import asyncio

import pytest

from app.rounds.events import RoundEventBroadcaster, RoundEventCapacityError


async def test_publish_wakes_up_subscriber():
    broadcaster = RoundEventBroadcaster()
    queue = broadcaster.subscribe()

    broadcaster.publish()

    await asyncio.wait_for(queue.get(), timeout=1)


async def test_publish_with_no_subscribers_does_not_raise():
    broadcaster = RoundEventBroadcaster()
    broadcaster.publish()  # no subscribers yet — must be a no-op, not an error


async def test_publish_coalesces_when_subscriber_has_not_drained():
    """The queue is maxsize=1: a second publish() before the subscriber reads
    the first notification must not block or raise — it's fine to drop it,
    since the subscriber will refetch full state anyway on the first one."""
    broadcaster = RoundEventBroadcaster()
    queue = broadcaster.subscribe()

    broadcaster.publish()
    broadcaster.publish()  # would raise QueueFull if not guarded

    assert queue.qsize() == 1


async def test_unsubscribe_stops_delivery():
    broadcaster = RoundEventBroadcaster()
    queue = broadcaster.subscribe()
    broadcaster.unsubscribe(queue)

    broadcaster.publish()

    assert queue.empty()


async def test_subscribe_rejects_past_the_cap():
    broadcaster = RoundEventBroadcaster(max_subscribers=3)
    for _ in range(3):
        broadcaster.subscribe()

    with pytest.raises(RoundEventCapacityError):
        broadcaster.subscribe()


async def test_unsubscribe_frees_a_capacity_slot():
    broadcaster = RoundEventBroadcaster(max_subscribers=1)
    queue = broadcaster.subscribe()

    with pytest.raises(RoundEventCapacityError):
        broadcaster.subscribe()

    broadcaster.unsubscribe(queue)
    broadcaster.subscribe()  # no longer at capacity