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

from .util import wrap_async
from ..web_agent import WebAgent

class ContextWebSocket:
    """
    WebSocket handler for context changes.
    Broadcasts context updates to all connected clients.
    """
    
    def __init__(self, agent: WebAgent):
        self._agent = agent
        self._clients: Set[web.WebSocketResponse] = set()
        self._agent.add_context_change_handler(wrap_async(self._handle_context_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_context_change(self, context: str, generated: bool):
        """Handle context changes from the WebAgent."""
        await self._broadcast_message({
            "context": context,
            "generated": generated
        })

    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 context
            await ws.send_json({
                "context": self._agent.context,
                "generated": True
            })
                
            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