> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adhdsimple.co.uk/llms.txt
> Use this file to discover all available pages before exploring further.

# Mobile System Overview

> High-level architecture overview of the ADHD Simple mobile application system

# Mobile System Overview

## Architecture Philosophy

The ADHD Simple mobile application follows an **offline-first, sync-enabled** architecture designed to provide patients with a reliable, intuitive experience for managing ADHD medications regardless of network connectivity.

## System Components

### 1. Mobile Application Layer

* **React Native + Expo**: Cross-platform mobile framework
* **TypeScript**: Type safety and development experience
* **Expo Router**: File-based navigation system
* **Local Storage**: AsyncStorage for offline data persistence

### 2. Shared Services Layer

* **Centralized Backend**: Single source of truth for all business logic
* **Supabase Database**: PostgreSQL with real-time capabilities
* **Edge Functions**: Serverless functions for API operations
* **Row Level Security**: Patient data isolation and access control

### 3. External Integrations

* **Stripe**: Payment processing and card management
* **Clinical System**: Doctor prescription management
* **Notification Services**: Push notifications and SMS

## Data Flow Architecture

```mermaid theme={null}
graph TB
    subgraph "Mobile App"
        A[Local Storage] --> B[Sync Service]
        B --> C[UI Components]
        C --> D[User Interactions]
    end
    
    subgraph "Shared Services"
        E[Edge Functions] --> F[Supabase Database]
        F --> G[Real-time Subscriptions]
    end
    
    subgraph "External Services"
        H[Stripe API] --> I[Payment Processing]
        J[Clinical System] --> K[Prescription Data]
        L[Notification Service] --> M[Push Notifications]
    end
    
    B <--> E
    I --> E
    K --> E
    M --> C
```

## Key Architectural Patterns

### 1. Offline-First Design

* **Local Data Persistence**: All critical data cached locally
* **Sync on Connect**: Automatic synchronization when online
* **Conflict Resolution**: Server-side validation and merging
* **Optimistic Updates**: Immediate UI feedback with background sync

### 2. Dual Storage System

* **Draft Storage**: Local-only data for incomplete operations
* **Synced Storage**: Cached server data for offline access
* **Clean Separation**: Clear boundaries between draft and live data
* **Automatic Cleanup**: Drafts removed after successful submission

### 3. Unified Checkout System

* **Shared Screens**: Common UI for different order types
* **Flow Convergence**: Multiple entry points, single checkout process
* **Type-Driven Logic**: Business logic determined by order type
* **Consistent UX**: Same experience regardless of flow origin

## Security & Compliance

### Data Protection

* **End-to-End Encryption**: Patient data encrypted in transit and at rest
* **Row Level Security**: Database-level access control
* **Token-Based Auth**: Secure session management
* **Local Encryption**: Sensitive data encrypted in local storage

### Healthcare Compliance

* **HIPAA Considerations**: Patient data handling protocols
* **Audit Trails**: Complete activity logging
* **Data Retention**: Automated cleanup policies
* **Access Controls**: Role-based permissions

## Performance Optimizations

### Mobile Performance

* **Lazy Loading**: On-demand resource loading
* **Image Optimization**: Cached and compressed assets
* **Bundle Splitting**: Reduced initial load time
* **Memory Management**: Efficient resource cleanup

### Network Efficiency

* **Batch Operations**: Multiple requests combined
* **Delta Sync**: Only sync changed data
* **Retry Logic**: Automatic retry with backoff
* **Offline Queuing**: Operations queued when offline

## Scalability Considerations

### Horizontal Scaling

* **Serverless Functions**: Auto-scaling edge functions
* **Database Scaling**: Supabase managed scaling
* **CDN Distribution**: Global asset delivery
* **Load Balancing**: Automatic traffic distribution

### Data Scaling

* **Partition Strategy**: Patient data partitioning
* **Archival System**: Historical data management
* **Cache Optimization**: Multi-level caching strategy
* **Query Optimization**: Efficient database queries

## Monitoring & Observability

### Application Monitoring

* **Performance Metrics**: App performance tracking
* **Error Tracking**: Crash reporting and analysis
* **User Analytics**: Usage pattern analysis
* **Health Checks**: System status monitoring

### Business Metrics

* **Order Completion**: Checkout success rates
* **Sync Performance**: Data synchronization metrics
* **Payment Success**: Transaction completion rates
* **User Engagement**: Feature usage statistics

## Development Workflow

### Code Organization

* **Monorepo Structure**: Shared components and services
* **Type Safety**: TypeScript throughout
* **Component Library**: Reusable UI components
* **Shared Types**: Common interfaces and models

### Quality Assurance

* **Automated Testing**: Unit and integration tests
* **Code Review**: Peer review process
* **Static Analysis**: Linting and type checking
* **Performance Testing**: Load and stress testing

## Deployment Strategy

### Mobile Deployment

* **EAS Update**: Over-the-air updates
* **App Store Distribution**: Native app stores
* **Beta Testing**: TestFlight and internal testing
* **Rollback Capability**: Quick reversion if needed

### Backend Deployment

* **Edge Function Deployment**: Automated CI/CD
* **Database Migrations**: Version-controlled schema changes
* **Environment Management**: Dev/staging/production isolation
* **Feature Flags**: Gradual feature rollouts

## Future Considerations

### Planned Enhancements

* **Offline Sync Improvements**: Enhanced conflict resolution
* **Real-time Features**: Live order status updates
* **Progressive Web App**: Web application support
* **API Expansion**: Additional integration capabilities

### Technical Debt Management

* **Code Refactoring**: Continuous improvement
* **Dependency Updates**: Regular maintenance
* **Performance Optimization**: Ongoing enhancements
* **Security Updates**: Regular security reviews

This architecture provides a robust, scalable foundation for the ADHD Simple mobile application while maintaining flexibility for future enhancements and requirements.