Remove existing push subscriptions when unregistering from proxy

Packages/PushNotifications/Sources/PushNotifications/DisabledPushManager.swift

@@ -17,6 +17,10 @@ class DisabledPushManager: _PushManager {
         nil
     }
     
+    var subscriptions: [PushSubscription] {
+        []
+    }
+    
     func createSubscription(account: UserAccountInfo) throws -> PushSubscription {
         throw Disabled()
     }

Packages/PushNotifications/Sources/PushNotifications/PushManager.swift

@@ -45,6 +45,7 @@ public protocol _PushManager {
     var enabled: Bool { get }
     var proxyRegistration: PushProxyRegistration? { get }
     
+    var subscriptions: [PushSubscription] { get }
     func createSubscription(account: UserAccountInfo) throws -> PushSubscription
     func removeSubscription(account: UserAccountInfo)
     func updateSubscription(account: UserAccountInfo, alerts: PushSubscription.Alerts, policy: PushSubscription.Policy)

Packages/PushNotifications/Sources/PushNotifications/PushManagerImpl.swift

@@ -40,7 +40,7 @@ class PushManagerImpl: _PushManager {
             defaults.setValue(newValue?.defaultsDict, forKey: "PushProxyRegistration")
         }
     }
-    private(set) var subscriptions: [PushSubscription] {
+    public private(set) var subscriptions: [PushSubscription] {
         get {
             if let array = defaults.array(forKey: "PushSubscriptions") as? [[String: Any]] {
                 return array.compactMap(PushSubscription.init(defaultsDict:))

Tusker/Screens/Preferences/Notifications/NotificationsPrefsView.swift

@@ -96,6 +96,21 @@ struct NotificationsPrefsView: View {
         do {
             try await PushManager.shared.unregister()
             pushProxyRegistration = nil
+            for subscription in PushManager.shared.subscriptions {
+                if let account = UserAccountsManager.shared.getAccount(id: subscription.accountID) {
+                    let mastodonController = MastodonController.getForAccount(account)
+                    do {
+                        try await mastodonController.deletePushSubscription()
+                        PushManager.shared.removeSubscription(account: account)
+                        PushManager.logger.debug("Push subscription removed on \(account.instanceURL)")
+                        // this is a bit of a hack. the PushInstanceSettingsViews need to know to update
+                        // their @State variables after we remove the subscription
+                        NotificationCenter.default.post(name: .pushSubscriptionRemoved, object: account.id)
+                    } catch {
+                        PushManager.logger.error("Erroring removing push subscription: \(String(describing: error))")
+                    }
+                }
+            }
             return true
         } catch {
             self.error = .unregistering(error)
@@ -120,3 +135,7 @@ private enum NotificationsSetupError: LocalizedError {
         }
     }
 }
+
+extension Notification.Name {
+    static let pushSubscriptionRemoved = Notification.Name("Tusker.pushSubscriptionRemoved")
+}

Tusker/Screens/Preferences/Notifications/PushInstanceSettingsView.swift

@@ -52,6 +52,13 @@ struct PushInstanceSettingsView: View {
         } message: {
             Text("You must grant permission on \(account.instanceURL.host!) to turn on push notifications.")
         }
+        .onReceive(NotificationCenter.default
+            .publisher(for: .pushSubscriptionRemoved)
+            .filter { ($0.object as? String) == account.id }
+        ) { _ in
+            mode = .off
+            subscription = nil
+        }
     }
     
     private func updateNotificationsEnabled(enabled: Bool) async -> Bool {