Starter project section 9

# Conflicts:
#	ecommerce_app/lib/src/features/orders/presentation/orders_list/orders_list_screen.dart

ecommerce_app/lib/src/features/cart/data/remote/remote_cart_repository.dart

@@ -13,5 +13,5 @@ abstract class RemoteCartRepository {
 
 final remoteCartRepositoryProvider = Provider<RemoteCartRepository>((ref) {
   // TODO: replace with "real" remote cart repository
-  return FakeRemoteCartRepository();
+  return FakeRemoteCartRepository(addDelay: false);
 });

ecommerce_app/lib/src/features/checkout/application/fake_checkout_service.dart

@@ -0,0 +1,69 @@
+import 'package:ecommerce_app/src/features/authentication/data/fake_auth_repository.dart';
+import 'package:ecommerce_app/src/features/cart/data/remote/remote_cart_repository.dart';
+import 'package:ecommerce_app/src/features/cart/domain/cart.dart';
+import 'package:ecommerce_app/src/features/orders/data/fake_orders_repository.dart';
+import 'package:ecommerce_app/src/features/orders/domain/order.dart';
+import 'package:ecommerce_app/src/features/products/data/fake_products_repository.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+/// A fake checkout service that doesn't process real payments.
+class FakeCheckoutService {
+  FakeCheckoutService(this.ref);
+  final Ref ref;
+
+  /// Temporary client-side logic for placing an order.
+  /// Part of this logic should run on the server, so that we can:
+  /// - setup a payment intent
+  /// - show the payment UI
+  /// - process the payment and fullfill the order
+  /// The server-side logic will be covered in course #2
+  Future<void> placeOrder() async {
+    final authRepository = ref.read(authRepositoryProvider);
+    final remoteCartRepository = ref.read(remoteCartRepositoryProvider);
+    final ordersRepository = ref.read(ordersRepositoryProvider);
+    // * Assertion operator is ok here since this method is only called from
+    // * a place where the user is signed in
+    final uid = authRepository.currentUser!.uid;
+    // 1. Get the cart object
+    final cart = await remoteCartRepository.fetchCart(uid);
+    final total = _totalPrice(cart);
+    // * If we want to make this code more testable, a DateTime builder
+    // * should be injected as a dependency
+    final orderDate = DateTime.now();
+    // * The orderId is a unique string that could be generated with the UUID
+    // * package. Since this is a fake service, we just derive it from the date.
+    final orderId = orderDate.toIso8601String();
+    // 2. Create an order
+    final order = Order(
+      id: orderId,
+      userId: uid,
+      items: cart.items,
+      orderStatus: OrderStatus.confirmed,
+      orderDate: orderDate,
+      total: total,
+    );
+    // 3. Save it using the repository
+    await ordersRepository.addOrder(uid, order);
+    // 4. Empty the cart
+    await remoteCartRepository.setCart(uid, const Cart());
+  }
+
+  // Helper method to calculate the total price
+  double _totalPrice(Cart cart) {
+    if (cart.items.isEmpty) {
+      return 0.0;
+    }
+    final producsRepository = ref.read(productsRepositoryProvider);
+    return cart.items.entries
+        // first extract quantity * price for each item
+        .map((entry) =>
+            entry.value * // quantity
+            producsRepository.getProduct(entry.key)!.price) // price
+        // then add them up
+        .reduce((value, element) => value + element);
+  }
+}
+
+final checkoutServiceProvider = Provider<FakeCheckoutService>((ref) {
+  return FakeCheckoutService(ref);
+});

ecommerce_app/lib/src/features/checkout/presentation/checkout_screen/checkout_screen.dart

@@ -5,17 +5,12 @@ import 'package:ecommerce_app/src/localization/string_hardcoded.dart';
 import 'package:flutter/material.dart';
 
 /// The two sub-routes that are presented as part of the checkout flow.
-/// TODO: add the address page as well (see [AddressScreen]).
 enum CheckoutSubRoute { register, payment }
 
 /// This is the root widget of the checkout flow, which is composed of 2 pages:
 /// 1. Register page
 /// 2. Payment page
-/// The correct page is displayed (and updated) based on whether the user is
-/// signed in.
-/// The logic for the entire flow is implemented in the
-/// [CheckoutScreenController], while UI updates are handled by a
-/// [PageController].
+/// TODO: Show the correct page based on whether the user is signed in.
 class CheckoutScreen extends StatefulWidget {
   const CheckoutScreen({super.key});
 
@@ -27,6 +22,7 @@ class _CheckoutScreenState extends State<CheckoutScreen> {
   final _controller = PageController();
 
   var _subRoute = CheckoutSubRoute.register;
+  // TODO: Load the correct initial page when this screen is presented
 
   @override
   void dispose() {

ecommerce_app/lib/src/features/orders/application/user_orders_provider.dart

@@ -0,0 +1,17 @@
+import 'package:ecommerce_app/src/features/authentication/data/fake_auth_repository.dart';
+import 'package:ecommerce_app/src/features/orders/data/fake_orders_repository.dart';
+import 'package:ecommerce_app/src/features/orders/domain/order.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+/// Watch the list of user orders
+/// NOTE: Only watch this provider if the user is signed in.
+final userOrdersProvider = StreamProvider.autoDispose<List<Order>>((ref) {
+  final user = ref.watch(authStateChangesProvider).value;
+  if (user != null) {
+    final ordersRepository = ref.watch(ordersRepositoryProvider);
+    return ordersRepository.watchUserOrders(user.uid);
+  } else {
+    // If the user is null, just return an empty screen.
+    return const Stream.empty();
+  }
+});

ecommerce_app/lib/src/features/orders/data/fake_orders_repository.dart

@@ -0,0 +1,39 @@
+import 'package:ecommerce_app/src/features/orders/domain/order.dart';
+import 'package:ecommerce_app/src/utils/delay.dart';
+import 'package:ecommerce_app/src/utils/in_memory_store.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+class FakeOrdersRepository {
+  FakeOrdersRepository({this.addDelay = true});
+  final bool addDelay;
+
+  /// A map of all the orders placed by each user, where:
+  /// - key: user ID
+  /// - value: list of orders for that user
+  final _orders = InMemoryStore<Map<String, List<Order>>>({});
+
+  // A stream that returns all the orders for a given user, ordered by date
+  Stream<List<Order>> watchUserOrders(String uid) {
+    return _orders.stream.map((ordersData) {
+      final ordersList = ordersData[uid] ?? [];
+      ordersList.sort(
+        (lhs, rhs) => rhs.orderDate.compareTo(lhs.orderDate),
+      );
+      return ordersList;
+    });
+  }
+
+  // A method to add a new order to the list for a given user
+  Future<void> addOrder(String uid, Order order) async {
+    await delay(addDelay);
+    final value = _orders.value;
+    final userOrders = value[uid] ?? [];
+    userOrders.add(order);
+    value[uid] = userOrders;
+    _orders.value = value;
+  }
+}
+
+final ordersRepositoryProvider = Provider<FakeOrdersRepository>((ref) {
+  return FakeOrdersRepository();
+});

ecommerce_app/lib/src/features/orders/presentation/orders_list/orders_list_screen.dart

@@ -1,58 +1,52 @@
+import 'package:ecommerce_app/src/common_widgets/async_value_widget.dart';
+import 'package:ecommerce_app/src/features/orders/application/user_orders_provider.dart';
 import 'package:ecommerce_app/src/features/orders/presentation/orders_list/order_card.dart';
 import 'package:ecommerce_app/src/localization/string_hardcoded.dart';
 import 'package:flutter/material.dart';
 import 'package:ecommerce_app/src/common_widgets/responsive_center.dart';
 import 'package:ecommerce_app/src/constants/app_sizes.dart';
 import 'package:ecommerce_app/src/features/orders/domain/order.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 /// Shows the list of orders placed by the signed-in user.
 class OrdersListScreen extends StatelessWidget {
   const OrdersListScreen({super.key});
 
   @override
   Widget build(BuildContext context) {
-    // TODO: Read from data source
-    final orders = [
-      Order(
-        id: 'abc',
-        userId: '123',
-        items: {
-          '1': 1,
-          '2': 2,
-          '3': 3,
-        },
-        orderStatus: OrderStatus.confirmed,
-        orderDate: DateTime.now(),
-        total: 104,
-      ),
-    ];
     return Scaffold(
       appBar: AppBar(
         title: Text('Your Orders'.hardcoded),
       ),
-      body: orders.isEmpty
-          ? Center(
-              child: Text(
-                'No previous orders'.hardcoded,
-                style: Theme.of(context).textTheme.displaySmall,
-                textAlign: TextAlign.center,
-              ),
-            )
-          : CustomScrollView(
-              slivers: <Widget>[
-                SliverList(
-                  delegate: SliverChildBuilderDelegate(
-                    (BuildContext context, int index) => ResponsiveCenter(
-                      padding: const EdgeInsets.all(Sizes.p8),
-                      child: OrderCard(
-                        order: orders[index],
+      body: Consumer(builder: (context, ref, _) {
+        final userOrdersValue = ref.watch(userOrdersProvider);
+        return AsyncValueWidget<List<Order>>(
+          value: userOrdersValue,
+          data: (orders) => orders.isEmpty
+              ? Center(
+                  child: Text(
+                    'No previous orders'.hardcoded,
+                    style: Theme.of(context).textTheme.displaySmall,
+                    textAlign: TextAlign.center,
+                  ),
+                )
+              : CustomScrollView(
+                  slivers: <Widget>[
+                    SliverList(
+                      delegate: SliverChildBuilderDelegate(
+                        (BuildContext context, int index) => ResponsiveCenter(
+                          padding: const EdgeInsets.all(Sizes.p8),
+                          child: OrderCard(
+                            order: orders[index],
+                          ),
+                        ),
+                        childCount: orders.length,
                       ),
                     ),
-                    childCount: orders.length,
-                  ),
+                  ],
                 ),
-              ],
-            ),
+        );
+      }),
     );
   }
 }