moneroBase58Decode function

Uint8List moneroBase58Decode(String encoded)

Implementation

Uint8List moneroBase58Decode(String encoded) {
  if (encoded.isEmpty) return Uint8List(0);

  final fullBlocks = encoded.length ~/ _fullEncodedBlockSize;
  final remainderChars = encoded.length % _fullEncodedBlockSize;

  if (remainderChars != 0 && !_decodedBlockSizes.containsKey(remainderChars)) {
    throw FormatException(
        'Invalid Monero base58 string length: ${encoded.length}');
  }

  final remainderBytes =
      remainderChars > 0 ? _decodedBlockSizes[remainderChars]! : 0;
  final totalBytes = fullBlocks * _fullBlockSize + remainderBytes;
  final result = Uint8List(totalBytes);
  var offset = 0;

  for (var i = 0; i < fullBlocks; i++) {
    final start = i * _fullEncodedBlockSize;
    final block = _decodeBlock(
        encoded.substring(start, start + _fullEncodedBlockSize));
    result.setRange(offset, offset + _fullBlockSize, block);
    offset += _fullBlockSize;
  }

  if (remainderChars > 0) {
    final start = fullBlocks * _fullEncodedBlockSize;
    final block = _decodeBlock(encoded.substring(start));
    result.setRange(offset, offset + remainderBytes, block);
  }

  return result;
}