import { describe, expect, test } from 'bun:test';
import { createWarmQueue } from './warm-queue.js';

describe('stream warm queue', () => {
  test('runs at the concurrency limit and drains queued requests FIFO', async () => {
    const started = [];
    const releases = new Map();
    const q = createWarmQueue({ concurrency: 2, maxQueued: 2, run: (id) => {
      started.push(id);
      return new Promise((resolve) => releases.set(id, resolve));
    } });

    q.enqueue('a'); q.enqueue('b'); q.enqueue('c');
    expect(q.pending).toBe(3);
    await Promise.resolve();
    expect(started).toEqual(['a', 'b']);
    releases.get('a')();
    await new Promise((resolve) => setTimeout(resolve, 0));
    expect(started).toEqual(['a', 'b', 'c']);
    releases.get('b')(); releases.get('c')();
    await new Promise((resolve) => setTimeout(resolve, 0));
    expect(q.pending).toBe(0);
  });

  test('deduplicates in-flight ids and rejects work past the queue bound', async () => {
    const releases = [];
    const q = createWarmQueue({ concurrency: 1, maxQueued: 1, run: () => new Promise((resolve) => releases.push(resolve)) });
    expect(q.enqueue('a')).toBe(true);
    await Promise.resolve();
    expect(q.enqueue('a')).toBe(true);
    expect(q.enqueue('b')).toBe(true);
    expect(q.enqueue('c')).toBe(false);
    releases[0]();
    await new Promise((resolve) => setTimeout(resolve, 0));
    releases[1]();
    await new Promise((resolve) => setTimeout(resolve, 0));
    expect(q.pending).toBe(0);
  });
});