import json

from fastapi import WebSocket


class ConnectionManager:
    """Manages active WebSocket connections keyed by BLE token."""

    def __init__(self) -> None:
        self._connections: dict[str, WebSocket] = {}

    async def connect(self, token: str, websocket: WebSocket) -> None:
        await websocket.accept()
        self._connections[token] = websocket

    def disconnect(self, token: str) -> None:
        self._connections.pop(token, None)

    async def send(self, token: str, message: dict) -> None:
        websocket = self._connections.get(token)
        if websocket is not None:
            await websocket.send_text(json.dumps(message))


manager = ConnectionManager()