import asyncio
import json
from datetime import datetime, timezone
from typing import Optional

_sse_queues: list[asyncio.Queue] = []


def subscribe_sse() -> asyncio.Queue:
    q: asyncio.Queue = asyncio.Queue(maxsize=200)
    _sse_queues.append(q)
    return q


def unsubscribe_sse(q: asyncio.Queue) -> None:
    try:
        _sse_queues.remove(q)
    except ValueError:
        pass


def emit_log(
    level: str,
    message: str,
    *,
    replica: str | None = None,
    replica_id: int | None = None,
    doc_id: int | None = None,
    run_id: int | None = None,
    session=None,
) -> Optional[int]:
    """Write to stdout JSON, optionally persist to DB and broadcast over SSE."""
    ts = datetime.now(timezone.utc).isoformat()
    stdout_payload: dict = {"ts": ts, "level": level, "msg": message}
    if replica:
        stdout_payload["replica"] = replica
    if doc_id is not None:
        stdout_payload["doc_id"] = doc_id
    print(json.dumps(stdout_payload), flush=True)

    log_id: Optional[int] = None
    if session is not None:
        from .models import Log

        log = Log(
            run_id=run_id,
            replica_id=replica_id,
            level=level,
            message=message,
            doc_id=doc_id,
        )
        session.add(log)
        session.commit()
        session.refresh(log)
        log_id = log.id

        sse_data = json.dumps(
            {
                "id": log_id,
                "ts": ts,
                "level": level,
                "message": message,
                "replica_id": replica_id,
                "doc_id": doc_id,
            }
        )
        for q in list(_sse_queues):
            try:
                q.put_nowait(sse_data)
            except asyncio.QueueFull:
                pass

    return log_id