import { test, expect, Page } from '@playwright/test';

// Relative luminance per WCAG, used to tell "light" from "dark" without
// asserting exact hex values, which would break on any palette tweak.
function luminance(rgb: string): number {
  const [r, g, b] = (rgb.match(/\d+(\.\d+)?/g) ?? ['0', '0', '0']).slice(0, 3).map(Number);
  const channel = (c: number) => {
    const s = c / 255;
    return s <= 0.03928 ? s / 12.92 : Math.pow((s + 0.055) / 1.055, 2.4);
  };
  return 0.2126 * channel(r) + 0.7152 * channel(g) + 0.0722 * channel(b);
}

const suffix = () => `t${Date.now().toString(36)}${Math.random().toString(36).slice(2, 7)}`;

// The Categories and Tags tabs render an empty state when there is nothing to
// show, and the shared dev database gets truncated by the backend integration
// suite. Seed what each test needs rather than depending on what happens to be
// there.
async function seed(page: Page) {
  const run = suffix();
  await page.request.post('/api/admin/categories', { data: { name: `Theme ${run}`, parent_id: null } });
  await page.request.post('/api/admin/tags', { data: { name: `theme-${run}` } });
}

async function switchToDark(page: Page) {
  await page.goto('/admin');
  const toggle = page.getByRole('switch');
  if ((await toggle.getAttribute('aria-checked')) !== 'true') {
    await toggle.click();
  }
  await expect(page.locator('body')).toHaveAttribute('data-theme', 'dark');
}

test.describe('Admin dark mode', () => {
  test('the active tab label is readable against the dark background', async ({ page }) => {
    await switchToDark(page);

    const label = page.locator('.ant-tabs-tab-active .ant-tabs-tab-btn').first();

    // The bug: colorPrimary stayed #1a1a1a in dark mode, so the active tab was
    // near-black text on a near-black background.
    await expect
      .poll(async () => luminance(await label.evaluate((el) => getComputedStyle(el).color)))
      .toBeGreaterThan(0.5);
  });

  test('the Categories tab follows the dark theme', async ({ page }) => {
    await seed(page);
    await switchToDark(page);
    await page.getByRole('tab', { name: 'Categories' }).click();

    const tree = page.locator('.ant-tabs-tabpane-active .ant-tree').first();
    await expect(tree).toBeVisible();
    const bg = await tree.evaluate((el) => getComputedStyle(el).backgroundColor);

    // The bug: deep imports from antd/lib loaded a second copy of antd that
    // never saw ConfigProvider, so this rendered pure white in dark mode.
    expect(luminance(bg)).toBeLessThan(0.5);
  });

  test('the Tags tab follows the dark theme', async ({ page }) => {
    await seed(page);
    await switchToDark(page);
    await page.getByRole('tab', { name: 'Tags' }).click();

    const table = page.locator('.ant-tabs-tabpane-active .ant-table').first();
    await expect(table).toBeVisible();
    const bg = await table.evaluate((el) => getComputedStyle(el).backgroundColor);
    expect(luminance(bg)).toBeLessThan(0.5);
  });

  test('the item form category selector follows the dark theme', async ({ page }) => {
    await switchToDark(page);
    await page.getByRole('button', { name: 'Add Item' }).click();
    await page.getByRole('dialog').getByLabel('Category', { exact: true }).click();

    const popup = page.locator('.ant-select-dropdown').first();
    await expect(popup).toBeVisible();
    const bg = await popup.evaluate((el) => getComputedStyle(el).backgroundColor);
    expect(luminance(bg)).toBeLessThan(0.5);
  });
});

test.describe('Admin copy', () => {
  test('uses American English spelling for color', async ({ page }) => {
    await seed(page);
    await page.goto('/admin');
    await page.getByRole('tab', { name: 'Tags' }).click();

    await expect(page.getByRole('columnheader', { name: 'Color' })).toBeVisible();
    await expect(page.getByText('Colour')).toHaveCount(0);
  });
});