"""WS-Hub (R1): EINE Queue + EIN Sender-Task — Broadcasts bleiben geordnet.
Payload ist nur ein dirty-Signal {typ, topic, bereich}; der Client lädt selbst."""
import asyncio
import json


class Hub:
    def __init__(self) -> None:
        self._clients: set = set()
        self._queue: asyncio.Queue | None = None
        self._loop: asyncio.AbstractEventLoop | None = None

    def bind_loop(self, loop: asyncio.AbstractEventLoop) -> None:
        self._loop = loop
        self._queue = asyncio.Queue()
        loop.create_task(self._sende_schleife())

    def push(self, tabelle: str, row: dict) -> None:
        """Thread-sicher aus der DB-Schicht aufrufbar."""
        if self._loop is None or self._queue is None:
            return
        bereich = {"tasks": "graph", "gate_laeufe": "graph", "befunde": "graph",
                   "runs": "run", "topics": "run"}.get(tabelle, "graph")
        msg = json.dumps({"typ": "dirty", "bereich": bereich}, ensure_ascii=False)
        self._loop.call_soon_threadsafe(self._queue.put_nowait, msg)

    async def _sende_schleife(self) -> None:
        while True:
            msg = await self._queue.get()
            tot = []
            for ws in list(self._clients):
                try:
                    await ws.send_text(msg)
                except Exception:
                    tot.append(ws)
            for ws in tot:
                self._clients.discard(ws)

    def connect(self, ws) -> None:
        self._clients.add(ws)

    def disconnect(self, ws) -> None:
        self._clients.discard(ws)


hub = Hub()