"""Async WebSocket ↔ guacd TCP bridge (Guacamole protocol relay)."""

from __future__ import annotations

import asyncio
import logging

from fastapi import WebSocket, WebSocketDisconnect

logger = logging.getLogger("nexus.guacamole.tunnel")


async def bridge_websocket_to_guacd(
    websocket: WebSocket,
    guacd_host: str,
    guacd_port: int,
) -> None:
    """Relay Guacamole instructions between browser and guacd."""
    reader: asyncio.StreamReader
    writer: asyncio.StreamWriter
    reader, writer = await asyncio.open_connection(guacd_host, guacd_port)

    async def ws_to_guacd() -> None:
        try:
            while True:
                data = await websocket.receive_text()
                writer.write(data.encode("utf-8"))
                await writer.drain()
        except WebSocketDisconnect:
            pass
        except Exception as exc:
            logger.debug("RDP WS→guacd ended: %s", exc)

    async def guacd_to_ws() -> None:
        try:
            while True:
                chunk = await reader.read(8192)
                if not chunk:
                    break
                await websocket.send_text(chunk.decode("utf-8", errors="replace"))
        except Exception as exc:
            logger.debug("RDP guacd→WS ended: %s", exc)

    ws_task = asyncio.create_task(ws_to_guacd())
    guacd_task = asyncio.create_task(guacd_to_ws())
    try:
        await asyncio.wait(
            [ws_task, guacd_task],
            return_when=asyncio.FIRST_COMPLETED,
        )
    finally:
        for task in (ws_task, guacd_task):
            task.cancel()
        writer.close()
        try:
            await writer.wait_closed()
        except Exception:
            pass