Building a Scrabble Companion with Gemini 2.0 - Move Analysis with Multiple LLMs

23-board-ai-smart-scrabble-gemini-1.dart

class GeminiService {
  late GenerativeModel _model;
  final ImageStorageService _imageStorage = ImageStorageService();
  final FirebaseService _firebaseService = FirebaseService();

  GeminiService() {
    // Initialize with Gemini 2.0 Flash
    _model = FirebaseVertexAI.instance
        .generativeModel(model: 'gemini-2.0-flash');
  }

  Future<Map<String, dynamic>> analyzeBoardImage(
    String sessionId,
    String imagePath,
  ) async {
    try {
      // Read current image bytes
      final currentImageBytes = await File(imagePath).readAsBytes();

      // Get board state
      final boardState = await _firebaseService.getBoardState(sessionId).first;
      final isFirstMove = boardState.isEmpty;

      if (isFirstMove) {
        // Handle first move analysis
        final response = await _model.generateContent([
          Content.multi([
            TextPart(_constructInitialBoardPrompt()),
            DataPart('image/jpeg', currentImageBytes),
          ]),
        ]);

        return {
          'status': 'success',
          'type': 'initial',
          'data': _parseGeminiResponse(response.text!, true),
        };
      } else {
        // Compare with previous state
        final response = await _model.generateContent([
          Content.multi([
            TextPart(_constructImageComparisonPrompt(boardState)),
            DataPart('image/jpeg', currentImageBytes),
          ]),
        ]);

        return {
          'status': 'success',
          'type': 'move',
          'data': _parseGeminiResponse(response.text!, false),
        };
      }
    } catch (e) {
      return {
        'status': 'error',
        'message': e.toString(),
      };
    }
  }

  // Prompt construction for initial board analysis
  String _constructInitialBoardPrompt() {
    return '''
    You are analyzing an image of an initial Scrabble board move.
    Accurately identify all visible letters and their positions.
    Return ONLY a JSON with this format:
    {
      "board": [
        {
          "letter": "A",
          "row": 7,
          "col": 7,
          "points": 1
        }
      ]
    }
    ''';
  }
}