/**
 * One-time backfill: recompute duration_seconds for every lesson
 * that has at least one saved page block.
 *
 * Run from the project root:
 *   node scripts/backfill-durations.js
 */

const path = require('path');
require('dotenv').config({ path: path.join(__dirname, '../.env') });

const sequelize = require('../config/db.config');
const LessonPage = require('../models/courses/lesson_page.mdl');
const { recomputeDurations } = require('../utils/duration.util');

(async () => {
  await sequelize.authenticate();
  console.log('DB connected.\n');

  const pages = await LessonPage.findAll({
    attributes: ['lesson_id', 'blocks'],
    where: sequelize.literal(`jsonb_array_length(blocks::jsonb) > 0`),
  });

  console.log(`Found ${pages.length} lessons with blocks. Recomputing...`);

  let ok = 0, fail = 0;
  for (const page of pages) {
    try {
      await recomputeDurations(page.lesson_id);
      process.stdout.write('.');
      ok++;
    } catch (err) {
      process.stdout.write('✗');
      console.error(`\n  lesson ${page.lesson_id}: ${err.message}`);
      fail++;
    }
  }

  console.log(`\n\nDone — ${ok} recomputed, ${fail} failed.`);
  await sequelize.close();
})();