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

function extractLessonArray(content, varNameCandidates) {
  for (const varName of varNameCandidates) {
    const re = new RegExp(varName.replace(/[-/\\^$*+?.()|[\]{}]/g, '\\$&') + "\\s*=\\s*\\[([\\s\\S]*?)\\];", 'm');
    const m = re.exec(content);
    if (m) return m[1];
  }
  return null;
}

function evalArrayText(arrayText) {
  const wrapped = '[' + arrayText + ']';
  const script = new vm.Script(wrapped, { filename: 'array.js' });
  const context = vm.createContext({});
  return script.runInContext(context);
}

function loadLessons(filePath, varCandidates) {
  const content = fs.readFileSync(filePath, 'utf8');
  const arrText = extractLessonArray(content, varCandidates);
  if (!arrText) return [];
  const arr = evalArrayText(arrText);
  return arr;
}

function main() {
  const repo = path.join(__dirname);
  const file1 = path.join(repo, 'bisaya-course-plan-24-43.js');
  const file2 = path.join(repo, 'bisaya-course-phase3-extension.js');

  const lessons1 = loadLessons(file1, ['const BISAYA_LESSONS_24_43_BASE', 'BISAYA_LESSONS_24_43_BASE', 'BISAYA_LESSONS_24_43']);
  const lessons2 = loadLessons(file2, ['export const BISAYA_PHASE3_LESSONS', 'BISAYA_PHASE3_LESSONS']);

  const mapping = {};
  for (const l of lessons1) {
    if (l && typeof l.num === 'number') mapping[l.num] = true;
  }
  for (const l of lessons2) {
    if (l && typeof l.num === 'number') mapping[l.num] = true;
  }

  // Also include any missing range 24..63
  for (let n = 24; n <= 63; n++) mapping[n] = true;

  const outDir = path.join(__dirname, '..', 'data');
  if (!fs.existsSync(outDir)) fs.mkdirSync(outDir, { recursive: true });
  const outFile = path.join(outDir, 'lesson-checkpoints.json');
  fs.writeFileSync(outFile, JSON.stringify(mapping, null, 2));
  console.log('Wrote', outFile);
  console.log('Marked lessons:', Object.keys(mapping).length);
}

main();