Merge pull request #20244 from wordpress-mobile/refactor-people-servi…

…ce-update-user

Refactor updating user role to save local user asynchronously

RELEASE-NOTES.txt

@@ -1,8 +1,8 @@
 22.0
 -----
+* [*] [internal] Refactored updating user role in the "People" screen on the "My Sites" tab. [#20244]
 * [*] [internal] Refactor managing social connections and social buttons in the "Sharing" screen. [#20265]
 
-
 21.9
 -----
 * [*] [internal] Refactored fetching posts in the Reader tab, including post related operations (i.e. like/unlike, save for later, etc.) [#20197]

WordPress/Classes/Services/PeopleService.swift

@@ -2,6 +2,10 @@ import Foundation
 import CocoaLumberjack
 import WordPressKit
 
+enum PeopleServiceError: Error {
+    case userNotFoundLocally(User)
+}
+
 /// Service providing access to the People Management WordPress.com API.
 ///
 struct PeopleService {
@@ -128,48 +132,52 @@ struct PeopleService {
     ///
     /// - Returns: A new Person instance, with the new Role already assigned.
     ///
-    func updateUser(_ user: User, role: String, failure: ((Error, User) -> Void)?) -> User {
-        var pristineRole: String?
-        var updated: User?
-        coreDataStack.performAndSave { context in
+    func updateUser(_ user: User, role: String, receiveUpdate: @escaping (User) -> Void, failure: ((Error, User) -> Void)?) {
+        coreDataStack.performAndSave({ context throws -> (String, User) in
             guard let managedPerson = managedPersonFromPerson(user, in: context) else {
-                return
+                throw PeopleServiceError.userNotFoundLocally(user)
             }
 
             // OP Reversal
-            pristineRole = managedPerson.role
+            let pristineRole = managedPerson.role
 
             // Pre-emptively update the role
             managedPerson.role = role
 
-            updated = User(managedPerson: managedPerson)
-        }
-
-        // Early exit if failed to update the user
-        guard let updated else {
-            return user
-        }
+            return (pristineRole, User(managedPerson: managedPerson))
+        }, completion: { result in
+            switch result {
+            case let .failure(error):
+                failure?(error, user)
+            case let .success((pristineRole, updated)):
+                receiveUpdate(updated)
+                self.updateRemoteUser(user, role: role, roleToRevertUponFailure: pristineRole, failure: failure)
+            }
+        }, on: .main)
+    }
 
-        // Hit the Backend
+    private func updateRemoteUser(_ user: User, role: String, roleToRevertUponFailure pristineRole: String, failure: ((Error, User) -> Void)?) {
         remote.updateUserRole(siteID, userID: user.ID, newRole: role, success: nil, failure: { error in
-
             DDLogError("### Error while updating person \(user.ID) in blog \(self.siteID): \(error)")
 
-            var reloadedPerson: User!
-            self.coreDataStack.performAndSave { context in
+            self.coreDataStack.performAndSave({ context in
                 guard let managedPerson = self.managedPersonFromPerson(user, in: context) else {
                     DDLogError("### Person with ID \(user.ID) deleted before update")
-                    return
+                    throw PeopleServiceError.userNotFoundLocally(user)
                 }
 
-                managedPerson.role = pristineRole!
+                managedPerson.role = pristineRole
 
-                reloadedPerson = User(managedPerson: managedPerson)
-            }
-            failure?(error, reloadedPerson)
+                return User(managedPerson: managedPerson)
+            }, completion: { result in
+                switch result {
+                case let .failure(error):
+                    failure?(error, user)
+                case let .success(reloadedPerson):
+                    failure?(error, reloadedPerson)
+                }
+            }, on: .main)
         })
-
-        return updated
     }
 
     /// Deletes a given User.

WordPress/Classes/ViewRelated/People/PersonViewController.swift

@@ -373,15 +373,13 @@ private extension PersonViewController {
             return
         }
 
-        let updated = service.updateUser(user, role: newRole) { (error, reloadedPerson) in
-            self.person = reloadedPerson
-            self.retryUpdatingRole(newRole)
+        service.updateUser(user, role: newRole) { updated in
+            self.person = updated
+            WPAnalytics.track(.personUpdated)
+        } failure: { [weak self] _, reloadedPerson in
+            self?.person = reloadedPerson
+            self?.retryUpdatingRole(newRole)
         }
-
-        // Optimistically refresh the UI
-        self.person = updated
-
-        WPAnalytics.track(.personUpdated)
     }
 
     func retryUpdatingRole(_ newRole: String) {