# Database Migrations

This directory contains SQL migration files for the Rustelo application database setup.

## Overview

The migration system sets up a complete database with authentication, content management, and auditing capabilities. **Rustelo now supports both PostgreSQL and SQLite** through a database-agnostic architecture.

## Migration Files

Rustelo provides **database-specific migration files** to support both PostgreSQL and SQLite:

### Database-Specific Files
- `001_initial_setup_postgres.sql` - PostgreSQL-optimized schema
- `001_initial_setup_sqlite.sql` - SQLite-optimized schema
- `002_add_2fa_support_postgres.sql` - PostgreSQL 2FA tables
- `002_add_2fa_support_sqlite.sql` - SQLite 2FA tables
- `003_rbac_system_postgres.sql` - PostgreSQL RBAC system

### Legacy Files
- `001_initial_setup.sql` - Legacy unified file (deprecated)
- `002_add_2fa_support.sql` - Legacy 2FA file (deprecated)

The migration system **automatically detects your database type** from the connection URL and runs the appropriate migration files.

### Schema Features

#### Authentication Tables
- **users** - Core user accounts and profile information
- **user_roles** - User role assignments for RBAC (Role-Based Access Control)
- **oauth_accounts** - External OAuth provider account links
- **sessions** - User session management
- **tokens** - Security tokens for password reset, email verification, etc.
- **permissions** - System permissions for fine-grained access control
- **role_permissions** - Role to permission mappings
- **user_audit_log** - Audit trail for user actions

#### Content Management Tables
- **page_contents** - Main content management table for pages, posts, and other content

#### Key Features
- **UUID Primary Keys** - All tables use UUID primary keys for better security
- **Comprehensive Indexing** - Optimized indexes for performance
- **Full-Text Search** - PostgreSQL full-text search capabilities
- **Audit Logging** - Complete audit trail for user actions
- **Role-Based Access Control** - Flexible permission system
- **Automatic Timestamps** - Automatic created_at/updated_at handling
- **Data Validation** - Comprehensive constraints and validation rules

## Database Schema

### User Management
```sql
users (id, email, username, password_hash, display_name, ...)
user_roles (user_id, role)
oauth_accounts (id, user_id, provider, provider_id, ...)
sessions (id, user_id, expires_at, ...)
tokens (id, user_id, token_type, token_hash, ...)
```

### Authorization
```sql
permissions (id, name, description, resource, action)
role_permissions (role, permission_id)
user_audit_log (id, user_id, action, resource, ...)
```

### Content Management
```sql
page_contents (id, slug, title, content, author_id, ...)
```

## Default Data

The migration includes default data:

### User Roles
- **admin** - Full system access
- **moderator** - Content management and user oversight
- **user** - Basic content creation
- **guest** - Read-only access

### Default Admin User
- **Username**: admin
- **Email**: admin@example.com
- **Password**: admin123 (⚠️ **CHANGE THIS IMMEDIATELY IN PRODUCTION!**)

### Sample Content
- Welcome page
- About page
- Sample blog post

## Functions and Triggers

### Automatic Triggers
- `update_updated_at_column()` - Updates timestamps automatically
- `assign_default_role()` - Assigns default role to new users

### Utility Functions
- `log_user_action()` - Logs user actions for auditing
- `cleanup_expired_auth_data()` - Cleans up expired sessions and tokens

## Running Migrations

### Using the Built-in Migration Runner (Recommended)
```bash
# The application automatically runs migrations on startup
cargo run

# Or use the database tool
cargo run --bin db_tool -- migrate
```

### Database Type Detection
The migration system automatically detects your database type from the `DATABASE_URL`:

```bash
# PostgreSQL - runs *_postgres.sql files
DATABASE_URL=postgresql://user:pass@localhost/database_name

# SQLite - runs *_sqlite.sql files  
DATABASE_URL=sqlite:data/app.db
```

### Using SQLx CLI
```bash
# Install sqlx-cli
cargo install sqlx-cli

# PostgreSQL migrations
sqlx migrate run --database-url "postgresql://username:password@localhost/database_name"

# SQLite migrations
sqlx migrate run --database-url "sqlite:data/app.db"
```

### Manual Migration
```bash
# PostgreSQL
psql -U username -d database_name -f 001_initial_setup_postgres.sql

# SQLite
sqlite3 data/app.db < 001_initial_setup_sqlite.sql
```

## Environment Setup

Configure your database connection using the `DATABASE_URL` environment variable:

### PostgreSQL
```env
DATABASE_URL=postgresql://username:password@localhost:5432/database_name
```

### SQLite
```env
DATABASE_URL=sqlite:data/app.db
```

### Additional Database Configuration
```env
# Connection pool settings (optional)
DATABASE_MAX_CONNECTIONS=10
DATABASE_MIN_CONNECTIONS=1
DATABASE_CONNECT_TIMEOUT=30
DATABASE_IDLE_TIMEOUT=600
DATABASE_MAX_LIFETIME=3600
```

## Security Considerations

1. **Change Default Admin Password** - The default admin password is `admin123`
2. **Review Permissions** - Customize role permissions based on your needs
3. **Configure OAuth** - Set up OAuth providers if using external authentication
4. **Enable SSL** - Use SSL connections in production (PostgreSQL)
5. **Backup Strategy** - Implement regular database backups
6. **File Permissions** - Secure SQLite database files (chmod 600)
7. **Database Location** - Store SQLite files outside web root

## Schema Evolution

For future schema changes:

1. Create **database-specific** migration files:
   - `003_new_feature_postgres.sql`
   - `003_new_feature_sqlite.sql`
2. Always use `CREATE TABLE IF NOT EXISTS` for safety
3. Add proper indexes for performance
4. Handle database-specific differences (UUID vs TEXT, etc.)
5. Test migrations on both database types
6. Include rollback scripts when possible
7. Test migrations on a copy of production data

### Database Differences to Consider
- **UUIDs**: PostgreSQL native vs SQLite TEXT
- **Timestamps**: PostgreSQL native vs SQLite TEXT (ISO 8601)
- **JSON**: PostgreSQL JSONB vs SQLite TEXT
- **Arrays**: PostgreSQL arrays vs SQLite JSON arrays
- **Booleans**: PostgreSQL BOOLEAN vs SQLite INTEGER

## Performance Notes

### PostgreSQL
- All tables have appropriate indexes for common queries
- Full-text search is enabled for content
- Partial indexes are used for filtered queries
- GIN indexes are used for JSONB and array columns
- Connection pooling for high concurrency

### SQLite
- Optimized indexes for single-user scenarios
- WAL mode enabled for better concurrency
- Foreign key constraints enabled
- Query planner optimizations
- Smaller memory footprint

## Troubleshooting

### Common Issues

#### PostgreSQL Issues
1. **Extension Error**: If you get an error about `uuid-ossp` extension, ensure your PostgreSQL user has superuser privileges or the extension is already installed.
2. **Permission Denied**: Ensure your database user has CREATE privileges.
3. **Connection Failed**: Check PostgreSQL service is running and connection details are correct.

#### SQLite Issues
1. **File Permission Error**: Ensure the SQLite file and directory have proper write permissions.
2. **Database Locked**: Close other connections to the SQLite file.
3. **Directory Not Found**: Ensure the directory for the SQLite file exists.

#### General Issues
1. **Constraint Violations**: Check that your data meets the constraint requirements (email format, username format, etc.).
2. **Migration Version Mismatch**: Ensure all migration files are present and properly numbered.
3. **Database Type Detection Failed**: Verify your `DATABASE_URL` format is correct.

### Verification

After running the migration, verify the setup:

#### PostgreSQL Verification
```sql
-- Check tables were created
SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';

-- Check default admin user
SELECT username, email, is_active FROM users WHERE username = 'admin';

-- Check permissions setup
SELECT COUNT(*) FROM permissions;
SELECT COUNT(*) FROM role_permissions;

-- Check sample content
SELECT slug, title, state FROM page_contents;
```

#### SQLite Verification
```sql
-- Check tables were created
SELECT name FROM sqlite_master WHERE type='table';

-- Check default admin user
SELECT username, email, is_active FROM users WHERE username = 'admin';

-- Check permissions setup
SELECT COUNT(*) FROM permissions;
SELECT COUNT(*) FROM role_permissions;

-- Check sample content
SELECT slug, title, state FROM page_contents;
```

## Backup and Restore

### PostgreSQL
```bash
# Create backup
pg_dump -U username -d database_name > backup.sql

# Restore backup
psql -U username -d database_name < backup.sql

# Compressed backup
pg_dump -U username -d database_name | gzip > backup.sql.gz
```

### SQLite
```bash
# Create backup (simple copy)
cp data/app.db data/app_backup.db

# Create SQL dump
sqlite3 data/app.db .dump > backup.sql

# Restore from SQL dump
sqlite3 data/app_new.db < backup.sql

# Online backup (while app is running)
sqlite3 data/app.db ".backup data/app_backup.db"
```

### Cross-Database Migration
```bash
# SQLite to PostgreSQL
sqlite3 data/app.db .dump | sed 's/INSERT INTO/INSERT INTO public./g' > backup.sql
psql -U username -d database_name < backup.sql

# Note: May require manual adjustments for data types
```

## Support

For issues or questions:
1. Check the application logs
2. Verify database connectivity
3. Review the migration file for any custom modifications
4. Consult the PostgreSQL documentation for specific errors