/* eslint-disable no-mixed-operators */
/* eslint-disable no-bitwise */

/* 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.
 */
// 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}`.toLowerCase(),
        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 if (`${prefix}${key}`.toLowerCase() === "distance") {
      result.push({
        variable: `${prefix}${key}`.toLowerCase(),
        value: object_item[key],
        unit: "mm",
        serie,
      });
    } else {
      result.push({
        variable: `${prefix}${key}`.toLowerCase(),
        value: object_item[key],
        serie,
      });
    }
  }

  return result;
}

function Decoder(bytes, port) {
  // Decode an uplink message from a buffer
  // (array) of bytes to an object of fields.
  let value = ((bytes[0] << 8) | bytes[1]) & 0x3fff;
  const batV = value / 1000; // Battery,units:V

  value = (bytes[2] << 8) | bytes[3];
  let distance = value; // distance,units:mm
  if (value === 0) distance = "No Sensor";
  else if (value < 280) distance = "Invalid Reading";

  return {
    Battery: { value: batV, unit: "V" },
    Distance: distance,
  };
}

// let payload = [
//   {
//     variable: "time",
//     value: 1571874770.422976,
//     serie: 1571874770524,
//   },
//   {
//     variable: "payload",
//     value: "4Be202000008000001",
//     serie: 1571874770524,
//   },
//   {
//     variable: "port",
//     value: 2,
//     serie: 1571874770524,
//   },
//   {
//     variable: "duplicate",
//     value: false,
//     serie: 1571874770524,
//   },
//   {
//     variable: "counter_up",
//     value: 38,
//     serie: 1571874770524,
//   },
//   {
//     variable: "rx_time",
//     value: 1571874770.3568993,
//     serie: 1571874770524,
//   },
//   {
//     variable: "encrypted_payload",
//     value: "c12oeBn03DxbfqcD",
//     serie: 1571874770524,
//   },
// ];
// Check if what is being stored is the ttn_payload.
// Payload is an environment variable. Is where what is being inserted to your device comes in.
// Payload always is an array of objects. [ { variable, value...}, {variable, value...} ...]
const payload_raw = payload.find((x) => x.variable === "payload" || x.variable === "payload_raw" || x.variable === "data");
if (payload_raw) {
  // Get a unique serie for the incoming data.
  const serie = payload_raw.serie || new Date().getTime();
  let vars_to_tago = [];
  // Parse the payload from your sensor to function parsePayload
  try {
    const decoded = Decoder(Buffer.from(payload_raw.value, "hex"));
    vars_to_tago = vars_to_tago.concat(toTagoFormat(decoded, 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);
}

// console.log(JSON.stringify(payload));