Get and build prompt from local JSON file

Here we map our AI actions to the prompt from the JSON file
to be able to use them.

scribe/lib/scribe/ai/domain/constants/ai_prompts.dart

@@ -1,91 +1,28 @@
 import 'package:scribe/scribe/ai/data/model/ai_message.dart';
 import 'package:scribe/scribe/ai/presentation/model/ai_action.dart';
 import 'package:scribe/scribe/ai/presentation/model/ai_scribe_menu_action.dart';
+import 'package:scribe/scribe/ai/domain/service/prompt_service.dart';
 
 class AIPrompts {
-  static const _performTask = "Perform only the following task:";
-  static const _preserveLanguagePrompt =
-      "Do not translate. Strictly keep the original language of the input text. For example, if it's French, keep French. If it's English, keep English.";
-  static const _doNotAddInfoPrompt =
-      "Do not add any extra information or interpret anything beyond the explicit task.";
+  static final PromptService _promptService = PromptService();
 
-  static List<AIMessage> buildPrompt(AIAction action, String? text) {
-    final prompt =  switch (action) {
+  static Future<List<AIMessage>> buildPrompt(AIAction action, String? text) async {
+    return switch (action) {
       PredefinedAction(action: final menuAction) =>
-      text?.trim().isNotEmpty == true
-          ? buildPredefinedPrompt(menuAction, text!)
-          :  throw ArgumentError('Text cannot be empty for predefined actions'),
+        buildActionPrompt(menuAction, text),
       CustomPromptAction(prompt: final customPrompt) =>
         buildCustomPrompt(customPrompt, text),
     };
-
-    final message = [AIMessage.ofUser(prompt)];
-
-    return message;
   }
 
-  static String buildPredefinedPrompt(AIScribeMenuAction action, String text) {
-    switch (action) {
-      case AIScribeMenuAction.correctGrammar:
-        return correctGrammar(text);
-      case AIScribeMenuAction.improveMakeShorter:
-        return improveMakeShorter(text);
-      case AIScribeMenuAction.improveExpandContext:
-        return improveExpandContext(text);
-      case AIScribeMenuAction.improveEmojify:
-        return improveEmojify(text);
-      case AIScribeMenuAction.improveTransformToBullets:
-        return improveTransformToBullets(text);
-      case AIScribeMenuAction.changeToneProfessional:
-        return changeToneTo(text, 'professional');
-      case AIScribeMenuAction.changeToneCasual:
-        return changeToneTo(text, 'casual');
-      case AIScribeMenuAction.changeTonePolite:
-        return changeToneTo(text, 'polite');
-      case AIScribeMenuAction.translateFrench:
-        return translateTo(text, 'French');
-      case AIScribeMenuAction.translateEnglish:
-        return translateTo(text, 'English');
-      case AIScribeMenuAction.translateRussian:
-        return translateTo(text, 'Russian');
-      case AIScribeMenuAction.translateVietnamese:
-        return translateTo(text, 'Vietnamese');
+  static Future<List<AIMessage>> buildActionPrompt(AIScribeMenuAction menuAction, String? text) async {
+    if (text == null || text.trim().isEmpty) {
+      throw ArgumentError('Text cannot be empty for predefined actions');
     }
+    return await _promptService.buildPromptByName(menuAction.promptId, text);
   }
 
-  static String improveMakeShorter(String text) {
-    return '$_performTask make the text shorter but preserve the meaning. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String improveExpandContext(String text) {
-    return '$_performTask expand the context of the text to make it more detailed and comprehensive. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String improveEmojify(String text) {
-    return '$_performTask add emojis to the important parts of the text. Do not try to rephrase or replace text. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String improveTransformToBullets(String text) {
-    return '$_performTask transform the text into a bullet list. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String correctGrammar(String text) {
-    return '$_performTask correct grammar and spelling. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String changeToneTo(String text, String tone) {
-    return '$_performTask change the tone to be $tone. $_preserveLanguagePrompt $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String translateTo(String text, String language) {
-    return '$_performTask translate. Translate the text to the specified language: $language. $_doNotAddInfoPrompt Text:\n\n$text';
-  }
-
-  static String buildCustomPrompt(String customPrompt, String? text) {
-    if (text == null) {
-      return customPrompt;
-    }
-
-    return 'You help the user write an email following his instruction: $customPrompt\n\nDo not output a subject or a signature, only the content of the email. Text:\n\n$text';
+  static Future<List<AIMessage>> buildCustomPrompt(String customPrompt, String? text) async {
+    return await _promptService.buildPromptByName(CustomPromptAction.promptId, text ?? '', task: customPrompt);
   }
 }

scribe/lib/scribe/ai/domain/model/prompt_data.dart

@@ -0,0 +1,77 @@
+import 'package:scribe/scribe/ai/data/model/ai_message.dart';
+
+class PromptData {
+  final List<Prompt> prompts;
+
+  PromptData({
+    required this.prompts,
+  });
+
+  factory PromptData.fromJson(Map<String, dynamic> json) {
+    final promptsJson = json['prompts'];
+    if (promptsJson is! List<dynamic>) {
+      return PromptData(prompts: []);
+    }
+    
+    return PromptData(
+      prompts: promptsJson
+          .whereType<Map<String, dynamic>>()
+          .map((promptJson) => Prompt.fromJson(promptJson))
+          .toList(),
+    );
+  }
+}
+
+class Prompt {
+  final String name;
+  final List<AIMessage> messages;
+
+  Prompt({
+    required this.name,
+    required this.messages,
+  });
+
+  factory Prompt.fromJson(Map<String, dynamic> json) {
+    final name = json['name'];
+    if (name is! String) {
+      throw const FormatException('Prompt name must be a non-null String');
+    }
+    
+    final messagesJson = json['messages'];
+    if (messagesJson is! List<dynamic>) {
+      return Prompt(name: name, messages: []);
+    }
+    
+    return Prompt(
+      name: name,
+      messages: messagesJson
+          .whereType<Map<String, dynamic>>()
+          .map((messageJson) => AIMessage.fromJson(messageJson))
+          .toList(),
+    );
+  }
+
+  List<AIMessage> buildPrompt(String inputText, {String? task}) {
+    final messages = <AIMessage>[];
+    for (final message in this.messages) {
+      if (message.role == 'system') {
+        messages.add(AIMessage.ofSystem(message.content));
+      } else if (message.role == 'user') {
+        final userContent = _replacePlaceholders(message.content, inputText, task);
+        messages.add(AIMessage.ofUser(userContent));
+      }
+    }
+    return messages;
+  }
+
+  String _replacePlaceholders(String content, String inputText, String? task) {
+    String result = content;
+    if (result.contains('{{input}}')) {
+      result = result.replaceAll('{{input}}', inputText);
+    }
+    if (task != null && result.contains('{{task}}')) {
+      result = result.replaceAll('{{task}}', task);
+    }
+    return result;
+  }
+}

scribe/lib/scribe/ai/domain/service/prompt_service.dart

@@ -0,0 +1,43 @@
+import 'dart:convert';
+import 'package:flutter/services.dart' show rootBundle;
+import 'package:scribe/scribe/ai/data/model/ai_message.dart';
+import 'package:scribe/scribe/ai/domain/model/prompt_data.dart';
+
+class PromptService {
+  static final PromptService _instance = PromptService._internal();
+  
+  factory PromptService() => _instance;
+  
+  PromptService._internal();
+  
+  PromptData? _promptData;
+  
+  Future<PromptData> loadPrompts() async {
+    if (_promptData != null) {
+      return _promptData!;
+    }
+    
+    try {
+      final jsonString = await rootBundle.loadString('packages/scribe/assets/prompts.json');
+      final jsonData = jsonDecode(jsonString) as Map<String, dynamic>;
+
+      _promptData = PromptData.fromJson(jsonData);
+      return _promptData!;
+    } catch (e) {
+      throw Exception('Failed to load prompts: $e');
+    }
+  }
+  
+  Future<Prompt> getPromptByName(String name) async {
+    final promptData = await loadPrompts();
+    return promptData.prompts.firstWhere(
+      (prompt) => prompt.name == name,
+      orElse: () => throw Exception('Prompt not found: $name'),
+    );
+  }
+  
+  Future<List<AIMessage>> buildPromptByName(String name, String inputText, {String? task}) async {
+    final prompt = await getPromptByName(name);
+    return prompt.buildPrompt(inputText, task: task);
+  }
+}

scribe/lib/scribe/ai/domain/usecases/generate_ai_text_interactor.dart

@@ -16,7 +16,7 @@ class GenerateAITextInteractor {
     String? selectedText,
   ) async {
     try {
-      final prompt = AIPrompts.buildPrompt(action, selectedText);
+      final prompt = await AIPrompts.buildPrompt(action, selectedText);
       final response = await _repository.generateMessage(prompt);
       return Right(GenerateAITextSuccess(response));
     } catch (e) {

scribe/lib/scribe/ai/presentation/model/ai_action.dart

@@ -25,4 +25,6 @@ class CustomPromptAction extends AIAction {
   String getLabel(ScribeLocalizations localizations) {
     return localizations.customPromptAction;
   }
+  
+  static const String promptId = 'custom-prompt-mail';
 }

scribe/lib/scribe/ai/presentation/model/ai_scribe_menu_action.dart

@@ -65,6 +65,23 @@ enum AIScribeMenuAction {
     }
   }
 
+  String get promptId {
+    return switch (this) {
+      AIScribeMenuAction.correctGrammar => 'correct-grammar',
+      AIScribeMenuAction.improveMakeShorter => 'make-shorter',
+      AIScribeMenuAction.improveExpandContext => 'expand-context',
+      AIScribeMenuAction.improveEmojify => 'emojify',
+      AIScribeMenuAction.improveTransformToBullets => 'transform-to-bullets',
+      AIScribeMenuAction.changeToneProfessional => 'change-tone-professional',
+      AIScribeMenuAction.changeToneCasual => 'change-tone-casual',
+      AIScribeMenuAction.changeTonePolite => 'change-tone-polite',
+      AIScribeMenuAction.translateFrench => 'translate-french',
+      AIScribeMenuAction.translateEnglish => 'translate-english',
+      AIScribeMenuAction.translateRussian => 'translate-russian',
+      AIScribeMenuAction.translateVietnamese => 'translate-vietnamese',
+    };
+  }
+
   String getFullLabel(ScribeLocalizations localizations) {
     final categoryLabel = category.getLabel(localizations);
     if (category.hasSubmenu) {

scribe/test/assets/test_prompts.json

@@ -0,0 +1,30 @@
+{
+  "prompts": [
+    {
+      "name": "test-prompt",
+      "messages": [
+        {
+          "role": "system",
+          "content": "You are a test assistant."
+        },
+        {
+          "role": "user",
+          "content": "INSTRUCTION:\nTest instruction.\n\nTEXT:\n{{input}}"
+        }
+      ]
+    },
+    {
+      "name": "test-prompt-with-task",
+      "messages": [
+        {
+          "role": "system",
+          "content": "You are a test assistant with task."
+        },
+        {
+          "role": "user",
+          "content": "INSTRUCTION:\n{{task}}\n\nTEXT:\n{{input}}"
+        }
+      ]
+    }
+  ]
+}

scribe/test/scribe/ai/domain/model/prompt_data_test.dart

@@ -0,0 +1,167 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:scribe/scribe/ai/domain/model/prompt_data.dart';
+import 'package:scribe/scribe/ai/data/model/ai_message.dart';
+
+void main() {
+  group('PromptData', () {
+    test('fromJson should parse prompts correctly', () {
+      // Arrange
+      final jsonData = {
+        "prompts": [
+          {
+            "name": "test-prompt-1",
+            "messages": [
+              {
+                "role": "system",
+                "content": "System message 1"
+              },
+              {
+                "role": "user",
+                "content": "User message 1"
+              }
+            ]
+          },
+          {
+            "name": "test-prompt-2",
+            "messages": [
+              {
+                "role": "system",
+                "content": "System message 2"
+              },
+              {
+                "role": "user",
+                "content": "User message 2"
+              }
+            ]
+          }
+        ]
+      };
+
+      // Act
+      final promptData = PromptData.fromJson(jsonData);
+
+      // Assert
+      expect(promptData.prompts.length, 2);
+      expect(promptData.prompts.first.name, 'test-prompt-1');
+      expect(promptData.prompts.last.name, 'test-prompt-2');
+      expect(promptData.prompts.first.messages.length, 2);
+      expect(promptData.prompts.last.messages.length, 2);
+    });
+
+    test('fromJson should handle empty prompts list', () {
+      // Arrange
+      final jsonData = {
+        "prompts": []
+      };
+
+      // Act
+      final promptData = PromptData.fromJson(jsonData);
+
+      // Assert
+      expect(promptData.prompts.length, 0);
+    });
+  });
+
+  group('Prompt', () {
+    test('fromJson should parse prompt correctly', () {
+      // Arrange
+      final jsonData = {
+        "name": "test-prompt",
+        "messages": [
+          {
+            "role": "system",
+            "content": "System message"
+          },
+          {
+            "role": "user",
+            "content": "User message with {{input}} placeholder"
+          }
+        ]
+      };
+
+      // Act
+      final prompt = Prompt.fromJson(jsonData);
+
+      // Assert
+      expect(prompt.name, 'test-prompt');
+      expect(prompt.messages.length, 2);
+      expect(prompt.messages.first.role, 'system');
+      expect(prompt.messages.first.content, 'System message');
+      expect(prompt.messages.last.role, 'user');
+      expect(prompt.messages.last.content, 'User message with {{input}} placeholder');
+    });
+
+    test('buildPrompt should replace input placeholder correctly', () {
+      // Arrange
+      final messages = [
+        const AIMessage(role: 'system', content: 'System message'),
+        const AIMessage(role: 'user', content: 'User message with {{input}} placeholder')
+      ];
+      final prompt = Prompt(name: 'test-prompt', messages: messages);
+
+      // Act
+      final result = prompt.buildPrompt('test input value');
+
+      // Assert
+      expect(result.length, 2);
+      expect(result.first.role, 'system');
+      expect(result.first.content, 'System message');
+      expect(result.last.role, 'user');
+      expect(result.last.content, 'User message with test input value placeholder');
+    });
+
+    test('buildPrompt should replace task placeholder when provided', () {
+      // Arrange
+      final messages = [
+        const AIMessage(role: 'system', content: 'System message'),
+        const AIMessage(role: 'user', content: 'Task: {{task}}, Input: {{input}}')
+      ];
+      final prompt = Prompt(name: 'test-prompt', messages: messages);
+
+      // Act
+      final result = prompt.buildPrompt('test input value', task: 'test task value');
+
+      // Assert
+      expect(result.length, 2);
+      expect(result.first.role, 'system');
+      expect(result.first.content, 'System message');
+      expect(result.last.role, 'user');
+      expect(result.last.content, 'Task: test task value, Input: test input value');
+    });
+
+    test('buildPrompt should not replace task placeholder when not provided', () {
+      // Arrange
+      final messages = [
+        const AIMessage(role: 'system', content: 'System message'),
+        const AIMessage(role: 'user', content: 'Task: {{task}}, Input: {{input}}')
+      ];
+      final prompt = Prompt(name: 'test-prompt', messages: messages);
+
+      // Act
+      final result = prompt.buildPrompt('test input value');
+
+      // Assert
+      expect(result.length, 2);
+      expect(result.first.role, 'system');
+      expect(result.first.content, 'System message');
+      expect(result.last.role, 'user');
+      expect(result.last.content, 'Task: {{task}}, Input: test input value');
+    });
+
+    test('buildPrompt should handle messages without placeholders', () {
+      // Arrange
+      final messages = [
+        const AIMessage(role: 'system', content: 'System message'),
+        const AIMessage(role: 'user', content: 'User message without placeholders')
+      ];
+      final prompt = Prompt(name: 'test-prompt', messages: messages);
+
+      // Act
+      final result = prompt.buildPrompt('test input', task: 'test task');
+
+      // Assert
+      expect(result.length, 2);
+      expect(result.last.content, 'User message without placeholders');
+    });
+  });
+}

scribe/test/scribe/ai/domain/service/prompt_service_test.dart

@@ -0,0 +1,101 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:scribe/scribe/ai/domain/service/prompt_service.dart';
+import 'package:scribe/scribe/ai/domain/model/prompt_data.dart';
+import 'package:scribe/scribe/ai/data/model/ai_message.dart';
+
+void main() {
+  setUpAll(() {
+    TestWidgetsFlutterBinding.ensureInitialized();
+  });
+
+  group('PromptService', () {
+    test('PromptService should be singleton', () {
+      // Act
+      final service1 = PromptService();
+      final service2 = PromptService();
+
+      // Assert
+      expect(service1, same(service2));
+    });
+
+    test('buildPromptByName should build prompt with input text', () async {
+      // Arrange
+      final service = PromptService();
+      
+      // Act - this will use the real prompts.json file
+      final messages = await service.buildPromptByName('change-tone-casual', 'Hello, how are you?');
+
+      // Assert
+      expect(messages.length, 2);
+      expect(messages.first.role, 'system');
+      expect(messages.last.role, 'user');
+      expect(messages.last.content, contains('Hello, how are you?'));
+    });
+
+    test('buildPromptByName should build prompt with input text and task', () async {
+      // Arrange
+      final service = PromptService();
+      
+      // Act - this will use the real prompts.json file
+      final messages = await service.buildPromptByName('custom-prompt-mail', 'Hello, how are you?', task: 'Make it more casual');
+
+      // Assert
+      expect(messages.length, 2);
+      expect(messages.first.role, 'system');
+      expect(messages.last.role, 'user');
+      expect(messages.last.content, contains('Hello, how are you?'));
+      expect(messages.last.content, contains('Make it more casual'));
+    });
+  });
+
+  group('PromptService getPromptByName', () {
+    test('getPromptByName should return correct prompt from data', () async {
+      // Arrange
+      final promptData = PromptData(
+        prompts: [
+          Prompt(
+            name: 'test-prompt',
+            messages: [
+              const AIMessage(role: 'system', content: 'System message'),
+              const AIMessage(role: 'user', content: 'User message with {{input}}')
+            ]
+          )
+        ]
+      );
+
+      // Act
+      final prompt = promptData.prompts.firstWhere(
+        (prompt) => prompt.name == 'test-prompt',
+        orElse: () => throw Exception('Prompt not found: test-prompt'),
+      );
+
+      // Assert
+      expect(prompt.name, 'test-prompt');
+      expect(prompt.messages.length, 2);
+    });
+
+    test('getPromptByName should throw exception for non-existent prompt', () async {
+      // Arrange
+      final promptData = PromptData(
+        prompts: [
+          Prompt(
+            name: 'test-prompt',
+            messages: [
+              const AIMessage(role: 'system', content: 'System message'),
+              const AIMessage(role: 'user', content: 'User message')
+            ]
+          )
+        ]
+      );
+
+      // Act & Assert
+      expect(
+        () => promptData.prompts.firstWhere(
+          (prompt) => prompt.name == 'non-existent-prompt',
+          orElse: () => throw Exception('Prompt not found: non-existent-prompt'),
+        ),
+        throwsException,
+      );
+    });
+  });
+}