'use strict';
const path = require('path');
const fs = require('fs');
const { argv } = require('process');

const readFile = fs.promises.readFile;
const writeFile = fs.promises.writeFile;
const readdir = fs.promises.readdir;

const loadScripts = async (readDir, writeDir) => {
  const normalizedDir = path.normalize(readDir);

  const files = await readdir(normalizedDir);

  const luaFiles = files.filter(file => path.extname(file) === '.lua');
  const writeFilenamePath = path.normalize(writeDir);

  if (!fs.existsSync(writeFilenamePath)) {
    fs.mkdirSync(writeFilenamePath);
  }

  let indexContent = "'use strict';\nmodule.exports = {\n";

  if (luaFiles.length === 0) {
    /**
     * To prevent unclarified runtime error "updateDelayset is not a function
     * @see https://github.com/OptimalBits/bull/issues/920
     */
    throw new Error('No .lua files found!');
  }

  for (let i = 0; i < luaFiles.length; i++) {
    const completedFilename = path.join(normalizedDir, luaFiles[i]);
    const longName = path.basename(luaFiles[i], '.lua');
    indexContent += `  ["${longName}"]: require('./${longName}'),\n`;

    await loadCommand(completedFilename, longName, writeFilenamePath);
  }
  indexContent += `}\n`;

  await writeFile(path.join(writeFilenamePath, 'index.js'), indexContent);
};

const loadCommand = async (filename, longName, writeFilenamePath) => {
  const filenamePath = path.resolve(filename);

  const content = (await readFile(filenamePath)).toString();

  const [name, num] = longName.split('-');
  const numberOfKeys = num && parseInt(num, 10);

  const newContent = `'use strict';
const content = \`${content}\`;
module.exports = {
  name: '${name}',
  content,${
    numberOfKeys
      ? `
  keys: ${numberOfKeys},`
      : ''
  }
};
`;
  await writeFile(path.join(writeFilenamePath, longName + '.js'), newContent);
};

loadScripts(argv[2], argv[3]);