import asyncio
from typing import Dict, Optional
from fastapi import WebSocket


class ConnectionManager:
    def __init__(self):
        self.connections: Dict[str, WebSocket] = {}
        self.lock = asyncio.Lock()

    async def add_connection(self, device_id: str, websocket: WebSocket):
        async with self.lock:
            self.connections[device_id] = websocket

    async def remove_connection(self, device_id: str):
        async with self.lock:
            if device_id in self.connections:
                del self.connections[device_id]

    async def get_connection(self, device_id: str) -> Optional[WebSocket]:
        async with self.lock:
            return self.connections.get(device_id)

    async def get_all_connections(self) -> Dict[str, WebSocket]:
        async with self.lock:
            return dict(self.connections)


connection_manager = ConnectionManager()