feat: add AI Training Mode with Bedrock exercise generation

.kiro/specs/ai-training-mode/tasks.md

@@ -6,21 +6,21 @@ Extend the existing training system with an AI-powered training mode (`AI_TRAINI
 
 ## Tasks
 
-- [ ] 1. Extend domain model and GraphQL schema
-  - [ ] 1.1 Add `AI_TRAINING` to `TrainingMode` type and add `AIExercise` interface in `backend/src/model/domain/Training.ts`
+- [x] 1. Extend domain model and GraphQL schema
+  - [x] 1.1 Add `AI_TRAINING` to `TrainingMode` type and add `AIExercise` interface in `backend/src/model/domain/Training.ts`
     - Extend `TrainingMode` to `'TEXT_INPUT' | 'MULTIPLE_CHOICE' | 'AI_TRAINING'`
     - Add `AIExercise` interface with `prompt`, `options`, `correctOptionIndex`, `exerciseType`, `sourceWord`
     - Add optional `aiExercises?: AIExercise[]` field to `TrainingExecution`
     - _Requirements: 1.2, 3.3, 3.4_
 
-  - [ ] 1.2 Update GraphQL schema in `backend/src/gql-schemas/schema.graphql`
+  - [x] 1.2 Update GraphQL schema in `backend/src/gql-schemas/schema.graphql`
     - Add `AI_TRAINING` to `TrainingMode` enum
     - Add `AIExercise` type with `prompt: String!`, `options: [String!]!`, `correctOptionIndex: Int!`, `exerciseType: String!`, `sourceWord: String!`
     - Add `aiExercises: [AIExercise!]` to `TrainingExecution` type
     - _Requirements: 1.1, 3.1, 3.2, 10.3_
 
-- [ ] 2. Implement AI exercise generation in AIService
-  - [ ] 2.1 Add `generateExercises` method to `backend/src/services/ai-service.ts`
+- [x] 2. Implement AI exercise generation in AIService
+  - [x] 2.1 Add `generateExercises` method to `backend/src/services/ai-service.ts`
     - Accept `words` array (with word, translation, definition, partOfSpeech, exampleSentence), `sourceLanguage`, `targetLanguage`, `userId`
     - Check rate limit via existing `checkRateLimit`
     - Build structured Bedrock prompt including all word fields and both languages
@@ -31,107 +31,107 @@ Extend the existing training system with an AI-powered training mode (`AI_TRAINI
     - Return `AIExercise[]`
     - _Requirements: 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 6.1, 6.2, 6.3, 7.1, 7.2, 7.3, 7.4_
 
-  - [ ]* 2.2 Write property test: AI exercise prompt construction includes all context (Property 2)
+  - [x]* 2.2 Write property test: AI exercise prompt construction includes all context (Property 2)
     - **Property 2: AI exercise prompt construction includes all context**
     - **Validates: Requirements 2.2, 2.5**
 
-  - [ ]* 2.3 Write property test: AI exercise parsing and validation (Property 3)
+  - [x]* 2.3 Write property test: AI exercise parsing and validation (Property 3)
     - **Property 3: AI exercise parsing and validation**
     - **Validates: Requirements 2.3, 2.6, 7.1, 7.3**
 
-  - [ ]* 2.4 Write property test: AI exercise round-trip serialization (Property 4)
+  - [x]* 2.4 Write property test: AI exercise round-trip serialization (Property 4)
     - **Property 4: AI exercise round-trip serialization**
     - **Validates: Requirements 7.5**
 
 
-  - [ ]* 2.5 Write unit tests for AI exercise generation edge cases
+  - [x]* 2.5 Write unit tests for AI exercise generation edge cases
     - Test `generateExercises` returns error when Bedrock fails (Req 2.7)
     - Test `generateExercises` returns rate limit error when limit exceeded (Req 6.1, 6.2)
     - Test `generateExercises` logs usage with userId, operation, tokenCount (Req 6.3)
     - Test Bedrock response with invalid JSON returns parsing error (Req 7.2)
     - Test all exercises invalid returns error (Req 7.4)
     - _Requirements: 2.7, 6.1, 6.2, 6.3, 7.2, 7.4_
 
-- [ ] 3. Checkpoint - Ensure all tests pass
+- [x] 3. Checkpoint - Ensure all tests pass
   - Ensure all tests pass, ask the user if questions arise.
 
-- [ ] 4. Implement AI training creation and start in TrainingService
-  - [ ] 4.1 Modify `createTraining` in `backend/src/services/training-service.ts` to accept `AI_TRAINING` mode
+- [x] 4. Implement AI training creation and start in TrainingService
+  - [x] 4.1 Modify `createTraining` in `backend/src/services/training-service.ts` to accept `AI_TRAINING` mode
     - For static AI trainings: word selection works identically to existing modes (fetch from vocab lists, shuffle, slice)
     - For randomized AI trainings: store `words: []` as with existing randomized behavior
     - No special handling needed beyond accepting the new mode value
     - _Requirements: 1.3, 5.3_
 
-  - [ ] 4.2 Modify `startTraining` in `backend/src/services/training-service.ts` to add AI_TRAINING branch
+  - [x] 4.2 Modify `startTraining` in `backend/src/services/training-service.ts` to add AI_TRAINING branch
     - For AI_TRAINING mode: select words (from `training.words` for static, dynamically for randomized)
     - Fetch vocabulary lists to get full word details (definition, partOfSpeech, exampleSentence) and language info (sourceLanguage, targetLanguage)
     - Call `AIService.generateExercises(words, sourceLanguage, targetLanguage, userId)`
     - Store `aiExercises` on the `TrainingExecution`, no `multipleChoiceOptions` for AI trainings
     - Error if fewer than 1 word available
     - _Requirements: 2.1, 4.1, 4.2, 4.3, 4.6, 5.1, 5.2_
 
-  - [ ] 4.3 Modify `submitAnswer` in `backend/src/services/training-service.ts` to add AI_TRAINING branch
+  - [x] 4.3 Modify `submitAnswer` in `backend/src/services/training-service.ts` to add AI_TRAINING branch
     - Look up `execution.aiExercises[wordIndex]`
     - Compare `parseInt(answer)` against `exercise.correctOptionIndex`
     - Build `TrainingResult` with prompt as `word`, correct option as `expectedAnswer`
     - Completion check: `results.length === aiExercises.length`
     - _Requirements: 4.4, 4.5_
 
-  - [ ]* 4.4 Write property test: AI training creation stores mode correctly (Property 1)
+  - [x]* 4.4 Write property test: AI training creation stores mode correctly (Property 1)
     - **Property 1: AI training creation stores mode correctly**
     - **Validates: Requirements 1.3**
 
-  - [ ]* 4.5 Write property test: AI training start produces one exercise per selected word (Property 5)
+  - [x]* 4.5 Write property test: AI training start produces one exercise per selected word (Property 5)
     - **Property 5: AI training start produces one exercise per selected word**
     - **Validates: Requirements 2.1, 4.1, 4.3**
 
-  - [ ]* 4.6 Write property test: AI answer submission and completion (Property 6)
+  - [x]* 4.6 Write property test: AI answer submission and completion (Property 6)
     - **Property 6: AI answer submission and completion**
     - **Validates: Requirements 4.4, 4.5**
 
-  - [ ]* 4.7 Write property test: Randomized AI training dynamic selection and generation (Property 7)
+  - [x]* 4.7 Write property test: Randomized AI training dynamic selection and generation (Property 7)
     - **Property 7: Randomized AI training dynamic selection and generation**
     - **Validates: Requirements 5.1, 5.2**
 
-  - [ ]* 4.8 Write property test: Non-AI trainings backward compatibility (Property 8)
+  - [x]* 4.8 Write property test: Non-AI trainings backward compatibility (Property 8)
     - **Property 8: Non-AI trainings backward compatibility**
     - **Validates: Requirements 10.1**
 
-  - [ ]* 4.9 Write unit tests for AI training service edge cases
+  - [x]* 4.9 Write unit tests for AI training service edge cases
     - Test start AI training with 0 available words returns error (Req 4.6)
     - Test existing TEXT_INPUT/MULTIPLE_CHOICE trainings unaffected by AI changes (Req 10.1, 10.2)
     - Test AI answer submission with correct and incorrect option indices (Req 4.4)
     - Test AI training completion after all exercises answered (Req 4.5)
     - _Requirements: 4.4, 4.5, 4.6, 10.1, 10.2_
 
-- [ ] 5. Checkpoint - Ensure all backend tests pass
+- [x] 5. Checkpoint - Ensure all backend tests pass
   - Ensure all tests pass, ask the user if questions arise.
 
-- [ ] 6. Update frontend training provider and creation UI
-  - [ ] 6.1 Update `startTraining` GraphQL mutation in `frontend/src/lib/providers/training_provider.dart` to fetch `aiExercises { prompt options correctOptionIndex exerciseType sourceWord }` on the execution response
+- [x] 6. Update frontend training provider and creation UI
+  - [x] 6.1 Update `startTraining` GraphQL mutation in `frontend/src/lib/providers/training_provider.dart` to fetch `aiExercises { prompt options correctOptionIndex exerciseType sourceWord }` on the execution response
     - _Requirements: 3.2, 9.1_
 
-  - [ ] 6.2 Add `AI_TRAINING` as a third `ChoiceChip` option in the mode selector on `frontend/src/lib/screens/training_creation_screen.dart`
+  - [x] 6.2 Add `AI_TRAINING` as a third `ChoiceChip` option in the mode selector on `frontend/src/lib/screens/training_creation_screen.dart`
     - Allow vocabulary list selection, word count, and randomized mode same as other modes
     - Send mode as `AI_TRAINING` in the `createTraining` mutation
     - _Requirements: 8.1, 8.2, 8.3_
 
-- [ ] 7. Create AI exercise display widget and update execution screen
-  - [ ] 7.1 Create `frontend/src/lib/widgets/ai_exercise_widget.dart`
+- [x] 7. Create AI exercise display widget and update execution screen
+  - [x] 7.1 Create `frontend/src/lib/widgets/ai_exercise_widget.dart`
     - Display exercise type label (e.g., "Verb Conjugation")
     - Display prompt sentence
     - Display answer options as tappable buttons
     - On selection, submit the option index as the answer via `submitAnswer`
     - Show correct/incorrect feedback with the correct answer highlighted
     - _Requirements: 9.1, 9.2, 9.3_
 
-  - [ ] 7.2 Update `frontend/src/lib/screens/training_execution_screen.dart` to handle AI_TRAINING mode
+  - [x] 7.2 Update `frontend/src/lib/screens/training_execution_screen.dart` to handle AI_TRAINING mode
     - When mode is AI_TRAINING, render `AIExerciseWidget` instead of text input or multiple choice
     - Show progress indicator (current exercise / total)
     - Navigate to results screen when all exercises completed
     - _Requirements: 9.1, 9.4_
 
-- [ ] 8. Final checkpoint - Ensure all tests pass
+- [x] 8. Final checkpoint - Ensure all tests pass
   - Ensure all tests pass, ask the user if questions arise.
 
 ## Notes

backend/src/gql-schemas/schema.graphql

@@ -27,6 +27,7 @@ enum PaymentProvider @aws_cognito_user_pools {
 enum TrainingMode @aws_cognito_user_pools {
   TEXT_INPUT
   MULTIPLE_CHOICE
+  AI_TRAINING
 }
 
 enum TrainingDirection @aws_cognito_user_pools {
@@ -106,6 +107,14 @@ type MultipleChoiceOption @aws_cognito_user_pools {
   options: [String!]!
 }
 
+type AIExercise @aws_cognito_user_pools {
+  prompt: String!
+  options: [String!]!
+  correctOptionIndex: Int!
+  exerciseType: String!
+  sourceWord: String!
+}
+
 type TrainingExecution @aws_cognito_user_pools {
   id: ID!
   trainingId: ID!
@@ -116,6 +125,7 @@ type TrainingExecution @aws_cognito_user_pools {
   results: [TrainingResult!]!
   multipleChoiceOptions: [MultipleChoiceOption!]
   words: [TrainingWord!]
+  aiExercises: [AIExercise!]
   correctCount: Int!
   incorrectCount: Int!
 }

backend/src/model/domain/Training.ts

@@ -2,7 +2,7 @@
  * Domain models for Training entity
  */
 
-export type TrainingMode = 'TEXT_INPUT' | 'MULTIPLE_CHOICE';
+export type TrainingMode = 'TEXT_INPUT' | 'MULTIPLE_CHOICE' | 'AI_TRAINING';
 export type TrainingDirection = 'WORD_TO_TRANSLATION' | 'TRANSLATION_TO_WORD';
 
 export interface TrainingWord {
@@ -41,6 +41,14 @@ export interface MultipleChoiceOption {
   correctOptionIndex: number;
 }
 
+export interface AIExercise {
+  prompt: string;
+  options: string[];
+  correctOptionIndex: number;
+  exerciseType: string;
+  sourceWord: string;
+}
+
 export interface TrainingExecution {
   id: string;
   trainingId: string;
@@ -51,6 +59,7 @@ export interface TrainingExecution {
   results: TrainingResult[];
   multipleChoiceOptions?: MultipleChoiceOption[];
   words?: TrainingWord[];
+  aiExercises?: AIExercise[];
   correctCount: number;
   incorrectCount: number;
 }