Admin Close Group for GV2

Signal/src/ViewControllers/ThreadSettings/ConversationSettingsViewController+Contents.swift

@@ -523,6 +523,28 @@ extension ConversationSettingsViewController {
     private func buildBlockAndLeaveSection() -> OWSTableSection {
         let section = OWSTableSection()
 
+        if canCloseGroupAsAdmin {
+            section.add(OWSTableItem(customCellBlock: { [weak self] in
+                guard let self = self else {
+                    owsFailDebug("Missing self")
+                    return OWSTableItem.newCell()
+                }
+
+                return OWSTableItem.buildCell(
+                    icon: .groupMemberRemoveFromGroup,
+                    itemName: OWSLocalizedString(
+                        "CLOSE_GROUP_ACTION",
+                        comment: "table cell label in conversation settings for an admin to close the group for everyone"
+                    ),
+                    customColor: UIColor.ows_accentRed,
+                    accessibilityIdentifier: UIView.accessibilityIdentifier(in: self, name: "close_group")
+                )
+            },
+            actionBlock: { [weak self] in
+                self?.didTapCloseGroup()
+            }))
+        }
+
         if isGroupThread, isLocalUserFullOrInvitedMember {
             section.add(OWSTableItem(customCellBlock: { [weak self] in
                 guard let self = self else {

Signal/src/ViewControllers/ThreadSettings/ConversationSettingsViewController.swift

@@ -145,6 +145,20 @@ class ConversationSettingsViewController: OWSTableViewController2, BadgeCollecti
         thread.isGroupThread
     }
 
+    /// Whether the local user can use "Close group" (GV2 admin with membership-edit rights).
+    var canCloseGroupAsAdmin: Bool {
+        guard let groupThread = thread as? TSGroupThread else {
+            return false
+        }
+        guard groupThread.isGroupV2Thread else {
+            return false
+        }
+        guard groupViewHelper.canEditConversationMembership else {
+            return false
+        }
+        return groupThread.isLocalUserFullMemberAndAdministrator
+    }
+
     // MARK: - View Lifecycle
 
     public override func viewDidLoad() {
@@ -680,6 +694,78 @@ class ConversationSettingsViewController: OWSTableViewController2, BadgeCollecti
         }
     }
 
+    func didTapCloseGroup() {
+        showCloseGroupConfirmAlert()
+    }
+
+    func showCloseGroupConfirmAlert() {
+        let alert = ActionSheetController(
+            title: OWSLocalizedString(
+                "CLOSE_GROUP_CONFIRM_TITLE",
+                comment: "Title for the confirmation alert when an admin closes a group for everyone."
+            ),
+            message: OWSLocalizedString(
+                "CLOSE_GROUP_CONFIRM_MESSAGE",
+                comment: "Message for the confirmation alert when an admin closes a group. Explains that all members will be removed, the admin will leave, and the action cannot be undone."
+            )
+        )
+        let closeAction = ActionSheetAction(
+            title: OWSLocalizedString(
+                "CLOSE_GROUP_CONFIRM_BUTTON",
+                comment: "Confirmation button to close a group for everyone."
+            ),
+            accessibilityIdentifier: UIView.accessibilityIdentifier(in: self, name: "close_group_confirm"),
+            style: .destructive
+        ) { [weak self] _ in
+            self?.performCloseGroupForEveryone()
+        }
+        alert.addAction(closeAction)
+        alert.addAction(OWSActionSheets.cancelAction)
+        presentActionSheet(alert)
+    }
+
+    private func performCloseGroupForEveryone() {
+        guard let groupThread = thread as? TSGroupThread else {
+            owsFailDebug("Invalid thread.")
+            return
+        }
+        guard let groupModelV2 = groupThread.groupModel as? TSGroupModelV2 else {
+            owsFailDebug("Invalid group model.")
+            return
+        }
+        guard let navigationController = self.navigationController else {
+            owsFailDebug("Invalid navigationController.")
+            return
+        }
+        let viewControllers = navigationController.viewControllers
+        guard let index = viewControllers.firstIndex(of: self),
+              index > 0 else {
+            owsFailDebug("Invalid navigation stack.")
+            return
+        }
+        let conversationViewController = viewControllers[index - 1]
+
+        GroupViewUtils.updateGroupWithActivityIndicator(
+            fromViewController: self,
+            updateBlock: {
+                try await GroupManager.closeGroupForEveryoneV2(groupModel: groupModelV2)
+            },
+            completion: { [weak self] in
+                guard let self else { return }
+                let threadToSoftDelete = self.thread
+                SSKEnvironment.shared.databaseStorageRef.write { transaction in
+                    DependenciesBridge.shared.threadSoftDeleteManager.softDelete(
+                        threads: [threadToSoftDelete],
+                        sendDeleteForMeSyncMessage: true,
+                        tx: transaction
+                    )
+                }
+                NotificationCenter.default.post(name: ChatListViewController.clearSearch, object: nil)
+                self.navigationController?.popToViewController(conversationViewController, animated: true)
+            }
+        )
+    }
+
     func didTapUnblockThread(completion: @escaping () -> Void = {}) {
         BlockListUIUtils.showUnblockThreadActionSheet(thread, from: self) { [weak self] _ in
             self?.reloadThreadAndUpdateContent()

Signal/translations/en.lproj/Localizable.strings

@@ -4135,6 +4135,18 @@
 /* Error indicating that a group could not be left. */
 "LEAVE_GROUP_FAILED" = "An error occurred while leaving the group.";
 
+/* table cell label in conversation settings for an admin to close the group for everyone */
+"CLOSE_GROUP_ACTION" = "Close Group";
+
+/* Title for the confirmation alert when an admin closes a group for everyone. */
+"CLOSE_GROUP_CONFIRM_TITLE" = "Close this group?";
+
+/* Message for the confirmation alert when an admin closes a group. Explains that all members will be removed, the admin will leave, and the action cannot be undone. */
+"CLOSE_GROUP_CONFIRM_MESSAGE" = "Everyone will be removed from the group, you will leave, and this chat will be deleted from your device. This action cannot be undone.";
+
+/* Confirmation button to close a group for everyone. */
+"CLOSE_GROUP_CONFIRM_BUTTON" = "Close Group";
+
 /* Text in a sheet explaining details about 'Legacy Groups'. */
 "LEGACY_GROUP_UNSUPPORTED_LEARN_MORE_BODY" = "\"Legacy Groups\" are groups that do not support features like @mentions and admins. Most Legacy Groups were upgraded either automatically or manually to \"New Groups.\" Due to a long period of inactivity, this group can no longer be upgraded.\n\nTo continue this chat, you must create a new group.";
 

SignalServiceKit/Groups/GroupManager.swift

@@ -565,6 +565,32 @@ public class GroupManager: NSObject {
         }
     }
 
+    /// Removes every other member, invite, and join request from the group, then leaves.
+    /// Call only when the local user is a full administrator; mirrors per-member removal semantics
+    /// from `removeFromGroupOrRevokeInviteV2` in a single GV2 change so the last-admin leave check passes.
+    public static func closeGroupForEveryoneV2(groupModel: TSGroupModelV2) async throws {
+        guard let localIdentifiers = DependenciesBridge.shared.tsAccountManager.localIdentifiersWithMaybeSneakyTransaction else {
+            throw OWSAssertionError("Missing localIdentifiers.")
+        }
+        var localServiceIds: Set<ServiceId> = [localIdentifiers.aci]
+        if let pni = localIdentifiers.pni {
+            localServiceIds.insert(pni)
+        }
+
+        let membership = groupModel.groupMembership
+        let serviceIdsToRemove = membership.allMembersOfAnyKindServiceIds.subtracting(localServiceIds)
+
+        try await updateGroupV2(groupModel: groupModel, description: "Close group for everyone") { groupChangeSet in
+            for serviceId in serviceIdsToRemove {
+                groupChangeSet.removeMember(serviceId)
+                if let aci = serviceId as? Aci, !membership.isInvitedMember(serviceId) {
+                    groupChangeSet.addBannedMember(aci)
+                }
+            }
+            groupChangeSet.setShouldLeaveGroupDeclineInvite()
+        }
+    }
+
     public static func revokeInvalidInvites(groupModel: TSGroupModelV2) async throws {
         try await updateGroupV2(groupModel: groupModel, description: "Revoke invalid invites") { groupChangeSet in
             groupChangeSet.revokeInvalidInvites()