from aiohttp import web, WSMsgType
from typing import Dict, Set
import asyncio

from .util import wrap_async
from ..web_io_buffer import WebIOBuffer

class StdoutWebSocket:
    """
    WebSocket handler for stdout changes.
    Broadcasts stdout updates to all connected clients.
    """
    
    def __init__(self, io_buffer: WebIOBuffer):
        self._io_buffer = io_buffer
        self._clients: Set[web.WebSocketResponse] = set()
        self._io_buffer.add_stdout_change_handler(wrap_async(self._handle_stdout_change))
        
    async def _broadcast_message(self, message: Dict):
        """Broadcast message to all connected clients."""
        disconnected = set()
        for ws in self._clients:
            try:
                await ws.send_json(message)
            except ConnectionResetError:
                disconnected.add(ws)
        self._clients -= disconnected

    async def _handle_stdout_change(self, output: str):
        """Handle stdout changes from the WebIOBuffer."""
        await self._broadcast_message({
            "output": output
        })

    async def handle_connection(self, request: web.Request) -> web.WebSocketResponse:
        """Handle new WebSocket connections."""
        ws = web.WebSocketResponse(heartbeat=30)
        await ws.prepare(request)
        
        self._clients.add(ws)
        
        try:
            # Send initial stdout content
            await ws.send_json({
                "output": self._io_buffer.get_stdout()
            })
                
            async for msg in ws:
                if msg.type == WSMsgType.ERROR:
                    print(f"WebSocket connection closed with error: {ws.exception()}")
        finally:
            self._clients.remove(ws)
            
        return ws