import { chromium } from 'playwright';
import AxeBuilder from '@axe-core/playwright';
import assert from 'node:assert/strict';
import { mkdir, writeFile } from 'node:fs/promises';

const origin = process.env.CMS_URL || 'http://127.0.0.1:8080';
const browser = await chromium.launch();
await mkdir('reports', { recursive: true });
const results = [];
// Accessibility problems caused by editorial colour choices, reported but not fatal.
const findings = [];
try {
  // The machine readable routes have a file extension, which the PHP built-in server would answer
  // itself. Without bin/dev-router.php they never reach the front controller - exactly the gap
  // that let them stay broken locally while every kernel test passed.
  const context = await browser.newContext();
  for (const [path, type] of [['/sitemap.xml', 'application/xml'], ['/robots.txt', 'text/plain'], ['/feed.xml', 'application/xml']]) {
    const response = await context.request.get(origin + path);
    assert.equal(response.status(), 200, path);
    assert.match(response.headers()['content-type'] ?? '', new RegExp(type), path);
  }
  results.push({ name: 'machine readable routes reachable', paths: 3 });
  await context.close();

  // A load budget, measured rather than assumed: what a page actually transfers, and how many
  // database queries it needed. Both are ceilings - a page that starts asking once per section
  // or shipping a megabyte of CSS fails here instead of only getting slower.
  {
    const budget = await browser.newContext({ viewport: { width: 1440, height: 1000 } });
    const page = await budget.newPage();
    const transferred = new Map();
    page.on('response', async response => {
      const type = (response.headers()['content-type'] ?? '').split(';')[0];
      const length = Number(response.headers()['content-length'] ?? 0);
      transferred.set(response.url(), { type, length });
    });
    for (const path of ['/', '/beitraege']) {
      transferred.clear();
      const response = await page.goto(origin + path, { waitUntil: 'networkidle' });
      const queries = Number(response.headers()['x-kant-queries'] ?? -1);
      const html = (await response.text()).length;
      const styles = [...transferred.values()].filter(entry => entry.type === 'text/css').reduce((sum, entry) => sum + entry.length, 0);
      const scripts = [...transferred.values()].filter(entry => entry.type.includes('javascript')).length;
      const requests = transferred.size;

      assert.ok(html < 150000, `${path}: HTML ${html} Bytes, Obergrenze 150000`);
      assert.ok(styles < 120000, `${path}: CSS ${styles} Bytes, Obergrenze 120000`);
      // A public page runs no script unless it carries tabs or its own; the budget keeps that honest.
      assert.equal(scripts, 0, `${path}: ${scripts} Skript(e) geladen`);
      assert.ok(requests <= 12, `${path}: ${requests} Anfragen, Obergrenze 12`);
      if (queries >= 0) assert.ok(queries <= 20, `${path}: ${queries} Datenbankabfragen, Obergrenze 20`);
      results.push({ name: `load budget ${path}`, html, styles, requests, queries });
      console.log(`Budget ${path}: HTML ${html} B, CSS ${styles} B, ${requests} Anfragen, ${queries} Abfragen, ${scripts} Skripte`);
    }
    await budget.close();
  }

  for (const width of [1440, 390]) {
    const context = await browser.newContext({ viewport: { width, height: 1000 } });
    const page = await context.newPage();
    const errors = [];
    page.on('pageerror', error => errors.push(error.message));
    for (const path of ['/', '/grundlagen', '/projektstand']) {
      const response = await page.goto(origin + path);
      assert.equal(response.status(), 200);
      assert.equal(await page.locator('h1').count(), 1);
      assert.equal(await page.locator('script').count(), 0);
      assert(await page.evaluate(() => document.documentElement.scrollWidth <= innerWidth), 'Horizontal overflow');
      const axe = await new AxeBuilder({ page }).withTags(['wcag2a', 'wcag2aa', 'wcag21aa', 'best-practice']).analyze();

      // A contrast failure has two very different causes, and they need different answers.
      // Comes from the theme or a stylesheet: a defect of the system, and the run must fail -
      // this is what caught the link colour that overrode every dark section.
      // Comes from a colour an editor set on one block: an editorial finding. It is reported on
      // every run and written into the report, but it must not turn a code change red, because
      // nobody can fix it in the code.
      const styledIds = new Set(await page.evaluate(() =>
        [...document.querySelectorAll('style')]
          .flatMap(node => [...node.textContent.matchAll(/#([a-zA-Z0-9_-]+)\s*[{:]/g)].map(match => match[1]))));
      const isEditorial = node => node.target.every(target =>
        typeof target === 'string' && target.startsWith('#') && styledIds.has(target.slice(1)));

      const defects = [];
      for (const violation of axe.violations) {
        const editorial = 'color-contrast' === violation.id ? violation.nodes.filter(isEditorial) : [];
        const rest = violation.nodes.filter(node => !editorial.includes(node));
        if (editorial.length > 0) {
          findings.push({
            path,
            width,
            id: violation.id,
            cause: 'Inhalt: im Editor gesetzte Farbe',
            nodes: editorial.map(node => ({ target: node.target, summary: node.failureSummary?.split('\n')[1]?.trim() })),
          });
        }
        if (rest.length > 0) defects.push({ id: violation.id, nodes: rest.map(node => node.target) });
      }
      assert.deepEqual(defects, [], JSON.stringify(defects, null, 1));
      results.push({ width, path, defects: defects.length, editorialFindings: findings.filter(f => f.path === path && f.width === width).length, checks: axe.passes.length });
      await page.screenshot({ path: `reports/${width}-${path === '/' ? 'home' : path.slice(1)}.png`, fullPage: true });
    }
    await page.goto(origin);
    await page.keyboard.press('Tab');
    assert.equal(await page.locator(':focus').innerText(), 'Zum Inhalt springen');
    await page.keyboard.press('Enter');
    assert.equal(await page.locator(':focus').getAttribute('id'), 'main');
    await page.getByRole('link', { name: 'Die Grundlage entdecken' }).click();
    assert.equal(new URL(page.url()).pathname, '/grundlagen');
    await page.getByRole('link', { name: 'Projektstand' }).click();
    assert.equal(new URL(page.url()).pathname, '/projektstand');
    assert.deepEqual(errors, []);
    await context.close();
  }
  const noJs = await browser.newPage({ javaScriptEnabled: false });
  await noJs.goto(origin);
  assert.match(await noJs.locator('h1').innerText(), /Deine Inhalte/);
  await noJs.getByRole('link', { name: 'Die Grundlage entdecken' }).click();
  assert.equal(new URL(noJs.url()).pathname, '/grundlagen');
  await writeFile('reports/browser.json', JSON.stringify({ origin, results, editorialFindings: findings, keyboard: 'passed', noJavaScript: 'passed' }, null, 2));
  console.log('Passed: 6 page/viewport accessibility checks, keyboard navigation, no-JS navigation.');
  if (findings.length > 0) {
    // Loud on every run: these are real accessibility problems, they are just fixed in the editor
    // rather than in the code, so they do not make a code change fail.
    console.log('\n' + findings.length + ' Barrierefreiheits-Befund(e) aus im Editor gesetzten Farben:');
    for (const finding of findings) {
      console.log('  ' + finding.path + ' (' + finding.width + ' px) ' + finding.id + ': ' + finding.nodes.map(n => n.target.join(',') + ' - ' + n.summary).join(' | '));
    }
    console.log('  Zu beheben im Editor, nicht im Code. Details auch in reports/browser.json.');
  }
} finally {
  await browser.close();
}