const { format, promisify } = require('util');
const exec = promisify(require('child_process').exec);

/* async function parseDig(output) {
  console.log('parseDig', output);
  const lines = output.split(/\n/);
  const result = {
    'A': [],
    'CNAME': []
  };
  for (const line of lines) {
    if (/^A (.*) from/.test(line)) {
      const scn = line.match(/^A (.*). from/)[1];
      result.A.push(scn);
    }
    if (/^CNAME (.*) from/.test(line)) {
      const scn = line.match(/^CNAME (.*). from/)[1];
      result.CNAME.push(scn);
    }
  }

  return result;
}*/

/**
 * Dig trace option wrapper method.
 *
 * @param {String} name
 * @returns {{A: String[], CNAME: String[]}} results
 */
function dig(name) {
  return new Promise(async (resolve, reject) => {
    if (typeof (name) !== 'string')
      throw new TypeError('name (string) is required');

    const cmd = format('dig %s +time=3 +retry=1', name);
    console.log('CMD', cmd);
    const { stdout, stderr } = await exec(cmd, { 'maxBuffer': 1024 * 1024 });
    // console.log('output', stdout, stderr);
    try {
      resolve(stdout);
    }
    catch (e) {
      reject(e);
    }
  });
}

module.exports = dig;
module.exports.default = dig;