From e4d8c4a1a18ec1a0a418e9af9c7f9e02b868e34c Mon Sep 17 00:00:00 2001
From: Anh Do <ado@duckduckgo.com>
Date: Thu, 5 Dec 2024 23:30:00 -0500
Subject: [PATCH] Handoff prototype

---
 DuckDuckGo/Application/AppDelegate.swift      | 13 ++++++
 DuckDuckGo/Info.plist                         |  4 ++
 .../Tab/View/BrowserTabViewController.swift   | 46 +++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/DuckDuckGo/Application/AppDelegate.swift b/DuckDuckGo/Application/AppDelegate.swift
index 3d79b94ed3..ebcc07561e 100644
--- a/DuckDuckGo/Application/AppDelegate.swift
+++ b/DuckDuckGo/Application/AppDelegate.swift
@@ -555,6 +555,8 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         Task { @MainActor in
             await subscriptionCookieManager.refreshSubscriptionCookie()
         }
+
+        WindowControllersManager.shared.lastKeyMainWindowController?.mainViewController.browserTabViewController.becomeCurrentActivity()
     }
 
     private func initializeSync() {
@@ -627,6 +629,17 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         urlEventHandler.handleFiles(files)
     }
 
+    func application(_ application: NSApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([any NSUserActivityRestoring]) -> Void) -> Bool {
+        guard userActivity.activityType == "com.duckduckgo.mobile.ios.web-browsing",
+              let mainWindowController = WindowControllersManager.shared.lastKeyMainWindowController?.mainViewController else {
+            return false
+        }
+
+        restorationHandler([mainWindowController.browserTabViewController])
+
+        return true
+    }
+
     // MARK: - PixelKit
 
     static func configurePixelKit() {
diff --git a/DuckDuckGo/Info.plist b/DuckDuckGo/Info.plist
index 68f7172023..f9834aeaa4 100644
--- a/DuckDuckGo/Info.plist
+++ b/DuckDuckGo/Info.plist
@@ -540,6 +540,10 @@
 	<false/>
 	<key>NSSupportsSuddenTermination</key>
 	<false/>
+	<key>NSUserActivityTypes</key>
+	<array>
+		<string>com.duckduckgo.mobile.ios.web-browsing</string>
+	</array>
 	<key>SUBSCRIPTION_APP_GROUP</key>
 	<string>$(SUBSCRIPTION_APP_GROUP)</string>
 	<key>SUEnableAutomaticChecks</key>
diff --git a/DuckDuckGo/Tab/View/BrowserTabViewController.swift b/DuckDuckGo/Tab/View/BrowserTabViewController.swift
index 4fbb30cf21..0d91da877e 100644
--- a/DuckDuckGo/Tab/View/BrowserTabViewController.swift
+++ b/DuckDuckGo/Tab/View/BrowserTabViewController.swift
@@ -323,6 +323,8 @@ final class BrowserTabViewController: NSViewController {
 
                 self.adjustFirstResponder(force: true)
                 removeExistingDialog()
+
+                self.updateCurrentActivity(url: selectedTabViewModel?.tab.content.urlForWebView)
             }
             .store(in: &cancellables)
     }
@@ -615,6 +617,13 @@ final class BrowserTabViewController: NSViewController {
         tabViewModel?.tab.webViewDidFinishNavigationPublisher.sink { [weak self] in
             self?.updateStateAndPresentContextualOnboarding()
         }.store(in: &tabViewModelCancellables)
+
+        tabViewModel?.tab.webView.publisher(for: \.url)
+            .dropFirst()
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] url in
+                self?.updateCurrentActivity(url: url)
+            }.store(in: &tabViewModelCancellables)
     }
 
     private func subscribeToUserDialogs(of tabViewModel: TabViewModel?) {
@@ -1510,3 +1519,40 @@ private extension NSViewController {
     }
 
 }
+
+extension BrowserTabViewController {
+    override func restoreUserActivityState(_ userActivity: NSUserActivity) {
+        guard userActivity.activityType == "com.duckduckgo.mobile.ios.web-browsing", let url = userActivity.webpageURL else {
+            return
+        }
+        openNewTab(with: .url(url, credential: nil, source: .appOpenUrl))
+    }
+
+    func becomeCurrentActivity() {
+        if userActivity?.webpageURL == nil {
+            userActivity?.invalidate()
+            userActivity = NSUserActivity(activityType: NSUserActivityTypeBrowsingWeb)
+            userActivity?.webpageURL = nil
+        }
+
+        userActivity?.becomeCurrent()
+    }
+
+    private func updateCurrentActivity(url: URL?) {
+        let newURL: URL? = {
+            guard let url, let scheme = url.scheme, ["http", "https"].contains(scheme) else { return nil }
+            return url
+        }()
+        guard newURL != userActivity?.webpageURL else { return }
+
+        userActivity?.invalidate()
+        if newURL != nil {
+            userActivity = NSUserActivity(activityType: "com.duckduckgo.mobile.ios.web-browsing")
+        } else {
+            userActivity = NSUserActivity(activityType: NSUserActivityTypeBrowsingWeb)
+        }
+        userActivity?.webpageURL = newURL
+
+        userActivity?.becomeCurrent()
+    }
+}