// Deterministic internal-link check over the built site (zero dependencies).
// Run AFTER `astro build`: scans dist/**/*.html for root-relative href/src
// values and fails (exit 1) if any target has no file in dist/. External
// URLs, mailto:, data: and pure-#fragment links are out of scope.
import { readdirSync, readFileSync, existsSync, statSync } from 'node:fs';
import { join } from 'node:path';
import { fileURLToPath } from 'node:url';

const DIST = fileURLToPath(new URL('../dist', import.meta.url));
if (!existsSync(DIST)) { console.error('dist/ not found — run `npm run build` first'); process.exit(1); }

const htmlFiles = [];
(function walk(dir) {
  for (const name of readdirSync(dir)) {
    const p = join(dir, name);
    if (statSync(p).isDirectory()) walk(p);
    else if (name.endsWith('.html')) htmlFiles.push(p);
  }
})(DIST);

const resolves = (path) => {
  const clean = decodeURI(path.split(/[?#]/)[0]);
  if (clean === '/') return true;
  return ['', '.html', '/index.html'].some((suffix) =>
    existsSync(join(DIST, clean.replace(/\/$/, '') + suffix)));
};

let broken = 0;
for (const file of htmlFiles) {
  const html = readFileSync(file, 'utf8');
  for (const [, , url] of html.matchAll(/\s(href|src)="(\/[^"]*)"/g)) {
    if (!resolves(url)) {
      console.error(`broken: ${url}  (in ${file.slice(DIST.length + 1)})`);
      broken++;
    }
  }
}
console.log(broken ? `${broken} broken internal link(s)` : `OK — ${htmlFiles.length} pages, all internal links resolve`);
process.exit(broken ? 1 : 0);