Recommend App: Add presenter to encapsulate display logic

WordPress/Classes/Utility/BuildInformation/FeatureFlag.swift

@@ -13,6 +13,7 @@ enum FeatureFlag: Int, CaseIterable, OverrideableFlag {
     case siteIconCreator
     case editorOnboardingHelpMenu
     case unifiedCommentsAndNotificationsList
+    case recommendAppToOthers
 
     /// Returns a boolean indicating if the feature is enabled
     var enabled: Bool {
@@ -43,6 +44,8 @@ enum FeatureFlag: Int, CaseIterable, OverrideableFlag {
             return BuildConfiguration.current ~= [.localDeveloper, .a8cBranchTest]
         case .unifiedCommentsAndNotificationsList:
             return true
+        case .recommendAppToOthers:
+            return false
         }
     }
 
@@ -91,6 +94,8 @@ extension FeatureFlag {
             return "Editor Onboarding Help Menu"
         case .unifiedCommentsAndNotificationsList:
             return "Unified List for Comments and Notifications"
+        case .recommendAppToOthers:
+            return "Recommend App to Others"
         }
     }
 

WordPress/Classes/ViewRelated/Sharing/ShareAppContentPresenter.swift

@@ -0,0 +1,129 @@
+/// Encapsulates the logic required to fetch, prepare, and present the contents for sharing the app to others.
+///
+/// The contents for sharing is first fetched from the API, so the share presentation logic is not synchronously executed.
+/// Callers are recommended to listen to progress changes by implementing `didUpdateLoadingState(_ loading:)` as this class' delegate.
+///
+class ShareAppContentPresenter {
+
+    // MARK: Public Properties
+
+    weak var delegate: ShareAppContentPresenterDelegate?
+
+    /// Tracks content fetch state.
+    private(set) var isLoading: Bool = false {
+        didSet {
+            guard isLoading != oldValue else {
+                return
+            }
+            delegate?.didUpdateLoadingState(isLoading)
+        }
+    }
+
+    // MARK: Private Properties
+
+    /// The API used for fetching the share app link. Anonymous profile is allowed.
+    private let api: WordPressComRestApi
+
+    private lazy var remote: ShareAppContentServiceRemote = {
+        ShareAppContentServiceRemote(wordPressComRestApi: api)
+    }()
+
+    /// In-memory cache. As long as the same presenter instance is used, there's no need to re-fetch the content everytime `shareContent` is called.
+    private var cachedContent: RemoteShareAppContent? = nil
+
+    // MARK: Initialization
+
+    /// Instantiates the presenter. When the provided account is nil, the presenter will default to anonymous API.
+    init(account: WPAccount? = nil) {
+        self.api = account?.wordPressComRestV2Api ?? .anonymousApi(userAgent: WPUserAgent.wordPress(), localeKey: WordPressComRestApi.LocaleKeyV2)
+    }
+
+    // MARK: Public Methods
+
+    /// Fetches the content needed for sharing, and presents the share sheet through the provided `sender` instance.
+    ///
+    /// - Parameters:
+    ///   - appName: The name of the app to be shared. Fetched contents will differ depending on the provided value.
+    ///   - sender: The view that will be presenting the share sheet.
+    ///   - sourceView: The view to be the anchor for the popover view on iPad.
+    ///   - completion: A closure that's invoked after the process completes.
+    func present(for appName: ShareAppName, in sender: UIViewController, sourceView: UIView? = nil, completion: (() -> Void)? = nil) {
+        let anchorView = sourceView ?? sender.view
+        if let content = cachedContent {
+            presentShareSheet(with: content, in: sender, sourceView: anchorView)
+            completion?()
+            return
+        }
+
+        guard !isLoading else {
+            completion?()
+            return
+        }
+
+        isLoading = true
+
+        remote.getContent(for: appName) { [weak self] result in
+            guard let self = self else { return }
+
+            switch result {
+            case .success(let content):
+                self.cachedContent = content
+                self.presentShareSheet(with: content, in: sender, sourceView: anchorView)
+
+            case .failure:
+                self.showFailureNotice(in: sender)
+            }
+
+            self.isLoading = false
+            completion?()
+        }
+    }
+}
+
+// MARK: - Delegate Definition
+
+protocol ShareAppContentPresenterDelegate: AnyObject {
+    /// Delegate method called everytime the presenter updates its loading state.
+    ///
+    /// - Parameter loading: The presenter's latest loading state.
+    func didUpdateLoadingState(_ loading: Bool)
+}
+
+// MARK: - Private Helpers
+
+private extension ShareAppContentPresenter {
+    /// Presents the share sheet by using `UIActivityViewController`. Contents to be shared will be constructed from the provided `content`.
+    ///
+    /// - Parameters:
+    ///   - content: The model containing information metadata for the sharing activity.
+    ///   - viewController: The view controller that will be presenting the activity.
+    ///   - sourceView: The view set to be the anchor for the popover.
+    func presentShareSheet(with content: RemoteShareAppContent, in viewController: UIViewController, sourceView: UIView?) {
+        guard let linkURL = content.linkURL() else {
+            return
+        }
+
+        let activityItems = [
+            ShareAppTextActivityItemSource(message: content.message) as Any,
+            linkURL as Any
+        ]
+
+        let activityViewController = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)
+        activityViewController.popoverPresentationController?.sourceView = sourceView
+        viewController.present(activityViewController, animated: true, completion: nil)
+    }
+
+    /// Shows a notice indicating that the share intent failed.
+    ///
+    func showFailureNotice(in viewController: UIViewController) {
+        viewController.displayNotice(title: .failureNoticeText, message: nil)
+    }
+}
+
+// MARK: Localized Strings
+
+private extension String {
+    static let failureNoticeText = NSLocalizedString("Something went wrong. Please try again.",
+                                                     comment: "Error message shown when user tries to share the app with others, "
+                                                        + "but failed due to unknown errors.")
+}

WordPress/Classes/ViewRelated/Sharing/ShareAppTextActivityItemSource.swift

@@ -0,0 +1,36 @@
+/// A text-type UIActivityItemSource for the share app activity.
+///
+/// Provides additional subject string so the subject line is filled when sharing the app via mail.
+///
+final class ShareAppTextActivityItemSource: NSObject {
+    private let message: String
+
+    init(message: String) {
+        self.message = message
+    }
+}
+
+// MARK: - UIActivityItemSource
+
+extension ShareAppTextActivityItemSource: UIActivityItemSource {
+    func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
+        // informs the activity controller that the activity type is text.
+        return String()
+    }
+
+    func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
+        return message
+    }
+
+    func activityViewController(_ activityViewController: UIActivityViewController, subjectForActivityType activityType: UIActivity.ActivityType?) -> String {
+        return .defaultSubjectText
+    }
+}
+
+// MARK: - Localized Strings
+
+private extension String {
+    static let defaultSubjectText = NSLocalizedString("WordPress Apps - Apps for any screen",
+                                                      comment: "Subject line for when sharing the app with others through mail or any other activity types "
+                                                        + "that support contains a subject field.")
+}