Architecture:
- Questions are primary objects in a bank, tagged with question categories
- QuestionCategory is a separate taxonomy from QuizCategory (different concepts)
- Extraction → questions added to bank, optionally tagged to a question category
- Quizzes can be created from: individual question selection, question category, or PDF extraction
Backend:
- QuestionCategory model + question_categories table
- question_category_id column on questions table (nullable, SET NULL on delete)
- GET/POST/PATCH/DELETE /api/question-categories/
- POST /api/question-categories/{id}/create-quiz — create quiz from all questions in a category
- PATCH /api/questions/{id}/category — assign single question to category
- PATCH /api/questions/bulk-category — assign multiple questions at once
- GET /api/questions/bank?category_id=&uncategorized= — filter by category
- QuizCreate schema now accepts question_category_id for extraction
- quiz_service.create_quiz_from_section accepts question_category_id param
Frontend:
- DocumentDetailPage: Add to Bank Category dropdown in Quiz Settings (optional)
Labels extracted questions with the selected category on creation
- QuestionBankPage: full rewrite
- Category chips for filtering (All / Uncategorized / named categories)
- Create category button inline
- Checkbox multi-select with bulk category assignment
- Create Quiz modal: choose from selected questions OR all from a category
- Each question shows its category badge and quiz source
- Study modal with instant answer feedback
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
- FastAPI backend with JWT auth, roles (admin/moderator/user)
- PDF upload (up to 500MB) with streaming, PyMuPDF text extraction
- ChromaDB vectorization per page with metadata
- LiteLLM AI question extraction from PDF (not generation)
- Image extraction from PDF pages, graceful fallback
- Quiz modes: timed (countdown timer) + learning (answers shown inline)
- Page-by-page question navigation with dot navigator
- TTS endpoint using LiteLLM (Google Vertex / OpenAI voices)
- Admin dashboard: AI model management per task, user role management
- Moderator role: upload PDFs, create sections, generate quizzes
- Spaced repetition reminders via SMTP email (SM-2 intervals)
- APScheduler daily reminder jobs
- Celery + Redis for background PDF processing
- React frontend with all pages
- Docker Compose deployment (nginx + backend + celery + redis)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>