/**
 * @file Self-hosted ReDoc API reference. ReDoc renders the OpenAPI spec as a
 * clean, three-panel reference document — a read-optimized complement to
 * Swagger UI's interactive "try it out" console (both are served from the same
 * `/api/openapi.json` spec). The ReDoc bundle is served from the repo itself
 * rather than a CDN, so the docs render fully offline / air-gapped, consistent
 * with the project's no-external-assets policy.
 *
 * The bundle is VENDORED (`server/vendor/redoc/`): `redoc.standalone.js` from
 * the `redoc` npm package 2.5.4, byte-for-byte, with its MIT `LICENSE` and the
 * bundled libraries' `redoc.standalone.js.LICENSE.txt`. The `redoc` package
 * itself is not a dependency — the server only ever serves this one browser
 * file, and the package pulled ~25 MB of Node-side dependencies into every
 * runtime install. To update: `npm pack redoc@<version>`, copy
 * `package/bundles/redoc.standalone.js` (+ `.LICENSE.txt`) over these files and
 * bump the version named here.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const path = require("path");

/**
 * Absolute path to the vendored ReDoc standalone bundle.
 * @returns {string}
 */
function redocBundlePath() {
  return path.join(__dirname, "..", "vendor", "redoc", "redoc.standalone.js");
}

/**
 * Minimal HTML shell that boots ReDoc against a spec URL using the
 * locally-served bundle. Makes no external network requests.
 *
 * @param {string} specUrl    URL the browser fetches the OpenAPI JSON from.
 * @param {string} bundleUrl  URL the page loads the ReDoc bundle from.
 * @param {string} title      Document <title> and browser-tab label.
 * @returns {string} A complete HTML document.
 */
function renderRedocHtml(specUrl, bundleUrl, title) {
  return `<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>${title}</title>
    <style>
      body {
        margin: 0;
        padding: 0;
      }
    </style>
  </head>
  <body>
    <redoc spec-url="${specUrl}"></redoc>
    <script src="${bundleUrl}"></script>
  </body>
</html>
`;
}

module.exports = { redocBundlePath, renderRedocHtml };