import { render, screen, waitFor, within } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import App from '../App';
import { vi, describe, test, expect } from 'vitest';
import { installAppLifecycle, buildFetchMock, renderApp, loadChapter, addChunk, findChunkCounter } from './appHarness.jsx';

installAppLifecycle();

// ---------------------------------------------------------------------------
// Every page has a way back to the dashboard
// ---------------------------------------------------------------------------
describe('Back to the dashboard', () => {
  const home = /back to home|bible study home/i;
  const dashboard = async () => expect(await screen.findByText('My Studies')).toBeInTheDocument();

  test.each([
    ['the Reader', async (u) => { await u.click(screen.getByRole('button', { name: /read bible/i })); await screen.findByText(/Genesis 1 · BSB/); }],
    ['Reading Plans', async (u) => { await u.click(screen.getByRole('button', { name: /reading plans/i })); await screen.findByText(/browse plans/i); }],
    ['Import', async (u) => { await u.click(screen.getByRole('button', { name: /import session list/i })); await screen.findByRole('heading', { name: /import session list/i }); }],
  ])('%s', async (_name, open) => {
    const u = userEvent.setup();
    await renderApp();
    await open(u);
    // each page is lazy-loaded, so its app bar may take a moment to replace the loading skeleton
    await u.click(await screen.findByRole('button', { name: home }));
    await dashboard();
  });

  test.each(['Chunks', 'Study', 'Outline', 'Script', 'Finish'])('the %s stage of a study', async (stage) => {
    const u = await loadChapter();
    addChunk('Paul, a servant', 'In hope of eternal');
    await screen.findByText('1 created');
    await u.click(screen.getByRole('button', { name: new RegExp(`^${stage}$`, 'i') }));
    await screen.findByRole('navigation', { name: /study stages/i });
    await u.click(screen.getByRole('button', { name: home }));
    await dashboard();
  });

  test('the Pronunciation guide', async () => {
    const u = await loadChapter();
    addChunk('Paul, a servant', 'Paul, a servant');
    await screen.findByText('1 created');
    await u.click(screen.getByRole('button', { name: /^script$/i }));
    await u.click(await screen.findByRole('button', { name: /pronunciation guide/i }));
    await screen.findByRole('heading', { name: /pronunciation guide/i });
    await u.click(screen.getByRole('button', { name: home }));
    await dashboard();
  });
});

// ---------------------------------------------------------------------------
// The home page the user chooses
// ---------------------------------------------------------------------------
describe('Chosen home page', () => {
  const homeBtn = /back to home|bible study home/i;

  test('the app opens on the chosen page', async () => {
    localStorage.setItem('start-page', 'reader');
    render(<App />);
    expect(await screen.findByText(/Genesis 1 · BSB/)).toBeInTheDocument();
    expect(screen.queryByText('My Studies')).not.toBeInTheDocument();
  });

  test('by default the app opens on My Studies', async () => {
    await renderApp();
    expect(screen.getByText('My Studies')).toBeInTheDocument();
  });

  test('Home buttons go to the chosen page, and to My Studies when you are already on it', async () => {
    localStorage.setItem('start-page', 'reader');
    const u = userEvent.setup();
    render(<App />);
    await screen.findByText(/Genesis 1 · BSB/);
    // already on the chosen page: Home means My Studies
    await u.click(screen.getByRole('button', { name: homeBtn }));
    expect(await screen.findByText('My Studies')).toBeInTheDocument();
    // from another page, Home is the chosen page
    await u.click(screen.getByRole('button', { name: /reading plans/i }));
    await screen.findByRole('heading', { name: /^reading plans$/i });
    await u.click(screen.getByRole('button', { name: homeBtn }));
    expect(await screen.findByText(/Genesis 1 · BSB/)).toBeInTheDocument();
  });

  test('the logo on a page with an app bar goes to the chosen page, and Studies always goes to My Studies', async () => {
    localStorage.setItem('start-page', 'plans');
    const u = userEvent.setup();
    render(<App />);
    await screen.findByRole('heading', { name: /^reading plans$/i }); // opened on Reading Plans
    await u.click(screen.getByRole('button', { name: homeBtn })); // already there -> My Studies
    await screen.findByText('My Studies');
    await u.click(screen.getByRole('button', { name: /import session list/i }));
    await screen.findByRole('heading', { name: /import session list/i });
    await u.click(screen.getByRole('button', { name: /bible study home/i }));
    expect(await screen.findByRole('heading', { name: /^reading plans$/i })).toBeInTheDocument();
    await u.click(screen.getByRole('button', { name: homeBtn })); // -> My Studies again
    await u.click(screen.getByRole('button', { name: /import session list/i }));
    await u.click(screen.getByRole('button', { name: /^studies$/i }));
    expect(await screen.findByText('My Studies')).toBeInTheDocument();
  });

  test('leaving a study with a different home page closes the study', async () => {
    localStorage.setItem('start-page', 'plans');
    const u = userEvent.setup();
    render(<App />);
    await screen.findByRole('heading', { name: /^reading plans$/i });
    await u.click(screen.getByRole('button', { name: homeBtn })); // to My Studies
    await u.click(screen.getAllByRole('button', { name: /new project/i })[0]);
    await u.click(await screen.findByRole('button', { name: /load chapter/i }));
    await screen.findByText(/Scripture & Chunks/i);
    await u.click(screen.getByRole('button', { name: homeBtn }));
    expect(await screen.findByRole('heading', { name: /^reading plans$/i })).toBeInTheDocument();
  });

  test('Settings changes it, and it is saved for next time', async () => {
    const user = { id: 'u1', email: 'reader@example.com', totpEnabled: false, podcastName: null, isAdmin: false };
    const json = (status, data) => Promise.resolve({ ok: status < 400, status, json: () => Promise.resolve(data) });
    const fallback = buildFetchMock();
    vi.stubGlobal('fetch', vi.fn((url, opts = {}) => {
      if (!url.startsWith('/api/')) return fallback(url, opts);
      const route = `${opts.method ?? 'GET'} ${url}`;
      if (route === 'GET /api/auth/me') return json(200, user);
      if (route === 'GET /api/projects') return json(200, []);
      if (route === 'GET /api/reader/ink') return json(200, {});
      if (route === 'GET /api/reader/marks') return json(200, { bookmarks: {}, highlights: [], updatedAt: 0 });
      if (route === 'GET /api/prefs') return json(200, { prefs: {} });
      if (route === 'PUT /api/prefs') return json(200, { prefs: {} });
      return json(404, { error: 'not mocked' });
    }));
    const u = userEvent.setup();
    await renderApp();
    await u.click(await screen.findByRole('button', { name: /account menu/i }));
    await u.click(await screen.findByRole('menuitem', { name: /settings/i }));
    await u.click(await screen.findByRole('tab', { name: 'Preferences' }));
    const prefs = within(await screen.findByRole('region', { name: 'Preferences' }));
    await u.click(within(prefs.getByRole('group', { name: 'Home page' })).getByRole('button', { name: 'Reading Plans' }));
    expect(localStorage.getItem('start-page')).toBe('plans');
    await u.click(screen.getByRole('button', { name: homeBtn })); // Settings back -> the new home page
    expect(await screen.findByRole('heading', { name: /^reading plans$/i })).toBeInTheDocument();
  });
});

describe('Resizable study column', () => {
  async function openStudy() {
    const u = await loadChapter();
    addChunk('Paul, a servant', 'In hope of eternal');
    await screen.findByText('1 created');
    await u.click(screen.getByRole('button', { name: /begin studying/i }));
    await findChunkCounter(1, 1);
    return u;
  }
  const columns = () => screen.getByRole('separator', { name: /resize side panel/i }).closest('aside').parentElement;

  test('the handle widens and narrows the right column and the choice is remembered', async () => {
    const u = await openStudy();
    const handle = screen.getByRole('separator', { name: /resize side panel/i });
    expect(columns().style.getPropertyValue('--study-right')).toBe(''); // default width
    handle.focus();
    await u.keyboard('{ArrowLeft}');
    expect(columns().style.getPropertyValue('--study-right')).toBe('472px');
    expect(localStorage.getItem('study-right-width')).toBe('472');
    await u.keyboard('{Shift>}{ArrowRight}{/Shift}');
    expect(columns().style.getPropertyValue('--study-right')).toBe('376px');
  });

  test('double-clicking the handle restores the default width', async () => {
    const u = await openStudy();
    const handle = screen.getByRole('separator', { name: /resize side panel/i });
    handle.focus();
    await u.keyboard('{ArrowLeft}');
    await u.dblClick(handle);
    expect(localStorage.getItem('study-right-width')).toBeNull();
    expect(columns().style.getPropertyValue('--study-right')).toBe('');
  });

  test('a saved width is applied when the study opens', async () => {
    localStorage.setItem('study-right-width', '560');
    await openStudy();
    expect(columns().style.getPropertyValue('--study-right')).toBe('560px');
  });
});

describe('Import template', () => {
  test('the Import page offers a Word template to download', async () => {
    const user = userEvent.setup();
    await renderApp();
    await user.click(screen.getByRole('button', { name: /import session list/i }));
    await user.click(await screen.findByRole('button', { name: /download template/i }));
    await waitFor(() => expect(URL.createObjectURL).toHaveBeenCalled());
    const blob = URL.createObjectURL.mock.calls.at(-1)[0];
    expect(blob.type).toMatch(/wordprocessingml/);
    // and the button comes back to normal afterwards
    expect(await screen.findByRole('button', { name: /download template/i })).toBeEnabled();
  });
});

describe('System chrome follows the theme', () => {
  test('the app tells the browser/OS the theme colour and scheme, and updates it when the theme changes', async () => {
    localStorage.setItem('reader-theme', 'dark');
    const user = userEvent.setup();
    await renderApp();
    const themeColor = () => document.head.querySelector('meta[name="theme-color"]')?.getAttribute('content');
    expect(themeColor()).toBe('#262421');
    expect(document.documentElement.style.colorScheme).toBe('dark');
    await user.click(screen.getByRole('button', { name: /account menu/i }));
    await user.click(screen.getByRole('button', { name: /^paper$/i }));
    expect(themeColor()).toBe('#f1ece0');
    expect(document.documentElement.style.colorScheme).toBe('light');
  });
});

describe('New pages start at the top', () => {
  test('moving to another page resets the scroll position', async () => {
    const user = userEvent.setup();
    await renderApp();
    const scroller = document.scrollingElement ?? document.documentElement;
    scroller.scrollTop = 480; // scrolled down on the dashboard
    await user.click(screen.getByRole('button', { name: /reading plans/i }));
    await screen.findByRole('heading', { name: /^reading plans$/i });
    expect(scroller.scrollTop).toBe(0);
    scroller.scrollTop = 300;
    await user.click(screen.getByRole('button', { name: /back to home|bible study home/i }));
    await screen.findByText('My Studies');
    expect(scroller.scrollTop).toBe(0);
  });
});