'use strict';

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

const RELEASES_DIR = path.join(__dirname, '../public/releases');
const MANIFEST_FILE = path.join(RELEASES_DIR, 'releases-manifest.json');

function semverCompare(a, b) {
  const aParts = (a || '0').split('.').map(Number);
  const bParts = (b || '0').split('.').map(Number);
  for (let i = 0; i < Math.max(aParts.length, bParts.length); i++) {
    const diff = (bParts[i] || 0) - (aParts[i] || 0); // descending: highest first
    if (diff !== 0) return diff;
  }
  return 0;
}

module.exports = function (app) {
  const router = require('express').Router();

  /**
   * GET /api/releases
   * Returns the sorted list of release entries (no markdown content).
   * Sorted by `ver` descending — highest version first (latest).
   */
  router.get('/', (req, res) => {
    fs.readFile(MANIFEST_FILE, 'utf8', (err, data) => {
      if (err) {
        return res.status(500).json({ error: 'Could not read releases manifest.' });
      }
      let manifest;
      try {
        manifest = JSON.parse(data);
      } catch (parseErr) {
        return res.status(500).json({ error: 'Releases manifest is malformed.' });
      }
      const revisions = (manifest && Array.isArray(manifest.revisions)) ? manifest.revisions : [];
      const sorted = [...revisions].sort((a, b) => semverCompare(a.ver, b.ver));
      res.json(sorted);
    });
  });

  app.use('/api/releases', router);
};