/* This is an example code for Everynet Parser.
** Everynet send several parameters to TagoIO. The job of this parse is to convert all these parameters into a TagoIO format.
** One of these parameters is the payload of your device. We find it too and apply the appropriate sensor parse.
**
** IMPORTANT: In most case, you will only need to edit the parsePayload function.
**
** Testing:
** You can do manual tests to this parse by using the Device Emulator. Copy and Paste the following code:
** [{ "variable": "everynet_payload", "value": "{ \"params\": { \"payload\": \"0109611395\" } }" }]
**
** The ignore_vars variable in this code should be used to ignore variables
** from the device that you don't want.
*/
// payload example from the documentation '00FE0001518000006A50000000'; | '0080CB750180415C0081FF';
// Add ignorable variables in this array.
const ignore_vars = ['device_addr', 'port', 'duplicate', 'network', 'packet_hash', 'application', 'device', 'packet_id'];


/**
 * Convert an object to TagoIO object format.
 * Can be used in two ways:
 * toTagoFormat({ myvariable: myvalue , anothervariable: anothervalue... })
 * toTagoFormat({ myvariable: { value: myvalue, unit: 'C', metadata: { color: 'green' }} , anothervariable: anothervalue... })
 *
 * @param {Object} object_item Object containing key and value.
 * @param {String} serie Serie for the variables
 * @param {String} prefix Add a prefix to the variables name
 */
function toTagoFormat(object_item, serie, prefix = '') {
  const result = [];
  for (const key in object_item) {
    if (ignore_vars.includes(key)) continue;

    if (typeof object_item[key] == 'object') {
      result.push({
        variable: object_item[key].variable || `${prefix}${key}`,
        value: object_item[key].value,
        serie: object_item[key].serie || serie,
        metadata: object_item[key].metadata,
        location: object_item[key].location,
        unit: object_item[key].unit,
      });
    } else {
      result.push({
        variable: `${prefix}${key}`,
        value: object_item[key],
        serie,
      });
    }
  }

  return result;
}

/**
 *  In the solutions params is where usually latitude and longitude for your antenna signal comes from.
 * @param {Object} solutions gateway object from everynet
 * @param {String|Number} serie serie for the variables
 */
function transformSolutionParam(solutions, serie) {
  let to_tago = [];
  for (const s of solutions) {
    let convert_json = {};
    convert_json.base_location = { value: `${s.lat}, ${s.lng}`, location: { lat: s.lat, lng: s.lng } };
    delete s.lat;
    delete s.lng;

    convert_json = { ...convert_json, ...s };
    to_tago = to_tago.concat(toTagoFormat(convert_json, serie));
  }

  return to_tago;
}

function parsePayload(payload_raw, serie) {
  // If your device is sending something different than hex, like base64, just specify it bellow.
  const buffer = Buffer.from(payload_raw, 'hex');

  const data = {};
  let msg_byte;
  let channel;
  for (let x = 1; x < buffer.length;) {
    switch (buffer[x]) {
      case 254: // FE
        msg_byte = Buffer.from(buffer.slice(x += 1, x += 4));
        data.elapsed_time = { value: msg_byte.readInt32BE(0), unit: 'seconds', serie };
        msg_byte = Buffer.from(buffer.slice(x, x += 4));
        data.energy_consumed = { value: msg_byte.readInt32BE(0), unit: 'W-h', serie };
        x += 1;
        break;
      case 0: // 00
        msg_byte = Buffer.from(buffer.slice(x += 1));
        data.energy_consumption_meter_status = { value: msg_byte.readUInt8(0) === 0 ? 'idde' : 'active', serie };
        x += 1;
        break;
      case 128: // 80
        channel = buffer[x - 1];
        msg_byte = Buffer.from(buffer.slice(x += 1, x += 2));
        if (channel === 0) {
          data.real_power = { value: msg_byte.readInt16BE(0) * 0.1, unit: 'W', serie };
        } else {
          data.apparent_power = { value: msg_byte.readInt16BE(0) * 0.1, unit: 'W', serie };
        }
        x += 1;
        break;
      case 129: // 81
        msg_byte = Buffer.from(buffer.slice(x += 1));
        data.power_factor = { value: msg_byte.readUInt8(0) < 254 ? msg_byte.readUInt8(0) : 'N/A', unit: 'W', serie };
        x += 1;
        break;
      case 116: // 74
        msg_byte = Buffer.from(buffer.slice(x += 1, x += 2));
        data.voltmeter = { value: msg_byte.readInt16BE(0) * 0.1, unit: 'Vrms', serie };
        x += 1;
        break;
      case 117: // 75
        msg_byte = Buffer.from(buffer.slice(x += 1, x += 2));
        data.ammeter = { value: msg_byte.readInt16BE(0) * 0.1, unit: 'Arms', serie };
        x += 1;
        break;
      case 1: // 01
        msg_byte = Buffer.from(buffer.slice(x += 1));
        data.relay_status = { value: msg_byte.readUInt8(0) === 0 ? 'Open' : 'Closed', serie };
        x += 1;
        break;
      default:
    }
  }

  return data;
}

const everynet_payload = payload.find(x => x.variable === 'payload' || x.variable === 'payload_raw' || x.variable === 'data');
if (everynet_payload) {
  // Get a unique serie for the incoming data.
  const serie = everynet_payload.serie || new Date().getTime();
  let vars_to_tago = [];
  try {
    vars_to_tago = vars_to_tago.concat(toTagoFormat(parsePayload(everynet_payload.value, serie), serie));
  } catch (e) {
    // Catch any error in the parse code and send to parse_error variable.
    vars_to_tago = vars_to_tago.concat({ variable: 'parse_error', value: e.message || e });
  }

  payload = payload.concat(vars_to_tago);
}