import { loadI18n } from '../test-support/i18n.js';
import assert from 'node:assert/strict';
import fs from 'node:fs/promises';
import path from 'node:path';
import test from 'node:test';
import vm from 'node:vm';
import { localizeHtml } from '../scripts/localize-html.js';

const root = path.resolve(import.meta.dirname, '..');

test('checked-in HTML has synchronized German defaults and accessible headings, labels and links before scripts load', async () => {
  const i18n = await loadI18n({});
  const html = await fs.readFile(path.join(root, 'public/index.html'), 'utf8');
  assert.equal(localizeHtml(html, key => i18n.t(key)), html, 'Run node scripts/localize-html.js after editing German texts');
  for (const match of html.matchAll(/<h[1-6]\b[^>]*>([\s\S]*?)<\/h[1-6]>/g)) assert.ok(match[1].replaceAll(/<[^>]*>/g, '').trim(), match[0]);
  for (const match of html.matchAll(/\baria-label="([^"]*)"/g)) assert.ok(match[1].trim(), 'Empty accessible label');
  for (const match of html.matchAll(/<a\b[^>]*>([\s\S]*?)<\/a>/g)) assert.ok(match[1].replaceAll(/<[^>]*>/g, '').trim(), match[0]);
  for (const match of html.matchAll(/<label\b([^>]*)>/g)) {
    const control = /\bfor="([^"]+)"/.exec(match[1])?.[1];
    assert.ok(control, `Missing label association: ${match[0]}`);
    assert.ok(html.includes(`id="${control}"`), `Missing control: ${control}`);
  }
});

test('HTML generation escapes text and attributes, preserves i18n markers and updates existing defaults', () => {
  const source = '<h1 data-i18n="heading">Old title</h1><button aria-label="Old label" data-i18n-aria-label="label">?</button>';
  const messages = { heading: '<New & title>', label: 'A "label" & $&' };
  const translate = key => messages[key];
  const result = localizeHtml(source, translate);
  assert.equal(result, '<h1 data-i18n="heading">&lt;New &amp; title&gt;</h1><button aria-label="A &quot;label&quot; &amp; $&amp;" data-i18n-aria-label="label">?</button>');
  assert.equal(localizeHtml(result, translate), result);
});

test('translations support placeholders, plurals and German fallback without treating text as HTML', async () => {
  const context = {};
  const i18n = await loadI18n(context);
  assert.equal(i18n.t('app.choose-route'), 'Strecke wählen');
  assert.equal(i18n.t('media.image.count', { count: 1 }), '1 Bild');
  assert.equal(i18n.t('media.image.count', { count: 2 }), '2 Bilder');
  assert.equal(i18n.t('app.next-station-summary', { value1: '<script>', value2: ' · 3 m' }), 'Nächste Station: <script> · 3 m');
  i18n.register('en', { 'app.choose-route': 'Choose a trail', 'media.image.count': { one: '{count} picture', other: '{count} pictures' } });
  assert.equal(i18n.setLanguage('en-GB', null), 'en');
  assert.equal(i18n.t('app.choose-route'), 'Choose a trail');
  assert.equal(i18n.t('media.image.count', { count: 0 }), '0 pictures');
  assert.equal(i18n.t('media.audio.count', { count: 1 }), '1 Tonaufnahme');
  assert.equal(i18n.setLanguage('fr', null), 'de');
  assert.throws(() => i18n.t('missing.key'), /Missing translation/);
});

test('language changes translate visible and spoken labels through textContent and retain text markers', async () => {
  const i18n = await loadI18n({});
  const make = entries => ({
    textContent: '',
    attributes: new Map(entries),
    dataset: Object.fromEntries(entries.map(([name, value]) => [name.slice(5).replaceAll(/-([a-z])/g, (_match, letter) => letter.toUpperCase()), value])),
    setAttribute(name, value) { this.attributes.set(name, value); }
  });
  const text = make([['data-i18n', 'app.choose-route']]);
  const attributes = ['aria-label', 'title', 'placeholder', 'alt'];
  const labels = new Map(attributes.map(attribute => [attribute, make([[`data-i18n-${attribute}`, 'app.choose-route']])]));
  const root = { documentElement: {}, querySelectorAll(selector) {
    if (selector === '[data-i18n]') return [text];
    for (const [attribute, label] of labels) {
      if (selector === `[data-i18n-${attribute}]`) return [label];
    }
    return [];
  } };
  i18n.apply(root);
  assert.equal(text.textContent, 'Strecke wählen');
  for (const [attribute, label] of labels) assert.equal(label.attributes.get(attribute), 'Strecke wählen');
  i18n.register('en', { 'app.choose-route': '<Choose a trail>' });
  i18n.setLanguage('en', root);
  assert.equal(text.textContent, '<Choose a trail>');
  for (const [attribute, label] of labels) assert.equal(label.attributes.get(attribute), '<Choose a trail>');
  assert.equal(root.documentElement.lang, 'en');
  assert.equal(text.attributes.get('data-i18n'), 'app.choose-route');
});

test('every static HTML and JavaScript text key exists in the central catalog and translations load before app modules', async () => {
  const i18n = await loadI18n({});
  const html = await fs.readFile(path.join(root, 'public/index.html'), 'utf8');
  for (const match of html.matchAll(/\bdata-i18n(?:-[\w-]+)?="([^"]+)"/g)) assert.equal(typeof i18n.t(match[1]), 'string', match[1]);
  for (const name of await fs.readdir(path.join(root, 'public/js'))) {
    if (!name.endsWith('.js')) continue;
    const source = await fs.readFile(path.join(root, 'public/js', name), 'utf8');
    for (const match of source.matchAll(/I18n\.t\(["']([^"']+)["']/g)) assert.equal(typeof i18n.t(match[1], { count: 2 }), 'string', match[1]);
  }
  assert.ok(html.indexOf('js/texts-de.js') < html.indexOf('js/i18n.js'));
  assert.ok(html.indexOf('js/texts-en.js') > html.indexOf('js/texts-de.js'));
  assert.ok(html.indexOf('js/texts-en.js') < html.indexOf('js/i18n.js'));
  assert.ok(html.indexOf('js/i18n.js') < html.indexOf('js/local-routes.js'));
});

test('browser language preferences select German or English, including regional variants and unavailable languages', async () => {
  const cases = [
    [{ languages: ['en-GB', 'de-DE'], language: 'de-DE' }, 'en', 'Choose a trail'],
    [{ languages: ['de-DE', 'en-US'] }, 'de', 'Strecke wählen'],
    [{ languages: ['fr-FR', 'en-US'] }, 'en', 'Choose a trail'],
    [{ language: 'EN-us' }, 'en', 'Choose a trail'],
    [{ languages: ['fr-FR'] }, 'de', 'Strecke wählen'],
    [{}, 'de', 'Strecke wählen']
  ];
  for (const [navigator, language, title] of cases) {
    const i18n = await loadI18n({ navigator });
    assert.equal(i18n.language, language);
    assert.equal(i18n.t('app.choose-route'), title);
    assert.equal(i18n.t('bootstrap-loader.steps.routes'), language === 'en' ? 'Loading trails …' : 'Strecken laden …');
  }
});

function leafMessages(node, prefix = '') {
  return Object.entries(node).flatMap(([key, value]) => {
    const path = prefix + key;
    return typeof value === 'string' ? [[path, value]] : leafMessages(value, `${path}.`);
  });
}

test('German and English catalogs have the same semantic keys, placeholders and plural forms', async () => {
  const context = {};
  const i18n = await loadI18n(context);
  const de = new Map(leafMessages(context.Wegwichtel.TextCatalogs.get('de')));
  const en = new Map(leafMessages(context.Wegwichtel.TextCatalogs.get('en')));
  assert.deepEqual([...en.keys()].sort(), [...de.keys()].sort());
  for (const [key, text] of de) {
    assert.ok(en.get(key).trim(), key);
    const placeholders = value => [...value.matchAll(/\{(\w+)\}/g)].map(match => match[1]).sort();
    assert.deepEqual(placeholders(en.get(key)), placeholders(text), key);
    assert.match(key, /^[a-z][a-z0-9.-]*$/, key);
    assert.ok(key.split('.').length <= 4, key);
  }
  i18n.setLanguage('en', null);
  assert.equal(i18n.t('app.no-route'), 'You have not created a trail of your own yet.');
  assert.equal(i18n.t('media.audio.count', { count: 1 }), '1 recording');
  assert.equal(i18n.t('media.audio.count', { count: 2 }), '2 recordings');
  for (const step of ['storage', 'jquery', 'jquery-ui', 'modules', 'server', 'routes', 'location']) assert.ok(i18n.t(`bootstrap-loader.steps.${step}`));
});

test('the generic text class and i18n can start with only the English language file', async () => {
  const context = { navigator: { language: 'en-GB' } };
  for (const name of ['texts-en', 'i18n']) {
    const filename = path.join(root, `public/js/${name}.js`);
    vm.runInNewContext(await fs.readFile(filename, 'utf8'), context, { filename });
  }
  assert.equal(context.Wegwichtel.Texts.name, 'WegwichtelTexts');
  assert.equal(context.Wegwichtel.I18n.language, 'en');
  assert.equal(context.Wegwichtel.I18n.t('app.choose-route'), 'Choose a trail');
  assert.equal(context.Wegwichtel.I18n.setLanguage('fr', null), 'en');
});