const {execSync} = require("child_process");
// const {promisify} = require("util");
// const promisifiedExec = promisify(exec);
const process = require("process");

module.exports.checkSudo = function () {
  return process.getuid && process.getuid() == 0 ? true : false;
};

module.exports.checkNodeVersion = function () {
  const currentApropriateVersion = 14, nodeVersion = process.versions.node.split('.');

  return +nodeVersion[0] > currentApropriateVersion ? true : false;
};

module.exports.checkPlatform = function () {
  // https://nodejs.org/api/process.html#process_process_platform
  return process.platform == "linux" ? true : false;
};

// module.exports.getDistroInfo = async function () {
//   let current = {
//     distributorID: null, distributorVersion: null
//   };

//   try {
//     // check version
//     let {stdout, stderr} = await promisifiedExec('lsb_release -i -r');

//     if (stderr) {
//       throw new Error(`Error while checking Linux distribution information: ${stderr}`);
//     };

//     if (stdout) {
//       // sanitize
//       let parsed = stdout
//       .split(/\r|\n/gi) // remove break lines
//       .map(x => x.replace(/\s/gi, "")) // remove spaces, only remains [e.g. DistributorID:Ubuntu]
//       .filter(x => x); // filter empty string

//       let findDistributorID = parsed.find(val => val.match(/^(DistributorID)/gi));
//       let findReleaseVersion = parsed.find(val => val.match(/^(Release)/gi));

//       if (findDistributorID) {
//         let splitViaColon = findDistributorID.split(/(:)/gi);
//         if (splitViaColon) current.distributorID = splitViaColon.pop().toLowerCase();
//       };

//       if (findReleaseVersion) {
//         let splitViaColon = findReleaseVersion.split(/(:)/gi);
//         if (splitViaColon) current.distributorVersion = splitViaColon.pop().toLowerCase();
//       };
//     };
//   } catch {};

//   return current;
// };

module.exports.checkPlatformExact = function () {
  // let distroInfo = await this.getDistroInfo();
  // if (!distroInfo?.distributorID || !distroInfo?.distributorVersion) {
  //   throw new Error("Missing distro platform information.");
  // };

  // // https://en.wikipedia.org/wiki/Uncomplicated_Firewall
  // let platform = distroInfo.distributorID;
  // if (String(platform).toLowerCase() !== "ubuntu") {
  //   throw new Error("node-ufw only supported on Ubuntu.");
  // };

  // return true;

  try {
    return execSync("cat /etc/*release | grep -E ^NAME")?.toString("utf-8").split('=').pop().replace(/(")/gi, "").toLowerCase() == "ubuntu" ? true : false;
  } catch (e) {
    console.error(e);
    return false;
  };
};

module.exports.checkAppropriatePort = function(port) {
  const portLimit = Math.round(2 ** 16 - 1);

  if (typeof port !== "number") throw new Error("The port must be type of number.");

  return (port > 0 || port <= portLimit) ? true : false;
};

module.exports.checkAppropriateIP = function(address) {
  if (typeof address !== "string") {
    throw new Error("The address must be type of string.");
  };

  // https://blog.markhatton.co.uk/2011/03/15/regular-expressions-for-ip-addresses-cidr-ranges-and-hostnames/
  // also support subnet/net mask
  let regex = new RegExp(/^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))?$/gi);
  return address.match(regex) !== null ? true : false;
};

// soon to be continued
// module.exports.checkPlatformVersion = function () {
//   let distroInfo = this.getDistroInfo();
//   if (!distroInfo?.distributorID || !distroInfo?.distributorVersion) {
//     throw new Error("Missing distro platform information.");
//   };
// };