Architecture Layers

Detailed overview of the system's layered architecture including client, application, and data layers.

Architecture Layers

The system follows a modern, layered architecture pattern that provides clear separation of concerns and maintainable code structure.

Client Layer

┌─────────────────────────────────────────────────────────────┐
│                        Client Layer                         │
├─────────────────────────────────────────────────────────────┤
│ • React Components (TSX)                                    │
│ • State Management (React Hooks)                            │
│ • UI Components (shadcn/ui)                                 │
│ • Client-side Routing (Next.js App Router)                  │
│ • Real-time Subscriptions (Supabase Realtime)               │
└─────────────────────────────────────────────────────────────┘

Responsibilities

User Interface Rendering: Display components and manage visual state
Client-side State Management: Handle local component state and global state
User Interactions: Process user events and interactions
Real-time Data Subscriptions: Manage live data updates from the server
Client-side Routing: Handle navigation and route changes

Technologies and Components

React 18 with Concurrent Features

Concurrent Rendering: Improved performance with time-slicing
Suspense: Better loading state management
Automatic Batching: Optimized state updates
Transition API: Smooth user experience during updates

Next.js App Router

File-based Routing: Intuitive route organization
Nested Layouts: Reusable layout components
Server Components: Hybrid rendering capabilities
Route Groups: Organized route structure

TypeScript Integration

Strong Typing: Compile-time error detection
IntelliSense: Enhanced development experience
Interface Definitions: Clear component contracts
Generic Components: Reusable typed components

Styling and UI Components

Tailwind CSS: Utility-first styling approach
shadcn/ui Library: Consistent component system
Responsive Design: Mobile-first approach
Theme System: Dark/light mode support

Client-Side Architecture Patterns

Component Organization

// Component structure example
interface ProductListProps {
  products: Product[]
  onProductSelect: (product: Product) => void
  loading?: boolean
}

export function ProductList({ products, onProductSelect, loading }: ProductListProps) {
  // Component logic and rendering
}

State Management

// Custom hooks for state management
export function useProductList() {
  const [products, setProducts] = useState<Product[]>([])
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  
  // State management logic
  return { products, loading, error, refetch }
}

Application Layer

┌─────────────────────────────────────────────────────────────┐
│                      Application Layer                      │
├─────────────────────────────────────────────────────────────┤
│ • Server Components & Server Actions                        │
│ • API Routes (/api/*)                                       │
│ • Middleware (Authentication, CORS)                         │
│ • Business Logic Services                                   │
│ • Data Validation & Transformation                          │
└─────────────────────────────────────────────────────────────┘

Responsibilities

Business Logic Processing: Core application functionality
Data Validation: Ensure data integrity and format
API Endpoint Handling: Process HTTP requests and responses
Authentication & Authorization: Secure access control
Server-side Rendering: Pre-render pages for performance

Server Components Architecture

Server Components

// Server component example
export default async function ProductPage({ params }: { params: { id: string } }) {
  const product = await getProduct(params.id)
  
  return (
    <div>
      <ProductDetails product={product} />
      <ProductInventory productId={params.id} />
    </div>
  )
}

Server Actions

// Server action for form handling
export async function createProduct(formData: FormData) {
  'use server'
  
  const validatedData = await validateProductData(formData)
  const result = await productService.create(validatedData)
  
  revalidatePath('/products')
  return result
}

API Route Structure

// API route example
export async function GET(request: Request) {
  try {
    const { searchParams } = new URL(request.url)
    const category = searchParams.get('category')
    
    const products = await productService.getByCategory(category)
    
    return NextResponse.json({ success: true, data: products })
  } catch (error) {
    return NextResponse.json({ success: false, error: error.message }, { status: 500 })
  }
}

Middleware Architecture

// Authentication middleware
export function middleware(request: NextRequest) {
  const token = request.cookies.get('auth-token')
  
  if (!token && isProtectedRoute(request.nextUrl.pathname)) {
    return NextResponse.redirect(new URL('/login', request.url))
  }
  
  return NextResponse.next()
}

Data Layer

┌─────────────────────────────────────────────────────────────┐
│                       Data Layer                            │
├─────────────────────────────────────────────────────────────┤
│ • Supabase Client                                           │
│ • PostgreSQL Database                                       │
│ • Row Level Security (RLS)                                  │
│ • Real-time Engine                                          │
│ • Edge Functions                                            │
└─────────────────────────────────────────────────────────────┘

Responsibilities

Data Persistence: Store and retrieve application data
Real-time Synchronization: Live data updates across clients
User Authentication: Secure user identity management
Database Security: Row-level security policies
Edge Computing: Distributed function execution

Supabase Integration

Database Client

// Supabase client configuration
import { createClient } from '@supabase/supabase-js'
import type { Database } from './database.types'

export const supabase = createClient<Database>(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
)

Typed Database Queries

// Type-safe database operations
export async function getProducts(category?: string) {
  let query = supabase
    .from('products')
    .select(`
      id,
      name,
      price,
      category:categories(name),
      inventory:inventory_items(quantity)
    `)
  
  if (category) {
    query = query.eq('category_id', category)
  }
  
  const { data, error } = await query
  
  if (error) throw new Error(error.message)
  return data
}

Real-time Subscriptions

// Real-time data subscription
export function useRealtimeProducts() {
  const [products, setProducts] = useState<Product[]>([])
  
  useEffect(() => {
    const channel = supabase
      .channel('products')
      .on('postgres_changes', 
        { event: '*', schema: 'public', table: 'products' },
        (payload) => {
          handleProductChange(payload)
        }
      )
      .subscribe()
    
    return () => supabase.removeChannel(channel)
  }, [])
  
  return products
}

Layer Communication

Data Flow Between Layers

// Example of cross-layer communication
// Client Layer -> Application Layer -> Data Layer

// 1. Client initiates request
const handleSubmit = async (formData: FormData) => {
  // Client layer validation
  const isValid = validateForm(formData)
  if (!isValid) return
  
  // Call server action (Application layer)
  const result = await createProduct(formData)
  
  if (result.success) {
    // Update client state
    setProducts(prev => [...prev, result.data])
  }
}

// 2. Server action processes request
export async function createProduct(formData: FormData) {
  'use server'
  
  // Application layer validation and processing
  const productData = await validateProductData(formData)
  
  // Data layer interaction
  const product = await supabase
    .from('products')
    .insert(productData)
    .select()
    .single()
  
  return { success: true, data: product }
}

Error Propagation

// Error handling across layers
try {
  // Data layer error
  const { data, error } = await supabase.from('products').select()
  if (error) throw new DatabaseError(error.message)
  
  // Application layer processing
  const processedData = await processProducts(data)
  
  return { success: true, data: processedData }
} catch (error) {
  // Application layer error handling
  if (error instanceof DatabaseError) {
    return { success: false, error: 'Database connection failed' }
  }
  
  return { success: false, error: 'Unknown error occurred' }
}

Best Practices

Layer Separation

Keep business logic in the application layer
Avoid direct database calls from client components
Use proper abstractions between layers
Maintain clear interface contracts

Performance Optimization

Leverage server components for initial data loading
Use client components only when interactivity is needed
Implement proper caching strategies at each layer
Optimize database queries with proper indexing

Security Considerations

Validate data at every layer boundary
Implement proper authentication checks
Use Row Level Security for database access
Sanitize all user inputs

Maintainability

Use TypeScript for type safety across layers
Implement consistent error handling patterns
Document layer responsibilities clearly
Regular code reviews and refactoring

System Architecture

Design Principles