import { flushPromises, mount, type VueWrapper } from '@vue/test-utils';
import { defineComponent, nextTick, ref } from 'vue';
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import {
  ApiError,
  getPhotoDownload,
  getPublicPhotos,
  type PublicAlbum,
  type PublicPhoto,
  type PublicPhotoDownload,
  type PublicPhotoList,
} from '../api/client';
import { createViewerI18n, type ViewerI18n } from '../i18n';
import PhotoLightbox from '../components/PhotoLightbox.vue';
import { usePhotoSequence } from '../feed/sequence';
import {
  isExpired,
  isWechatWebview,
  useDownload,
  type DownloadController,
} from '../download/useDownload';
import { makeAlbum } from './fixtures';

// P4a Task 4 下载（T12 收口）：开关→入口可见性矩阵、分体菜单选项、微信 UA
// 判定与引导浮层、过期凭证重取一次、失败提示、复制深链。

vi.mock('../api/client', async (importOriginal) => {
  const actual = await importOriginal<typeof import('../api/client')>();
  return {
    ...actual,
    getPublicPhotos: vi.fn(),
    getPublicPhoto: vi.fn(),
    getPhotoDownload: vi.fn(),
  };
});

const mockedGetPublicPhotos = vi.mocked(getPublicPhotos);
const mockedGetPhotoDownload = vi.mocked(getPhotoDownload);

const WECHAT_IOS_UA =
  'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 MicroMessenger/8.0.49(0x18003133) NetType/WIFI Language/zh_CN';
const WECHAT_ANDROID_UA =
  'Mozilla/5.0 (Linux; Android 14; Pixel 8) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/122.0.0.0 Mobile Safari/537.36 MicroMessenger/8.0.49.2500(0x28004935)';
const WECHAT_WINDOWS_UA =
  'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 MicroMessenger/7.0.20.1781(0x670c0123) WindowsWechat(0x63090a13)';
const PLAIN_IOS_SAFARI_UA =
  'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1';
const DESKTOP_CHROME_UA =
  'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36';

function makePhoto(id: string): PublicPhoto {
  return {
    photoId: id,
    width: 800,
    height: 500,
    thumb: { url: `http://img.test/${id}-thumb.jpg?s=1`, expiresAt: '2026-10-01T00:00:00.000Z' },
    browse: { url: `http://img.test/${id}-browse.jpg?s=1`, expiresAt: '2026-10-01T00:00:00.000Z' },
    likeCount: 0,
    publishedAt: '2026-10-01T00:00:00.000Z',
  };
}

function makeList(items: PublicPhoto[]): PublicPhotoList {
  return { items, nextCursor: null, hasMore: false };
}

function credential(url: string, expiresAt: string, variant: 'browse' | 'original'): PublicPhotoDownload {
  return { url, expiresAt, variant };
}

const FUTURE = new Date(Date.now() + 14 * 60_000).toISOString();
const PAST = new Date(Date.now() - 60_000).toISOString();

function stubUserAgent(ua: string): void {
  Object.defineProperty(window.navigator, 'userAgent', { value: ua, configurable: true });
}

function restoreUserAgent(): void {
  // 删除实例自有属性，回落原型 getter（jsdom 原始 UA）。
  delete (window.navigator as { userAgent?: string }).userAgent;
}

let i18n: ViewerI18n;
const mounted: VueWrapper[] = [];

/** window.open 桩（记录调用即可）：经工厂推导 spy 类型，绕开 spyOn 泛型约束。 */
function spyWindowOpen() {
  return vi.spyOn(window, 'open').mockReturnValue({} as Window);
}
let openSpy: ReturnType<typeof spyWindowOpen>;

/** 宿主实例形态：setup 暴露 albumRef/currentRef（ref 经代理解包）+ download 控制器。 */
interface HostVm {
  albumRef: PublicAlbum | null;
  currentRef: string;
  download: DownloadController;
}

/** 宿主：sequence + 相册 ref + 下载控制器 + lightbox（镜像 ActivityPage 组装）。 */
function mountLightbox(album: PublicAlbum): VueWrapper & { vm: HostVm } {
  const Host = defineComponent({
    components: { PhotoLightbox },
    setup() {
      const sequence = usePhotoSequence({
        token: ref('tok-dl'),
        locale: ref('zh-CN'),
        category: ref(null),
      });
      const albumRef = ref<PublicAlbum | null>(album);
      const current = ref('p1');
      const download = useDownload({
        token: ref('tok-dl'),
        album: () => albumRef.value,
        photoId: () => current.value,
      });
      return { sequence, photoId: current, currentRef: current, download, albumRef };
    },
    template: `<PhotoLightbox v-model:photo-id="photoId" :sequence="sequence" :download="download" />`,
  });
  const wrapper = mount(Host, { global: { plugins: [i18n] } });
  mounted.push(wrapper);
  return wrapper as VueWrapper & { vm: HostVm };
}

describe('photo download (P4a Task 4)', () => {
  beforeEach(() => {
    localStorage.clear();
    i18n = createViewerI18n('zh-CN');
    mockedGetPublicPhotos.mockReset().mockResolvedValue(makeList([makePhoto('p1'), makePhoto('p2')]));
    mockedGetPhotoDownload.mockReset();
    openSpy = spyWindowOpen();
  });

  afterEach(() => {
    while (mounted.length > 0) {
      mounted.pop()?.unmount();
    }
    restoreUserAgent();
    vi.restoreAllMocks();
  });

  it('detects WeChat webview UAs (iOS/Android/Windows) and passes others', () => {
    for (const ua of [WECHAT_IOS_UA, WECHAT_ANDROID_UA, WECHAT_WINDOWS_UA]) {
      expect(isWechatWebview(ua)).toBe(true);
    }
    for (const ua of [PLAIN_IOS_SAFARI_UA, DESKTOP_CHROME_UA, '']) {
      expect(isWechatWebview(ua)).toBe(false);
    }
  });

  it('treats expiresAt at-or-before now as expired', () => {
    expect(isExpired(PAST)).toBe(true);
    expect(isExpired(new Date().toISOString())).toBe(true);
    expect(isExpired(FUTURE)).toBe(false);
    expect(isExpired('not-a-date')).toBe(false); // 非法时间戳不误判过期
  });

  it('controller model: switch matrix incl. off/on cascade (original implies browse)', async () => {
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();
    const controller = wrapper.vm.download;

    // on/off（夹具缺省）。
    expect(controller.canDownload).toBe(true);
    expect(controller.canDownloadOriginal).toBe(false);

    const cases: Array<[boolean, boolean, boolean, boolean]> = [
      // [downloadEnabled, originalDownloadEnabled, canDownload, canDownloadOriginal]
      [true, true, true, true],
      [true, false, true, false],
      [false, false, false, false],
      [false, true, false, false], // 级联：browse 关则 original 项不出现
    ];
    for (const [downloadEnabled, originalDownloadEnabled, can, canOriginal] of cases) {
      wrapper.vm.albumRef = makeAlbum({ downloadEnabled, originalDownloadEnabled });
      await flushPromises();
      expect(controller.canDownload).toBe(can);
      expect(controller.canDownloadOriginal).toBe(canOriginal);
    }
  });

  it('toolbar visibility: off/on → no entry; on/off → single button; on/on → split', async () => {
    // off/off：无下载入口。
    const off = mountLightbox(makeAlbum({ downloadEnabled: false, originalDownloadEnabled: false }));
    await flushPromises();
    expect(off.find('.download-group').exists()).toBe(false);

    // on/off：单按钮，无 caret/菜单。
    const browseOnly = mountLightbox(makeAlbum());
    await flushPromises();
    expect(browseOnly.find('.download-main').exists()).toBe(true);
    expect(browseOnly.find('.download-caret').exists()).toBe(false);

    // on/on：分体按钮（caret 出现，菜单默认收起）。
    const split = mountLightbox(makeAlbum({ originalDownloadEnabled: true }));
    await flushPromises();
    expect(split.find('.download-caret').exists()).toBe(true);
    expect(split.find('.download-menu').exists()).toBe(false);
    // 主按钮 aria 展开 = false。
    expect(split.find('.download-caret').attributes('aria-expanded')).toBe('false');
  });

  it('split menu offers both variants; picking original requests the original endpoint', async () => {
    mockedGetPhotoDownload.mockResolvedValue(credential('http://img.test/p1-original.jpg', FUTURE, 'original'));
    const wrapper = mountLightbox(makeAlbum({ originalDownloadEnabled: true }));
    await flushPromises();

    await wrapper.find('.download-caret').trigger('click');
    const items = wrapper.findAll('.download-menu button');
    expect(items.map((item) => item.text())).toEqual(['浏览图', '原图']);

    await items[1]!.trigger('click');
    await flushPromises();
    expect(mockedGetPhotoDownload).toHaveBeenCalledWith('tok-dl', 'p1', 'original');
    expect(openSpy).toHaveBeenCalledWith('http://img.test/p1-original.jpg', '_blank', 'noopener,noreferrer');
    // 选择后菜单收起。
    expect(wrapper.find('.download-menu').exists()).toBe(false);
  });

  it('main button downloads browse; expired credential is re-requested exactly once', async () => {
    // 首响应已过期（缓存/时钟漂移）→ 重取一次 → 打开第二个 URL。
    mockedGetPhotoDownload
      .mockResolvedValueOnce(credential('http://img.test/p1-browse-stale.jpg', PAST, 'browse'))
      .mockResolvedValueOnce(credential('http://img.test/p1-browse-fresh.jpg', FUTURE, 'browse'));
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click');
    await flushPromises();
    expect(mockedGetPhotoDownload).toHaveBeenCalledTimes(2);
    expect(mockedGetPhotoDownload).toHaveBeenCalledWith('tok-dl', 'p1', 'browse');
    expect(openSpy).toHaveBeenCalledWith('http://img.test/p1-browse-fresh.jpg', '_blank', 'noopener,noreferrer');
  });

  it('fresh credential opens directly without a second request; failure shows a retryable notice', async () => {
    mockedGetPhotoDownload.mockResolvedValue(credential('http://img.test/p1-browse.jpg', FUTURE, 'browse'));
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click');
    await flushPromises();
    expect(mockedGetPhotoDownload).toHaveBeenCalledTimes(1);
    expect(openSpy).toHaveBeenCalledWith('http://img.test/p1-browse.jpg', '_blank', 'noopener,noreferrer');
    expect(wrapper.find('.download-failed').exists()).toBe(false);

    // 端点失败（网络/403 等）→ 失败提示可再见（再次点击重试）。
    openSpy.mockClear();
    mockedGetPhotoDownload.mockReset().mockRejectedValue(new Error('boom'));
    await wrapper.find('.download-main').trigger('click');
    await flushPromises();
    expect(wrapper.find('.download-failed[role="alert"]').text()).toContain('下载失败');
    expect(openSpy).not.toHaveBeenCalled();
  });

  it('attributes an async failure to the photo that triggered the download, not the current one', async () => {
    // 在途请求挂起期间切图：错误归属触发时的 photoId（UI-02 §5.4）。
    let rejectDownload!: (error: Error) => void;
    mockedGetPhotoDownload.mockReset().mockImplementation(
      () =>
        new Promise((_resolve, reject) => {
          rejectDownload = reject;
        }),
    );
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click'); // p1 触发
    wrapper.vm.currentRef = 'p2'; // 请求在途时切到 p2
    rejectDownload(new Error('boom'));
    await flushPromises();

    expect(wrapper.vm.download.failedFor).toBe('p1');
    expect(wrapper.find('.download-failed').exists()).toBe(false); // p2 不背锅

    wrapper.vm.currentRef = 'p1'; // 切回 p1：错误提示可见
    await nextTick();
    expect(wrapper.find('.download-failed[role="alert"]').text()).toContain('下载失败');
  });

  it('DOWNLOAD_DISABLED surfaces the dedicated localized notice (T15 漏译修复)', async () => {
    // 相册中途关闭下载开关（载荷仍开但端点 403）→ 专属文案而非通用失败。
    mockedGetPhotoDownload.mockReset().mockRejectedValue(
      new ApiError('DOWNLOAD_DISABLED', 'downloads disabled', 403, null),
    );
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click');
    await flushPromises();
    expect(wrapper.find('.download-failed[role="alert"]').text()).toContain('该相册未开放下载');
    expect(wrapper.find('.download-failed').text()).not.toContain('下载失败');
  });

  it('WeChat webview: click opens the guidance overlay instead of hitting the endpoint', async () => {
    stubUserAgent(WECHAT_IOS_UA);
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click');
    await flushPromises();
    expect(wrapper.find('.wechat-guide[role="dialog"]').exists()).toBe(true);
    expect(wrapper.find('.wechat-guide h2').text()).toBe('保存图片指引');
    expect(mockedGetPhotoDownload).not.toHaveBeenCalled();
    expect(openSpy).not.toHaveBeenCalled();

    // 知道了：浮层收起（再点击可重新触发）。
    await wrapper.find('.guide-dismiss').trigger('click');
    expect(wrapper.find('.wechat-guide').exists()).toBe(false);
  });

  it('guidance copy link writes the current photo deep link with feedback', async () => {
    stubUserAgent(WECHAT_IOS_UA);
    const writeText = vi.fn().mockResolvedValue(undefined);
    Object.defineProperty(window.navigator, 'clipboard', { value: { writeText }, configurable: true });
    const wrapper = mountLightbox(makeAlbum());
    await flushPromises();

    await wrapper.find('.download-main').trigger('click');
    await wrapper.find('.guide-copy').trigger('click');
    await flushPromises();
    expect(writeText).toHaveBeenCalledWith(window.location.href);
    expect(wrapper.find('.copy-status').text()).toBe('已复制链接');
  });
});