# Backend Documentation Index

## Overview

This directory contains comprehensive documentation of the Biblical Guide backend architecture. The analysis covers the complete backend system including database design, authentication, APIs, payment processing, and admin functionality.

## Documentation Files

### 1. BACKEND_ARCHITECTURE_ANALYSIS.md (Primary Document)
**Size**: 29 KB | **Lines**: 890 | **Sections**: 13

Complete architectural documentation covering:

- **Section 1**: Database Schema (32 models)
  - User Management
  - Bible Data Models
  - User Content Models
  - Communication Models
  - Prayer System Models
  - Reading Plans Models
  - Payment & Subscription Models
  - Content Management Models
  - User Preferences

- **Section 2**: Authentication System
  - JWT Token Architecture
  - User Registration/Login Flow
  - Admin Authentication
  - Permission System
  - Client-Side Auth Management

- **Section 3**: Payment & Subscription System
  - Stripe Configuration
  - Donation Flow
  - Subscription Flow
  - Webhook Handling
  - Conversation Limit Management

- **Section 4**: API Structure & Endpoints
  - Framework & Runtime
  - 12 API Categories
  - 70+ Documented Endpoints
  - Request/Response Patterns

- **Section 5**: Key Business Logic
  - Conversation Limit System
  - Prayer System Features
  - Reading Plans
  - Chat System
  - Vector Search
  - Admin Features

- **Section 6-13**: Additional Topics
  - External Integrations
  - File Storage
  - Technology Stack
  - Environment Variables
  - Current Status & Notes
  - Data Relationships
  - API Response Patterns
  - Deployment Considerations

**Best For**: Comprehensive understanding, onboarding new developers, system design decisions

---

### 2. BACKEND_QUICK_REFERENCE.md (Quick Lookup)
**Size**: 9.2 KB | **Lines**: 353 | **Sections**: 14

Quick reference guide for common tasks:

- **Model Index**: 32 models organized by category
- **Authentication Table**: Endpoints, methods, auth requirements
- **API Endpoints**: Organized by category with example URLs
- **Subscription Tiers**: Feature comparison table
- **Data Constraints**: Unique constraints and cascades
- **Webhook Events**: Stripe events and their effects
- **Admin Permissions**: Role-based access matrix
- **Limits & Defaults**: Important configuration values
- **Query Patterns**: Common Prisma queries
- **Environment Checklist**: Required variables
- **Development Tasks**: Common npm scripts
- **Performance Tips**: Optimization guidelines
- **Troubleshooting**: Common issues and solutions
- **Resource Links**: External documentation

**Best For**: Day-to-day reference, quick lookups, during development

---

## Key Information at a Glance

### Technology Stack
| Component | Technology | Version |
|-----------|-----------|---------|
| Framework | Next.js | 15.5.3 |
| Database | PostgreSQL | Latest |
| ORM | Prisma | 6.16.2 |
| Auth | JWT | via jsonwebtoken 9.0.2 |
| Payments | Stripe | 19.1.0 |
| Email | Mailgun | 12.0.3 |
| AI | Azure OpenAI | Custom |
| Validation | Zod | 3.25.76 |

### Database Statistics
- **Total Models**: 32
- **Total Indexes**: 25+
- **Unique Constraints**: 20+
- **Foreign Key Cascades**: 8
- **Text Fields**: 15+ (for long content)
- **JSON Fields**: 5 (for flexible data)

### API Statistics
- **Total Endpoints**: 70+
- **Public Endpoints**: 15
- **Protected Endpoints**: 40
- **Admin Endpoints**: 25+
- **Webhook Endpoints**: 2
- **Categories**: 12

### Authentication
- **User Token Expiry**: 7 days
- **Admin Token Expiry**: 24 hours (8 hours for cookie)
- **Password Hash Rounds**: 10 (bcryptjs)
- **Session Expiry**: 7 days
- **Admin Roles**: Admin, Moderator
- **Permission Types**: 13

### Subscription System
- **Free Tier Limit**: 10 conversations/month
- **Premium Tier Limit**: Unlimited
- **Webhook Events Handled**: 9+
- **Payment Methods**: Stripe (card)
- **Donation Presets**: $5, $10, $25, $50, $100, $250

## Quick Start References

### Common Tasks

**Find Information About**:
- Specific API endpoint → Search "API STRUCTURE" in ARCHITECTURE_ANALYSIS.md or check QUICK_REFERENCE.md
- Database model → "DATABASE SCHEMA" in ARCHITECTURE_ANALYSIS.md or MODEL quick index
- Authentication → "AUTHENTICATION SYSTEM" section
- Payment flow → "PAYMENT & SUBSCRIPTION SYSTEM" section
- Admin panel → "ADMIN ENDPOINTS" in QUICK_REFERENCE.md

**For Development**:
- Set up environment → QUICK_REFERENCE.md "Environment Setup Checklist"
- Common database queries → QUICK_REFERENCE.md "Common Query Patterns"
- API testing → Check each endpoint in ARCHITECTURE_ANALYSIS.md Section 4
- Troubleshooting → QUICK_REFERENCE.md "Troubleshooting" section

**For Deployment**:
- Production checklist → ARCHITECTURE_ANALYSIS.md Section 13
- Environment variables → ARCHITECTURE_ANALYSIS.md Section 9
- Migrations → QUICK_REFERENCE.md "Common Development Tasks"
- Monitoring → ARCHITECTURE_ANALYSIS.md "Monitoring & Logging"

## Data Models by Feature

### Bible Reading
- BibleVersion, BibleBook, BibleChapter, BibleVerse
- BiblePassage (with embeddings)
- ReadingHistory

### User Content
- Bookmark, ChapterBookmark
- Highlight, Note
- ReadingHistory

### User Engagement
- PrayerRequest, Prayer, UserPrayer
- ReadingPlan, UserReadingPlan, UserReadingProgress
- ChatConversation, ChatMessage

### Monetization
- Subscription, Donation
- User (subscription fields)

### Administration
- Page, MediaFile
- SocialMediaLink, MailgunSettings

## Security Features

### Authentication
- JWT-based token authentication
- bcryptjs password hashing (10 rounds)
- Session tracking in database
- HttpOnly cookies for admin tokens
- CSRF protection via SameSite

### Authorization
- Role-based access control (User/Admin/Moderator)
- Fine-grained permissions (13 types)
- Per-endpoint permission checks
- Cascade deletion on user removal

### Data Protection
- Encrypted Mailgun API keys in database
- Stripe webhook signature verification
- Secure token generation (UUID)
- Proper SQL parameter binding via Prisma

## Performance Optimizations

### Database
- Strategic indexing on frequently queried fields
- Composite indexes for complex queries
- Unique constraints prevent duplicates
- Select-only queries reduce data transfer
- Proper relationship handling with include

### API
- Bible version caching (1 hour + 2hr stale-while-revalidate)
- Pagination for list endpoints
- Selective field selection
- Connection pooling via Prisma

### Frontend
- JWT stored in localStorage
- Client-side token expiration check
- Lazy loading of relationships

## Disabled Features

### Chat Feature (Currently Disabled)
- **Endpoint**: `POST /api/chat`
- **Status**: Returns 503 Service Unavailable
- **Reason**: Azure OpenAI configuration needed
- **Features Blocked**:
  - AI responses
  - Vector search for Bible verses
  - Conversation persistence
  - Limit enforcement

### Password Reset
- Structure in place but incomplete
- Mailgun integration available
- Email template defined

## Integration Points

### External Services
1. **Stripe** - Payments, subscriptions, webhooks
2. **Azure OpenAI** - AI chat responses
3. **Mailgun** - Email delivery
4. **PostgreSQL** - Data persistence
5. **pgvector** - Vector embeddings (optional)

### Internal Services
1. **JWT** - Token generation/verification
2. **bcryptjs** - Password hashing
3. **Zod** - Input validation
4. **Prisma** - Database ORM

## Contribution Guidelines

When modifying the backend:

1. **Database Changes**
   - Update schema.prisma
   - Create migration: `npx prisma migrate dev`
   - Update BACKEND_ARCHITECTURE_ANALYSIS.md

2. **API Changes**
   - Follow existing patterns in /app/api
   - Use Zod schemas for validation
   - Add error handling with NextResponse
   - Update BACKEND_QUICK_REFERENCE.md endpoint list

3. **Authentication Changes**
   - Update lib/auth/* files
   - Verify JWT payload structure
   - Test with client-side auth management
   - Update ARCHITECTURE_ANALYSIS.md Section 2

4. **Payment Changes**
   - Update lib/stripe-server.ts or lib/subscription-utils.ts
   - Add/update webhook handlers
   - Update ARCHITECTURE_ANALYSIS.md Section 3
   - Test with Stripe test keys

## Related Documents

### In This Directory
- BACKEND_ARCHITECTURE_ANALYSIS.md (this document)
- BACKEND_QUICK_REFERENCE.md
- BACKEND_DOCUMENTATION_INDEX.md (this file)

### In Repository Root
- README.md (project overview)
- package.json (dependencies)
- .env.example (environment template)

### Prisma Files
- prisma/schema.prisma (database schema)
- prisma/migrations/* (migration history)

## Useful Commands

```bash
# Database
npx prisma migrate deploy      # Apply migrations
npx prisma generate            # Generate Prisma client
npx prisma studio              # Open database UI

# Development
npm run dev                     # Start dev server
npm run build                   # Build for production
npm run import-bible            # Import Bible data

# Analysis
grep -r "export async function" app/api/  # Find all endpoints
grep -r "model " prisma/schema.prisma    # List all models
```

## Support & Questions

### For Understanding
1. Read BACKEND_QUICK_REFERENCE.md first (faster)
2. Dive into BACKEND_ARCHITECTURE_ANALYSIS.md for details
3. Check specific endpoint files in app/api/

### For Debugging
1. Check QUICK_REFERENCE.md "Troubleshooting"
2. Enable logging: `log: ['query', 'error']` in Prisma client
3. Use `npx prisma studio` to inspect data
4. Check API route logs and error messages

### For Adding Features
1. Plan database changes in schema.prisma
2. Create API route in app/api/
3. Update documentation
4. Test with auth headers if needed
5. Configure webhooks if needed

## Version History

| Date | Changes | Version |
|------|---------|---------|
| 2025-11-05 | Initial comprehensive analysis | 1.0 |

---

**Last Updated**: November 5, 2025
**Document Version**: 1.0
**Backend Status**: Production-ready (chat feature disabled)

For the latest information, always refer to the source files in `/root/biblical-guide/`.