decodeGeneric static method

({Uint8List data, String hrp}) decodeGeneric(String address)

Decodes a generic Bech32 address. Returns (hrp, data).

Implementation

static ({String hrp, Uint8List data}) decodeGeneric(String address) {
  final lower = address.toLowerCase();
  final upper = address.toUpperCase();

  if (address != lower && address != upper) {
    throw FormatException('Mixed case in Bech32 address');
  }

  final pos = lower.lastIndexOf('1');
  if (pos < 1 || pos + 7 > lower.length || lower.length > 90) {
    throw FormatException('Invalid Bech32 format');
  }

  final hrp = lower.substring(0, pos);
  final dataStr = lower.substring(pos + 1);

  final data = <int>[];
  for (final c in dataStr.split('')) {
    final index = _charset.indexOf(c);
    if (index < 0) {
      throw FormatException('Invalid Bech32 character: $c');
    }
    data.add(index);
  }

  // Use constant 1 (Bech32)
  if (!_verifyChecksum(hrp, data, false)) {
    throw FormatException('Invalid Bech32 checksum');
  }

  final values = data.sublist(0, data.length - 6);
  if (values.isEmpty) {
    // Empty data allowed? Maybe. But usually not.
  }

  final program = _convertBits(values, 5, 8, false);
  return (hrp: hrp, data: Uint8List.fromList(program));
}