openai service

books_flutter/lib/services/gemini_service.dart

@@ -1,12 +1,115 @@
+import 'dart:io';
+import 'dart:convert';
+import 'package:google_generative_ai/google_generative_ai.dart';
 import '../models/models.dart';
 
 class GeminiService {
-  GeminiService({required String apiKey});
+  final String apiKey;
+  late final GenerativeModel _model;
 
-  Future<Book?> analyzeBookCover(String base64Image) async {
-    // Placeholder - Gemini API integration would go here
-    // Would use google_generative_ai package to send the image
-    // and extract book metadata via structured JSON output
-    return null;
+  GeminiService({required this.apiKey}) {
+    _model = GenerativeModel(model: 'gemini-1.5-flash', apiKey: apiKey);
+  }
+
+  Future<Book?> analyzeBookCover(String imagePath) async {
+    try {
+      // Read the image file
+      final imageFile = File(imagePath);
+      final imageBytes = await imageFile.readAsBytes();
+      final base64Image = base64Encode(imageBytes);
+
+      // Create the prompt for book analysis
+      const prompt = '''
+Analyze this book cover image and extract the following information in JSON format:
+{
+  "title": "book title (required)",
+  "author": "author name (required)", 
+  "genre": "fiction/fantasy/science/detective/biography/other",
+  "annotation": "brief description or summary if visible, otherwise generate a generic one"
+}
+
+Rules:
+- Extract exact text from the cover
+- If genre is unclear, choose the most appropriate one
+- If annotation is not visible, create a brief generic description
+- Return ONLY valid JSON, no additional text
+- Ensure all required fields are present
+''';
+
+      // Create the image part for the model
+      final imagePart = Content.data('image/jpeg', imageBytes);
+
+      // Generate content with both text and image
+      final response = await _model.generateContent([
+        Content.text(prompt),
+        imagePart,
+      ]);
+
+      final responseText = response.text?.trim();
+
+      if (responseText == null || responseText.isEmpty) {
+        print('Empty response from Gemini');
+        return null;
+      }
+
+      // Extract JSON from response (handle potential markdown formatting)
+      String jsonString = responseText;
+      if (jsonString.contains('```json')) {
+        jsonString = jsonString.split('```json')[1].split('```')[0].trim();
+      } else if (jsonString.contains('```')) {
+        jsonString = jsonString.split('```')[1].split('```')[0].trim();
+      }
+
+      // Parse JSON response
+      final Map<String, dynamic> jsonData = json.decode(jsonString);
+
+      // Create Book object with extracted data
+      final Book book = (
+        id: DateTime.now().millisecondsSinceEpoch.toString(),
+        title: jsonData['title']?.toString() ?? 'Неизвестная книга',
+        author: jsonData['author']?.toString() ?? 'Неизвестный автор',
+        genre: _normalizeGenre(jsonData['genre']?.toString()),
+        annotation: jsonData['annotation']?.toString() ?? 'Нет описания',
+        coverUrl: null, // Will be set by the caller
+        pages: null,
+        language: 'Russian',
+        publishedYear: DateTime.now().year,
+        rating: 5.0,
+        status: 'want_to_read',
+        progress: null,
+        isFavorite: false,
+      );
+
+      return book;
+    } catch (e) {
+      print('Error analyzing book cover: $e');
+      return null;
+    }
+  }
+
+  String _normalizeGenre(String? genre) {
+    if (genre == null || genre.isEmpty) return 'other';
+
+    final normalized = genre.toLowerCase().trim();
+
+    // Map various genre names to our standard genres
+    final genreMap = {
+      'фантастика': 'fiction',
+      'fantasy': 'fantasy',
+      'фэнтези': 'fantasy',
+      'science': 'science',
+      'научпоп': 'science',
+      'научная': 'science',
+      'biography': 'biography',
+      'биография': 'biography',
+      'detective': 'detective',
+      'детектив': 'detective',
+      'роман': 'other',
+      'novel': 'other',
+      'poetry': 'other',
+      'поэзия': 'other',
+    };
+
+    return genreMap[normalized] ?? normalized;
   }
 }