Optimize invites list (part 2) (#1268)

* Optimise invites list

* Fix failing tests

* Cleanup

* Add weak self

* Refactor ReportContentViewModelTests

ElementX/Sources/Screens/InvitesScreen/InvitesScreenModels.swift

@@ -21,6 +21,10 @@ enum InvitesScreenViewModelAction {
 struct InvitesScreenViewState: BindableState {
     var invites: [InvitesScreenRoomDetails] = []
     var bindings: InvitesScreenViewStateBindings = .init()
+
+    // ideally we wanted to derive this state from `invites` being `Optional.none`.
+    // But we needed to make it a non optional array due to a strange crash in release builds (https://github.com/vector-im/element-x-ios/pull/1120)
+    var isLoading = true
 }
 
 struct InvitesScreenViewStateBindings {

ElementX/Sources/Screens/InvitesScreen/InvitesScreenViewModel.swift

@@ -28,7 +28,7 @@ class InvitesScreenViewModel: InvitesScreenViewModelType, InvitesScreenViewModel
     private let previouslySeenInvites: Set<String>
     private let actionsSubject: PassthroughSubject<InvitesScreenViewModelAction, Never> = .init()
     @CancellableTask private var fetchInvitersTask: Task<Void, Never>?
-    
+
     var actions: AnyPublisher<InvitesScreenViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
     }
@@ -75,62 +75,57 @@ class InvitesScreenViewModel: InvitesScreenViewModelType, InvitesScreenViewModel
         }
         
         inviteSummaryProvider.roomListPublisher
-            .receive(on: DispatchQueue.main)
+            .removeDuplicates()
             .sink { [weak self] roomSummaries in
                 guard let self else { return }
-                
-                let invites = self.buildInvites(from: roomSummaries)
-                appSettings.seenInvites = Set(invites.map(\.roomDetails.id))
-                self.state.invites = invites
 
-                fetchInviters(invites: invites)
+                fetchInvitersTask = Task { [weak self] in
+                    guard let self else { return }
+                    let fullInvites = await self.buildInvites(from: roomSummaries)
+                    guard !Task.isCancelled else { return }
+                    self.state.invites = fullInvites
+                    self.state.isLoading = false
+                    self.appSettings.seenInvites = Set(fullInvites.map(\.roomDetails.id))
+                }
             }
             .store(in: &cancellables)
     }
-    
-    private func buildInvites(from summaries: [RoomSummary]) -> [InvitesScreenRoomDetails] {
-        summaries.compactMap { summary in
-            guard case .filled(let details) = summary else {
-                return nil
-            }
-            return InvitesScreenRoomDetails(roomDetails: details, isUnread: !previouslySeenInvites.contains(details.id))
-        }
-    }
 
-    private func fetchInviters(invites: [InvitesScreenRoomDetails]) {
-        fetchInvitersTask = Task { [weak self] in
-            await withTaskGroup(of: (String, RoomMemberProxyProtocol)?.self) { group in
-                for invite in invites {
-                    group.addTask { [weak self] in
-                        let roomID = invite.roomDetails.id
-                        guard let inviter = await self?.fetchInviter(for: roomID) else {
+    private func buildInvites(from summaries: [RoomSummary]) async -> [InvitesScreenRoomDetails] {
+        await Task.detached {
+            let invites: [InvitesScreenRoomDetails] = summaries.compactMap { summary in
+                guard case .filled(let details) = summary else {
+                    return nil
+                }
+                return InvitesScreenRoomDetails(roomDetails: details, isUnread: !self.previouslySeenInvites.contains(details.id))
+            }
+
+            // fetch the inviters...
+            return await withTaskGroup(of: (Int, RoomMemberProxyProtocol)?.self) { [clientProxy = self.clientProxy] group in
+                var invitesWithInviters = invites
+
+                for inviteIndex in 0..<invites.count {
+                    group.addTask {
+                        let roomID = invites[inviteIndex].roomDetails.id
+                        guard let inviter = await clientProxy.roomForIdentifier(roomID)?.inviter() else {
                             return nil
                         }
-                        return (roomID, inviter)
+                        return (inviteIndex, inviter)
                     }
                 }
 
                 for await result in group {
-                    guard let self, !Task.isCancelled else {
-                        break
-                    }
-
-                    guard let (roomID, inviter) = result else {
+                    guard let (inviteIndex, inviter) = result else {
                         continue
                     }
 
-                    guard let inviteIndex = self.state.invites.firstIndex(where: { $0.roomDetails.id == roomID }) else {
-                        return
-                    }
-
-                    self.state.invites[inviteIndex].inviter = inviter
+                    invitesWithInviters[inviteIndex].inviter = inviter
                 }
+
+                return invitesWithInviters
             }
         }
-    }
-
-    private func fetchInviter(for roomID: String) async -> RoomMemberProxyProtocol? {
-        await clientProxy.roomForIdentifier(roomID)?.inviter()
+        .value
     }
 
     private func startDeclineFlow(invite: InvitesScreenRoomDetails) {

ElementX/Sources/Screens/InvitesScreen/View/InvitesScreen.swift

@@ -20,6 +20,23 @@ struct InvitesScreen: View {
     @ObservedObject var context: InvitesScreenViewModel.Context
     
     var body: some View {
+        Group {
+            if context.viewState.isLoading {
+                ProgressView()
+            } else {
+                mainContent
+            }
+        }
+        .background(Color.compound.bgCanvasDefault.ignoresSafeArea())
+        .navigationTitle(L10n.actionInvitesList)
+        .alert(item: $context.alertInfo)
+        .track(screen: .invites)
+    }
+    
+    // MARK: - Private
+
+    @ViewBuilder
+    private var mainContent: some View {
         ScrollView {
             if !context.viewState.invites.isEmpty {
                 LazyVStack(spacing: 0) {
@@ -34,14 +51,8 @@ struct InvitesScreen: View {
                 noInvitesContent
             }
         }
-        .background(Color.compound.bgCanvasDefault.ignoresSafeArea())
-        .navigationTitle(L10n.actionInvitesList)
-        .alert(item: $context.alertInfo)
-        .track(screen: .invites)
     }
     
-    // MARK: - Private
-    
     private var noInvitesContent: some View {
         Text(L10n.screenInvitesEmptyList)
             .font(.compound.bodyLG)

ElementX/Sources/Services/Room/RoomProxy.swift

@@ -85,10 +85,10 @@ class RoomProxy: RoomProxyProtocol {
 
         subscribeToBackpagination()
         
-        innerTimelineProvider = RoomTimelineProvider(currentItems: result.items,
-                                                     updatePublisher: updatesPublisher,
-                                                     backPaginationStatePublisher: backPaginationStateSubject.eraseToAnyPublisher())
-
+        innerTimelineProvider = await RoomTimelineProvider(currentItems: result.items,
+                                                           updatePublisher: updatesPublisher,
+                                                           backPaginationStatePublisher: backPaginationStateSubject.eraseToAnyPublisher())
+        
         Task {
             await fetchMembers()
             await updateMembers()
@@ -209,7 +209,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func sendReadReceipt(for eventID: String) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -229,7 +229,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func sendMessageEventContent(_ messageContent: RoomMessageEventContent) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -243,7 +243,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func sendMessage(_ message: String, inReplyTo eventID: String? = nil) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -266,7 +266,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func toggleReaction(_ reaction: String, to eventID: String) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -286,7 +286,7 @@ class RoomProxy: RoomProxyProtocol {
                    imageInfo: ImageInfo,
                    progressSubject: CurrentValueSubject<Double, Never>?,
                    requestHandle: (SendAttachmentJoinHandleProtocol) -> Void) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -311,7 +311,7 @@ class RoomProxy: RoomProxyProtocol {
                    videoInfo: VideoInfo,
                    progressSubject: CurrentValueSubject<Double, Never>?,
                    requestHandle: (SendAttachmentJoinHandleProtocol) -> Void) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -335,7 +335,7 @@ class RoomProxy: RoomProxyProtocol {
                    audioInfo: AudioInfo,
                    progressSubject: CurrentValueSubject<Double, Never>?,
                    requestHandle: (SendAttachmentJoinHandleProtocol) -> Void) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -359,7 +359,7 @@ class RoomProxy: RoomProxyProtocol {
                   fileInfo: FileInfo,
                   progressSubject: CurrentValueSubject<Double, Never>?,
                   requestHandle: (SendAttachmentJoinHandleProtocol) -> Void) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -384,7 +384,7 @@ class RoomProxy: RoomProxyProtocol {
                       description: String?,
                       zoomLevel: UInt8?,
                       assetType: AssetType?) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -402,7 +402,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func retrySend(transactionID: String) async {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -413,7 +413,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func cancelSend(transactionID: String) async {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -424,7 +424,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func editMessage(_ newMessage: String, original eventID: String) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -442,7 +442,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func redact(_ eventID: String) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -460,7 +460,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func reportContent(_ eventID: String, reason: String?) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -490,7 +490,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func getMember(userID: String) async -> Result<RoomMemberProxyProtocol, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -506,7 +506,7 @@ class RoomProxy: RoomProxyProtocol {
     }
     
     func ignoreUser(_ userID: String) async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }
@@ -528,7 +528,7 @@ class RoomProxy: RoomProxyProtocol {
     }
 
     func leaveRoom() async -> Result<Void, RoomProxyError> {
-        sendMessageBackgroundTask = backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
+        sendMessageBackgroundTask = await backgroundTaskService.startBackgroundTask(withName: backgroundTaskName, isReusable: true)
         defer {
             sendMessageBackgroundTask?.stop()
         }

ElementX/Sources/Services/Room/RoomProxyProtocol.swift

@@ -43,7 +43,6 @@ enum RoomProxyError: Error, Equatable {
     case failedUploadingAvatar
 }
 
-@MainActor
 // sourcery: AutoMockable
 protocol RoomProxyProtocol {
     var id: String { get }

ElementX/Sources/Services/Room/RoomSummary/RoomSummaryProviderProtocol.swift

@@ -41,7 +41,7 @@ enum RoomSummaryProviderState {
     }
 }
 
-enum RoomSummary: CustomStringConvertible {
+enum RoomSummary: CustomStringConvertible, Equatable {
     case empty
     case filled(details: RoomSummaryDetails)
     case invalidated(details: RoomSummaryDetails)
@@ -74,6 +74,17 @@ enum RoomSummary: CustomStringConvertible {
             return "\(String(describing: Self.self)): Filled(\(details.id))"
         }
     }
+
+    static func == (lhs: RoomSummary, rhs: RoomSummary) -> Bool {
+        switch (lhs, rhs) {
+        case (.empty, .empty):
+            return true
+        case (.filled(let lhsDetails), .filled(let rhsDetails)), (.invalidated(let lhsDetails), .invalidated(let rhsDetails)):
+            return lhsDetails.id == rhsDetails.id
+        default:
+            return false
+        }
+    }
 }
 
 protocol RoomSummaryProviderProtocol {