import AxeBuilder from '@axe-core/playwright';
import { expect, test, type Page } from '@playwright/test';

import { contextForUser } from './helpers';

/**
 * Akzent-Theming (issue #184, ADR 0018 Stufe B): Presets und freie Farbe
 * laufen durch dieselbe Ableitung; die Wahl wirkt sofort, überlebt den
 * Reload (ui.theme.css-Cache via theme-init.js) und bleibt per Konstruktion
 * lesbar — der axe-Smoke prüft das exemplarisch mit einer grellen freien
 * Farbe in beiden Modi. Klassen-Hooks statt lokalisierter Texte.
 */

const BASE = process.env.E2E_BASE_URL ?? 'http://localhost:5173';

const accentRadio = (page: Page, value: string) =>
  page.locator(`input[name="theme-accent"][value="${value}"]`);

const effectiveAccent = (page: Page) =>
  page.evaluate(() =>
    getComputedStyle(document.documentElement).getPropertyValue('--color-accent').trim(),
  );

test('accent choice applies instantly, persists, and default removes the override', async ({
  browser,
}) => {
  const context = await contextForUser(browser, BASE, 'fixture-user');
  const page = await context.newPage();
  await page.emulateMedia({ colorScheme: 'light' });
  await page.goto('/settings');
  await page.locator('input[name="theme-accent"]').first().waitFor();

  // Default: Teichgrün, kein Override-Style.
  await expect(accentRadio(page, 'pond-green')).toBeChecked();
  expect(await effectiveAccent(page)).toBe('#2f6f4f');
  expect(await page.locator('#user-theme').count()).toBe(0);

  // Preset: wirkt sofort über das user-theme-Style-Element.
  await accentRadio(page, 'lake-blue').check();
  expect(await effectiveAccent(page)).toBe('#2b5f8f');
  expect(await page.locator('#user-theme').count()).toBe(1);

  // Persistenz: theme-init.js injiziert den ui.theme.css-Cache pre-paint.
  await page.reload();
  await page.locator('input[name="theme-accent"]').first().waitFor();
  await expect(accentRadio(page, 'lake-blue')).toBeChecked();
  expect(await effectiveAccent(page)).toBe('#2b5f8f');

  // Der Akzent gilt je Modus abgeleitet — Dunkelmodus bekommt einen
  // helleren Wert als das Light-Preset (nie denselben Hex).
  await page.locator('.topbar__theme').click(); // system -> light
  await page.locator('.topbar__theme').click(); // light -> dark
  const darkAccent = await effectiveAccent(page);
  expect(darkAccent).not.toBe('#2b5f8f');
  expect(darkAccent).toMatch(/^#[0-9a-f]{6}$/);

  // Zurück auf Standard: Override und Cache verschwinden.
  await page.locator('.topbar__theme').click(); // dark -> system
  await accentRadio(page, 'pond-green').check();
  expect(await page.locator('#user-theme').count()).toBe(0);
  expect(await page.evaluate(() => window.localStorage.getItem('ui.theme.css'))).toBeNull();

  await context.close();
});

test('a garish custom accent is derived readable — axe passes in both modes', async ({
  browser,
}) => {
  const context = await contextForUser(browser, BASE, 'fixture-user');
  const page = await context.newPage();
  await page.emulateMedia({ colorScheme: 'light' });
  await page.goto('/settings');
  await page.locator('input[name="theme-accent"]').first().waitFor();

  // Grelles Gelb als freie Farbe: die Ableitung muss hell einen deutlich
  // dunkleren Wert liefern — nie den Roh-Hex.
  await page.locator('.accent-color-input').fill('#ffff00');
  await expect(accentRadio(page, 'custom')).toBeChecked();
  const lightAccent = await effectiveAccent(page);
  expect(lightAccent).not.toBe('#ffff00');

  const TAGS = ['wcag2a', 'wcag21a', 'wcag2aa', 'wcag21aa'];
  for (const scheme of ['light', 'dark'] as const) {
    await page.emulateMedia({ colorScheme: scheme });
    // Modus konkret machen: System folgt emulateMedia (theme.ts-Listener).
    await expect
      .poll(() => page.evaluate(() => document.documentElement.dataset.theme))
      .toBe(scheme);
    const results = await new AxeBuilder({ page }).withTags(TAGS).analyze();
    expect(
      results.violations.map((v) => ({ rule: v.id, help: v.help })),
      `axe mit grellem Akzent (${scheme})`,
    ).toEqual([]);
  }

  await context.close();
});