Added logic to unsubscribe for legacy one-to-one PNs

SessionMessagingKit/Sending & Receiving/Notifications/Models/LegacyUnsubscribeRequest.swift

@@ -0,0 +1,14 @@
+// Copyright © 2023 Rangeproof Pty Ltd. All rights reserved.
+
+import Foundation
+import SessionSnodeKit
+
+extension PushNotificationAPI {
+    struct LegacyUnsubscribeRequest: Codable {
+        private let token: String
+        
+        init(token: String) {
+            self.token = token
+        }
+    }
+}

SessionMessagingKit/Sending & Receiving/Notifications/PushNotificationAPI.swift

@@ -115,7 +115,42 @@ public enum PushNotificationAPI {
                                         }
                                     }
                                 )
-                                .map { _ in () }
+                                .flatMap { _ in
+                                    guard UserDefaults.standard[.hasUnregisteredForLegacyPushNotifications] != true else {
+                                        return Just(())
+                                            .setFailureType(to: Error.self)
+                                            .eraseToAnyPublisher()
+                                    }
+                                    
+                                    return PushNotificationAPI
+                                        .send(
+                                            request: PushNotificationAPIRequest(
+                                                endpoint: .legacyUnregister,
+                                                body: LegacyUnsubscribeRequest(
+                                                    token: hexEncodedToken
+                                                )
+                                            )
+                                        )
+                                        .retry(maxRetryCount)
+                                        .handleEvents(
+                                            receiveCompletion: { result in
+                                                switch result {
+                                                    case .finished:
+                                                        /// Save that we've already unsubscribed
+                                                        ///
+                                                        /// **Note:** The server can return an error (`response.code != 0`) but
+                                                        /// that means the server properly processed the request and the error is likely
+                                                        /// due to the device not actually being previously subscribed for notifications
+                                                        /// rather than actually failing to unsubscribe
+                                                        UserDefaults.standard[.hasUnregisteredForLegacyPushNotifications] = true
+                                                        
+                                                    case .failure: SNLog("Couldn't unsubscribe for legacy notifications.")
+                                                }
+                                            }
+                                        )
+                                        .map { _ in () }
+                                        .eraseToAnyPublisher()
+                                }
                                 .eraseToAnyPublisher()
                         ].appending(
                             // FIXME: Remove this once legacy groups are deprecated

SessionUtilitiesKit/General/SNUserDefaults.swift

@@ -31,6 +31,7 @@ public enum SNUserDefaults {
         case hasSeenCallIPExposureWarning
         case hasSeenCallMissedTips
         case isUsingFullAPNs
+        case hasUnregisteredForLegacyPushNotifications
         case wasUnlinked
         case isMainAppActive
         case isCallOngoing