#! /usr/bin/env runjs

var KeyPairGenerator = java.security.KeyPairGenerator;
var Bytes = Packages.me.hatter.tools.commons.bytes.Bytes;
var UnixArgsUtil = Packages.me.hatter.tools.commons.args.UnixArgsUtil;
var SSHKeyGen = Packages.me.hatter.tools.commons.security.ssh.SSHKeyGen;

var main = () => {
  UnixArgsUtil.parseGlobalArgs($ARGS);
  var args = UnixArgsUtil.ARGS.args();
  if (UnixArgsUtil.ARGS.flags().containsAny('h', 'help')) {
    println('sshkeygen.js - Generate SSH keypair.')
    println();
    println('sshkeygen.js [--h[elp]] [-keyLength 4096] [-serverName server_name]');
    return;
  }

  var kpg = KeyPairGenerator.getInstance("RSA");
  var keyLen = $$.asInt(UnixArgsUtil.ARGS.kvalue('keyLength') || '2048');
  if (keyLen < 1024) {
    println('Key length is less than 1024 bit: ' + keyLen);
    return;
  }
  kpg.initialize(keyLen);
  var kp = kpg.generateKeyPair();

  println(SSHKeyGen.encodePublicKey(kp.getPublic(), UnixArgsUtil.ARGS.kvalue('serverName') || 'test@example.com'));
  println(Bytes.from(kp.getPrivate().getEncoded()).asPem('PRIVATE KEY'));
};

main();