Add notifications for error status codes

Sources/App/Environments/AppEnvironment.swift

@@ -2,14 +2,28 @@
 //  Mocka
 //
 
-import Foundation
+import Combine
 import MockaServer
 import SwiftUI
 
 /// App environment object shared by all the `View`s of the application.
 final class AppEnvironment: ObservableObject {
+  /// Whether or not the in-app notifications are enabled.
+  @Published var areInAppNotificationEnabled: Bool = Logic.Settings.Notifications.areInAppNotificationEnabled {
+    didSet {
+      Logic.Settings.Notifications.areInAppNotificationEnabled = areInAppNotificationEnabled
+    }
+  }
+
+  /// The subscription for mapping the failed requests into `InAppNotifications`.
+  var failedRequestsNotificationSubscription: AnyCancellable?
+
   /// Whether the server is currently running.
-  @Published var isServerRunning: Bool = false
+  @Published var isServerRunning: Bool = false {
+    didSet {
+      Logic.Settings.Notifications.updateFailedRequestsNotificationSubscription(in: self)
+    }
+  }
 
   /// The selected app section, selected by using the app's Sidebar.
   @Published var selectedSection: SidebarSection = .server

Sources/App/Helpers/SFSymbol.swift

@@ -6,6 +6,9 @@ import Foundation
 
 /// The San Francisco Symbol enum.
 enum SFSymbol: String {
+  /// The bell icon.
+  case bell
+
   /// Document icon.
   case document = "doc.fill"
 

Sources/App/Helpers/Typealiases.swift

@@ -4,8 +4,14 @@
 
 import Foundation
 
-/// An `API` path.
-typealias Path = [String]
+/// A closure for reacting to a permission authorization request.
+typealias AuthorizationRequestCompletion = (Bool, Error?) -> Void
+
+/// A closure block with a parameter.
+typealias CustomInteraction<T> = (T) -> Void
 
 /// A closure with no parameters, and no output.
 typealias Interaction = () -> Void
+
+/// An `API` path.
+typealias Path = [String]

Sources/App/Logic/Notification+Logic.swift

@@ -0,0 +1,100 @@
+//
+//  Mocka
+//
+
+import SwiftUI
+import UserNotifications
+
+extension Logic.Settings {
+  /// The logic related to notifications settings of the app.
+  enum Notifications {}
+}
+
+extension Logic.Settings.Notifications {
+  /// Whether or not the in-app notifications are enabled.
+  @AppStorage(UserDefaultKey.areInAppNotificationEnabled) static var areInAppNotificationEnabled: Bool = false
+
+  /// The `UNUserNotificationCenter` used for handling notifications.
+  private static var notificationCenter: UNUserNotificationCenter {
+    .current()
+  }
+
+  /// Builds an `UNNotificationRequest` with the given `notification`'s content and adds it to the notification center.
+  ///
+  /// - Parameters:
+  ///   - notification: The in app
+  ///   - identifier: The identifier of the request that will be built.
+  ///   - completion: The block to execute with the results. If the notification is successfully scheduled the returned error is `nil`.
+  ///
+  /// - Note: This method does nothing when `areInAppNotificationEnabled` is `false`.
+  static func add(notification: InAppNotification, with identifier: String = UUID().uuidString, completion: CustomInteraction<Error?>? = nil) {
+    addNotificationRequest(with: notification.content, identifier: identifier, completion: completion)
+  }
+
+  /// Builds an `UNNotificationRequest` with the given `content` and adds it to the notification center.
+  ///
+  /// - Parameters:
+  ///   - content: The content of the request.
+  ///   - identifier: The identifier of the request that will be built.
+  ///   - completion: The block to execute with the results. If the notification is successfully scheduled the returned error is `nil`.
+  ///
+  /// - Note: This method does nothing when `areInAppNotificationEnabled` is `false`.
+  static func addNotificationRequest(
+    with content: UNNotificationContent,
+    identifier: String = UUID().uuidString,
+    completion: CustomInteraction<Error?>? = nil
+  ) {
+    guard areInAppNotificationEnabled else {
+      return
+    }
+
+    requestNotificationsAuthorizationIfNecessary { isPermissionGiven, error in
+      let request = UNNotificationRequest(identifier: identifier, content: content, trigger: nil)
+      notificationCenter.add(request, withCompletionHandler: completion)
+    }
+  }
+
+  /// Requests notifications permissions if the user never answered to it.
+  ///
+  /// - Parameter completion: The closure excecuted when the user answers the request.
+  static func requestNotificationsAuthorizationIfNecessary(_ completion: @escaping AuthorizationRequestCompletion) {
+    UNUserNotificationCenter.current()
+      .getNotificationSettings { settings in
+        switch settings.authorizationStatus {
+        case .notDetermined:
+          UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound], completionHandler: completion)
+
+        case .authorized, .provisional:
+          completion(true, nil)
+
+        case .denied:
+          completion(
+            false, NSError(domain: "App Permissions", code: 0, userInfo: [NSLocalizedDescriptionKey: "User denied notifications permissions"]))
+
+        @unknown default:
+          completion(false, NSError(domain: "App Permissions", code: 0, userInfo: [NSLocalizedDescriptionKey: "Unknown authorizationStatus value"]))
+          return
+        }
+      }
+  }
+
+  /// Updates the `failedRequestsNotificationSubscription` in the given `appEnvironment`.
+  ///
+  /// - Parameter appEnvironment: The `AppEnvironment` instance to be updated.
+  static func updateFailedRequestsNotificationSubscription(in appEnvironment: AppEnvironment) {
+    guard appEnvironment.isServerRunning else {
+      appEnvironment.failedRequestsNotificationSubscription = nil
+      return
+    }
+
+    appEnvironment.failedRequestsNotificationSubscription = appEnvironment.server.networkExchangesPublisher
+      .receive(on: RunLoop.main)
+      .filter {
+        let statusCode = $0.response.status.code
+        return statusCode >= 300 && statusCode <= 600
+      }
+      .sink {
+        Logic.Settings.Notifications.add(notification: .failedResponse(statusCode: $0.response.status.code, path: $0.response.uri.path))
+      }
+  }
+}

Sources/App/Logic/Settings+Logic.swift

@@ -2,52 +2,52 @@
 //  Mocka
 //
 
-import Foundation
 import UniformTypeIdentifiers
 
 extension Logic {
   /// The logic related to settings of the app.
-  enum Settings {
-    /// The name of the file containing the server's configuration.
-    static let serverConfigurationFileName = "serverConfiguration.json"
-
-    /// Checks if the workspace `URL` saved in the `UserDefaults` is valid.
-    /// That is, it is not nil, it exists, and it contains the `serverConfiguration.json` file.
-    static var isWorkspaceURLValid: Bool {
-      guard let savedWorkspaceURL = UserDefaults.standard.url(forKey: UserDefaultKey.workspaceURL) else {
-        return false
-      }
+  enum Settings {}
+}
 
-      return
-        FileManager.default.fileExists(atPath: savedWorkspaceURL.path)
-        && uniformType(of: savedWorkspaceURL) == UTType.folder
-        && serverConfigurationFileExists(at: savedWorkspaceURL)
+extension Logic.Settings {
+  /// The name of the file containing the server's configuration.
+  static let serverConfigurationFileName = "serverConfiguration.json"
+
+  /// Checks if the workspace `URL` saved in the `UserDefaults` is valid.
+  /// That is, it is not nil, it exists, and it contains the `serverConfiguration.json` file.
+  static var isWorkspaceURLValid: Bool {
+    guard let savedWorkspaceURL = UserDefaults.standard.url(forKey: UserDefaultKey.workspaceURL) else {
+      return false
     }
 
-    /// The server configuration.
-    ///
-    /// This variable extracts the hostname and port of the server from the `serverConfigurationFileName`.
-    /// In addition, it tries to fetch all the requests from the workspace path.
-    /// Should either of the two steps fail, it returns nil.
-    static var serverConfiguration: ServerConfiguration? {
-      guard
-        let workspaceURL = UserDefaults.standard.url(forKey: UserDefaultKey.workspaceURL),
-        let settingsFileData = FileManager.default.contents(
-          atPath: workspaceURL.appendingPathComponent(serverConfigurationFileName, isDirectory: false).path
-        ),
-        let serverConfiguration = try? JSONDecoder().decode(ServerConnectionConfiguration.self, from: settingsFileData),
-        let requests = try? Logic.SourceTree.requests()
-      else {
-        return nil
-      }
+    return
+      FileManager.default.fileExists(atPath: savedWorkspaceURL.path)
+      && uniformType(of: savedWorkspaceURL) == UTType.folder
+      && serverConfigurationFileExists(at: savedWorkspaceURL)
+  }
 
-      return ServerConfiguration(hostname: serverConfiguration.hostname, port: serverConfiguration.port, requests: requests)
+  /// The server configuration.
+  ///
+  /// This variable extracts the hostname and port of the server from the `serverConfigurationFileName`.
+  /// In addition, it tries to fetch all the requests from the workspace path.
+  /// Should either of the two steps fail, it returns nil.
+  static var serverConfiguration: ServerConfiguration? {
+    guard
+      let workspaceURL = UserDefaults.standard.url(forKey: UserDefaultKey.workspaceURL),
+      let settingsFileData = FileManager.default.contents(
+        atPath: workspaceURL.appendingPathComponent(serverConfigurationFileName, isDirectory: false).path
+      ),
+      let serverConfiguration = try? JSONDecoder().decode(ServerConnectionConfiguration.self, from: settingsFileData),
+      let requests = try? Logic.SourceTree.requests()
+    else {
+      return nil
     }
+
+    return ServerConfiguration(hostname: serverConfiguration.hostname, port: serverConfiguration.port, requests: requests)
   }
 }
 
 extension Logic.Settings {
-
   /// Updates the server configuration file or creates it at the workspace root folder.
   /// - Throws: `MockaError.workspacePathDoesNotExist`,
   ///           `MockaError.failedToEncode`.

Sources/App/Mocka.swift

@@ -40,6 +40,7 @@ struct Mocka: App {
 
     Settings {
       AppSettings()
+        .environmentObject(appEnvironment)
     }
   }
 }

Sources/App/Models/InAppNotification.swift

@@ -0,0 +1,26 @@
+//
+//  Mocka
+//
+
+import UserNotifications
+
+/// An in-app notification to be showed to the user.
+enum InAppNotification {
+  /// The in-app notification for when a request fails.
+  case failedResponse(statusCode: UInt, path: String)
+
+  /// The `UNNotificationContent` for the in-app notification.
+  var content: UNNotificationContent {
+    let content = UNMutableNotificationContent()
+
+    switch self {
+    case let .failedResponse(statusCode, path):
+      content.body = "Received response with \(statusCode) status code."
+      content.title = "Request failed!"
+      content.subtitle = "Endpoint: \(path)"
+      content.sound = .default
+    }
+
+    return content
+  }
+}

Sources/App/Models/UserDefaultKey.swift

@@ -6,6 +6,9 @@ import Foundation
 
 /// The `Key`s used to save and fetch values from `UserDefaults`.
 enum UserDefaultKey {
+  /// The key for retrieving the activation status of the in-app notifications.
+  static let areInAppNotificationEnabled = "areInAppNotificationEnabled"
+
   /// The workspace path that should be used when fetching and saving the requests and responses created by the user.
   static let workspaceURL = "workspaceURL"
 }

Sources/App/Views/Sections/Server/List/ServerListViewModel.swift

@@ -14,7 +14,7 @@ final class ServerListViewModel: ObservableObject {
   /// The text that filters the requests.
   @Published var filterText: String = ""
 
-  /// The array of `NetworkExchange`s.
+  /// The array of `NetworkExchange`s to be shown in the view.
   @Published var networkExchanges: [NetworkExchange] = []
 
   /// The `Set` containing the list of subscriptions.
@@ -39,11 +39,11 @@ final class ServerListViewModel: ObservableObject {
 
   /// Creates a new instance with a `Publisher` of `NetworkExchange`s.
   /// - Parameter networkExchangesPublisher: The publisher of `NetworkExchange`s.
-  init(networkExchangesPublisher: AnyPublisher<NetworkExchange, Never>) {
-    networkExchangesPublisher
+  init(networkExchangesPublisher: AnyPublisher<NetworkExchange, Never>?) {
+    networkExchangesPublisher?
       .receive(on: RunLoop.main)
-      .sink { [weak self] in
-        self?.networkExchanges.append($0)
+      .sink { [weak self] networkExchange in
+        self?.networkExchanges.append(networkExchange)
       }
       .store(in: &subscriptions)
   }

Sources/App/Views/Sections/Settings/AppSettings.swift

@@ -6,6 +6,8 @@ import SwiftUI
 
 /// This is the main app settings `Settings`.
 struct AppSettings: View {
+  /// The app environment object.
+  @EnvironmentObject var appEnvironment: AppEnvironment
 
   // MARK: - Body
 
@@ -15,6 +17,13 @@ struct AppSettings: View {
         .tabItem {
           Label("Server", systemImage: SFSymbol.document.rawValue)
         }
+
+      NotificationsSettings(viewModel: NotificationsSettingsViewModel(areInAppNotificationEnabled: appEnvironment.areInAppNotificationEnabled))
+        .tabItem {
+          Label("Notifications", systemImage: SFSymbol.bell.rawValue)
+        }
     }
+    .padding(25)
+    .frame(minWidth: 0, maxWidth: .infinity, alignment: .top)
   }
 }

Sources/App/Views/Sections/Settings/Notifications/NotificationsSettings.swift

@@ -0,0 +1,18 @@
+//
+//  Mocka
+//
+
+import SwiftUI
+
+/// The notifications settings view.
+struct NotificationsSettings: View {
+  /// The `ViewModel` for the view.
+  @State var viewModel: NotificationsSettingsViewModel
+
+  var body: some View {
+    VStack {
+      Toggle("Notifiche per request fallite", isOn: $viewModel.areInAppNotificationEnabled)
+        .toggleStyle(CheckboxToggleStyle())
+    }
+  }
+}

Sources/App/Views/Sections/Settings/Notifications/NotificationsSettingsViewModel.swift

@@ -0,0 +1,15 @@
+//
+//  Mocka
+//
+
+import SwiftUI
+
+/// The `ViewModel` for the `NotificationsSettingsView`.
+struct NotificationsSettingsViewModel {
+  /// Whether or not the in-app notifications are enabled.
+  var areInAppNotificationEnabled: Bool = Logic.Settings.Notifications.areInAppNotificationEnabled {
+    didSet {
+      Logic.Settings.Notifications.areInAppNotificationEnabled = areInAppNotificationEnabled
+    }
+  }
+}