import { mount, type VueWrapper } from '@vue/test-utils';
import { nextTick } from 'vue';
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import HeartParticles from '../components/viewer/HeartParticles.vue';
import { setReducedMotion } from '../ui/prefs';

// UI-02 V05 HeartParticles 单测（§6.2/§6.3）：burst 生成粒子上限 12（超限弃
// 最旧）、动画时长后自清理、页面隐藏即清空、「减少动画」时不生成/开启即清空。
// 粒子为纯装饰层（aria-hidden + pointer-events:none）。

const mounted: VueWrapper[] = [];

interface ParticlesExposed {
  burst: (count: number) => void;
}

function mountParticles(): VueWrapper & { vm: ParticlesExposed } {
  const wrapper = mount(HeartParticles);
  mounted.push(wrapper);
  return wrapper as VueWrapper & { vm: ParticlesExposed };
}

function setHidden(hidden: boolean): void {
  Object.defineProperty(document, 'hidden', { value: hidden, configurable: true });
  document.dispatchEvent(new Event('visibilitychange'));
}

describe('heart particles (UI-02 V05)', () => {
  beforeEach(() => {
    localStorage.clear();
    setReducedMotion(false);
    vi.useFakeTimers();
  });

  afterEach(() => {
    while (mounted.length > 0) mounted.pop()?.unmount();
    vi.useRealTimers();
    setReducedMotion(false);
    setHidden(false);
  });

  it('creates particles on burst and removes them after the float animation', async () => {
    const wrapper = mountParticles();

    wrapper.vm.burst(3);
    await nextTick();
    expect(wrapper.findAll('.heart-particles-zone .particle')).toHaveLength(3);

    // 动画时长上限 1.8s + 收尾缓冲：之后自清理（不留冻结的过期粒子）。
    await vi.advanceTimersByTimeAsync(2000);
    expect(wrapper.findAll('.particle')).toHaveLength(0);
  });

  it('caps concurrent particles at 12, dropping the oldest', async () => {
    const wrapper = mountParticles();

    wrapper.vm.burst(10);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(10);

    wrapper.vm.burst(5);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(12);
  });

  it('clears particles and timers when the page becomes hidden', async () => {
    const wrapper = mountParticles();

    wrapper.vm.burst(6);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(6);

    setHidden(true);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(0);

    // 隐藏期间清理的计时器不再复活（§6.3 不回放）。
    await vi.advanceTimersByTimeAsync(2000);
    expect(wrapper.findAll('.particle')).toHaveLength(0);
  });

  it('does not render particles under reduced motion, and clears in-flight ones when it turns on', async () => {
    const wrapper = mountParticles();

    setReducedMotion(true);
    wrapper.vm.burst(4);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(0); // 不漂浮（§6.3）

    setReducedMotion(false);
    wrapper.vm.burst(2);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(2);

    // 漂浮中途开启「减少动画」：在屏粒子立即清空（不残留冻结心形）。
    setReducedMotion(true);
    await nextTick();
    expect(wrapper.findAll('.particle')).toHaveLength(0);
  });
});