Move search users into a dedicated service (#789)

* add users provider with test

* add ui test for search users

* add changelog

* Update ElementX/Sources/Services/Users/UsersProvider.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* add error handling in usersprovider

* remove empty section

* add search in invite users

* add CancellableTask, add setup App Settings in UnitTest, screenshots

* rename of UserDiscoveryService

* Update ElementX/Sources/Other/Extensions/Publisher.swift

Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

* new error management for User Discovery Service

* Update ElementX/Sources/Other/CancellableTask.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* Update ElementX/Sources/Services/Users/UserDiscoveryService.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* fix invite users and start chat errors

* use only one task to fetch user profile

---------

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>
Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

ElementX/Sources/Screens/InviteUsers/InviteUsersCoordinator.swift

@@ -19,6 +19,7 @@ import SwiftUI
 
 struct InviteUsersCoordinatorParameters {
     let userSession: UserSessionProtocol
+    let userDiscoveryService: UserDiscoveryServiceProtocol
 }
 
 enum InviteUsersCoordinatorAction {
@@ -38,7 +39,7 @@ final class InviteUsersCoordinator: CoordinatorProtocol {
     init(parameters: InviteUsersCoordinatorParameters) {
         self.parameters = parameters
         
-        viewModel = InviteUsersViewModel(userSession: parameters.userSession)
+        viewModel = InviteUsersViewModel(userSession: parameters.userSession, userDiscoveryService: parameters.userDiscoveryService)
     }
     
     func start() {

ElementX/Sources/Screens/InviteUsers/InviteUsersModels.swift

@@ -16,6 +16,10 @@
 
 import Foundation
 
+enum InviteUsersErrorType: Error {
+    case unknown
+}
+
 enum InviteUsersViewModelAction {
     case close
 }
@@ -23,7 +27,7 @@ enum InviteUsersViewModelAction {
 struct InviteUsersViewState: BindableState {
     var bindings = InviteUsersViewStateBindings()
     
-    var usersSection: SearchUsersSection = .init(type: .empty, users: [])
+    var usersSection: UserDiscoverySection = .init(type: .suggestions, users: [])
     var selectedUsers: [UserProfile] = []
     
     var isSearching: Bool {
@@ -45,7 +49,7 @@ struct InviteUsersViewStateBindings {
     var searchQuery = ""
     
     /// Information describing the currently displayed alert.
-    var alertInfo: AlertInfo<ClientProxyError>?
+    var alertInfo: AlertInfo<InviteUsersErrorType>?
 }
 
 enum InviteUsersViewAction {

ElementX/Sources/Screens/InviteUsers/InviteUsersViewModel.swift

@@ -21,17 +21,19 @@ typealias InviteUsersViewModelType = StateStoreViewModel<InviteUsersViewState, I
 
 class InviteUsersViewModel: InviteUsersViewModelType, InviteUsersViewModelProtocol {
     private let userSession: UserSessionProtocol
+    private let userDiscoveryService: UserDiscoveryServiceProtocol
     private let actionsSubject: PassthroughSubject<InviteUsersViewModelAction, Never> = .init()
     
     var actions: AnyPublisher<InviteUsersViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
     }
     
-    init(userSession: UserSessionProtocol) {
+    init(userSession: UserSessionProtocol, userDiscoveryService: UserDiscoveryServiceProtocol) {
         self.userSession = userSession
+        self.userDiscoveryService = userDiscoveryService
         super.init(initialViewState: InviteUsersViewState(), imageProvider: userSession.mediaProvider)
         
-        fetchSuggestions()
+        setupSubscriptions()
     }
     
     // MARK: - Public
@@ -65,11 +67,53 @@ class InviteUsersViewModel: InviteUsersViewModelType, InviteUsersViewModelProtoc
 
     // MARK: - Private
     
-    private func fetchSuggestions() {
-        guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
-            state.usersSection = .init(type: .empty, users: [])
+    private func setupSubscriptions() {
+        context.$viewState
+            .map(\.bindings.searchQuery)
+            .debounceAndRemoveDuplicates()
+            .sink { [weak self] _ in
+                self?.fetchUsers()
+            }
+            .store(in: &cancellables)
+    }
+    
+    @CancellableTask
+    private var fetchUsersTask: Task<Void, Never>?
+    
+    private func fetchUsers() {
+        guard searchQuery.count >= 3 else {
+            fetchSuggestions()
             return
         }
-        state.usersSection = .init(type: .suggestions, users: [.mockAlice, .mockBob, .mockCharlie])
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.searchProfiles(with: searchQuery)
+            guard !Task.isCancelled else { return }
+            handleResult(for: .searchResult, result: result)
+        }
+    }
+    
+    private func fetchSuggestions() {
+        guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
+            state.usersSection = .init(type: .suggestions, users: [])
+            return
+        }
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.fetchSuggestions()
+            guard !Task.isCancelled else { return }
+            handleResult(for: .suggestions, result: result)
+        }
+    }
+    
+    private func handleResult(for sectionType: UserDiscoverySectionType, result: Result<[UserProfile], UserDiscoveryErrorType>) {
+        switch result {
+        case .success(let users):
+            state.usersSection = .init(type: sectionType, users: users)
+        case .failure:
+            break
+        }
+    }
+    
+    private var searchQuery: String {
+        context.searchQuery
     }
 }

ElementX/Sources/Screens/InviteUsers/View/InviteUsersScreen.swift

@@ -44,10 +44,10 @@ struct InviteUsersScreen: View {
     /// The content shown in the form when a search query has been entered.
     @ViewBuilder
     private var searchContent: some View {
-        if context.viewState.hasEmptySearchResults {
-            noResultsContent
-        } else {
-            Form {
+        Form {
+            if context.viewState.hasEmptySearchResults {
+                noResultsContent
+            } else {
                 usersSection
             }
         }
@@ -72,7 +72,7 @@ struct InviteUsersScreen: View {
                 .buttonStyle(FormButtonStyle(accessory: .selection(isSelected: context.viewState.isUserSelected(user))))
             }
         } header: {
-            if let title = context.viewState.usersSection.type.title {
+            if let title = context.viewState.usersSection.title {
                 Text(title)
             }
         }
@@ -120,7 +120,10 @@ struct InviteUsersScreen_Previews: PreviewProvider {
     static let viewModel = {
         let userSession = MockUserSession(clientProxy: MockClientProxy(userID: "@userid:example.com"),
                                           mediaProvider: MockMediaProvider())
-        return InviteUsersViewModel(userSession: userSession)
+        let userDiscoveryService = UserDiscoveryServiceMock()
+        userDiscoveryService.fetchSuggestionsReturnValue = .success([.mockAlice])
+        userDiscoveryService.searchProfilesWithReturnValue = .success([.mockAlice])
+        return InviteUsersViewModel(userSession: userSession, userDiscoveryService: userDiscoveryService)
     }()
     
     static var previews: some View {

ElementX/Sources/Screens/StartChat/StartChatCoordinator.swift

@@ -21,6 +21,7 @@ struct StartChatCoordinatorParameters {
     let userSession: UserSessionProtocol
     weak var userIndicatorController: UserIndicatorControllerProtocol?
     let navigationStackCoordinator: NavigationStackCoordinator?
+    let userDiscoveryService: UserDiscoveryServiceProtocol
 }
 
 enum StartChatCoordinatorAction {
@@ -41,7 +42,7 @@ final class StartChatCoordinator: CoordinatorProtocol {
     init(parameters: StartChatCoordinatorParameters) {
         self.parameters = parameters
         
-        viewModel = StartChatViewModel(userSession: parameters.userSession, userIndicatorController: parameters.userIndicatorController)
+        viewModel = StartChatViewModel(userSession: parameters.userSession, userIndicatorController: parameters.userIndicatorController, userDiscoveryService: parameters.userDiscoveryService)
     }
     
     func start() {
@@ -69,7 +70,7 @@ final class StartChatCoordinator: CoordinatorProtocol {
     // MARK: - Private
     
     private func presentInviteUsersScreen() {
-        let inviteParameters = InviteUsersCoordinatorParameters(userSession: parameters.userSession)
+        let inviteParameters = InviteUsersCoordinatorParameters(userSession: parameters.userSession, userDiscoveryService: parameters.userDiscoveryService)
         let coordinator = InviteUsersCoordinator(parameters: inviteParameters)
         coordinator.actions.sink { [weak self] result in
             switch result {

ElementX/Sources/Screens/StartChat/StartChatModels.swift

@@ -16,6 +16,11 @@
 
 import Foundation
 
+enum StartChatErrorType: Error {
+    case failedCreatingRoom
+    case unknown
+}
+
 enum StartChatViewModelAction {
     case close
     case createRoom
@@ -24,7 +29,7 @@ enum StartChatViewModelAction {
 
 struct StartChatViewState: BindableState {
     var bindings = StartChatScreenViewStateBindings()
-    var usersSection: SearchUsersSection = .init(type: .empty, users: [])
+    var usersSection: UserDiscoverySection = .init(type: .suggestions, users: [])
 
     var isSearching: Bool {
         !bindings.searchQuery.isEmpty
@@ -39,7 +44,7 @@ struct StartChatScreenViewStateBindings {
     var searchQuery = ""
     
     /// Information describing the currently displayed alert.
-    var alertInfo: AlertInfo<ClientProxyError>?
+    var alertInfo: AlertInfo<StartChatErrorType>?
 }
 
 enum StartChatViewAction {

ElementX/Sources/Screens/StartChat/StartChatViewModel.swift

@@ -22,6 +22,7 @@ typealias StartChatViewModelType = StateStoreViewModel<StartChatViewState, Start
 class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     private let userSession: UserSessionProtocol
     private let actionsSubject: PassthroughSubject<StartChatViewModelAction, Never> = .init()
+    private let userDiscoveryService: UserDiscoveryServiceProtocol
     
     var actions: AnyPublisher<StartChatViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
@@ -29,13 +30,13 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     
     weak var userIndicatorController: UserIndicatorControllerProtocol?
     
-    init(userSession: UserSessionProtocol, userIndicatorController: UserIndicatorControllerProtocol?) {
+    init(userSession: UserSessionProtocol, userIndicatorController: UserIndicatorControllerProtocol?, userDiscoveryService: UserDiscoveryServiceProtocol) {
         self.userSession = userSession
         self.userIndicatorController = userIndicatorController
+        self.userDiscoveryService = userDiscoveryService
         super.init(initialViewState: StartChatViewState(), imageProvider: userSession.mediaProvider)
         
         setupBindings()
-        fetchSuggestions()
     }
     
     // MARK: - Public
@@ -70,87 +71,61 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     
     private func displayError(_ type: ClientProxyError) {
         switch type {
-        case .failedRetrievingDirectRoom:
-            state.bindings.alertInfo = AlertInfo(id: type,
-                                                 title: L10n.commonError,
-                                                 message: L10n.screenStartChatErrorStartingChat)
-        case .failedCreatingRoom:
-            state.bindings.alertInfo = AlertInfo(id: type,
+        case .failedCreatingRoom, .failedRetrievingDirectRoom:
+            state.bindings.alertInfo = AlertInfo(id: .failedCreatingRoom,
                                                  title: L10n.commonError,
                                                  message: L10n.screenStartChatErrorStartingChat)
+        case .failedSearchingUsers:
+            state.bindings.alertInfo = AlertInfo(id: .unknown)
         default:
-            state.bindings.alertInfo = AlertInfo(id: type)
+            break
         }
     }
     
     private func setupBindings() {
         context.$viewState
             .map(\.bindings.searchQuery)
-            .map { query in
-                // debounce search queries but make sure clearing the search updates immediately
-                let milliseconds = query.isEmpty ? 0 : 500
-                return Just(query).delay(for: .milliseconds(milliseconds), scheduler: DispatchQueue.main)
-            }
-            .switchToLatest()
-            .removeDuplicates()
+            .debounceAndRemoveDuplicates()
             .sink { [weak self] _ in
-                self?.fetchData()
+                self?.fetchUsers()
             }
             .store(in: &cancellables)
     }
     
-    private func fetchData() {
+    @CancellableTask
+    private var fetchUsersTask: Task<Void, Never>?
+    
+    private func fetchUsers() {
         guard searchQuery.count >= 3 else {
             fetchSuggestions()
             return
         }
-        
-        Task {
-            await searchProfiles()
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.searchProfiles(with: searchQuery)
+            guard !Task.isCancelled else { return }
+            handleResult(for: .searchResult, result: result)
         }
     }
     
-    private func searchProfiles() async {
-        // copies the current query to check later if fetched data must be shown or not
-        let committedQuery = searchQuery
-        
-        async let queriedProfile = getProfileIfPossible()
-        async let searchedUsers = clientProxy.searchUsers(searchTerm: committedQuery, limit: 5)
-        
-        await updateState(committedQuery: committedQuery,
-                          queriedProfile: queriedProfile,
-                          searchResults: try? searchedUsers.get())
-    }
-    
-    private func updateState(committedQuery: String, queriedProfile: UserProfile?, searchResults: SearchUsersResults?) {
-        guard committedQuery == searchQuery else {
-            return
-        }
-        
-        let localProfile = queriedProfile ?? UserProfile(searchQuery: searchQuery)
-        let allResults = merge(localProfile: localProfile, searchResults: searchResults?.results)
-        
-        state.usersSection = .init(type: .searchResult, users: allResults)
-    }
-    
-    private func merge(localProfile: UserProfile?, searchResults: [UserProfile]?) -> [UserProfile] {
-        guard let localProfile else {
-            return searchResults ?? []
-        }
-        
-        let filteredSearchResult = searchResults?.filter {
-            $0.userID != localProfile.userID
-        } ?? []
-
-        return [localProfile] + filteredSearchResult
-    }
-    
     private func fetchSuggestions() {
         guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
-            state.usersSection = .init(type: .empty, users: [])
+            state.usersSection = .init(type: .suggestions, users: [])
             return
         }
-        state.usersSection = .init(type: .suggestions, users: [.mockAlice, .mockBob, .mockCharlie])
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.fetchSuggestions()
+            guard !Task.isCancelled else { return }
+            handleResult(for: .suggestions, result: result)
+        }
+    }
+    
+    private func handleResult(for sectionType: UserDiscoverySectionType, result: Result<[UserProfile], UserDiscoveryErrorType>) {
+        switch result {
+        case .success(let users):
+            state.usersSection = .init(type: sectionType, users: users)
+        case .failure:
+            break
+        }
     }
     
     private func createDirectRoom(with user: UserProfile) async {
@@ -165,14 +140,6 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
         }
     }
     
-    private func getProfileIfPossible() async -> UserProfile? {
-        guard searchQuery.isMatrixIdentifier else {
-            return nil
-        }
-        
-        return try? await clientProxy.getProfile(for: searchQuery).get()
-    }
-    
     private var clientProxy: ClientProxyProtocol {
         userSession.clientProxy
     }
@@ -196,18 +163,3 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
         userIndicatorController?.retractIndicatorWithId(Self.loadingIndicatorIdentifier)
     }
 }
-
-private extension String {
-    var isMatrixIdentifier: Bool {
-        MatrixEntityRegex.isMatrixUserIdentifier(self)
-    }
-}
-
-private extension UserProfile {
-    init?(searchQuery: String) {
-        guard searchQuery.isMatrixIdentifier else {
-            return nil
-        }
-        self.init(userID: searchQuery)
-    }
-}

ElementX/Sources/Screens/StartChat/View/StartChatScreen.swift

@@ -92,7 +92,7 @@ struct StartChatScreen: View {
                     .buttonStyle(FormButtonStyle())
                 }
             } header: {
-                if let title = context.viewState.usersSection.type.title {
+                if let title = context.viewState.usersSection.title {
                     Text(title)
                 }
             }
@@ -131,12 +131,19 @@ struct StartChatScreen: View {
 // MARK: - Previews
 
 struct StartChat_Previews: PreviewProvider {
-    static var previews: some View {
+    static let viewModel = {
         let userSession = MockUserSession(clientProxy: MockClientProxy(userID: "@userid:example.com"),
                                           mediaProvider: MockMediaProvider())
-        let regularViewModel = StartChatViewModel(userSession: userSession, userIndicatorController: nil)
+        let userDiscoveryService = UserDiscoveryServiceMock()
+        userDiscoveryService.fetchSuggestionsReturnValue = .success([.mockAlice])
+        userDiscoveryService.searchProfilesWithReturnValue = .success([.mockAlice])
+        let viewModel = StartChatViewModel(userSession: userSession, userIndicatorController: nil, userDiscoveryService: userDiscoveryService)
+        return viewModel
+    }()
+    
+    static var previews: some View {
         NavigationView {
-            StartChatScreen(context: regularViewModel.context)
+            StartChatScreen(context: viewModel.context)
                 .tint(.element.accent)
         }
     }

ElementX/Sources/Screens/UserDiscoverySection/SearchUsersSection.swift

@@ -16,22 +16,21 @@
 
 import Foundation
 
-struct SearchUsersSection {
-    let type: SearchUserSectionType
+struct UserDiscoverySection {
+    let type: UserDiscoverySectionType
     let users: [UserProfile]
-}
-
-enum SearchUserSectionType: Equatable {
-    case searchResult
-    case suggestions
-    case empty
     
     var title: String? {
-        switch self {
-        case .searchResult, .empty:
+        switch type {
+        case .searchResult:
             return nil
         case .suggestions:
-            return L10n.commonSuggestions
+            return users.isEmpty ? nil : L10n.commonSuggestions
         }
     }
 }
+
+enum UserDiscoverySectionType: Equatable {
+    case searchResult
+    case suggestions
+}