//see: https://github.com/thesolarnomad/lora-serialization/blob/master/examples/ttn_decoder.js
function Encoder(json, port) {
  return encode([json.delay, json.myFlags], [uint16, bitmap]);
  //delay = seconds, up to 65535 seconds = 18.204167 hours
  //{"delay": 60, "myFlags": [true, true, true, true, true, false, true, true]}  minutes delay between readings
}
//based on: https://github.com/thesolarnomad/lora-serialization/blob/master/src/decoder.js
var intToBytes = function(i, byteSize) {
  var buf = [];
  for (var x = 0; x < byteSize; x++) {
    buf[x] = i >> (x * 8) & 0xFF;
  }
  return buf;
};

var uint8 = function(i) {
  if (isNaN(i) || i < 0 || i > 255) {
    throw new Error('int be in range 0..255');
  }
  return intToBytes(i, uint8.BYTES);
};
uint8.BYTES = 1;

var uint16 = function(i) {
  if (isNaN(i) || i < 0 || i > 65535) {
    throw new Error('int be in range 0..65535');
  }
  return intToBytes(i, uint16.BYTES);
};
uint16.BYTES = 2;

var bitmap = function(a, b, c, d, e, f, g, h) { // eslint-disable-line no-unused-vars
  var base = [];
  for(var i = 0; i < 8; i++) {
    var bit = arguments[i];
    if (typeof bit === 'undefined') {
      base[i] = false;
    } else if (typeof bit !== 'boolean') {
      throw new TypeError('Arguments must be of type boolean');
    } else {
      base[i] = bit;
    }
  }
  var bm = parseInt(base.map(Number).join(''), 2);
  return intToBytes(bm, bitmap.BYTES);
};
bitmap.BYTES = 1;

var encode = function(values, mask) {
  if (!Array.isArray(values)) {
    throw new TypeError('Values must be an array');
  }
  if (!Array.isArray(mask)) {
    throw new TypeError('Mask must be an array');
  }
  if (values.length > mask.length) {
    throw new Error('Mask length is ' + mask.length + ' whereas input is ' + values.length);
  }

  return values
    .reduce(function(acc, args, i) {
      return acc.concat(mask[i].apply(null, Array.isArray(args) ? args : [args]));
    }, []);
};

if (typeof module === 'object' && typeof module.exports !== 'undefined') {
  module.exports = {
    uint8: uint8,
    uint16: uint16,
    bitmap: bitmap,
    encode: encode
  };
}