#!/usr/bin/env node
const fs = require('fs');
const path = require('path');

const repoRoot = process.cwd();
const pkgPath = path.join(repoRoot, 'package.json');
const publicDir = path.join(repoRoot, 'public');
if (!fs.existsSync(pkgPath) || !fs.existsSync(publicDir)) process.exit(0);

const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'));
const version = pkg.version;
if (!version) {
  console.error('package.json version missing');
  process.exit(1);
}

function walkHtmlFiles(dir) {
  const out = [];
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    const full = path.join(dir, entry.name);
    if (entry.isDirectory()) out.push(...walkHtmlFiles(full));
    else if (entry.isFile() && entry.name.endsWith('.html')) out.push(full);
  }
  return out;
}

function isLocalAsset(rawUrl) {
  return !/^(?:[a-z]+:|\/\/|#)/i.test(rawUrl);
}

function withVersion(rawUrl) {
  const [baseWithQuery, hash = ''] = rawUrl.split('#');
  const [pathname, query = ''] = baseWithQuery.split('?');
  const params = new URLSearchParams(query);
  params.set('v', version);
  const qs = params.toString();
  return pathname + (qs ? '?' + qs : '') + (hash ? '#' + hash : '');
}

const htmlFiles = walkHtmlFiles(publicDir);
let changed = 0;
for (const file of htmlFiles) {
  let content = fs.readFileSync(file, 'utf8');
  const next = content
    .replace(/(<link\b[^>]*href=["'])([^"']+\.css(?:\?[^"']*)?)(["'][^>]*>)/gi, (m, p1, url, p3) => {
      return isLocalAsset(url) ? p1 + withVersion(url) + p3 : m;
    })
    .replace(/(<script\b(?![^>]*type=["']application\/json["'])[^>]*\bsrc=["'])([^"']+\.js(?:\?[^"']*)?)(["'][^>]*>\s*<\/script>)/gi, (m, p1, url, p3) => {
      return isLocalAsset(url) ? p1 + withVersion(url) + p3 : m;
    });
  if (next !== content) {
    fs.writeFileSync(file, next);
    changed += 1;
  }
}

if (changed > 0) console.log('Synced versioned assets in ' + changed + ' HTML file(s).');