ws")
async def websocket_endpoint(
    websocket: WebSocket,
    token: str = Query(..., description="JWT access token per autenticazione"),
) -> None:
    """
    WebSocket endpoint autenticato via JWT query param.
    Invia eventi real-time per il tenant dell'utente connesso.
    """
    # Autenticazione: valida JWT
    try:
        payload = decode_token(token)
        if payload.get("type") != "access":
            await websocket.close(code=4001, reason="Token non valido")
            return

        tenant_id_str = payload.get("tid")
        user_id_str = payload.get("sub")
        if not tenant_id_str or not user_id_str:
            await websocket.close(code=4001, reason="Token malformato")
            return

        tenant_id = uuid.UUID(tenant_id_str)
        user_id = uuid.UUID(user_id_str)

    except (JWTError, ValueError):
        await websocket.close(code=4001, reason="Token non valido")
        return

    # Connessione accettata
    await manager.connect(websocket, tenant_id)
    logger.info(
        "WS autenticato",
        extra={"user_id": str(user_id), "tenant_id": str(tenant_id)},
    )

    # Invia ack di connessione
    try:
        await websocket.send_json({
            "type": "connected",
            "tenant_id": str(tenant_id),
            "user_id": str(user_id),
        })
    except Exception:
        await manager.disconnect(websocket, tenant_id)
        return

    # Heartbeat task
    async def send_pings() -> None:
        while True:
            try:
                await asyncio.sleep(30)
                await websocket.send_json({"type": "ping"})
            except Exception:
                break

    ping_task = asyncio.create_task(send_pings())

    try:
        # Mantieni la connessione aperta, gestisci messaggi client (pong, ecc.)
        while True:
            try:
                data = await asyncio.wait_for(websocket.receive_text(), timeout=35.0)
                # Gestisci pong dal client (opzionale)
                if data == "pong":
                    continue
            except asyncio.TimeoutError:
                # Nessun messaggio dal client in 35s: connessione morta
                break
            except WebSocketDisconnect:
                break

    finally:
        ping_task.cancel()
        await manager.disconnect(websocket, tenant_id)