Introduced the concepts of room summary and event brief.

ElementX.xcodeproj/project.pbxproj

@@ -7,6 +7,12 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		181A317727F703E300B8305B /* RoomSummaryProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317427F703E300B8305B /* RoomSummaryProtocol.swift */; };
+		181A317827F703E300B8305B /* RoomSummary.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317527F703E300B8305B /* RoomSummary.swift */; };
+		181A317927F703E300B8305B /* MockRoomSummary.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317627F703E300B8305B /* MockRoomSummary.swift */; };
+		181A317B27F70AEB00B8305B /* EventBrief.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317A27F70AEB00B8305B /* EventBrief.swift */; };
+		181A317D27F70B1E00B8305B /* EventBriefFactory.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317C27F70B1E00B8305B /* EventBriefFactory.swift */; };
+		181A317F27F70CCA00B8305B /* EventBriefFactoryProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 181A317E27F70CCA00B8305B /* EventBriefFactoryProtocol.swift */; };
 		182BC48127C4EBBB00A30C33 /* Kingfisher in Frameworks */ = {isa = PBXBuildFile; productRef = 182BC48027C4EBBB00A30C33 /* Kingfisher */; };
 		183E023427E4A73C00903BED /* MemberDetailsProviderProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 183E023327E4A73C00903BED /* MemberDetailsProviderProtocol.swift */; };
 		183E023627E4A79D00903BED /* RoomTimelineProviderProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 183E023527E4A79D00903BED /* RoomTimelineProviderProtocol.swift */; };
@@ -141,6 +147,12 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		181A317427F703E300B8305B /* RoomSummaryProtocol.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RoomSummaryProtocol.swift; sourceTree = "<group>"; };
+		181A317527F703E300B8305B /* RoomSummary.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RoomSummary.swift; sourceTree = "<group>"; };
+		181A317627F703E300B8305B /* MockRoomSummary.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MockRoomSummary.swift; sourceTree = "<group>"; };
+		181A317A27F70AEB00B8305B /* EventBrief.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventBrief.swift; sourceTree = "<group>"; };
+		181A317C27F70B1E00B8305B /* EventBriefFactory.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventBriefFactory.swift; sourceTree = "<group>"; };
+		181A317E27F70CCA00B8305B /* EventBriefFactoryProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EventBriefFactoryProtocol.swift; sourceTree = "<group>"; };
 		183E023327E4A73C00903BED /* MemberDetailsProviderProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemberDetailsProviderProtocol.swift; sourceTree = "<group>"; };
 		183E023527E4A79D00903BED /* RoomTimelineProviderProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RoomTimelineProviderProtocol.swift; sourceTree = "<group>"; };
 		1850252427B6918C002E6B18 /* ElementX.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = ElementX.app; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -288,6 +300,19 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		181A317327F703E300B8305B /* RoomSummary */ = {
+			isa = PBXGroup;
+			children = (
+				181A317427F703E300B8305B /* RoomSummaryProtocol.swift */,
+				181A317527F703E300B8305B /* RoomSummary.swift */,
+				181A317627F703E300B8305B /* MockRoomSummary.swift */,
+				181A317E27F70CCA00B8305B /* EventBriefFactoryProtocol.swift */,
+				181A317C27F70B1E00B8305B /* EventBriefFactory.swift */,
+				181A317A27F70AEB00B8305B /* EventBrief.swift */,
+			);
+			path = RoomSummary;
+			sourceTree = "<group>";
+		};
 		1850251B27B6918C002E6B18 = {
 			isa = PBXGroup;
 			children = (
@@ -398,12 +423,13 @@
 		18C5744727E1D84000D70937 /* Room */ = {
 			isa = PBXGroup;
 			children = (
-				18C5744827E1D84000D70937 /* RoomProxyProtocol.swift */,
-				18C5744A27E1D84000D70937 /* RoomProxy.swift */,
 				18C5744B27E1D84000D70937 /* MockRoomProxy.swift */,
 				18C5745527E1DCA800D70937 /* RoomMessageFactory.swift */,
+				18C5744A27E1D84000D70937 /* RoomProxy.swift */,
+				18C5744827E1D84000D70937 /* RoomProxyProtocol.swift */,
 				18DF7C5127E4753A00291672 /* Members */,
 				18C5744927E1D84000D70937 /* Messages */,
+				181A317327F703E300B8305B /* RoomSummary */,
 			);
 			path = Room;
 			sourceTree = "<group>";
@@ -924,6 +950,7 @@
 			files = (
 				18F2BADE27D25B4000DD1988 /* KeychainControllerProtocol.swift in Sources */,
 				18C5745027E1D87800D70937 /* RoomMessageProtocol.swift in Sources */,
+				181A317727F703E300B8305B /* RoomSummaryProtocol.swift in Sources */,
 				18DF7C4C27E4672C00291672 /* EventBasedTimelineItemProtocol.swift in Sources */,
 				189E496527F4777400D86BA3 /* NoticeRoomTimelineView.swift in Sources */,
 				18F2BAED27D25B4000DD1988 /* FullscreenLoadingActivityPresenter.swift in Sources */,
@@ -944,6 +971,7 @@
 				18F2BB1227D25B4000DD1988 /* LoginScreenViewModel.swift in Sources */,
 				18F2BAE727D25B4000DD1988 /* RoundedToastView.swift in Sources */,
 				18F2BAF227D25B4000DD1988 /* WeakDictionaryKeyReference.swift in Sources */,
+				181A317827F703E300B8305B /* RoomSummary.swift in Sources */,
 				183E023627E4A79D00903BED /* RoomTimelineProviderProtocol.swift in Sources */,
 				18DF7C4727E4670600291672 /* TextRoomTimelineItem.swift in Sources */,
 				18F2BAE027D25B4000DD1988 /* NavigationRouter.swift in Sources */,
@@ -963,6 +991,8 @@
 				18C5745627E1DCA800D70937 /* RoomMessageFactory.swift in Sources */,
 				18F2BB1127D25B4000DD1988 /* RoomScreenModels.swift in Sources */,
 				18F2BADB27D25B4000DD1988 /* AuthenticationCoordinator.swift in Sources */,
+				181A317B27F70AEB00B8305B /* EventBrief.swift in Sources */,
+				181A317927F703E300B8305B /* MockRoomSummary.swift in Sources */,
 				1850256F27B6A135002E6B18 /* AppDelegate.swift in Sources */,
 				18F2BAE627D25B4000DD1988 /* NavigationRouterType.swift in Sources */,
 				18F2BAE927D25B4000DD1988 /* ActivityPresentable.swift in Sources */,
@@ -974,6 +1004,7 @@
 				18DF7C5327E4754500291672 /* MemberDetailsProvider.swift in Sources */,
 				18F2BAE227D25B4000DD1988 /* NavigationRouterStoreProtocol.swift in Sources */,
 				18DDB72E27EF936D000F1ABF /* MatrixEntitityRegex.swift in Sources */,
+				181A317D27F70B1E00B8305B /* EventBriefFactory.swift in Sources */,
 				18F2BB1727D25B4000DD1988 /* LoginScreenCoordinator.swift in Sources */,
 				18F2BAF527D25B4000DD1988 /* WeakKeyDictionary.swift in Sources */,
 				18F2BADF27D25B4000DD1988 /* NavigationRouterStore.swift in Sources */,
@@ -995,6 +1026,7 @@
 				18F2BADD27D25B4000DD1988 /* KeychainController.swift in Sources */,
 				18920C1227F2347600A717B5 /* NoticeRoomTimelineItem.swift in Sources */,
 				18920C0E27F233FF00A717B5 /* NoticeRoomMessage.swift in Sources */,
+				181A317F27F70CCA00B8305B /* EventBriefFactoryProtocol.swift in Sources */,
 				18F2BAFB27D25B4000DD1988 /* HomeScreenCoordinator.swift in Sources */,
 				18F2BB0C27D25B4000DD1988 /* RoomScreenCoordinator.swift in Sources */,
 				18DDB72127EB9D57000F1ABF /* ElementXAttributeScope.swift in Sources */,

ElementX/Sources/AppCoordinator.swift

@@ -80,7 +80,10 @@ class AppCoordinator: AuthenticationCoordinatorDelegate, Coordinator {
             fatalError("User session should be already setup at this point")
         }
         
-        let parameters = HomeScreenCoordinatorParameters(userSession: userSession, mediaProvider: userSession.mediaProvider)
+        let parameters = HomeScreenCoordinatorParameters(userSession: userSession,
+                                                         mediaProvider: userSession.mediaProvider,
+                                                         eventBriefFactory: EventBriefFactory(),
+                                                         attributedStringBuilder: AttributedStringBuilder())
         let coordinator = HomeScreenCoordinator(parameters: parameters)
         
         coordinator.completion = { [weak self] result in

ElementX/Sources/Screens/HomeScreen/HomeScreenCoordinator.swift

@@ -20,6 +20,8 @@ import Combine
 struct HomeScreenCoordinatorParameters {
     let userSession: UserSession
     let mediaProvider: MediaProviderProtocol
+    let eventBriefFactory: EventBriefFactoryProtocol
+    let attributedStringBuilder: AttributedStringBuilderProtocol
 }
 
 enum HomeScreenCoordinatorResult {
@@ -37,6 +39,8 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
     private let hostingController: UIViewController
     private var viewModel: HomeScreenViewModelProtocol
     
+    private var roomSummaries: [RoomSummary] = []
+    
     private var cancellables = Set<AnyCancellable>()
     
     // MARK: Public
@@ -50,10 +54,11 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
     init(parameters: HomeScreenCoordinatorParameters) {
         self.parameters = parameters
         
-        let userDisplayName = self.parameters.userSession.userDisplayName ?? self.parameters.userSession.userIdentifier
+        let userDisplayName = parameters.userSession.userDisplayName ?? parameters.userSession.userIdentifier
         viewModel = HomeScreenViewModel(userDisplayName: userDisplayName,
-                                        userAvatarURL: self.parameters.userSession.userAvatarURL,
+                                        userAvatarURL: parameters.userSession.userAvatarURL,
-                                        mediaProvider: self.parameters.mediaProvider)
+                                        mediaProvider: parameters.mediaProvider,
+                                        attributedStringBuilder: parameters.attributedStringBuilder)
         
         let view = HomeScreen(context: viewModel.context)
         hostingController = UIHostingController(rootView: view)
@@ -91,6 +96,16 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
     // MARK: - Private
     
     func updateRoomsList() {
-        self.viewModel.updateWithRoomList(parameters.userSession.rooms)
+        self.roomSummaries = parameters.userSession.rooms.map { roomProxy in
+            if let summary = self.roomSummaries.first(where: { $0.id == roomProxy.id }) {
+                return summary
+            }
+            
+            return RoomSummary(roomProxy: roomProxy,
+                               mediaProvider: parameters.mediaProvider,
+                               eventBriefFactory: parameters.eventBriefFactory)
+        }
+        
+        self.viewModel.updateWithRoomList(roomSummaries)
     }
 }

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -25,9 +25,11 @@ typealias HomeScreenViewModelType = StateStoreViewModel<HomeScreenViewState,
 class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol {
     
     private let mediaProvider: MediaProviderProtocol
+    private let attributedStringBuilder: AttributedStringBuilderProtocol
     
     private var roomUpdateListeners = Set<AnyCancellable>()
-    private var roomList: [RoomProxyProtocol]? {
+
+    private var roomList: [RoomSummaryProtocol]? {
         didSet {
             self.state.isLoadingRooms = (roomList?.count ?? 0 == 0)
         }
@@ -37,8 +39,13 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     
     // MARK: - Setup
     
-    init(userDisplayName: String, userAvatarURL: String?, mediaProvider: MediaProviderProtocol) {
+    init(userDisplayName: String,
+         userAvatarURL: String?,
+         mediaProvider: MediaProviderProtocol,
+         attributedStringBuilder: AttributedStringBuilderProtocol) {
         self.mediaProvider = mediaProvider
+        self.attributedStringBuilder = attributedStringBuilder
+        
         super.init(initialViewState: HomeScreenViewState(userDisplayName: userDisplayName, isLoadingRooms: true))
         
         if let userAvatarURL = userAvatarURL {
@@ -63,24 +70,31 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         }
     }
     
-    func updateWithRoomList(_ roomList: [RoomProxyProtocol]) {
+    func updateWithRoomList(_ roomList: [RoomSummaryProtocol]) {
         self.roomList = roomList
         
-        state.rooms = roomList.map { roomProxy in
+        state.rooms = roomList.map { roomSummary in
-            buildRoomFromProxy(roomProxy)
+            buildOrUpdateRoomFromSummary(roomSummary)
         }
         
         roomUpdateListeners.removeAll()
         
-        roomList.forEach({ roomProxy  in
+        roomList.forEach({ roomSummary  in
-            roomProxy.callbacks.sink { [weak self] callback in
+            roomSummary.callbacks.sink { [weak self] callback in
+                guard let self = self else {
+                    return
+                }
+                
                 switch callback {
-                case .updatedMessages:
+                case .updatedData:
-                    self?.loadLastMessageForRoomWithIdentifier(roomProxy.id)
+                    if let index = self.state.rooms.firstIndex(where: { $0.id == roomSummary.id }) {
+                        self.state.rooms[index] = self.buildOrUpdateRoomFromSummary(roomSummary)
+                    }
                 }
             }
             .store(in: &roomUpdateListeners)
         })
+        
     }
     
     func updateWithUserAvatar(_ avatar: UIImage?) {
@@ -90,100 +104,47 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     // MARK: - Private
     
     private func loadRoomDataForIdentifier(_ roomIdentifier: String) {
-        let room = state.rooms.first(where: { $0.id == roomIdentifier })
+        guard let roomSummary = roomList?.first(where: { $0.id == roomIdentifier }) else {
-        
+            MXLog.error("Invalid room identifier")
-        if room?.avatar == nil {
-            loadAvatarForRoomWithIdentifier(roomIdentifier)
-        }
-        
-        if room?.displayName == nil {
-            loadRoomDisplayNameForRoomWithIdentifier(roomIdentifier)
-        }
-        
-        if room?.lastMessage == nil {
-            loadLastMessageForRoomWithIdentifier(roomIdentifier)
-        }
-    }
-    
-    private func loadAvatarForRoomWithIdentifier(_ roomIdentifier: String) {
-        guard let room = roomList?.filter({ $0.id == roomIdentifier }).first,
-              let avatarURLString = room.avatarURL else {
-                  return
-              }
-        
-        mediaProvider.loadImageFromURL(avatarURLString) { [weak self] result in
-            guard let self = self else { return }
-            if case let .success(image) = result {
-                self.updateAvatar(image, forRoomWithIdentifier: roomIdentifier)
-            }
-        }
-    }
-    
-    private func updateAvatar(_ avatar: UIImage?, forRoomWithIdentifier roomIdentifier: String) {
-        guard let index = self.state.rooms.firstIndex(where: { $0.id == roomIdentifier }) else {
             return
         }
         
-        self.state.rooms[index].avatar = avatar
+        roomSummary.loadData()
     }
     
-    private func loadRoomDisplayNameForRoomWithIdentifier(_ roomIdentifier: String) {
+    private func buildOrUpdateRoomFromSummary(_ roomSummary: RoomSummaryProtocol) -> HomeScreenRoom {
-        guard let room = roomList?.filter({ $0.id == roomIdentifier }).first else {
+        
-            return
+        let lastMessage = lastMessageFromEventBrief(roomSummary.lastMessage)
+        
+        guard var room = self.state.rooms.first(where: { $0.id == roomSummary.id }) else {
+            return HomeScreenRoom(id: roomSummary.id,
+                                  displayName: roomSummary.name,
+                                  topic: roomSummary.topic,
+                                  lastMessage: lastMessage,
+                                  avatar: roomSummary.avatar,
+                                  isDirect: roomSummary.isDirect,
+                                  isEncrypted: roomSummary.isEncrypted,
+                                  isSpace: roomSummary.isSpace,
+                                  isTombstoned: roomSummary.isTombstoned)
         }
         
-        room.displayName { [weak self] result in
+        room.avatar = roomSummary.avatar
-            guard let self = self else { return }
+        room.displayName = roomSummary.displayName
-            
+        room.lastMessage = lastMessage
-            switch result {
+        
-            case .success(let displayName):
+        return room
-                self.updateDisplayName(displayName, forRoomWithIdentifier: roomIdentifier)
-            default:
-                break
-            }
-        }
     }
     
-    private func updateDisplayName(_ displayName: String, forRoomWithIdentifier roomIdentifier: String) {
+    private func lastMessageFromEventBrief(_ eventBrief: EventBrief?) -> String? {
-        guard let index = self.state.rooms.firstIndex(where: { $0.id == roomIdentifier }) else {
+        guard let eventBrief = eventBrief else {
-            return
+            return nil
         }
         
-        self.state.rooms[index].displayName = displayName
+        if let htmlBody = eventBrief.htmlBody,
-    }
+           let lastMessageAttributedString = attributedStringBuilder.fromHTML(htmlBody) {
-    
+            return "\(eventBrief.senderName): \(String(lastMessageAttributedString.characters))"
-    private func loadLastMessageForRoomWithIdentifier(_ roomIdentifier: String) {
+        } else {
-        guard let room = roomList?.filter({ $0.id == roomIdentifier }).first else {
+            return "\(eventBrief.senderName): \(eventBrief.body)"
-            return
         }
-        
-        if let lastMessage = room.messages.last {
-            self.updateLastMessage(lastMessage.body, forRoomWithIdentifier: roomIdentifier)
-            return
-        }
-        
-        room.paginateBackwards(count: 1, callback: nil)
-    }
-    
-    private func updateLastMessage(_ lastMessage: String, forRoomWithIdentifier roomIdentifier: String) {
-        guard let index = self.state.rooms.firstIndex(where: { $0.id == roomIdentifier }) else {
-            return
-        }
-        
-        self.state.rooms[index].lastMessage = lastMessage
-    }
-    
-    private func buildRoomFromProxy(_ roomProxy: RoomProxyProtocol) -> HomeScreenRoom {
-        let avatar = mediaProvider.imageForURL(roomProxy.avatarURL)
-        
-        return HomeScreenRoom(id: roomProxy.id,
-                              displayName: roomProxy.name,
-                              topic: roomProxy.topic,
-                              lastMessage: roomProxy.messages.last?.body,
-                              avatar: avatar,
-                              isDirect: roomProxy.isDirect,
-                              isEncrypted: roomProxy.isEncrypted,
-                              isSpace: roomProxy.isSpace,
-                              isTombstoned: roomProxy.isTombstoned)
     }
 }

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModelProtocol.swift

@@ -22,5 +22,5 @@ protocol HomeScreenViewModelProtocol {
     
     var context: HomeScreenViewModelType.Context { get }
     
-    func updateWithRoomList(_ roomList: [RoomProxyProtocol])
+    func updateWithRoomList(_ roomList: [RoomSummaryProtocol])
 }

ElementX/Sources/Screens/HomeScreen/View/HomeScreen.swift

@@ -153,11 +153,12 @@ struct HomeScreen_Previews: PreviewProvider {
     static var previews: some View {
         let viewModel = HomeScreenViewModel(userDisplayName: "Johnny Appleseed",
                                             userAvatarURL: nil,
-                                            mediaProvider: MockMediaProvider())
+                                            mediaProvider: MockMediaProvider(),
+                                            attributedStringBuilder: AttributedStringBuilder())
         
-        let rooms = [MockRoomProxy(displayName: "Alfa"),
+        let rooms = [MockRoomSummary(displayName: "Alpha"),
-                     MockRoomProxy(displayName: "Beta"),
+                     MockRoomSummary(displayName: "Beta"),
-                     MockRoomProxy(displayName: "Omega")]
+                     MockRoomSummary(displayName: "Omega")]
         
         viewModel.updateWithRoomList(rooms)
         

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

@@ -0,0 +1,17 @@
+//
+//  EventBrief.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import Foundation
+
+struct EventBrief {
+    let id: String
+    let senderName: String
+    let body: String
+    let htmlBody: String?
+    let date: Date
+}

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

@@ -0,0 +1,41 @@
+//
+//  EventBriefFactory.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import Foundation
+
+struct EventBriefFactory: EventBriefFactoryProtocol {
+    
+    func eventBriefForMessage(_ message: RoomMessageProtocol?) -> EventBrief? {
+        guard let message = message else {
+            return nil
+        }
+        
+        switch message {
+        case is ImageRoomMessage:
+            return nil
+        case let message as TextRoomMessage:
+            return buildEventBrief(message: message, htmlBody: message.htmlBody)
+        case let message as NoticeRoomMessage:
+            return buildEventBrief(message: message, htmlBody: message.htmlBody)
+        case let message as EmoteRoomMessage:
+            return buildEventBrief(message: message, htmlBody: message.htmlBody)
+        default:
+            fatalError("Unknown room message.")
+        }
+    }
+    
+    // MARK: - Private
+    
+    private func buildEventBrief(message: RoomMessageProtocol, htmlBody: String?) -> EventBrief {
+        return EventBrief(id: message.id,
+                          senderName: message.sender,
+                          body: message.body,
+                          htmlBody: htmlBody,
+                          date: message.originServerTs)
+    }
+}

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

@@ -0,0 +1,13 @@
+//
+//  EventBriefFactoryProtocol.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import Foundation
+
+protocol EventBriefFactoryProtocol {
+    func eventBriefForMessage(_ message: RoomMessageProtocol?) -> EventBrief?
+}

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

@@ -0,0 +1,38 @@
+//
+//  MockRoomSummary.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import UIKit
+import Combine
+
+struct MockRoomSummary: RoomSummaryProtocol {
+    var id: String = UUID().uuidString
+    
+    var name: String?
+    
+    var topic: String?
+    
+    var isDirect: Bool = false
+    
+    var isEncrypted: Bool = false
+    
+    var isSpace: Bool = false
+    
+    var isTombstoned: Bool = false
+    
+    var displayName: String?
+    
+    var lastMessage: EventBrief?
+    
+    var avatar: UIImage?
+    
+    func loadData() {
+        
+    }
+    
+    var callbacks = PassthroughSubject<RoomSummaryCallback, Never>()
+}

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

@@ -0,0 +1,145 @@
+//
+//  RoomSummary.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import Foundation
+import UIKit
+import Combine
+
+class RoomSummary: RoomSummaryProtocol {
+    private let roomProxy: RoomProxyProtocol
+    private let mediaProvider: MediaProviderProtocol
+    private let eventBriefFactory: EventBriefFactoryProtocol
+    
+    private var hasLoadedData = false
+    private var roomUpdateListeners = Set<AnyCancellable>()
+    
+    var id: String {
+        roomProxy.id
+    }
+    
+    var name: String? {
+        roomProxy.name
+    }
+    
+    var topic: String? {
+        roomProxy.topic
+    }
+    
+    var isDirect: Bool {
+        roomProxy.isDirect
+    }
+    
+    var isEncrypted: Bool {
+        roomProxy.isEncrypted
+    }
+    
+    var isSpace: Bool {
+        roomProxy.isSpace
+    }
+    
+    var isTombstoned: Bool {
+        roomProxy.isTombstoned
+    }
+    
+    private(set) var displayName: String? {
+        didSet {
+            self.callbacks.send(.updatedData)
+        }
+    }
+    
+    private(set) var lastMessage: EventBrief? {
+        didSet {
+            self.callbacks.send(.updatedData)
+        }
+    }
+    
+    private(set) var avatar: UIImage? {
+        didSet {
+            self.callbacks.send(.updatedData)
+        }
+    }
+    
+    let callbacks = PassthroughSubject<RoomSummaryCallback, Never>()
+    
+    init(roomProxy: RoomProxyProtocol, mediaProvider: MediaProviderProtocol, eventBriefFactory: EventBriefFactoryProtocol) {
+        self.roomProxy = roomProxy
+        self.mediaProvider = mediaProvider
+        self.eventBriefFactory = eventBriefFactory
+        
+        lastMessage = eventBriefFactory.eventBriefForMessage(roomProxy.messages.last)
+        
+        roomProxy.callbacks.sink { [weak self] callback in
+            guard let self = self else {
+                return
+            }
+            
+            switch callback {
+            case .updatedMessages:
+                self.lastMessage = self.eventBriefFactory.eventBriefForMessage(self.roomProxy.messages.last)
+            }
+        }
+        .store(in: &roomUpdateListeners)
+    }
+    
+    func loadData() {
+        if hasLoadedData {
+            return
+        }
+        
+        loadDisplayName()
+        loadLastMessage()
+        loadAvatar()
+        
+        hasLoadedData = true
+    }
+    
+    // MARK: - Private
+    
+    private func loadDisplayName() {
+        roomProxy.displayName { [weak self] result in
+            guard let self = self else { return }
+            
+            switch result {
+            case .success(let displayName):
+                self.displayName = displayName
+            case .failure(let error):
+                MXLog.error("Failed fetching room display name with error: \(error)")
+            }
+        }
+    }
+    
+    private func loadLastMessage() {
+        if roomProxy.messages.last == nil {
+            roomProxy.paginateBackwards(count: 1) { [weak self] result in
+                guard let self = self else { return }
+                
+                switch result {
+                case .success:
+                    self.lastMessage = self.eventBriefFactory.eventBriefForMessage(self.roomProxy.messages.last)
+                case .failure(let error):
+                    MXLog.error("Failed back paginating with error: \(error)")
+                }
+            }
+        }
+    }
+    
+    private func loadAvatar() {
+        if let avatarURL = roomProxy.avatarURL {
+            mediaProvider.loadImageFromURL(avatarURL) { [weak self] result in
+                guard let self = self else { return }
+                
+                switch result {
+                case .success(let image):
+                    self.avatar = image
+                case .failure(let error):
+                    MXLog.error("Failed fetching room avatar with error: \(error)")
+                }
+            }
+        }
+    }
+}

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

@@ -0,0 +1,32 @@
+//
+//  RoomSummaryProtocol.swift
+//  ElementX
+//
+//  Created by Stefan Ceriu on 01/04/2022.
+//  Copyright © 2022 Element. All rights reserved.
+//
+
+import UIKit
+import Combine
+
+enum RoomSummaryCallback {
+    case updatedData
+}
+
+protocol RoomSummaryProtocol {
+    var id: String { get }
+    var name: String? { get }
+    var topic: String? { get }
+    var isDirect: Bool { get }
+    var isEncrypted: Bool { get }
+    var isSpace: Bool { get }
+    var isTombstoned: Bool { get }
+    
+    var displayName: String? { get }
+    var lastMessage: EventBrief? { get }
+    var avatar: UIImage? { get }
+    
+    var callbacks: PassthroughSubject<RoomSummaryCallback, Never> { get }
+    
+    func loadData()
+}