import 'package:abawo_bt_app/model/shifter_types.dart';
import 'package:abawo_bt_app/service/dfu_protocol.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  group('DfuProtocol CRC32', () {
    test('matches known vector', () {
      final crc = DfuProtocol.crc32('123456789'.codeUnits);
      expect(crc, 0xCBF43926);
    });
  });

  group('DfuProtocol control payload encoding', () {
    test('encodes START payload with exact 11-byte LE layout', () {
      final payload = DfuProtocol.encodeStartPayload(
        const DfuStartPayload(
          totalLength: 0x1234,
          imageCrc32: 0x89ABCDEF,
          sessionId: 0x22,
          flags: universalShifterDfuFlagEncrypted,
        ),
      );

      expect(payload.length, 11);
      expect(
        payload,
        [
          universalShifterDfuOpcodeStart,
          0x34,
          0x12,
          0x00,
          0x00,
          0xEF,
          0xCD,
          0xAB,
          0x89,
          0x22,
          universalShifterDfuFlagEncrypted,
        ],
      );
    });

    test('encodes FINISH and ABORT payloads as one byte', () {
      expect(
          DfuProtocol.encodeFinishPayload(), [universalShifterDfuOpcodeFinish]);
      expect(
          DfuProtocol.encodeAbortPayload(), [universalShifterDfuOpcodeAbort]);
    });
  });

  group('DfuProtocol data frame building', () {
    test('builds 64-byte frames and handles final partial payload', () {
      final image = List<int>.generate(80, (index) => index);
      final frames = DfuProtocol.buildDataFrames(image);

      expect(frames.length, 2);

      expect(frames[0].sequence, 0);
      expect(frames[0].offset, 0);
      expect(frames[0].payloadLength, universalShifterDfuFramePayloadSizeBytes);
      expect(frames[0].bytes.length, universalShifterDfuFrameSizeBytes);
      expect(frames[0].bytes.sublist(1, 64), image.sublist(0, 63));

      expect(frames[1].sequence, 1);
      expect(frames[1].offset, 63);
      expect(frames[1].payloadLength, 17);
      expect(frames[1].bytes.length, universalShifterDfuFrameSizeBytes);
      expect(frames[1].bytes.sublist(1, 18), image.sublist(63, 80));
    });
  });

  group('DfuProtocol sequence and ACK helpers', () {
    test('wraps sequence values and computes ack+1 rewind', () {
      expect(DfuProtocol.nextSequence(0x00), 0x01);
      expect(DfuProtocol.nextSequence(0xFF), 0x00);

      expect(DfuProtocol.rewindSequenceFromAck(0x05), 0x06);
      expect(DfuProtocol.rewindSequenceFromAck(0xFF), 0x00);
    });

    test('computes wrapping sequence distance', () {
      expect(DfuProtocol.sequenceDistance(250, 2), 8);
      expect(DfuProtocol.sequenceDistance(1, 1), 0);
    });
  });
}