import asyncio
from fastapi import FastAPI, WebSocket
from fastapi.responses import HTMLResponse
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI()

@app.get("/")
def read_root():
    return HTMLResponse("<h1>Redis WebSocket Proxy Running</h1>")

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    logger.info("WebSocket connection accepted.")
    
    try:
        # Connect to local Redis TCP port
        reader, writer = await asyncio.open_connection("127.0.0.1", 6379)
        logger.info("Connected to local Redis.")
    except Exception as e:
        logger.error(f"Failed to connect to local Redis: {e}")
        await websocket.close()
        return

    async def pipe_ws_to_tcp():
        try:
            while True:
                data = await websocket.receive_bytes()
                writer.write(data)
                await writer.drain()
        except Exception as e:
            logger.info(f"ws_to_tcp closed: {e}")

    async def pipe_tcp_to_ws():
        try:
            while True:
                data = await reader.read(4096)
                if not data:
                    break
                await websocket.send_bytes(data)
        except Exception as e:
            logger.info(f"tcp_to_ws closed: {e}")

    try:
        await asyncio.gather(
            pipe_ws_to_tcp(),
            pipe_tcp_to_ws(),
            return_exceptions=True
        )
    finally:
        writer.close()
        try:
            await websocket.close()
        except:
            pass
        logger.info("Connection closed.")