name: pdf_chat_app description: A Flutter application to chat with uploaded PDFs. publish_to: 'none' # Remove this line if you wish to publish to pub.dev version: 1.0.0+1 environment: sdk: '>=3.0.0 <4.0.0' dependencies: flutter: sdk: flutter cupertino_icons: ^1.0.6 # Use the latest version file_picker: ^6.1.1 # For picking files http: ^1.1.0 # For making API calls path: ^1.8.3 # For handling file paths (needed for http multipart) dev_dependencies: flutter_test: sdk: flutter flutter_lints: ^3.0.1 # Use the latest version flutter: uses-material-design: true import 'package:flutter/material.dart'; import 'package:pdf_chat_app/pdf_chat_screen.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( title: 'PDF Chat App', theme: ThemeData( // Define the default brightness and colors. brightness: Brightness.dark, // Set overall theme to dark primaryColor: const Color(0xFFF2EFE1), // Primary color for AppBar, etc. scaffoldBackgroundColor: const Color.fromARGB(255, 48, 47, 47), // Background color // Define the default `TextTheme`. Use this to specify the default // text styling for headlines, titles, bodies of text, and more. textTheme: const TextTheme( displayLarge: TextStyle(fontSize: 72.0, fontWeight: FontWeight.bold, color: Color(0xFFF2EFE1)), titleLarge: TextStyle(fontSize: 24.0, fontStyle: FontStyle.italic, color: Color(0xFFF2EFE1)), bodyMedium: TextStyle(fontSize: 14.0, fontFamily: 'Hind', color: Color(0xFFF2EFE1)), ), // Define the default `AppBarTheme`. appBarTheme: const AppBarTheme( backgroundColor: Color(0xFFF2EFE1), // AppBar background foregroundColor: Color.fromARGB(255, 48, 47, 47), // AppBar text/icon color titleTextStyle: TextStyle( color: Color.fromARGB(255, 48, 47, 47), fontSize: 20, fontWeight: FontWeight.bold, ), ), // Define the default `ElevatedButtonTheme`. elevatedButtonTheme: ElevatedButtonThemeData( style: ElevatedButton.styleFrom( backgroundColor: const Color(0xFFF2EFE1), // Button background foregroundColor: const Color.fromARGB(255, 48, 47, 47), // Button text color ), ), // Define the default `InputDecorationTheme` for TextFields. inputDecorationTheme: const InputDecorationTheme( filled: true, fillColor: Color.fromARGB(255, 60, 60, 60), // TextField background hintStyle: TextStyle(color: Colors.grey), labelStyle: TextStyle(color: Color(0xFFF2EFE1)), border: OutlineInputBorder( borderSide: BorderSide(color: Color(0xFFF2EFE1)), ), enabledBorder: OutlineInputBorder( borderSide: BorderSide(color: Color(0xFFF2EFE1)), ), focusedBorder: OutlineInputBorder( borderSide: BorderSide(color: Colors.white, width: 2.0), ), ), colorScheme: ColorScheme.fromSeed( seedColor: const Color(0xFFF2EFE1), brightness: Brightness.dark, background: const Color.fromARGB(255, 48, 47, 47), primary: const Color(0xFFF2EFE1), ).copyWith(background: const Color.fromARGB(255, 48, 47, 47)), ), home: const PdfChatScreen(), ); } } import 'dart:convert'; import 'dart:io'; import 'package:flutter/material.dart'; import 'package:file_picker/file_picker.dart'; import 'package:http/http.dart' as http; import 'package:path/path.dart' as p; // For basename class PdfChatScreen extends StatefulWidget { const PdfChatScreen({super.key}); @override State createState() => _PdfChatScreenState(); } class _PdfChatScreenState extends State { List _pickedFiles = []; final TextEditingController _questionController = TextEditingController(); String _apiResponse = ''; bool _isLoadingProcessing = false; bool _isLoadingAsking = false; bool _isProcessed = false; String _errorMessage = ''; // --- Configuration --- // IMPORTANT: Replace with your actual backend URL final String _baseUrl = "http://127.0.0.1:5000"; // Example: Use localhost for local dev // --------------------- Future _pickPdfs() async { setState(() { _errorMessage = ''; // Clear previous errors _apiResponse = ''; // Clear previous response _isProcessed = false; // Reset processed state }); try { FilePickerResult? result = await FilePicker.platform.pickFiles( type: FileType.custom, allowedExtensions: ['pdf'], allowMultiple: true, ); if (result != null) { setState(() { _pickedFiles = result.files; }); } else { // User canceled the picker if (mounted) { ScaffoldMessenger.of(context).showSnackBar( const SnackBar(content: Text('File picking cancelled.')), ); } } } catch (e) { setState(() { _errorMessage = "Error picking files: $e"; }); if (mounted) { ScaffoldMessenger.of(context).showSnackBar( SnackBar(content: Text('Error picking files: $e')), ); } } } Future _processPdfs() async { if (_pickedFiles.isEmpty) { if (mounted) { ScaffoldMessenger.of(context).showSnackBar( const SnackBar(content: Text('Please select PDF files first.')), ); } return; } setState(() { _isLoadingProcessing = true; _errorMessage = ''; _apiResponse = ''; _isProcessed = false; }); final url = Uri.parse('$_baseUrl/process_pdfs'); var request = http.MultipartRequest('POST', url); for (var file in _pickedFiles) { if (file.path != null) { request.files.add(await http.MultipartFile.fromPath('files', file.path!)); } else { // Handle web platform if needed (file.bytes) if (mounted) { ScaffoldMessenger.of(context).showSnackBar( SnackBar(content: Text('Error: File path is null for ${file.name}. Cannot upload.')), ); } setState(() { _isLoadingProcessing = false; }); return; // Stop processing if any file path is null } } try { final streamedResponse = await request.send(); final response = await http.Response.fromStream(streamedResponse); if (response.statusCode == 200) { final responseData = jsonDecode(response.body); setState(() { _apiResponse = responseData['message'] ?? 'Processing successful!'; _isProcessed = true; // Mark as processed }); if (mounted) { ScaffoldMessenger.of(context).showSnackBar( SnackBar(content: Text(_apiResponse)), ); } } else { final responseData = jsonDecode(response.body); setState(() { _errorMessage = "Error processing PDFs: ${response.statusCode} - ${responseData['error'] ?? response.reasonPhrase}"; _isProcessed = false; }); } } catch (e) { setState(() { _errorMessage = "Network or server error during processing: $e"; _isProcessed = false; }); } finally { setState(() { _isLoadingProcessing = false; }); } } Future _askQuestion() async { if (!_isProcessed) { if (mounted) { ScaffoldMessenger.of(context).showSnackBar( const SnackBar(content: Text('Please process the PDFs first.')), ); } return; } if (_questionController.text.isEmpty) { if (mounted) { ScaffoldMessenger.of(context).showSnackBar( const SnackBar(content: Text('Please enter a question.')), ); } return; } setState(() { _isLoadingAsking = true; _errorMessage = ''; _apiResponse = ''; // Clear previous response before asking new question }); // --- Assumption: Backend has an endpoint like '/ask_question' --- // This endpoint needs to know which processed context to use. // This might involve session IDs, user IDs, or passing back an ID // from the /process_pdfs response. Adjust accordingly based on your API. final url = Uri.parse('$_baseUrl/ask_question'); // ADJUST THIS ENDPOINT // ----------------------------------------------------------------- try { final response = await http.post( url, headers: {'Content-Type': 'application/json'}, body: jsonEncode({'question': _questionController.text}), ); if (response.statusCode == 200) { final responseData = jsonDecode(response.body); // Assuming the response contains an 'answer' field setState(() { _apiResponse = responseData['answer'] ?? 'No answer received.'; }); } else { final responseData = jsonDecode(response.body); setState(() { _errorMessage = "Error asking question: ${response.statusCode} - ${responseData['error'] ?? response.reasonPhrase}"; }); } } catch (e) { setState(() { _errorMessage = "Network or server error while asking: $e"; }); } finally { setState(() { _isLoadingAsking = false; }); } } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: const Text('PDF Chat'), ), body: Padding( padding: const EdgeInsets.all(16.0), child: SingleChildScrollView( // Allows scrolling if content overflows child: Column( crossAxisAlignment: CrossAxisAlignment.stretch, children: [ // --- File Picker Section --- ElevatedButton.icon( icon: const Icon(Icons.picture_as_pdf), label: const Text('Select PDFs'), onPressed: _isLoadingProcessing || _isLoadingAsking ? null : _pickPdfs, ), const SizedBox(height: 10), if (_pickedFiles.isNotEmpty) Container( padding: const EdgeInsets.all(8.0), decoration: BoxDecoration( border: Border.all(color: Theme.of(context).primaryColor.withOpacity(0.5)), borderRadius: BorderRadius.circular(5), ), child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text("Selected Files:", style: Theme.of(context).textTheme.titleLarge?.copyWith(fontSize: 16)), const SizedBox(height: 5), Wrap( // Use Wrap for better layout of multiple files spacing: 8.0, // Horizontal space between chips runSpacing: 4.0, // Vertical space between lines children: _pickedFiles.map((file) => Chip( label: Text(p.basename(file.name)), // Use path.basename onDeleted: _isLoadingProcessing || _isLoadingAsking ? null : () { setState(() { _pickedFiles.remove(file); _isProcessed = false; // Need to reprocess if files change _apiResponse = ''; _errorMessage = ''; }); }, )).toList(), ), ], ), ), const SizedBox(height: 20), // --- Process Button --- if (_pickedFiles.isNotEmpty) ElevatedButton.icon( icon: _isLoadingProcessing ? Container( width: 24, height: 24, padding: const EdgeInsets.all(2.0), child: const CircularProgressIndicator(strokeWidth: 3), ) : const Icon(Icons.cloud_upload), label: const Text('Process PDFs'), onPressed: _isLoadingProcessing || _isLoadingAsking ? null : _processPdfs, ), const SizedBox(height: 20), // --- Question Input Section --- TextField( controller: _questionController, decoration: const InputDecoration( labelText: 'Ask a question about the PDFs', hintText: 'Enter your question here...', ), enabled: _isProcessed && !_isLoadingAsking, // Enable only after processing maxLines: 3, // Allow multi-line questions ), const SizedBox(height: 10), ElevatedButton.icon( icon: _isLoadingAsking ? Container( width: 24, height: 24, padding: const EdgeInsets.all(2.0), child: const CircularProgressIndicator(strokeWidth: 3), ) : const Icon(Icons.question_answer), label: const Text('Ask Question'), onPressed: _isProcessed && !_isLoadingAsking && !_isLoadingProcessing ? _askQuestion : null, // Enable only when ready ), const SizedBox(height: 20), // --- Response/Error Display Section --- if (_errorMessage.isNotEmpty) Padding( padding: const EdgeInsets.symmetric(vertical: 8.0), child: Text( 'Error: $_errorMessage', style: const TextStyle(color: Colors.redAccent, fontWeight: FontWeight.bold), ), ), if (_apiResponse.isNotEmpty) Container( padding: const EdgeInsets.all(12.0), decoration: BoxDecoration( color: Colors.black.withOpacity(0.2), borderRadius: BorderRadius.circular(5), border: Border.all(color: Theme.of(context).primaryColor.withOpacity(0.5)), ), child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text( _isLoadingAsking ? "Thinking..." : (_isProcessed && _apiResponse.contains('successful') ? "Processing Status:" : "Answer:"), // Better context label style: Theme.of(context).textTheme.titleLarge?.copyWith(fontSize: 16) ), const SizedBox(height: 8), Text( _apiResponse, style: Theme.of(context).textTheme.bodyMedium?.copyWith(fontSize: 15), ), ], ), ), ], ), ), ), ); } @override void dispose() { _questionController.dispose(); super.dispose(); } }