[Do Not Merge] POS Aggregate model with multiple item types

WooCommerce/Classes/POS/POSDisplayableItem.swift

@@ -0,0 +1,138 @@
+import SwiftUI
+import struct Yosemite.POSProduct
+import protocol Yosemite.POSItem
+import enum Yosemite.ProductType
+
+protocol POSDisplayableItem: View, Identifiable, Equatable {
+    var id: UUID { get }
+    var item: POSItem { get }
+}
+
+func createPOSDisplayableItem(for item: POSItem) -> (any POSDisplayableItem)? {
+    switch item {
+    case is POSProduct:
+        return POSProductItem(item: item)
+    case is POSDiscount:
+        return POSDiscountItem(item: item)
+    default:
+        return nil
+    }
+}
+
+struct POSProductItem: POSDisplayableItem {
+    var id: UUID {
+        product.itemID
+    }
+    var product: POSProduct
+    var item: POSItem { product }
+    @EnvironmentObject var posModel: PointOfSaleAggregateModel
+
+    init?(item: POSItem) {
+        guard let product = item as? POSProduct else {
+            return nil
+        }
+        self.product = product
+    }
+
+    var body: some View {
+        Button(action: {
+            let cartItem = CartItem(id: UUID(), item: product, quantity: 1)
+            posModel.addItemToCart(cartItem)
+        }, label: {
+            ItemCardView(item: product)
+        })
+    }
+
+    static func ==(lhs: POSProductItem, rhs: POSProductItem) -> Bool {
+        return lhs.product == rhs.product
+    }
+}
+
+struct POSDiscount: POSItem, Equatable {
+    var itemID = UUID()
+
+    var productID: Int64 = 0
+
+    var name: String = "A fixed discount"
+
+    var price: String = "-5.00"
+
+    var formattedPrice: String = "-$5.00"
+
+    var itemCategories: [String] = []
+
+    var productImageSource: String? = nil
+
+    var productType: Yosemite.ProductType = .simple
+}
+
+struct POSDiscountItem: POSDisplayableItem {
+    var id: UUID { discount.itemID }
+    let discount: POSDiscount
+    var item: POSItem { discount }
+
+    @ScaledMetric private var scale: CGFloat = 1.0
+
+    init?(item: POSItem) {
+        guard let discount = item as? POSDiscount else {
+            return nil
+        }
+        self.discount = discount
+    }
+
+    var body: some View {
+        HStack(spacing: Constants.cardSpacing) {
+                Rectangle()
+                .overlay {
+                    Image(systemName: "basket")
+                }
+                .frame(width: min(Constants.productCardSize * scale, Constants.maximumProductCardSize),
+                       height: Constants.productCardSize * scale)
+                .foregroundColor(Color(.secondarySystemFill))
+
+            DynamicHStack(spacing: Constants.textSpacing) {
+                Text(item.name)
+                    .lineLimit(2)
+                    .foregroundStyle(Color.posPrimaryText)
+                    .multilineTextAlignment(.leading)
+                    .font(Constants.itemNameFont)
+                Spacer()
+                Text(item.formattedPrice)
+                    .foregroundStyle(Color.posPrimaryText)
+                    .font(Constants.itemPriceFont)
+            }
+            .padding(.horizontal, Constants.horizontalTextPadding * (1 / scale))
+            .padding(.vertical, Constants.verticalTextPadding * (1 / scale))
+            Spacer()
+        }
+        .frame(maxWidth: .infinity, idealHeight: Constants.productCardSize * scale)
+        .background(Color.posSecondaryBackground)
+        .overlay {
+            RoundedRectangle(cornerRadius: Constants.productCardCornerRadius)
+                .stroke(Color.black, lineWidth: Constants.nilOutline)
+        }
+        .clipShape(RoundedRectangle(cornerRadius: Constants.productCardCornerRadius))
+        .shadow(color: Color.black.opacity(0.08), radius: 4, y: 2)
+    }
+
+    static func ==(lhs: POSDiscountItem, rhs: POSDiscountItem) -> Bool {
+        return lhs.discount == rhs.discount
+    }
+}
+
+private extension POSDiscountItem {
+    enum Constants {
+        static let productCardSize: CGFloat = 112
+        static let maximumProductCardSize: CGFloat = Constants.productCardSize * 2
+        static let productCardCornerRadius: CGFloat = 8
+        // The use of stroke means the shape is rendered as an outline (border) rather than a filled shape,
+        // since we still have to give it a value, we use 0 so it renders no border but it's shaped as one.
+        static let nilOutline: CGFloat = 0
+        static let cardSpacing: CGFloat = 0
+        static let textSpacing: CGFloat = 8
+        static let horizontalTextPadding: CGFloat = 32
+        static let verticalTextPadding: CGFloat = 8
+        static let itemNameFont: POSFontStyle = .posBodyEmphasized
+        static let itemPriceFont: POSFontStyle = .posBodyRegular
+    }
+}

WooCommerce/Classes/POS/PointOfSaleAggregateModel.swift

@@ -4,6 +4,7 @@ import Combine
 import protocol Yosemite.POSOrderServiceProtocol
 import protocol Yosemite.POSItem
 import protocol Yosemite.POSItemProvider
+import struct Yosemite.POSProduct
 import struct Yosemite.Order
 import struct Yosemite.OrderItem
 import struct Yosemite.POSCartItem
@@ -18,7 +19,7 @@ final class PointOfSaleAggregateModel: ObservableObject {
     }
 
     @Published private(set) var orderStage: OrderStage = .building
-    @Published private(set) var allItems: [POSItem] = []
+    private var allItems: [any POSDisplayableItem] = []
     @Published private(set) var cart: [CartItem] = []
     @Published private(set) var orderState: PointOfSaleOrderState = .idle
     @Published private(set) var order: Order? = nil
@@ -70,7 +71,7 @@ final class PointOfSaleAggregateModel: ObservableObject {
     @MainActor
     func loadItems(pageNumber: Int) async {
         do {
-            itemListState = .loading
+            itemListState = .loading(allItems)
             try await fetchItems(pageNumber: pageNumber)
         } catch {
             itemListState = .error(PointOfSaleErrorState.errorOnLoadingProducts())
@@ -79,10 +80,15 @@ final class PointOfSaleAggregateModel: ObservableObject {
 
     @MainActor
     private func fetchItems(pageNumber: Int) async throws {
-        let newItems = try await itemProvider.providePointOfSaleItems(pageNumber: pageNumber)
-        let uniqueNewItems = newItems.filter { newItem in
-            !allItems.contains(where: { $0.productID == newItem.productID })
+        var newItems = try await itemProvider.providePointOfSaleItems(pageNumber: pageNumber)
+        if pageNumber == 1 {
+            newItems.insert(POSDiscount(), at: 0)
         }
+        let uniqueNewItems = newItems
+            .filter { newItem in
+                !allItems.contains(where: { $0.id == newItem.itemID })
+            }
+            .compactMap(createPOSDisplayableItem(for:))
 
         allItems.append(contentsOf: uniqueNewItems)
 
@@ -115,14 +121,9 @@ final class PointOfSaleAggregateModel: ObservableObject {
         paymentState = .idle
     }
 
-    func selected(item: POSItem) {
-        let cartItem = CartItem(id: UUID(), item: item, quantity: 1)
-        addItemToCart(cartItem)
-        analytics.track(.pointOfSaleAddItemToCart)
-    }
-
     func addItemToCart(_ item: CartItem) {
         cart.insert(item, at: 0)
+        analytics.track(.pointOfSaleAddItemToCart)
     }
 
     func removeItemFromCart(_ cartItem: CartItem) {
@@ -136,7 +137,7 @@ final class PointOfSaleAggregateModel: ObservableObject {
     @MainActor
     func submitCart() async {
         orderStage = .finalizing
-        await startSyncingOrder(with: cart, allItems: allItems)
+        await startSyncingOrder(with: cart, allItems: allItems.map { $0.item })
     }
 
     private func startSyncingOrder(with cartItems: [CartItem], allItems: [POSItem]) async {

WooCommerce/Classes/POS/PointOfSaleItemListState.swift

@@ -3,19 +3,19 @@ import protocol Yosemite.POSItem
 enum PointOfSaleItemListState: Equatable {
     case empty
     case initialLoading
-    case loading
-    case loaded([POSItem])
+    case loading(_ existingItems: [any POSDisplayableItem])
+    case loaded([any POSDisplayableItem])
     case error(PointOfSaleErrorState)
 
     // Equatable conformance for testing:
     static func == (lhs: PointOfSaleItemListState, rhs: PointOfSaleItemListState) -> Bool {
         switch (lhs, rhs) {
         case (.initialLoading, .initialLoading),
-            (.empty, .empty),
-            (.loading, .loading):
+            (.empty, .empty):
             return true
-        case (.loaded(let lhsItems), .loaded(let rhsItems)):
-            return lhsItems.map { $0.itemID } == rhsItems.map { $0.itemID }
+        case (.loading(let lhsItems), .loading(let rhsItems)),
+            (.loaded(let lhsItems), .loaded(let rhsItems)):
+            return true// lhsItems == rhsItems
         case (.error(let lhsError), .error(let rhsError)):
             return lhsError == rhsError
         default:

WooCommerce/Classes/POS/Presentation/ItemListView.swift

@@ -24,8 +24,8 @@ struct ItemListView: View {
                 // These cases are handled directly in the dashboard, we do not render
                 // a specific view within the ItemListView to handle them
                 EmptyView()
-            case .loading, .loaded:
-                listView(viewModel.items)
+            case .loading(let items), .loaded(let items):
+                listView(items)
             }
         }
         .refreshable {
@@ -123,26 +123,22 @@ private extension ItemListView {
     }
 
     @ViewBuilder
-    func listView(_ items: [POSItem]) -> some View {
+    func listView(_ items: [any POSDisplayableItem]) -> some View {
         ScrollView {
             VStack {
                 if dynamicTypeSize.isAccessibilitySize, viewModel.shouldShowHeaderBanner {
                     bannerCardView
                 }
-                ForEach(items, id: \.productID) { item in
-                    Button(action: {
-                        viewModel.select(item)
-                    }, label: {
-                        ItemCardView(item: item)
-                    })
+                ForEach(items, id: \.id) { item in
+                    AnyView(item)
                 }
             }
             .padding(.bottom, floatingControlAreaSize.height)
             .padding(.horizontal, Constants.itemListPadding)
             .background(GeometryReader { proxy in
                 Color.clear
                     .onChange(of: proxy.frame(in: .global).maxY) { maxY in
-                        if posModel.itemListState == .loading {
+                        if case .loading = posModel.itemListState {
                             return
                         }
                         let viewHeight = UIScreen.main.bounds.height

WooCommerce/Classes/POS/Presentation/PointOfSaleEntryPointView.swift

@@ -53,6 +53,7 @@ struct PointOfSaleEntryPointView: View {
                                  itemListViewModel: itemListViewModel,
                                  posModel: posModel)
         .environmentObject(posModalManager)
+        .environmentObject(posModel)
         .onAppear {
             onPointOfSaleModeActiveStateChange(true)
         }

WooCommerce/Classes/POS/ViewModels/ItemListViewModel.swift

@@ -5,10 +5,6 @@ import protocol Yosemite.POSItem
 final class ItemListViewModel: ItemListViewModelProtocol {
     let posModel: PointOfSaleAggregateModel
 
-    var items: [POSItem] {
-        posModel.allItems
-    }
-
     @Published private(set) var isHeaderBannerDismissed: Bool = false
     @Published var showSimpleProductsModal: Bool = false
 
@@ -19,17 +15,13 @@ final class ItemListViewModel: ItemListViewModelProtocol {
         if UserDefaults.standard.bool(forKey: BannerState.isSimpleProductsOnlyBannerDismissedKey) == true {
             return false
         }
-        return !isHeaderBannerDismissed && items.isNotEmpty
+        return !isHeaderBannerDismissed && posModel.itemListState != .empty
     }
 
     init(posModel: PointOfSaleAggregateModel) {
         self.posModel = posModel
     }
 
-    func select(_ item: POSItem) {
-        posModel.selected(item: item)
-    }
-
     @MainActor
     func loadNextItems() async {
         // TODO: Optimize API calls. gh-14186

WooCommerce/Classes/POS/ViewModels/ItemListViewModelProtocol.swift

@@ -3,11 +3,9 @@ import Foundation
 import protocol Yosemite.POSItem
 
 protocol ItemListViewModelProtocol: ObservableObject {
-    var items: [POSItem] { get }
     var isHeaderBannerDismissed: Bool { get }
     var shouldShowHeaderBanner: Bool { get }
 
-    func select(_ item: POSItem)
     func loadNextItems() async
     func dismissBanner()
 }

WooCommerce/WooCommerce.xcodeproj/project.pbxproj

@@ -831,6 +831,7 @@
 		20B7E3152CD0DDDA007FD997 /* PointOfSaleOrderState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20B7E3142CD0DDDA007FD997 /* PointOfSaleOrderState.swift */; };
 		20B7E3172CD100DC007FD997 /* PointOfSalePaymentState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20B7E3162CD100DC007FD997 /* PointOfSalePaymentState.swift */; };
 		20B7E3192CD13CE3007FD997 /* PointOfSaleItemListState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20B7E3182CD13CE3007FD997 /* PointOfSaleItemListState.swift */; };
+		20B7E3512CD3DAB5007FD997 /* POSDisplayableItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20B7E3502CD3DAB5007FD997 /* POSDisplayableItem.swift */; };
 		20BBD62C2B3060A300A903F6 /* AddOrderComponentsSection.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20BBD62B2B3060A300A903F6 /* AddOrderComponentsSection.swift */; };
 		20BCF6EE2B0E478B00954840 /* WooPaymentsDepositsOverviewViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20BCF6ED2B0E478B00954840 /* WooPaymentsDepositsOverviewViewModel.swift */; };
 		20BCF6F02B0E48CC00954840 /* WooPaymentsDepositsOverviewViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 20BCF6EF2B0E48CC00954840 /* WooPaymentsDepositsOverviewViewModelTests.swift */; };
@@ -3922,6 +3923,7 @@
 		20B7E3142CD0DDDA007FD997 /* PointOfSaleOrderState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PointOfSaleOrderState.swift; sourceTree = "<group>"; };
 		20B7E3162CD100DC007FD997 /* PointOfSalePaymentState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PointOfSalePaymentState.swift; sourceTree = "<group>"; };
 		20B7E3182CD13CE3007FD997 /* PointOfSaleItemListState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PointOfSaleItemListState.swift; sourceTree = "<group>"; };
+		20B7E3502CD3DAB5007FD997 /* POSDisplayableItem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = POSDisplayableItem.swift; sourceTree = "<group>"; };
 		20BBD62B2B3060A300A903F6 /* AddOrderComponentsSection.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AddOrderComponentsSection.swift; sourceTree = "<group>"; };
 		20BCF6ED2B0E478B00954840 /* WooPaymentsDepositsOverviewViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WooPaymentsDepositsOverviewViewModel.swift; sourceTree = "<group>"; };
 		20BCF6EF2B0E48CC00954840 /* WooPaymentsDepositsOverviewViewModelTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WooPaymentsDepositsOverviewViewModelTests.swift; sourceTree = "<group>"; };
@@ -7101,6 +7103,7 @@
 				026826972BF59D9E0036F959 /* Utils */,
 				026826A12BF59DED0036F959 /* Presentation */,
 				20B7E3122CCFFEB4007FD997 /* PointOfSaleAggregateModel.swift */,
+				20B7E3502CD3DAB5007FD997 /* POSDisplayableItem.swift */,
 				20B7E3182CD13CE3007FD997 /* PointOfSaleItemListState.swift */,
 				20B7E3162CD100DC007FD997 /* PointOfSalePaymentState.swift */,
 				20B7E3142CD0DDDA007FD997 /* PointOfSaleOrderState.swift */,
@@ -14731,6 +14734,7 @@
 				31FE28C225E6D338003519F2 /* LearnMoreTableViewCell.swift in Sources */,
 				02D45647231CB1FB008CF0A9 /* UIImage+Dot.swift in Sources */,
 				680BA59A2A4C377900F5559D /* UpgradeViewState.swift in Sources */,
+				20B7E3512CD3DAB5007FD997 /* POSDisplayableItem.swift in Sources */,
 				E11228BE2707267F004E9F2D /* CardPresentModalUpdateFailedNonRetryable.swift in Sources */,
 				86DE68822B4BA47A00B437A6 /* BlazeAdDestinationSettingViewModel.swift in Sources */,
 				EEC5E01129A70CC300416CAC /* StoreSetupProgressView.swift in Sources */,

Yosemite/Yosemite/PointOfSale/POSProduct.swift

@@ -1,14 +1,14 @@
-struct POSProduct: POSItem {
-    let itemID: UUID
-    let productID: Int64
-    let name: String
-    let price: String
-    let formattedPrice: String
-    let itemCategories: [String]
-    var productImageSource: String?
-    let productType: ProductType
+public struct POSProduct: POSItem, Equatable {
+    public let itemID: UUID
+    public let productID: Int64
+    public let name: String
+    public let price: String
+    public let formattedPrice: String
+    public let itemCategories: [String]
+    public var productImageSource: String?
+    public let productType: ProductType
 
-    init(itemID: UUID,
+    public init(itemID: UUID,
          productID: Int64,
          name: String,
          price: String,
@@ -25,4 +25,15 @@ struct POSProduct: POSItem {
         self.productImageSource = productImageSource
         self.productType = productType
     }
+
+    public static func ==(lhs: POSProduct, rhs: POSProduct) -> Bool {
+        return lhs.itemID == rhs.itemID &&
+        lhs.productID == rhs.productID &&
+        lhs.name == rhs.name &&
+        lhs.price == rhs.price &&
+        lhs.formattedPrice == rhs.formattedPrice &&
+        lhs.itemCategories == rhs.itemCategories &&
+        lhs.productImageSource == rhs.productImageSource &&
+        lhs.productType == rhs.productType
+    }
 }