From 95f734dfa2d19fb97a189611a33202eac886cebf Mon Sep 17 00:00:00 2001
From: Mauro Romito <mauro.romito@element.io>
Date: Thu, 13 Jul 2023 19:24:41 +0200
Subject: [PATCH] basic implementation

---
 .../Mocks/Generated/GeneratedMocks.swift      | 26 +++++++++++++++++++
 .../RoomScreen/RoomScreenViewModel.swift      | 21 ++++++++++++---
 .../Sources/Services/Room/RoomProxy.swift     | 13 ++++++++++
 .../Services/Room/RoomProxyProtocol.swift     |  4 +++
 4 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/ElementX/Sources/Mocks/Generated/GeneratedMocks.swift b/ElementX/Sources/Mocks/Generated/GeneratedMocks.swift
index bc4844e698..b0d578cfe5 100644
--- a/ElementX/Sources/Mocks/Generated/GeneratedMocks.swift
+++ b/ElementX/Sources/Mocks/Generated/GeneratedMocks.swift
@@ -451,6 +451,11 @@ class RoomProxyMock: RoomProxyProtocol {
         set(value) { underlyingHasUnreadNotifications = value }
     }
     var underlyingHasUnreadNotifications: Bool!
+    var currentUserID: String {
+        get { return underlyingCurrentUserID }
+        set(value) { underlyingCurrentUserID = value }
+    }
+    var underlyingCurrentUserID: String!
     var name: String?
     var displayName: String?
     var topic: String?
@@ -1093,6 +1098,27 @@ class RoomProxyMock: RoomProxyProtocol {
             return uploadAvatarMediaReturnValue
         }
     }
+    //MARK: - canUserRedact
+
+    var canUserRedactUserIDCallsCount = 0
+    var canUserRedactUserIDCalled: Bool {
+        return canUserRedactUserIDCallsCount > 0
+    }
+    var canUserRedactUserIDReceivedUserID: String?
+    var canUserRedactUserIDReceivedInvocations: [String] = []
+    var canUserRedactUserIDReturnValue: Result<Bool, RoomProxyError>!
+    var canUserRedactUserIDClosure: ((String) async -> Result<Bool, RoomProxyError>)?
+
+    func canUserRedact(userID: String) async -> Result<Bool, RoomProxyError> {
+        canUserRedactUserIDCallsCount += 1
+        canUserRedactUserIDReceivedUserID = userID
+        canUserRedactUserIDReceivedInvocations.append(userID)
+        if let canUserRedactUserIDClosure = canUserRedactUserIDClosure {
+            return await canUserRedactUserIDClosure(userID)
+        } else {
+            return canUserRedactUserIDReturnValue
+        }
+    }
 }
 class RoomTimelineProviderMock: RoomTimelineProviderProtocol {
     var updatePublisher: AnyPublisher<TimelineProviderUpdate, Never> {
diff --git a/ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift b/ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift
index 820eb6173a..063ab14616 100644
--- a/ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift
+++ b/ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift
@@ -34,6 +34,8 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
     private let analytics: AnalyticsService
     private unowned let userIndicatorController: UserIndicatorControllerProtocol
     private let notificationCenterProtocol: NotificationCenterProtocol
+
+    private var canCurrentUserRedact = false
     
     init(timelineController: RoomTimelineControllerProtocol,
          mediaProvider: MediaProviderProtocol,
@@ -104,7 +106,14 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         case .markRoomAsRead:
             Task { await markRoomAsRead() }
         case .timelineItemMenu(let itemID):
-            showTimelineItemActionMenu(for: itemID)
+            Task {
+                if case let .success(value) = await roomProxy.canUserRedact(userID: roomProxy.currentUserID) {
+                    canCurrentUserRedact = value
+                } else {
+                    canCurrentUserRedact = false
+                }
+                showTimelineItemActionMenu(for: itemID)
+            }
         case .timelineItemMenuAction(let itemID, let action):
             processTimelineItemMenuAction(action, itemID: itemID)
         case .displayCameraPicker:
@@ -408,9 +417,11 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         
         actions.append(.copyPermalink)
         
-        if item.isOutgoing {
+        if canRedactItem(item) {
             actions.append(.redact)
-        } else {
+        }
+
+        if !item.isOutgoing {
             actions.append(.report)
         }
 
@@ -424,6 +435,10 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
 
         return .init(actions: actions, debugActions: debugActions)
     }
+
+    private func canRedactItem(_ item: EventBasedTimelineItemProtocol) -> Bool  {
+        item.isOutgoing || (canCurrentUserRedact && !roomProxy.isDirect)
+    }
     
     // swiftlint:disable:next cyclomatic_complexity function_body_length
     private func processTimelineItemMenuAction(_ action: TimelineItemMenuAction, itemID: TimelineItemIdentifier) {
diff --git a/ElementX/Sources/Services/Room/RoomProxy.swift b/ElementX/Sources/Services/Room/RoomProxy.swift
index 88f3810b9c..09de1ca363 100644
--- a/ElementX/Sources/Services/Room/RoomProxy.swift
+++ b/ElementX/Sources/Services/Room/RoomProxy.swift
@@ -55,6 +55,10 @@ class RoomProxy: RoomProxyProtocol {
         innerTimelineProvider
     }
 
+    var currentUserID: String {
+        room.currentUserId()
+    }
+
     deinit {
         roomTimelineObservationToken?.cancel()
         backPaginationStateObservationToken?.cancel()
@@ -647,6 +651,15 @@ class RoomProxy: RoomProxyProtocol {
         }
     }
 
+    func canUserRedact(userID: String) async -> Result<Bool, RoomProxyError> {
+        do {
+            return try await .success(room.canUserRedact(userId: userID))
+        } catch {
+            MXLog.error("Failed checking if the user can redact with error: \(error)")
+            return .failure(.failedCheckingPermission)
+        }
+    }
+
     // MARK: - Private
     
     /// Force the timeline to load member details so it can populate sender profiles whenever we add a timeline listener
diff --git a/ElementX/Sources/Services/Room/RoomProxyProtocol.swift b/ElementX/Sources/Services/Room/RoomProxyProtocol.swift
index b33dbab6ab..fb2dc05d03 100644
--- a/ElementX/Sources/Services/Room/RoomProxyProtocol.swift
+++ b/ElementX/Sources/Services/Room/RoomProxyProtocol.swift
@@ -41,6 +41,7 @@ enum RoomProxyError: Error, Equatable {
     case failedSettingRoomTopic
     case failedRemovingAvatar
     case failedUploadingAvatar
+    case failedCheckingPermission
 }
 
 // sourcery: AutoMockable
@@ -54,6 +55,7 @@ protocol RoomProxyProtocol {
     var canonicalAlias: String? { get }
     var alternativeAliases: [String] { get }
     var hasUnreadNotifications: Bool { get }
+    var currentUserID: String { get }
     
     var name: String? { get }
     var displayName: String? { get }
@@ -159,6 +161,8 @@ protocol RoomProxyProtocol {
     func removeAvatar() async -> Result<Void, RoomProxyError>
     
     func uploadAvatar(media: MediaInfo) async -> Result<Void, RoomProxyError>
+
+    func canUserRedact(userID: String) async -> Result<Bool, RoomProxyError>
 }
 
 extension RoomProxyProtocol {