import { createServer } from 'node:http';
import { readFile, stat } from 'node:fs/promises';
import path from 'node:path';
import { chromium } from 'playwright';

const dist = path.resolve('dist');
const routes = [
  '/',
  '/articles/',
  '/articles/greatai-ai-deployment-api/',
  '/writing/',
  '/writing/greatai-ai-deployment-api/',
  '/projects/',
  '/about/',
];
const widths = [320, 390, 430];

function contentType(file) {
  if (file.endsWith('.html')) return 'text/html; charset=utf-8';
  if (file.endsWith('.css')) return 'text/css; charset=utf-8';
  if (file.endsWith('.js')) return 'text/javascript; charset=utf-8';
  if (file.endsWith('.svg')) return 'image/svg+xml';
  if (file.endsWith('.png')) return 'image/png';
  if (file.endsWith('.jpg') || file.endsWith('.jpeg')) return 'image/jpeg';
  if (file.endsWith('.webp')) return 'image/webp';
  if (file.endsWith('.woff2')) return 'font/woff2';
  return 'application/octet-stream';
}

async function resolveFile(url) {
  const parsed = new URL(url, 'http://localhost');
  const safePath = path
    .normalize(decodeURIComponent(parsed.pathname))
    .replace(/^\/+/, '')
    .replace(/^(\.\.(\/|\\|$))+/, '');
  const candidate = path.join(dist, safePath);
  const candidates = [
    candidate,
    path.join(candidate, 'index.html'),
    path.join(dist, `${safePath}.html`),
  ];

  for (const file of candidates) {
    try {
      const fileStat = await stat(file);
      if (fileStat.isFile()) return file;
    } catch {
      // Try the next candidate.
    }
  }

  return path.join(dist, '404.html');
}

const server = createServer(async (req, res) => {
  try {
    const file = await resolveFile(req.url ?? '/');
    const body = await readFile(file);
    res.writeHead(200, { 'content-type': contentType(file) });
    res.end(body);
  } catch (error) {
    res.writeHead(500, { 'content-type': 'text/plain; charset=utf-8' });
    res.end(String(error));
  }
});

await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
const { port } = server.address();
const browser = await chromium.launch({ headless: true });
const failures = [];

async function measureViewport(page) {
  for (let attempt = 0; attempt < 3; attempt += 1) {
    try {
      await page.waitForLoadState('load');
      return await page.evaluate(() => ({
        scrollWidth: document.documentElement.scrollWidth,
        clientWidth: document.documentElement.clientWidth,
      }));
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error);
      if (attempt === 2 || !/Execution context was destroyed|navigation/i.test(message)) {
        throw error;
      }
      await page.waitForLoadState('load').catch(() => {});
    }
  }
}

try {
  for (const width of widths) {
    const page = await browser.newPage({
      viewport: { width, height: 900 },
      javaScriptEnabled: false,
    });

    for (const route of routes) {
      await page.goto(`http://127.0.0.1:${port}${route}`, { waitUntil: 'load' });
      if (route.startsWith('/writing/')) {
        await page
          .waitForURL((url) => url.pathname.startsWith('/articles/'), { timeout: 1000 })
          .catch(() => {});
      }
      const result = await measureViewport(page);

      if (result.scrollWidth > result.clientWidth + 1) {
        failures.push(
          `${route} overflows at ${width}px: ${result.scrollWidth}px > ${result.clientWidth}px`
        );
      }
    }

    await page.close();
  }
} finally {
  await browser.close();
  server.close();
}

if (failures.length > 0) {
  console.error(failures.join('\n'));
  process.exit(1);
}

console.log('No horizontal overflow detected at 320px, 390px, or 430px.');