add cart

lib/features/cart/presentation/providers/cart_provider.dart

@@ -0,0 +1,177 @@
+/// Cart Provider
+///
+/// State management for shopping cart using Riverpod.
+library;
+
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:worker/features/cart/presentation/providers/cart_state.dart';
+import 'package:worker/features/products/domain/entities/product.dart';
+
+part 'cart_provider.g.dart';
+
+/// Cart Notifier
+///
+/// Manages cart state including:
+/// - Adding/removing items
+/// - Updating quantities
+/// - Warehouse selection
+/// - Discount code application
+/// - Cart summary calculations
+@riverpod
+class Cart extends _$Cart {
+  @override
+  CartState build() {
+    final initialState = CartState.initial();
+    // Initialize with Diamond tier discount (15%)
+    // TODO: Get actual tier from user profile
+    return initialState.copyWith(
+      memberTier: 'Diamond',
+      memberDiscountPercent: 15.0,
+    );
+  }
+
+  /// Add product to cart
+  void addToCart(Product product, {double quantity = 1.0}) {
+    final existingItemIndex = state.items.indexWhere(
+      (item) => item.product.productId == product.productId,
+    );
+
+    if (existingItemIndex >= 0) {
+      // Update quantity if item already exists
+      updateQuantity(
+        product.productId,
+        state.items[existingItemIndex].quantity + quantity,
+      );
+    } else {
+      // Add new item
+      final newItem = CartItemData(
+        product: product,
+        quantity: quantity,
+      );
+
+      state = state.copyWith(
+        items: [...state.items, newItem],
+      );
+      _recalculateTotal();
+    }
+  }
+
+  /// Remove product from cart
+  void removeFromCart(String productId) {
+    state = state.copyWith(
+      items: state.items.where((item) => item.product.productId != productId).toList(),
+    );
+    _recalculateTotal();
+  }
+
+  /// Update item quantity
+  void updateQuantity(String productId, double newQuantity) {
+    if (newQuantity <= 0) {
+      removeFromCart(productId);
+      return;
+    }
+
+    final updatedItems = state.items.map((item) {
+      if (item.product.productId == productId) {
+        return item.copyWith(quantity: newQuantity);
+      }
+      return item;
+    }).toList();
+
+    state = state.copyWith(items: updatedItems);
+    _recalculateTotal();
+  }
+
+  /// Increment quantity
+  void incrementQuantity(String productId) {
+    final item = state.items.firstWhere(
+      (item) => item.product.productId == productId,
+    );
+    updateQuantity(productId, item.quantity + 1);
+  }
+
+  /// Decrement quantity
+  void decrementQuantity(String productId) {
+    final item = state.items.firstWhere(
+      (item) => item.product.productId == productId,
+    );
+    updateQuantity(productId, item.quantity - 1);
+  }
+
+  /// Clear entire cart
+  void clearCart() {
+    state = CartState.initial();
+  }
+
+  /// Select warehouse
+  void selectWarehouse(String warehouse) {
+    state = state.copyWith(selectedWarehouse: warehouse);
+  }
+
+  /// Apply discount code
+  void applyDiscountCode(String code) {
+    // TODO: Validate with backend
+    // For now, simulate discount application
+    if (code.isNotEmpty) {
+      state = state.copyWith(
+        discountCode: code,
+        discountCodeApplied: true,
+      );
+      _recalculateTotal();
+    }
+  }
+
+  /// Remove discount code
+  void removeDiscountCode() {
+    state = state.copyWith(
+      discountCode: null,
+      discountCodeApplied: false,
+    );
+    _recalculateTotal();
+  }
+
+  /// Recalculate cart totals
+  void _recalculateTotal() {
+    // Calculate subtotal
+    final subtotal = state.items.fold<double>(
+      0.0,
+      (sum, item) => sum + (item.product.basePrice * item.quantity),
+    );
+
+    // Calculate member tier discount
+    final memberDiscount = subtotal * (state.memberDiscountPercent / 100);
+
+    // Calculate shipping (free for now)
+    const shippingFee = 0.0;
+
+    // Calculate total
+    final total = subtotal - memberDiscount + shippingFee;
+
+    state = state.copyWith(
+      subtotal: subtotal,
+      memberDiscount: memberDiscount,
+      shippingFee: shippingFee,
+      total: total,
+    );
+  }
+
+  /// Get total quantity of all items
+  double get totalQuantity {
+    return state.items.fold<double>(
+      0.0,
+      (sum, item) => sum + item.quantity,
+    );
+  }
+}
+
+/// Cart item count provider
+@riverpod
+int cartItemCount(Ref ref) {
+  return ref.watch(cartProvider).items.length;
+}
+
+/// Cart total provider
+@riverpod
+double cartTotal(Ref ref) {
+  return ref.watch(cartProvider).total;
+}