"""Tests for app/queue.py — Job queue with single-worker processing (#95)."""
import asyncio
import pytest
from app.queue import (
    enqueue,
    get_queue_status,
    QueueFullError,
    _queue,
    _stats,
)


@pytest.fixture(autouse=True)
def clean_queue():
    """Drain the queue before each test."""
    while not _queue.empty():
        try:
            _queue.get_nowait()
        except asyncio.QueueEmpty:
            break
    _stats["processed"] = 0
    _stats["failed"] = 0
    yield


class TestEnqueue:
    @pytest.mark.asyncio
    async def test_enqueue_returns_position(self):
        async def noop():
            pass
        pos = await enqueue("j1", noop)
        assert pos == 1

    @pytest.mark.asyncio
    async def test_enqueue_increments_position(self):
        async def noop():
            pass
        await enqueue("j1", noop)
        pos2 = await enqueue("j2", noop)
        assert pos2 == 2

    @pytest.mark.asyncio
    async def test_queue_full_raises(self):
        async def noop():
            pass
        # Fill queue to capacity
        for i in range(50):
            await enqueue(f"fill-{i}", noop)
        with pytest.raises(QueueFullError):
            await enqueue("overflow", noop)


class TestGetQueueStatus:
    def test_empty_queue_status(self):
        status = get_queue_status()
        assert status["pending"] == 0
        assert status["max_size"] == 50
        assert status["estimated_wait_seconds"] == 0

    @pytest.mark.asyncio
    async def test_status_reflects_pending(self):
        async def noop():
            pass
        await enqueue("j1", noop)
        await enqueue("j2", noop)
        status = get_queue_status()
        assert status["pending"] == 2
        assert status["estimated_wait_seconds"] > 0