// Décodeur LoRaWAN officiel : LHT52 - Temperature & Humidity Sensor (Dragino)
// Source : https://github.com/TheThingsNetwork/lorawan-devices/blob/master/vendor/dragino/lht52.js
// The Things Network Device Repository, fichier publié par le constructeur, distribué sans modification.
// Format : decodeUplink(input) (TTN v3 / ChirpStack v4). Hébergé par smartbuildings.fr.

function str_pad(byte) {
  var zero = '0';
  var hex = byte.toString(16);
  var tmp = 2 - hex.length;
  return zero.substr(0, tmp) + hex;
}

function decodeUplink(input) {
  var port = input.fPort;
  var bytes = input.bytes;
  var data = {};
  switch (input.fPort) {
    case 2:
      {
        if (bytes.length == 11) {
          data.TempC_SHT = parseFloat(((((bytes[0] << 24) >> 16) | bytes[1]) / 100).toFixed(2));
          data.Hum_SHT = parseFloat(((((bytes[2] << 24) >> 16) | bytes[3]) / 10).toFixed(1));
          data.TempC_DS = parseFloat(((((bytes[4] << 24) >> 16) | bytes[5]) / 100).toFixed(2));

          data.Ext = bytes[6];
          data.Systimestamp = (bytes[7] << 24) | (bytes[8] << 16) | (bytes[9] << 8) | bytes[10];
        } else {
          data.Status = 'RPL data or sensor reset';
        }
      }
      return {
        data: data,
      };
      break;

    case 3:
      {
        data.Status = 'Data retrieved, your need to parse it by the application server';
      }
      return {
        data: data,
      };
      break;

    case 4:
      {
        data.DS18B20_ID = str_pad(bytes[0]) + str_pad(bytes[1]) + str_pad(bytes[2]) + str_pad(bytes[3]) + str_pad(bytes[4]) + str_pad(bytes[5]) + str_pad(bytes[6]) + str_pad(bytes[7]);
      }
      return {
        data: data,
      };
      break;

    case 5:
      {
        data.Sensor_Model = bytes[0];
        data.Firmware_Version = str_pad((bytes[1] << 8) | bytes[2]);
        data.Freq_Band = bytes[3];
        data.Sub_Band = bytes[4];
        data.Bat_mV = (bytes[5] << 8) | bytes[6];
      }
      return {
        data: data,
      };
      break;

    default:
      return {
        errors: ['unknown FPort'],
      };
  }
}

function normalizeUplink(input) {
  var data = [];

  if (input.data.TempC_SHT) {
    data.push({
      air: {
        location: 'indoor',
        temperature: input.data.TempC_SHT,
        relativeHumidity: input.data.Hum_SHT,
      },
    });
  }

  if (input.data.TempC_DS) {
    data.push({
      air: {
        location: 'outdoor',
        temperature: input.data.TempC_DS,
      },
    });
  }

  if (input.data.Bat_mV) {
    data.push({
      battery: input.data.Bat_mV,
    });
  }

  return { data: data };
}