/* eslint-disable no-self-compare */
// no import here as this runs without babel
const fs = require('fs');
const path = require('path');

const hiddenFile = /(^(\.|\/\.))|(.md$)/g;

function getFilesFor(dir) {
  let targetDir = path.join(__dirname, dir);
  return fs.readdirSync(targetDir)
    .filter(file => !hiddenFile.test(file))
    .map(function(file) {
      let superBlock;
      if (fs.statSync(path.join(targetDir, file)).isFile()) {
        return {file: file};
      }
      superBlock = file;
      return getFilesFor(path.join(dir, superBlock))
        .map(function(data) {
          return {
            file: path.join(superBlock, data.file),
            superBlock: superBlock
          };
        });
    })
    .reduce(function(files, entry) {
      return files.concat(entry);
    }, []);
}

function superblockInfo(filePath) {
  let parts = (filePath || '').split('-');
  let order = parseInt(parts[0], 10);
  if (isNaN(order)) {
    return {order: 0, name: filePath};
  } else {
    return {
      order: order,
      name: parts.splice(1).join('-')
    };
  }
}

module.exports = function getChallenges(challengesDir) {
  if (!challengesDir) {
    challengesDir = 'challenges';
  }
  return getFilesFor(challengesDir)
    .map(function(data) {
      const challengeSpec = require('./' + challengesDir + '/' + data.file);
      let superInfo = superblockInfo(data.superBlock);
      challengeSpec.fileName = data.file;
      challengeSpec.superBlock = superInfo.name;
      challengeSpec.superOrder = superInfo.order;
      return challengeSpec;
    });
};