Mark items as read

Hax/Domain/Models/ReadItems.swift

@@ -0,0 +1,56 @@
+//
+//  ReadItems.swift
+//  Hax
+//
+//  Created by Luis Fariña on 22/2/25.
+//
+
+import Foundation
+
+@MainActor
+@Observable
+final class ReadItems {
+
+    // MARK: Properties
+
+    static let shared = ReadItems()
+    private let userDefaults: UserDefaults
+    private let limit: Int
+    private let key = UserDefaults.Key.readItems
+    private var itemIdentifiers: [Int]
+    private var itemIdentifierSet: Set<Int> = []
+
+    // MARK: Initialization
+
+    init(userDefaults: UserDefaults = .standard, limit: Int = 100) {
+        self.userDefaults = userDefaults
+        self.limit = limit
+        itemIdentifiers = userDefaults
+            .array(forKey: key) as? [Int] ?? []
+        itemIdentifierSet = Set(itemIdentifiers)
+    }
+
+    // MARK: Methods
+
+    func add(_ itemIdentifier: Int) {
+        if contains(itemIdentifier),
+           let index = itemIdentifiers.firstIndex(of: itemIdentifier) {
+            itemIdentifiers.remove(at: index)
+            itemIdentifiers.append(itemIdentifier)
+        } else {
+            itemIdentifiers.append(itemIdentifier)
+
+            if itemIdentifiers.count > limit {
+                itemIdentifiers = itemIdentifiers.suffix(limit)
+            }
+
+            itemIdentifierSet.insert(itemIdentifier)
+        }
+
+        userDefaults.set(itemIdentifiers, forKey: key)
+    }
+
+    func contains(_ itemIdentifier: Int) -> Bool {
+        itemIdentifierSet.contains(itemIdentifier)
+    }
+}

Hax/Extensions/UserDefaultsExtension.swift

@@ -12,6 +12,7 @@ extension UserDefaults {
     enum Key {
         static let defaultFeed = "defaultFeed"
         static let numberOfLaunches = "numberOfLaunches"
+        static let readItems = "readItems"
         static let reviewHasBeenRequested = "reviewHasBeenRequested"
         static let url = "url"
     }

Hax/HaxApp.swift

@@ -42,6 +42,7 @@ struct HaxApp: App {
     var body: some Scene {
         WindowGroup {
             MainView(model: mainViewModel)
+                .environment(ReadItems.shared)
                 .onContinueUserActivity(
                     Constant.readItemUserActivity
                 ) { userActivity in

Hax/Presentation/Components/View Models/ItemRowViewModel.swift

@@ -57,6 +57,9 @@ protocol ItemRowViewModelProtocol {
     /// The action to be carried out when tapping a link in the body of the item.
     var onLinkTap: OnLinkTap? { get }
 
+    /// Whether the item has been read before.
+    var isRead: Bool { get }
+
     /// Whether the index of the item should be displayed.
     var shouldDisplayIndex: Bool { get }
 
@@ -83,6 +86,7 @@ struct ItemRowViewModel: ItemRowViewModelProtocol {
     let onUserTap: OnUserTap?
     let onNumberOfCommentsTap: OnNumberOfCommentsTap?
     let onLinkTap: OnLinkTap?
+    let isRead: Bool
 
     var shouldDisplayIndex: Bool {
         view == .feed
@@ -120,6 +124,7 @@ struct ItemRowViewModel: ItemRowViewModelProtocol {
         onUserTap: OnUserTap? = nil,
         onNumberOfCommentsTap: OnNumberOfCommentsTap? = nil,
         onLinkTap: OnLinkTap? = nil,
+        isRead: Bool = false,
         commentIsHighlighted: Bool = false
     ) {
         self.view = view
@@ -128,6 +133,7 @@ struct ItemRowViewModel: ItemRowViewModelProtocol {
         self.onUserTap = onUserTap
         self.onNumberOfCommentsTap = onNumberOfCommentsTap
         self.onLinkTap = onLinkTap
+        self.isRead = isRead
         self.commentIsHighlighted = commentIsHighlighted
     }
 }

Hax/Presentation/Components/Views/ItemList.swift

@@ -18,6 +18,7 @@ struct ItemList: View {
     @Binding var selectedItem: Item?
     @Binding var translationPopoverIsPresented: Bool
     @Binding var textToBeTranslated: String
+    @Environment(ReadItems.self) private var readItems
 
     // MARK: Body
 
@@ -33,6 +34,8 @@ struct ItemList: View {
                         } else {
                             selectedItem = item
                         }
+
+                        readItems.add(item.id)
                     } label: {
                         ItemRowView(
                             model: ItemRowViewModel(
@@ -41,7 +44,8 @@ struct ItemList: View {
                                 item: item,
                                 onNumberOfCommentsTap: {
                                     selectedItem = item
-                                }
+                                },
+                                isRead: readItems.contains(item.id)
                             )
                         )
                     }

Hax/Presentation/Components/Views/ItemRowView.swift

@@ -32,6 +32,9 @@ struct ItemRowView<Model: ItemRowViewModelProtocol>: View {
                         Text(title)
                             .font(titleFont)
                             .fontWeight(titleFontWeight)
+                            .foregroundStyle(
+                                model.isRead ? .secondary : .primary
+                            )
                     }
                     if model.shouldDisplayBody,
                        let body = model.item.markdownBody {
@@ -88,6 +91,7 @@ struct ItemRowView<Model: ItemRowViewModelProtocol>: View {
                 }
             }
         }
+        .opacity(model.isRead ? 0.7 : 1)
         .padding(.vertical, 5)
     }
 }

Hax/Presentation/Screens/Views/ItemView.swift

@@ -125,6 +125,8 @@ struct ItemView<Model: ItemViewModelProtocol>: View {
             Task {
                 await model.onViewAppear()
             }
+
+            ReadItems.shared.add(model.item.id)
         }
         .refreshable {
             await model.onRefreshRequest()

HaxTests/Mocks/UserDefaultsMock.swift

@@ -11,12 +11,14 @@ final class UserDefaultsMock: UserDefaults {
 
     // MARK: Properties
 
-    private var dictionary: [String: Any] = [:]
+    private(set) var setCallCount = Int.zero
     private(set) var stringCallCount = Int.zero
+    private var dictionary: [String: Any] = [:]
 
     // MARK: Methods
 
     override func set(_ value: Any?, forKey defaultName: String) {
+        setCallCount += 1
         dictionary[defaultName] = value
     }
 
@@ -25,4 +27,8 @@ final class UserDefaultsMock: UserDefaults {
 
         return dictionary[defaultName] as? String
     }
+
+    override func array(forKey defaultName: String) -> [Any]? {
+        dictionary[defaultName] as? [Any]
+    }
 }

HaxTests/Tests/Domain/Models/ReadItemsTests.swift

@@ -0,0 +1,88 @@
+//
+//  ReadItemsTests.swift
+//  HaxTests
+//
+//  Created by Luis Fariña on 27/2/25.
+//
+
+import Testing
+@testable import Hax
+
+@MainActor
+struct ReadItemsTests {
+
+    // MARK: Properties
+
+    private let sut: ReadItems
+    private let userDefaultsMock: UserDefaultsMock
+
+    // MARK: Initialization
+
+    init() {
+        userDefaultsMock = UserDefaultsMock()
+        userDefaultsMock.set([1, 2], forKey: "readItems")
+        sut = ReadItems(userDefaults: userDefaultsMock, limit: 3)
+    }
+
+    // MARK: Tests
+
+    @Test func add_givenItemIsNotReadAndLimitIsNotExceeded() {
+        // When
+        sut.add(3)
+
+        // Then
+        for itemIdentifier in [1, 2, 3] {
+            #expect(sut.contains(itemIdentifier))
+        }
+        #expect(userDefaultsMock.setCallCount == 2)
+    }
+
+    @Test func add_givenItemIsNotReadAndLimitIsExceeded() {
+        // Given
+        sut.add(3)
+
+        // When
+        sut.add(4)
+
+        // Then
+        for itemIdentifier in [2, 3, 4] {
+            #expect(sut.contains(itemIdentifier))
+        }
+        #expect(userDefaultsMock.setCallCount == 3)
+    }
+
+    @Test func add_givenItemIsRead() {
+        // Given
+        sut.add(3)
+
+        // When
+        sut.add(1)
+
+        // Then
+        for itemIdentifier in [2, 3, 1] {
+            #expect(sut.contains(itemIdentifier))
+        }
+        #expect(userDefaultsMock.setCallCount == 3)
+    }
+
+    @Test func contains_givenItemIsNotRead() {
+        // When
+        let contains = sut.contains(3)
+
+        // Then
+        #expect(!contains)
+        #expect(userDefaultsMock.setCallCount == 1)
+    }
+
+    @Test func contains_givenItemIsRead() {
+        // Given
+        sut.add(3)
+
+        // When
+        let contains = sut.contains(3)
+
+        // Then
+        #expect(contains)
+        #expect(userDefaultsMock.setCallCount == 2)
+    }
+}