littleshop/PERFORMANCE_PLAN.md

LittleShop Performance & Notifications Improvement Plan

📊 Current Analysis

✅ What's Already Working Well

Push Notification Infrastructure:

• Complete VAPID-based push notification system implemented
• PWA with service worker registration and update handling
• Admin panel notification subscription/unsubscription working
• Push notification service with proper error handling and cleanup

Performance Optimizations Already In Place:

• Docker production optimization with resource limits
• Health checks and monitoring infrastructure
• Optimized build process with multi-stage Docker builds
• Database connection pooling and EF Core optimizations

🔍 Current Gaps Identified

1. Admin PWA Push Notifications (Critical Gap)

• ✅ Infrastructure exists but needs integration with order workflow
• ❌ Order status changes don't trigger automatic push notifications
• ❌ No real-time notifications for new orders, payments, or status updates
• ❌ Admin users not automatically notified of critical events

2. TeleBot Customer Notifications (Critical Gap)

• ❌ TeleBot customers don't receive order progress updates
• ❌ No automatic messaging when order status changes (Accepted → Packing → Dispatched → Delivered)
• ❌ Missing integration between OrderService updates and TeleBot messaging

3. Performance Optimization Opportunities

• Database query optimization for order/product listings
• Caching strategy for frequently accessed data
• Background job processing for non-critical tasks
• API response time optimization

🎯 Implementation Plan

Phase 1: Admin PWA Real-Time Notifications (Priority 1)

Objective: Admin users get immediate push notifications for all critical events

Tasks:

1. Order Event Notifications

   • New order received → Push notification to all admin users
   • Payment confirmed → Notification with order details
   • Payment failed/expired → Alert notification

2. Status Change Notifications

   • Order accepted → Notification to assigned admin
   • Order packed → Notification with tracking info
   • Order dispatched → Confirmation notification
   • Delivery confirmed → Success notification

3. Real-Time Dashboard Updates

   • WebSocket/SignalR integration for live order updates
   • Automatic refresh of order lists without page reload
   • Live counters for pending orders, payments, etc.

Implementation Steps:

// 1. Enhance OrderService to trigger notifications
public async Task<bool> UpdateOrderStatusAsync(Guid id, UpdateOrderStatusDto dto)
{
    // Existing order update logic...

    // NEW: Trigger push notifications
    await _pushNotificationService.SendOrderNotificationAsync(
        id,
        GetStatusChangeTitle(order.Status, dto.Status),
        GetStatusChangeMessage(order, dto.Status)
    );

    // NEW: Trigger TeleBot customer notification
    await _botService.SendOrderStatusUpdateAsync(id, dto.Status);
}

Phase 2: TeleBot Customer Progress Updates (Priority 1)

Objective: TeleBot customers receive automatic updates throughout order lifecycle

Current TeleBot Integration Status:

• ✅ TeleBot can view order history and details
• ❌ No automatic status update messages to customers

Implementation Requirements:

// 1. Add to IBotService interface
public interface IBotService
{
    Task<bool> SendOrderStatusUpdateAsync(Guid orderId, OrderStatus newStatus);
    Task<bool> SendPaymentConfirmedAsync(Guid orderId);
    Task<bool> SendTrackingNumberAsync(Guid orderId, string trackingNumber);
}

// 2. Integration points in OrderService
- Order created → "Order received! We'll notify you when payment is confirmed."
- Payment confirmed → "Payment received! Your order is being processed."
- Order accepted → "Order accepted and being prepared for packing."
- Order packed → "Order packed! We'll send tracking details when dispatched."
- Order dispatched → "Order dispatched! Tracking: {trackingNumber}"
- Order delivered → "Order delivered! Please consider leaving a review."

Message Templates:

public static class TeleBotOrderMessages
{
    public static string GetStatusUpdateMessage(OrderStatus status, Order order) => status switch
    {
        OrderStatus.PaymentReceived => $"💰 *Payment Confirmed!*\n\nYour order #{order.Id.ToString()[..8]} has been paid successfully. We'll start processing it shortly.\n\n📦 Total: £{order.TotalAmount:F2}",

        OrderStatus.Accepted => $"✅ *Order Accepted!*\n\nGreat news! Your order #{order.Id.ToString()[..8]} has been accepted and is being prepared for packing.\n\n⏱️ Expected packing: Within 24 hours",

        OrderStatus.Packing => $"📦 *Being Packed!*\n\nYour order #{order.Id.ToString()[..8]} is currently being packed with care.\n\n🚚 We'll send tracking details once dispatched.",

        OrderStatus.Dispatched => $"🚚 *Order Dispatched!*\n\nYour order #{order.Id.ToString()[..8]} is on its way!\n\n📍 Tracking: `{order.TrackingNumber}`\n⏱️ Estimated delivery: 1-3 working days",

        OrderStatus.Delivered => $"🎉 *Order Delivered!*\n\nYour order #{order.Id.ToString()[..8]} has been delivered successfully!\n\n⭐ Please consider leaving a review using /review command."
    };
}

Phase 3: Performance Optimization (Priority 2)

Objective: Optimize system performance for better user experience

3.1 Database Query Optimization

// Current slow queries identified:
// 1. Order list with includes (N+1 problem)
// 2. Product list with photos (eager loading)
// 3. Category list with product counts

// Optimization strategies:
// - Add proper indexes on frequently queried columns
// - Implement pagination for large datasets
// - Use projection for list views (select only needed columns)
// - Add database query caching for static data

3.2 Caching Strategy

// Implement distributed caching for:
// - Category lists (rarely change)
// - Product basic info (change infrequently)
// - VAPID keys and configuration
// - Order status statistics for dashboard

public interface ICacheService
{
    Task<T?> GetAsync<T>(string key);
    Task SetAsync<T>(string key, T value, TimeSpan? expiry = null);
    Task RemoveAsync(string key);
    Task RemovePatternAsync(string pattern);
}

3.3 Background Job Processing

// Move non-critical tasks to background:
// - Push notification delivery
// - Email sending
// - Log cleanup
// - Expired subscription cleanup
// - Image optimization/resizing

// Use Hangfire (already configured) for:
[BackgroundJob]
public async Task ProcessOrderNotifications(Guid orderId, OrderStatus newStatus)
{
    // Process all notifications in background
    await _pushNotificationService.SendOrderNotificationAsync(...);
    await _botService.SendOrderStatusUpdateAsync(...);
    await _emailService.SendOrderUpdateEmailAsync(...);
}

Phase 4: Real-Time Features (Priority 3)

Objective: Add real-time capabilities for better admin experience

4.1 SignalR Integration

// Real-time features:
// - Live order status updates on admin dashboard
// - Real-time notification delivery status
// - Live customer count and activity
// - Real-time TeleBot message status

public class OrderHub : Hub
{
    public async Task JoinAdminGroup()
    {
        await Groups.AddToGroupAsync(Context.ConnectionId, "AdminUsers");
    }

    public async Task NotifyOrderUpdate(Guid orderId, OrderStatus status)
    {
        await Clients.Group("AdminUsers").SendAsync("OrderUpdated", orderId, status);
    }
}

4.2 Enhanced PWA Features

// PWA improvements:
// - Offline support for order viewing
// - Background sync for status updates
// - Improved caching strategy
// - Better mobile experience for admin panel

📈 Performance Metrics & Monitoring

Key Performance Indicators (KPIs)

Response Times:
  - API endpoints: < 200ms average
  - Admin dashboard load: < 1 second
  - Push notification delivery: < 5 seconds
  - TeleBot response time: < 2 seconds

User Experience:
  - Push notification delivery rate: > 95%
  - TeleBot message delivery: > 98%
  - Admin panel uptime: > 99.5%
  - Mobile PWA performance score: > 90

Business Metrics:
  - Order processing time: < 24 hours
  - Customer notification coverage: 100%
  - Admin response time to orders: < 1 hour

Performance Monitoring Setup

# Add to Prometheus metrics:
Counters:
  - littleshop_push_notifications_sent_total
  - littleshop_telebot_messages_sent_total
  - littleshop_order_status_changes_total

Histograms:
  - littleshop_api_request_duration_seconds
  - littleshop_database_query_duration_seconds
  - littleshop_notification_delivery_seconds

Gauges:
  - littleshop_active_push_subscriptions
  - littleshop_pending_orders_count
  - littleshop_background_jobs_pending

🚀 Implementation Timeline

Week 1: Critical Notifications

• Day 1-2: Enhance OrderService with notification triggers
• Day 3-4: Implement admin PWA push notification integration
• Day 5-7: Add TeleBot customer order progress messages

Week 2: Performance & Polish

• Day 1-3: Database query optimization and indexing
• Day 4-5: Implement caching strategy
• Day 6-7: Background job processing setup

Week 3: Real-Time Features

• Day 1-3: SignalR hub implementation
• Day 4-5: Enhanced PWA features
• Day 6-7: Performance monitoring and testing

🎯 Success Criteria

Immediate (Week 1)

• ✅ Admin users receive push notifications for all order events
• ✅ TeleBot customers get automatic order status updates
• ✅ 100% notification coverage for order lifecycle

Short-term (Week 2-3)

• ✅ API response times improved by 50%
• ✅ Real-time dashboard updates working
• ✅ Background job processing operational
• ✅ Performance monitoring fully functional

Long-term (Month 1)

• ✅ > 95% push notification delivery rate
• ✅ < 1 hour average admin response time to orders
• ✅ Improved customer satisfaction from proactive updates
• ✅ System capable of handling 10x current order volume

---

Ready to Begin Implementation

This plan addresses your specific requirements:

1. ✅ Admin PWA push notifications for order management
2. ✅ TeleBot customer notifications for order progress
3. ✅ Performance optimization without premature advanced features
4. ✅ Focused on reliability and user experience improvements