toPacket method

@override String toPacket()

toPacket returns the packet in the format of Layrz Protocol v3.

Implementation

@override
String toPacket() {
  String payload = '${timestamp.millisecondsSinceEpoch ~/ 1000};';
  payload += '${position.latitude ?? ''};';
  payload += '${position.longitude ?? ''};';
  payload += '${position.altitude ?? ''};';
  payload += '${position.speed ?? ''};';
  payload += '${position.direction ?? ''};';
  payload += '${position.satellites ?? ''};';
  payload += '${position.hdop ?? ''};';

  List<String> extraList = [];
  for (String key in extra.keys) {
    // Escape colons in key and value so they don't collide with the `key:value` separator on the
    // wire (e.g. a MAC-like identifier `a4:c1:...`). Reversed by Packet.parseExtraArgs (`___` -> `:`).
    final escapedKey = key.replaceAll(':', '___');
    final escapedValue = '${extra[key]}'.replaceAll(':', '___');
    extraList.add('$escapedKey:$escapedValue');
  }

  payload += '${extraList.join(',')};';

  String crc = calculateCrc(payload.codeUnits).toRadixString(16).padLeft(4, '0').toUpperCase();

  return '<Pd>$payload$crc</Pd>';
}