const fs = require('fs');
const path = require('path');

const root = path.resolve(__dirname, '..');
const templatePath = path.join(root, 'shared-html', 'index.template.html');
const template = fs.readFileSync(templatePath, 'utf8');

const updaterMarkup = `<div id="update-notifier" class="update-notifier hidden">
              <button id="update-download-btn" title="Download Update"><i data-lucide="download"></i></button>
              <button id="update-install-btn" title="Install Update" class="hidden"><i data-lucide="arrow-up-circle"></i></button>
            </div>`;

const variants = {
  web: {
    styles_href: '/static/styles.css',
    lucide_src: '/static/vendor/lucide.min.js',
    app_src: '/static/app.js?v=20260227-shared-core-1',
    web_downloads: `<div class="auth-downloads">
        <span>Desktop downloads:</span>
        <a href="/static/installers/chattz-windows.exe">Windows</a>
        <a href="/static/installers/chattz-linux.rpm">Linux (RPM)</a>
      </div>`,
    desktop_updater: updaterMarkup,
    outPath: path.join(root, 'static', 'index.html'),
  },
  desktop: {
    styles_href: '../static/styles.css',
    lucide_src: '../static/vendor/lucide.min.js',
    app_src: 'app.js?v=20260227-shared-core-1',
    web_downloads: '',
    desktop_updater: updaterMarkup,
    outPath: path.join(root, 'desktop', 'index.html'),
  },
};

for (const variant of Object.values(variants)) {
  let output = template;
  for (const [key, value] of Object.entries(variant)) {
    if (key === 'outPath') continue;
    const token = `{{${key}}}`;
    if (value === '') {
      output = output.replace(new RegExp(`^[ \\t]*\\{\\{${key}\\}\\}[ \\t]*\\n?`, 'm'), '');
      continue;
    }
    output = output.replaceAll(token, value);
  }

  if (/\{\{[a-z_]+\}\}/i.test(output)) {
    throw new Error(`Unresolved template placeholders remain in ${variant.outPath}`);
  }

  fs.writeFileSync(
    variant.outPath,
    `<!-- Generated from shared-html/index.template.html. Do not edit directly. -->\n${output}`,
    'utf8'
  );
}