'use strict';

module.exports.create = function (cli, dnsd) {
  var server = require('dgram').createSocket({
    type: cli.udp6 ? 'udp6' : 'udp4'
  , reuseAddr: true
  });
  server.bind({
    port: cli.port
  , address: cli.address
  });

  var handlers = {};
  handlers.onError = function (err) {
    if ('EACCES' === err.code) {
      console.error("");
      console.error("EACCES: Couldn't bind to port. You probably need to use sudo, authbind, or setcap.");
      console.error("");
      process.exit(123);
      return;
    }
    console.error("error:", err.stack);
    server.close();
  };

  handlers.onMessage = function (nb, rinfo) {
    //console.log('[DEBUG] got a UDP message', nb.length);
    //console.log(nb.toString('hex'));

    dnsd.onMessage(nb, function (err, newAb, dbgmsg) {
      // TODO send legit error message
      if (err) { server.send(Buffer.from([0x00])); return; }
      server.send(newAb, rinfo.port, rinfo.address, function () {
        console.log(dbgmsg, rinfo.port, rinfo.address);
      });
    });
  };

  handlers.onListening = function () {
    /*jshint validthis:true*/
    var server = this;

    if (cli.mdns || '224.0.0.251' === cli.nameserver) {
      server.setBroadcast(true);
      server.addMembership(cli.nameserver);
    }

    console.log('');
    console.log('Bound and Listening:');
    console.log(server.address().address + '#' + server.address().port + ' (' + server.type + ')');
  };

  server.on('error', handlers.onError);
  server.on('message', handlers.onMessage);
  server.on('listening', handlers.onListening);

  return server;
};