extractMeasurementData static method

Uint8List extractMeasurementData(Uint8List rawData)

Extracts measurement data from raw blocks.

Each block is 18 bytes: 2-byte block index (little endian) + 16 bytes data. The last block may be smaller (2-byte index + remaining data). Blocks are sorted by their index to handle out-of-order BLE delivery. Returns the measurement data with block indices stripped.

Implementation

static Uint8List extractMeasurementData(Uint8List rawData) {
  if (rawData.isEmpty) return rawData;

  // Step 1: Parse blocks into a map keyed by block index
  final Map<int, List<int>> blockMap = {};
  int offset = 0;

  while (offset < rawData.length) {
    // Read 2-byte block index (little endian)
    if (offset + 2 > rawData.length) break;
    final blockIndex = (rawData[offset + 1] << 8) | rawData[offset];
    offset += 2;

    // Read up to 16 bytes of data
    final remaining = rawData.length - offset;
    final dataLen = remaining > 16 ? 16 : remaining;
    if (dataLen > 0) {
      blockMap[blockIndex] = rawData.sublist(offset, offset + dataLen);
      offset += dataLen;
    }
  }

  // Step 2: Sort blocks by their index
  final sortedBlockIndices = blockMap.keys.toList()..sort();

  // Step 3: Combine sorted blocks
  final output = BytesBuilder();
  for (final blockIndex in sortedBlockIndices) {
    output.add(blockMap[blockIndex]!);
  }

  return output.toBytes();
}