import { describe, expect, it, vi } from 'vitest';

import type { DownloadSpec } from '../src/shared/protocol/index.js';
import {
  ContextMenus,
  GRAB_TAB_COMMAND,
  LINK_MENU_ID,
  MEDIA_MENU_ID,
  type ContextMenusDeps,
} from '../src/background/context-menus.js';

class Event<A extends unknown[]> {
  fns: Array<(...a: A) => void> = [];
  addListener = (f: (...a: A) => void): void => void this.fns.push(f);
  removeListener = (f: (...a: A) => void): void => {
    this.fns = this.fns.filter((x) => x !== f);
  };
  emit(...a: A): void {
    for (const f of this.fns) f(...a);
  }
}

function harness(over: Partial<ContextMenusDeps> = {}) {
  const created: Array<{ id: string; contexts: string[] }> = [];
  const onClicked = new Event<[{ menuItemId: string | number; linkUrl?: string; srcUrl?: string; pageUrl?: string }, unknown]>();
  const onCommand = new Event<[string, unknown]>();
  const menus = {
    create: (p: { id: string; title: string; contexts: string[] }) => void created.push({ id: p.id, contexts: p.contexts }),
    removeAll: vi.fn(async () => undefined),
    onClicked,
  };
  const addDownload = vi.fn(async (_spec: DownloadSpec) => ({ taskId: 't' }));
  const tabs = { query: vi.fn(async () => [{ url: 'https://example.com/watch' }]) };
  const onError = vi.fn();
  const deps: ContextMenusDeps = {
    addDownload: addDownload as unknown as ContextMenusDeps['addDownload'],
    menus: menus as unknown as ContextMenusDeps['menus'],
    tabs: tabs as unknown as ContextMenusDeps['tabs'],
    commands: { onCommand } as unknown as ContextMenusDeps['commands'],
    onError,
    ...over,
  };
  return { cm: new ContextMenus(deps), created, onClicked, onCommand, addDownload, tabs, onError, menus };
}

describe('ContextMenus', () => {
  it('registers a link item and a media item after clearing stale ones', async () => {
    const { cm, created, menus } = harness();
    await cm.register();
    expect(menus.removeAll).toHaveBeenCalled();
    expect(created).toEqual([
      { id: LINK_MENU_ID, contexts: ['link'] },
      { id: MEDIA_MENU_ID, contexts: ['image', 'video', 'audio'] },
    ]);
  });

  it('a link click sends linkUrl + pageUrl referrer to download.add', async () => {
    const { cm, onClicked, addDownload } = harness();
    await cm.register();
    onClicked.emit(
      { menuItemId: LINK_MENU_ID, linkUrl: 'https://cdn.example.com/a.zip', pageUrl: 'https://example.com/p' },
      undefined,
    );
    await Promise.resolve();
    expect(addDownload).toHaveBeenCalledWith({
      url: 'https://cdn.example.com/a.zip',
      referrer: 'https://example.com/p',
    } satisfies DownloadSpec);
  });

  it('a media click uses srcUrl', async () => {
    const { cm, onClicked, addDownload } = harness();
    await cm.register();
    onClicked.emit({ menuItemId: MEDIA_MENU_ID, srcUrl: 'https://v.example.com/clip.mp4', pageUrl: 'https://v.example.com' }, undefined);
    await Promise.resolve();
    expect(addDownload.mock.calls[0]![0].url).toBe('https://v.example.com/clip.mp4');
  });

  it('ignores a click on some other extension menu item', async () => {
    const { cm, onClicked, addDownload } = harness();
    await cm.register();
    onClicked.emit({ menuItemId: 'someone-elses-item', linkUrl: 'https://x/a.zip' }, undefined);
    await Promise.resolve();
    expect(addDownload).not.toHaveBeenCalled();
  });

  it('rejects a non-http link with a user-facing error, no download', async () => {
    const { cm, onClicked, addDownload, onError } = harness();
    await cm.register();
    onClicked.emit({ menuItemId: LINK_MENU_ID, linkUrl: 'ftp://legacy/a.zip' }, undefined);
    await Promise.resolve();
    expect(addDownload).not.toHaveBeenCalled();
    expect(onError).toHaveBeenCalledWith(expect.stringMatching(/http/));
  });

  it('the grab-tab command downloads the active tab URL', async () => {
    const { cm, onCommand, addDownload, tabs } = harness();
    await cm.register();
    onCommand.emit(GRAB_TAB_COMMAND, undefined);
    await Promise.resolve();
    await Promise.resolve();
    expect(tabs.query).toHaveBeenCalled();
    expect(addDownload.mock.calls[0]![0].url).toBe('https://example.com/watch');
  });

  it('the grab-tab command prefers the tab handed to the listener', async () => {
    const { cm, onCommand, addDownload, tabs } = harness();
    await cm.register();
    onCommand.emit(GRAB_TAB_COMMAND, { url: 'https://direct.example/page' });
    await Promise.resolve();
    expect(tabs.query).not.toHaveBeenCalled();
    expect(addDownload.mock.calls[0]![0].url).toBe('https://direct.example/page');
  });

  it('surfaces a download.add failure through onError', async () => {
    const { cm, onClicked, onError } = harness({
      addDownload: vi.fn().mockRejectedValue(new Error('daemon down')) as unknown as ContextMenusDeps['addDownload'],
    });
    await cm.register();
    onClicked.emit({ menuItemId: LINK_MENU_ID, linkUrl: 'https://x/a.zip' }, undefined);
    await Promise.resolve();
    await Promise.resolve();
    expect(onError).toHaveBeenCalledWith(expect.stringMatching(/daemon down/));
  });

  it('dispose() detaches listeners', async () => {
    const { cm, onClicked, addDownload } = harness();
    await cm.register();
    cm.dispose();
    onClicked.emit({ menuItemId: LINK_MENU_ID, linkUrl: 'https://x/a.zip' }, undefined);
    await Promise.resolve();
    expect(addDownload).not.toHaveBeenCalled();
  });
});