🛒 Implement Complete Shopping Cart Feature with Navigation Integration

[Copilot]

This PR implements a comprehensive shopping cart system for the OctoCAT Supply Chain Management application, addressing all requirements from issue #[issue-number]. The implementation includes cart state management, navigation integration, and a full-featured cart page with order summary functionality.

What's Changed

Cart State Management

• CartContext: Implemented React Context API with TypeScript for global cart state management
• Reducer Pattern: Complete cart reducer with actions for ADD_TO_CART, REMOVE_FROM_CART, UPDATE_QUANTITY, APPLY_COUPON, CLEAR_CART, and SET_SHIPPING
• Persistence: Added localStorage integration to maintain cart state across browser sessions
• Real-time Calculations: Automatic subtotal, discount, shipping, and grand total calculations

Navigation Integration

• Cart Icon: Added shopping cart icon to the navigation bar with real-time item count badge
• Interactive Badge: Badge displays current item count (supports 99+ items) and updates dynamically
• Hover Effects: Smooth transitions and visual feedback on cart icon interaction
• Routing: Integrated cart icon navigation to the new /cart route

Cart Page Implementation

• Responsive Table Layout: Created cart items table with columns for serial number, product image, name, unit price, quantity controls, total, and remove action
• Quantity Management: Increment/decrement buttons with validation and automatic total updates
• Order Summary Panel: Displays subtotal, discount calculations, shipping costs, and grand total
• Coupon System: Functional coupon code input with validation (supports SAVE5, DISCOUNT10, WELCOME coupons)
• Action Buttons: "Update Cart" and "Proceed To Checkout" buttons with proper disabled states

Product Integration

• Seamless Integration: Updated Products page to work with the cart system
• Real Functionality: Replaced placeholder alerts with actual cart operations
• Data Flow: Proper handling of product data (images, names, prices, SKUs) to cart
• User Feedback: Quantity selectors reset after adding items to cart

Design & Accessibility

• Dark Theme Support: Consistent styling with the existing application theme
• Responsive Design: Mobile-first approach using Tailwind CSS
• Accessibility: ARIA labels, keyboard navigation, and screen reader support
• Empty State: Helpful empty cart page with call-to-action to browse products
• Breadcrumb Navigation: Clear navigation path (Home / Cart)

Technical Implementation

State Structure

interface CartState {
  items: CartItem[];
  subtotal: number;
  discount: number;
  shipping: number;
  grandTotal: number;
  itemCount: number;
  couponCode?: string;
}

Key Features

• Type Safety: Full TypeScript implementation with proper interfaces
• Error Handling: Graceful fallbacks for missing product images
• Performance: Efficient state updates and re-renders
• Code Quality: Clean, maintainable code following React best practices

Screenshots

Homepage with Cart Icon:

Cart Page - Light Mode:

Cart Page - Dark Mode:

Testing & Quality Assurance

• ✅ Manual Testing: All features tested and verified working
• ✅ Security: CodeQL analysis shows no vulnerabilities
• ✅ Linting: No ESLint errors or warnings
• ✅ Build: Frontend builds successfully without errors
• ✅ Cross-browser: Tested on multiple browsers and screen sizes

Files Changed

• New: frontend/src/context/CartContext.tsx - Cart state management
• New: frontend/src/components/Cart.tsx - Main cart page component
• New: frontend/src/components/CartItem.tsx - Individual cart item component
• New: frontend/src/components/OrderSummary.tsx - Order summary and checkout panel
• Modified: frontend/src/components/Navigation.tsx - Added cart icon with badge
• Modified: frontend/src/components/entity/product/Products.tsx - Cart integration
• Modified: frontend/src/App.tsx - Added cart route and provider

The shopping cart system is now fully functional and ready for production use, providing users with a complete e-commerce experience within the OctoCAT Supply application.

Fixes #2

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Copilot]

Copilot wasn't able to review any files in this pull request.