/* Protocol - protocol constants */

/* Command code => mnemonic */
module.exports.types = {
  0: 'reserved',
  1: 'connect',
  2: 'connack',
  3: 'publish',
  4: 'puback',
  5: 'pubrec',
  6: 'pubrel',
  7: 'pubcomp',
  8: 'subscribe',
  9: 'suback',
  10: 'unsubscribe',
  11: 'unsuback',
  12: 'pingreq',
  13: 'pingresp',
  14: 'disconnect',
  15: 'reserved'
};

/* Mnemonic => Command code */
module.exports.codes = {};
for(var k in module.exports.types) {
  var v = module.exports.types[k];
  module.exports.codes[v] = k;
}

/* Header */
module.exports.CMD_SHIFT = 4;
module.exports.CMD_MASK = 0xF0;
module.exports.DUP_MASK = 0x08;
module.exports.QOS_MASK = 0x03;
module.exports.QOS_SHIFT = 1;
module.exports.RETAIN_MASK = 0x01;

/* Length */
module.exports.LENGTH_MASK = 0x7F;
module.exports.LENGTH_FIN_MASK = 0x80;

/* Connect */
module.exports.USERNAME_MASK = 0x80;
module.exports.PASSWORD_MASK = 0x40;
module.exports.WILL_RETAIN_MASK = 0x20;
module.exports.WILL_QOS_MASK = 0x18;
module.exports.WILL_QOS_SHIFT = 3;
module.exports.WILL_FLAG_MASK = 0x04;
module.exports.CLEAN_SESSION_MASK = 0x02;