yhsung · yhsung · Jun 19, 2025 · Jun 19, 2025
diff --git a/README.md b/README.md
@@ -20,3 +20,4 @@ samples, guidance on mobile development, and a full API reference.
 - Attach images to your chat messages.
 - Preview a thumbnail of the attached image before sending.
 - Thumbnail preview appears in the chat after sending a message with an image.
+- Upload PDF files, generate embeddings, and receive a summary from the selected LLM service.
diff --git a/lib/models/message.dart b/lib/models/message.dart
@@ -21,12 +21,14 @@ class Message {
   final String content;
   final DateTime timestamp;
   final String? imageBase64;
+  final List<double>? embedding;
 
   Message({
     String? id,
     required this.role,
     required this.content,
     this.imageBase64,
+    this.embedding,
     DateTime? timestamp,
   }) : id = id ?? const Uuid().v4(),
        timestamp = timestamp ?? DateTime.now();
@@ -36,13 +38,15 @@ class Message {
     MessageRole? role,
     String? content,
     String? imageBase64,
+    List<double>? embedding,
     DateTime? timestamp,
   }) {
     return Message(
       id: id ?? this.id,
       role: role ?? this.role,
       content: content ?? this.content,
       imageBase64: imageBase64 ?? this.imageBase64,
+      embedding: embedding ?? this.embedding,
       timestamp: timestamp ?? this.timestamp,
     );
   }
@@ -53,6 +57,7 @@ class Message {
       'role': role.toString().split('.').last,
       'content': content,
       if (imageBase64 != null) 'imageBase64': imageBase64,
+      if (embedding != null) 'embedding': embedding,
       'timestamp': timestamp.toIso8601String(),
     };
   }
@@ -66,6 +71,7 @@ class Message {
       ),
       content: json['content'],
       imageBase64: json['imageBase64'],
+      embedding: (json['embedding'] as List?)?.map((e) => (e as num).toDouble()).toList(),
       timestamp: DateTime.parse(json['timestamp']),
     );
   }

diff --git a/lib/providers/chat_providers.dart b/lib/providers/chat_providers.dart
@@ -181,4 +181,55 @@ class ActiveChatSessionNotifier extends StateNotifier<ChatSession?> {
       _ref.read(isLoadingProvider.notifier).state = false;
     }
   }
+
+  Future<void> sendMessageWithPdf(
+    String content,
+    String pdfText,
+  ) async {
+    if (state == null) return;
+
+    ChatSession? updatedSession;
+
+    _ref.read(isLoadingProvider.notifier).state = true;
+
+    try {
+      final llmService = _ref.read(selectedLlmServiceProvider);
+
+      final embedding = await llmService.embedText(pdfText);
+
+      final userMessage = Message(
+        role: MessageRole.user,
+        content: content,
+        embedding: embedding,
+      );
+
+      updatedSession = state!.addMessage(userMessage);
+      state = updatedSession;
+      _ref.read(chatSessionsProvider.notifier).updateSession(updatedSession!);
+
+      final messagesWithPdf = [
+        ...updatedSession.messages,
+        Message(role: MessageRole.user, content: pdfText),
+      ];
+
+      final assistantMessage =
+          await llmService.sendMessage(messagesWithPdf);
+
+      final finalSession = updatedSession.addMessage(assistantMessage);
+      state = finalSession;
+      _ref.read(chatSessionsProvider.notifier).updateSession(finalSession);
+    } catch (e) {
+      final errorMessage = Message(
+        role: MessageRole.assistant,
+        content: 'Error: ${e.toString()}',
+      );
+
+      final sessionForError = updatedSession ?? state!;
+      final finalSession = sessionForError.addMessage(errorMessage);
+      state = finalSession;
+      _ref.read(chatSessionsProvider.notifier).updateSession(finalSession);
+    } finally {
+      _ref.read(isLoadingProvider.notifier).state = false;
+    }
+  }
 }
diff --git a/lib/services/azure_openai_service.dart b/lib/services/azure_openai_service.dart
@@ -129,4 +129,46 @@ class AzureOpenAiService implements LlmService {
   Future<String> getApiVersion() async {
     return await _secureStorage.read(key: _apiVersionKey) ?? _defaultApiVersion;
   }
+
+  @override
+  Future<List<double>> embedText(String text) async {
+    final apiKey = await _secureStorage.read(key: _apiKeyKey);
+    final endpoint = await _secureStorage.read(key: _endpointKey);
+    final deployment = await getCurrentModel();
+    final apiVersion = await _secureStorage.read(key: _apiVersionKey) ?? _defaultApiVersion;
+
+    if (apiKey == null || apiKey.isEmpty) {
+      throw Exception('Azure OpenAI API key not configured');
+    }
+
+    if (endpoint == null || endpoint.isEmpty) {
+      throw Exception('Azure OpenAI endpoint not configured');
+    }
+
+    final url = '$endpoint/openai/deployments/$deployment/embeddings?api-version=$apiVersion';
+
+    try {
+      final response = await _dio.post(
+        url,
+        options: Options(
+          headers: {
+            'api-key': apiKey,
+            'Content-Type': 'application/json',
+          },
+        ),
+        data: {
+          'input': text,
+        },
+      );
+
+      if (response.statusCode == 200) {
+        final data = response.data['data'][0]['embedding'] as List;
+        return data.map((e) => (e as num).toDouble()).toList();
+      } else {
+        throw Exception('Failed to get embedding from Azure OpenAI: ${response.statusCode}');
+      }
+    } catch (e) {
+      throw Exception('Error requesting embedding from Azure OpenAI: $e');
+    }
+  }
 }
diff --git a/lib/services/llm_service.dart b/lib/services/llm_service.dart
@@ -15,6 +15,9 @@ abstract class LlmService {
     List<Message> messages,
     String base64Image,
   );
+
+  /// Generate an embedding vector for the provided text
+  Future<List<double>> embedText(String text);
 
   /// Get the available models for this service
   Future<List<String>> getAvailableModels();

diff --git a/lib/services/ollama_service.dart b/lib/services/ollama_service.dart
@@ -123,4 +123,30 @@ class OllamaService implements LlmService {
   Future<String> getEndpoint() async {
     return await _secureStorage.read(key: _endpointKey) ?? _defaultEndpoint;
   }
+
+  @override
+  Future<List<double>> embedText(String text) async {
+    final endpoint = await _secureStorage.read(key: _endpointKey) ?? _defaultEndpoint;
+    final model = await getCurrentModel();
+
+    try {
+      final response = await _dio.post(
+        '$endpoint/api/embeddings',
+        options: Options(headers: {'Content-Type': 'application/json'}),
+        data: {
+          'model': model,
+          'prompt': text,
+        },
+      );
+
+      if (response.statusCode == 200) {
+        final data = response.data['embedding'] as List;
+        return data.map((e) => (e as num).toDouble()).toList();
+      } else {
+        throw Exception('Failed to get embedding from Ollama: ${response.statusCode}');
+      }
+    } catch (e) {
+      throw Exception('Error communicating with Ollama: $e');
+    }
+  }
 }
diff --git a/lib/services/openai_service.dart b/lib/services/openai_service.dart
@@ -118,6 +118,43 @@ class OpenAiService implements LlmService {
     }
   }
 
+  @override
+  Future<List<double>> embedText(String text) async {
+    final apiKey = await _secureStorage.read(key: _apiKeyKey);
+    if (apiKey == null || apiKey.isEmpty) {
+      throw Exception('OpenAI API key not configured');
+    }
+
+    const embeddingModel = 'text-embedding-3-small';
+
+    try {
+      final response = await _dio.post(
+        '$_baseUrl/embeddings',
+        options: Options(
+          headers: {
+            'Authorization': 'Bearer $apiKey',
+            'Content-Type': 'application/json',
+          },
+        ),
+        data: {
+          'model': embeddingModel,
+          'input': text,
+        },
+      );
+
+      if (response.statusCode == 200) {
+        final data = response.data['data'][0]['embedding'] as List;
+        return data.map((e) => (e as num).toDouble()).toList();
+      } else {
+        throw Exception(
+          'Failed to get embedding from OpenAI: ${response.statusCode}',
+        );
+      }
+    } catch (e) {
+      throw Exception('Error requesting embedding from OpenAI: $e');
+    }
+  }
+
   @override
   Future<List<String>> getAvailableModels() async {
     return ['gpt-3.5-turbo', 'gpt-4', 'gpt-4-turbo'];

diff --git a/lib/ui/screens/chat_screen.dart b/lib/ui/screens/chat_screen.dart
@@ -4,6 +4,8 @@ import 'dart:io';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:image_picker/image_picker.dart';
+import 'package:file_picker/file_picker.dart';
+import 'package:pdf_text/pdf_text.dart';
 import '../../models/message.dart';
 import '../../providers/chat_providers.dart';
 import '../widgets/message_bubble.dart';
@@ -92,6 +94,7 @@ class _MessageInputState extends ConsumerState<MessageInput> {
   final TextEditingController _controller = TextEditingController();
   bool _canSend = false;
   File? _selectedImage;
+  File? _selectedPdf;
 
   @override
   void initState() {
@@ -109,7 +112,8 @@ class _MessageInputState extends ConsumerState<MessageInput> {
   void _updateCanSend() {
     final text = _controller.text.trim();
     setState(() {
-      _canSend = text.isNotEmpty || _selectedImage != null;
+      _canSend =
+          text.isNotEmpty || _selectedImage != null || _selectedPdf != null;
     });
   }
 
@@ -124,23 +128,45 @@ class _MessageInputState extends ConsumerState<MessageInput> {
     }
   }
 
+  Future<void> _pickPdf() async {
+    final result = await FilePicker.platform.pickFiles(
+      type: FileType.custom,
+      allowedExtensions: ['pdf'],
+    );
+    if (result != null && result.files.single.path != null) {
+      setState(() {
+        _selectedPdf = File(result.files.single.path!);
+        _updateCanSend();
+      });
+    }
+  }
+
   Future<void> _sendMessage() async {
     final text = _controller.text.trim();
-    if (text.isEmpty && _selectedImage == null) return;
+    if (text.isEmpty && _selectedImage == null && _selectedPdf == null) return;
 
     if (_selectedImage != null) {
       final bytes = await _selectedImage!.readAsBytes();
       final base64Image = base64Encode(bytes);
       await ref
           .read(activeChatSessionProvider.notifier)
           .sendMessageWithImage(text, base64Image);
+    } else if (_selectedPdf != null) {
+      final doc = await PDFDoc.fromFile(_selectedPdf!);
+      final pdfText = await doc.text;
+      final displayText =
+          text.isNotEmpty ? text : 'Summarize PDF: ${_selectedPdf!.path.split('/').last}';
+      await ref
+          .read(activeChatSessionProvider.notifier)
+          .sendMessageWithPdf(displayText, pdfText);
     } else {
       await ref.read(activeChatSessionProvider.notifier).sendMessage(text);
     }
 
     _controller.clear();
     setState(() {
       _selectedImage = null;
+      _selectedPdf = null;
       _updateCanSend();
     });
   }
@@ -194,6 +220,50 @@ class _MessageInputState extends ConsumerState<MessageInput> {
                 ],
               ),
             ),
+          if (_selectedPdf != null)
+            Padding(
+              padding: const EdgeInsets.only(bottom: 8.0),
+              child: Stack(
+                alignment: Alignment.topRight,
+                children: [
+                  Container(
+                    padding: const EdgeInsets.all(8.0),
+                    decoration: BoxDecoration(
+                      color: Theme.of(context).colorScheme.secondaryContainer,
+                      borderRadius: BorderRadius.circular(8.0),
+                    ),
+                    child: Row(
+                      mainAxisSize: MainAxisSize.min,
+                      children: [
+                        const Icon(Icons.picture_as_pdf, size: 24),
+                        const SizedBox(width: 8),
+                        Text(_selectedPdf!.path.split('/').last),
+                      ],
+                    ),
+                  ),
+                  GestureDetector(
+                    onTap: () {
+                      setState(() {
+                        _selectedPdf = null;
+                        _updateCanSend();
+                      });
+                    },
+                    child: Container(
+                      padding: const EdgeInsets.all(2.0),
+                      decoration: BoxDecoration(
+                        color: Colors.black54,
+                        borderRadius: BorderRadius.circular(12.0),
+                      ),
+                      child: const Icon(
+                        Icons.close,
+                        size: 16,
+                        color: Colors.white,
+                      ),
+                    ),
+                  ),
+                ],
+              ),
+            ),
           Row(
             children: [
               Expanded(
@@ -228,6 +298,14 @@ class _MessageInputState extends ConsumerState<MessageInput> {
                 color: Theme.of(context).colorScheme.secondary,
               ),
               const SizedBox(width: 8.0),
+              IconButton(
+                icon: Icon(
+                  _selectedPdf == null ? Icons.picture_as_pdf : Icons.check,
+                ),
+                onPressed: isLoading ? null : _pickPdf,
+                color: Theme.of(context).colorScheme.secondary,
+              ),
+              const SizedBox(width: 8.0),
               FutureBuilder<bool>(
                 future: isConfigured,
                 builder: (context, snapshot) {

diff --git a/pubspec.yaml b/pubspec.yaml
@@ -52,6 +52,8 @@ dependencies:
   intl: ^0.19.0
   path_provider: ^2.1.2
   image_picker: ^1.0.4
+  file_picker: ^10.2.0
+  pdf_text: ^0.5.0
 
 dev_dependencies:
   flutter_test: