Merge pull request #43 from loki-project/server-deletion

User Initiated Group Message Deletion

Signal.xcodeproj/project.pbxproj

@@ -2615,17 +2615,17 @@
 		B8439518228510E9000563FE /* Loki */ = {
 			isa = PBXGroup;
 			children = (
+				B821F2F72272CED3002C88C0 /* AccountDetailsViewController.swift */,
 				B8162F0222891AD600D46544 /* FriendRequestView.swift */,
 				B8162F0422892C5F00D46544 /* FriendRequestViewDelegate.swift */,
-				B89841E222B7579F00B1BDC6 /* NewConversationViewController.swift */,
-				B821F2F72272CED3002C88C0 /* AccountDetailsViewController.swift */,
-				B821F2F92272CEEE002C88C0 /* SeedViewController.swift */,
-				24A830A12293CD0100F4CAC0 /* LokiP2PServer.swift */,
 				B845B4D3230CD09000D759F0 /* LokiGroupChatPoller.swift */,
+				24A830A12293CD0100F4CAC0 /* LokiP2PServer.swift */,
 				B825849F2315024B001B41CB /* LokiRSSFeedPoller.swift */,
+				B89841E222B7579F00B1BDC6 /* NewConversationViewController.swift */,
 				B825848A230F94FE001B41CB /* QRCodeViewController.swift */,
 				B8258491230FA5DA001B41CB /* ScanQRCodeViewController.h */,
 				B8258492230FA5E9001B41CB /* ScanQRCodeViewController.m */,
+				B821F2F92272CEEE002C88C0 /* SeedViewController.swift */,
 			);
 			path = Loki;
 			sourceTree = "<group>";

Signal/src/AppDelegate.m

@@ -1504,7 +1504,7 @@ static NSTimeInterval launchStartedAt;
 
 - (LKGroupChat *)lokiPublicChat
 {
-    return [[LKGroupChat alloc] initWithServerID:@(LKGroupChatAPI.publicChatServerID).unsignedIntegerValue server:LKGroupChatAPI.publicChatServer displayName:NSLocalizedString(@"Loki Public Chat", @"") isDeletable:true];
+    return [[LKGroupChat alloc] initWithServerID:LKGroupChatAPI.publicChatServerID server:LKGroupChatAPI.publicChatServer displayName:NSLocalizedString(@"Loki Public Chat", @"") isDeletable:true];
 }
 
 - (LKRSSFeed *)lokiNewsFeed

Signal/src/Loki/LokiGroupChatPoller.swift

@@ -4,11 +4,16 @@ public final class LokiGroupChatPoller : NSObject {
     private let group: LokiGroupChat
     private var pollForNewMessagesTimer: Timer? = nil
     private var pollForDeletedMessagesTimer: Timer? = nil
+    private var pollForModerationPermissionTimer: Timer? = nil
     private var hasStarted = false
+    private let userHexEncodedPublicKey = OWSIdentityManager.shared().identityKeyPair()!.hexEncodedPublicKey
     
+    // MARK: Settings
     private let pollForNewMessagesInterval: TimeInterval = 4
     private let pollForDeletedMessagesInterval: TimeInterval = 20
+    private let pollForModerationPermissionInterval: TimeInterval = 10 * 60
     
+    // MARK: Lifecycle
     @objc(initForGroup:)
     public init(for group: LokiGroupChat) {
         self.group = group
@@ -20,42 +25,80 @@ public final class LokiGroupChatPoller : NSObject {
         pollForNewMessagesTimer = Timer.scheduledTimer(withTimeInterval: pollForNewMessagesInterval, repeats: true) { [weak self] _ in self?.pollForNewMessages() }
         pollForNewMessages() // Perform initial update
         pollForDeletedMessagesTimer = Timer.scheduledTimer(withTimeInterval: pollForDeletedMessagesInterval, repeats: true) { [weak self] _ in self?.pollForDeletedMessages() }
+        pollForModerationPermissionTimer = Timer.scheduledTimer(withTimeInterval: pollForModerationPermissionInterval, repeats: true) { [weak self] _ in self?.pollForModerationPermission() }
         hasStarted = true
     }
     
     @objc public func stop() {
         pollForNewMessagesTimer?.invalidate()
         pollForDeletedMessagesTimer?.invalidate()
+        pollForModerationPermissionTimer?.invalidate()
         hasStarted = false
     }
     
+    // MARK: Polling
     private func pollForNewMessages() {
+        // Prepare
         let group = self.group
-        let _ = LokiGroupChatAPI.getMessages(for: group.serverID, on: group.server).done { messages in
-            messages.reversed().forEach { message in
-                let senderHexEncodedPublicKey = message.hexEncodedPublicKey
-                let endIndex = senderHexEncodedPublicKey.endIndex
-                let cutoffIndex = senderHexEncodedPublicKey.index(endIndex, offsetBy: -8)
-                let senderDisplayName = "\(message.displayName) (...\(senderHexEncodedPublicKey[cutoffIndex..<endIndex]))"
-                let id = group.id.data(using: String.Encoding.utf8)!
-                let x1 = SSKProtoGroupContext.builder(id: id, type: .deliver)
-                x1.setName(group.displayName)
-                let x2 = SSKProtoDataMessage.builder()
-                x2.setTimestamp(message.timestamp)
-                x2.setGroup(try! x1.build())
-                x2.setBody(message.body)
-                let messageServerID = message.serverID!
+        let userHexEncodedPublicKey = self.userHexEncodedPublicKey
+        // Processing logic for incoming messages
+        func processIncomingMessage(_ message: LokiGroupMessage) {
+            let senderHexEncodedPublicKey = message.hexEncodedPublicKey
+            let endIndex = senderHexEncodedPublicKey.endIndex
+            let cutoffIndex = senderHexEncodedPublicKey.index(endIndex, offsetBy: -8)
+            let senderDisplayName = "\(message.displayName) (...\(senderHexEncodedPublicKey[cutoffIndex..<endIndex]))"
+            let id = group.id.data(using: String.Encoding.utf8)!
+            let x1 = SSKProtoGroupContext.builder(id: id, type: .deliver)
+            x1.setName(group.displayName)
+            let x2 = SSKProtoDataMessage.builder()
+            x2.setTimestamp(message.timestamp)
+            x2.setGroup(try! x1.build())
+            x2.setBody(message.body)
+            if let messageServerID = message.serverID {
                 let publicChatInfo = SSKProtoPublicChatInfo.builder()
                 publicChatInfo.setServerID(messageServerID)
                 x2.setPublicChatInfo(try! publicChatInfo.build())
-                let x3 = SSKProtoContent.builder()
-                x3.setDataMessage(try! x2.build())
-                let x4 = SSKProtoEnvelope.builder(type: .ciphertext, timestamp: message.timestamp)
-                x4.setSource(senderDisplayName)
-                x4.setSourceDevice(OWSDevicePrimaryDeviceId)
-                x4.setContent(try! x3.build().serializedData())
-                OWSPrimaryStorage.shared().dbReadWriteConnection.readWrite { transaction in
-                    SSKEnvironment.shared.messageManager.throws_processEnvelope(try! x4.build(), plaintextData: try! x3.build().serializedData(), wasReceivedByUD: false, transaction: transaction)
+            }
+            let x3 = SSKProtoContent.builder()
+            x3.setDataMessage(try! x2.build())
+            let x4 = SSKProtoEnvelope.builder(type: .ciphertext, timestamp: message.timestamp)
+            x4.setSource(senderDisplayName)
+            x4.setSourceDevice(OWSDevicePrimaryDeviceId)
+            x4.setContent(try! x3.build().serializedData())
+            let storage = OWSPrimaryStorage.shared()
+            storage.dbReadWriteConnection.readWrite { transaction in
+                SSKEnvironment.shared.messageManager.throws_processEnvelope(try! x4.build(), plaintextData: try! x3.build().serializedData(), wasReceivedByUD: false, transaction: transaction)
+            }
+        }
+        // Processing logic for outgoing messages
+        func processOutgoingMessage(_ message: LokiGroupMessage) {
+            guard let messageServerID = message.serverID else { return }
+            let storage = OWSPrimaryStorage.shared()
+            var isDuplicate = false
+            storage.dbReadConnection.read { transaction in
+                let id = storage.getIDForMessage(withServerID: UInt(messageServerID), in: transaction)
+                isDuplicate = id != nil
+            }
+            guard !isDuplicate else { return }
+            guard let groupID = group.id.data(using: .utf8) else { return }
+            let thread = TSGroupThread.getOrCreateThread(withGroupId: groupID)
+            let message = TSOutgoingMessage(outgoingMessageWithTimestamp: message.timestamp, in: thread, messageBody: message.body, attachmentIds: [], expiresInSeconds: 0,
+                expireStartedAt: 0, isVoiceMessage: false, groupMetaMessage: .deliver, quotedMessage: nil, contactShare: nil, linkPreview: nil)
+            storage.dbReadWriteConnection.readWrite { transaction in
+                message.update(withSentRecipient: group.server, wasSentByUD: false, transaction: transaction)
+                message.saveGroupChatMessageID(messageServerID, in: transaction)
+                guard let messageID = message.uniqueId else { return print("[Loki] Failed to save group message.") }
+                storage.setIDForMessageWithServerID(UInt(messageServerID), to: messageID, in: transaction)
+            }
+        }
+        // Poll
+        let _ = LokiGroupChatAPI.getMessages(for: group.serverID, on: group.server).done { messages in
+            messages.reversed().forEach { message in
+                let senderHexEncodedPublicKey = message.hexEncodedPublicKey
+                if (senderHexEncodedPublicKey != userHexEncodedPublicKey) {
+                    processIncomingMessage(message)
+                } else {
+                    processOutgoingMessage(message)
                 }
             }
         }
@@ -73,4 +116,14 @@ public final class LokiGroupChatPoller : NSObject {
             }
         }
     }
+    
+    private func pollForModerationPermission() {
+        let group = self.group
+        let _ = LokiGroupChatAPI.userHasModerationPermission(for: group.serverID, on: group.server).done { isModerator in
+            let storage = OWSPrimaryStorage.shared()
+            storage.dbReadWriteConnection.readWrite { transaction in
+                storage.setIsModerator(isModerator, for: UInt(group.serverID), on: group.server, in: transaction)
+            }
+        }
+    }
 }

Signal/src/Models/MessageActions.swift

@@ -86,7 +86,7 @@ class ConversationViewItemActions: NSObject {
             actions.append(copyTextAction)
         }
 
-        if !isGroup {
+        if !isGroup || conversationViewItem.userCanDeleteGroupMessage {
             let deleteAction = MessageActionBuilder.deleteMessage(conversationViewItem: conversationViewItem, delegate: delegate)
             actions.append(deleteAction)
         }

Signal/src/ViewControllers/ColorPickerViewController.swift

@@ -305,6 +305,7 @@ class ColorPickerView: UIView, ColorViewDelegate {
 
 @objc
 private class MockConversationViewItem: NSObject, ConversationViewItem {
+    var userCanDeleteGroupMessage: Bool = false
     var interaction: TSInteraction = TSMessage()
     var interactionType: OWSInteractionType = OWSInteractionType.unknown
     var quotedReply: OWSQuotedReplyModel?

Signal/src/ViewControllers/ConversationView/ConversationViewItem.h

@@ -67,6 +67,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType);
 @property (nonatomic, readonly, nullable) OWSQuotedReplyModel *quotedReply;
 
 @property (nonatomic, readonly) BOOL isGroupThread;
+@property (nonatomic, readonly) BOOL userCanDeleteGroupMessage;
 
 @property (nonatomic, readonly) BOOL hasBodyText;
 

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -9,11 +9,14 @@
 #import "OWSMessageHeaderView.h"
 #import "OWSSystemMessageCell.h"
 #import "Session-Swift.h"
+#import "AnyPromise.h"
 #import <SignalMessaging/OWSUnreadIndicator.h>
 #import <SignalServiceKit/NSData+Image.h>
 #import <SignalServiceKit/NSString+SSK.h>
 #import <SignalServiceKit/OWSContact.h>
 #import <SignalServiceKit/TSInteraction.h>
+#import <SignalServiceKit/SSKEnvironment.h>
+#import <SignalServiceKit/SignalServiceKit-Swift.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -198,6 +201,11 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     }
 }
 
+- (OWSPrimaryStorage *)primaryStorage
+{
+    return SSKEnvironment.shared.primaryStorage;
+}
+
 - (NSString *)itemId
 {
     return self.interaction.uniqueId;
@@ -1162,6 +1170,27 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 - (void)deleteAction
 {
     [self.interaction remove];
+    
+    if (self.isGroupThread) {
+        // Skip if the thread is an RSS feed
+        TSGroupThread *groupThread = (TSGroupThread *)self.interaction.thread;
+        if (groupThread.isRSSFeed) return;
+        
+        // Only allow deletion on incoming and outgoing messages
+        OWSInteractionType interationType = self.interaction.interactionType;
+        if (interationType != OWSInteractionType_IncomingMessage && interationType != OWSInteractionType_OutgoingMessage) return;
+        
+        // Make sure it's a public chat message
+        TSMessage *message = (TSMessage *)self.interaction;
+        if (!message.isGroupChatMessage) return;
+        
+        // Delete the message
+        BOOL isSentByUser = (interationType == OWSInteractionType_OutgoingMessage);
+        [[LKGroupChatAPI deleteMessageWithID:message.isGroupChatMessage forGroup:LKGroupChatAPI.publicChatServerID onServer:LKGroupChatAPI.publicChatServer isSentByUser:isSentByUser].catch(^(NSError *error) {
+            // Roll back
+            [self.interaction save];
+        }) retainUntilComplete];
+    }
 }
 
 - (BOOL)hasBodyTextActionContent
@@ -1204,6 +1233,34 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     return NO;
 }
 
+- (BOOL)userCanDeleteGroupMessage
+{
+    if (!self.isGroupThread) return false;
+    
+    // Ensure the thread is a public chat and not an RSS feed
+    TSGroupThread *groupThread = (TSGroupThread *)self.interaction.thread;
+    if (groupThread.isRSSFeed) return false;
+    
+    // Only allow deletion on incoming and outgoing messages
+    OWSInteractionType interationType = self.interaction.interactionType;
+    if (interationType != OWSInteractionType_OutgoingMessage && interationType != OWSInteractionType_IncomingMessage) return false;
+    
+    // Make sure it's a public chat message
+    TSMessage *message = (TSMessage *)self.interaction;
+    if (!message.isGroupChatMessage) return false;
+    
+    // Only allow deletion on incoming messages if the user has moderation permission
+    if (interationType == OWSInteractionType_IncomingMessage) {
+        __block BOOL isModerator;
+        [[self primaryStorage].dbReadWriteConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+            isModerator = [[self primaryStorage] isModeratorForGroup:LKGroupChatAPI.publicChatServerID onServer:LKGroupChatAPI.publicChatServer in:transaction];
+        }];
+        if (!isModerator) return false;
+    }
+
+    return true;
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Loki/API/LokiGroupChatAPI.swift

@@ -11,7 +11,7 @@ public final class LokiGroupChatAPI : NSObject {
     // MARK: Public Chat
     @objc public static let publicChatServer = "https://chat.lokinet.org"
     @objc public static let publicChatMessageType = "network.loki.messenger.publicChat"
-    @objc public static let publicChatServerID = 1
+    @objc public static let publicChatServerID: UInt64 = 1
     
     // MARK: Convenience
     private static var userDisplayName: String {
@@ -28,7 +28,7 @@ public final class LokiGroupChatAPI : NSObject {
     
     // MARK: Error
     public enum Error : Swift.Error {
-        case tokenParsingFailed, tokenDecryptionFailed, messageParsingFailed, deletionParsingFailed
+        case parsingFailed, decryptionFailed
     }
     
     // MARK: Database
@@ -87,7 +87,7 @@ public final class LokiGroupChatAPI : NSObject {
         return TSNetworkManager.shared().makePromise(request: request).map { $0.responseObject }.map { rawResponse in
             guard let json = rawResponse as? JSON, let base64EncodedChallenge = json["cipherText64"] as? String, let base64EncodedServerPublicKey = json["serverPubKey64"] as? String,
                 let challenge = Data(base64Encoded: base64EncodedChallenge), var serverPublicKey = Data(base64Encoded: base64EncodedServerPublicKey) else {
-                throw Error.tokenParsingFailed
+                throw Error.parsingFailed
             }
             // Discard the "05" prefix if needed
             if (serverPublicKey.count == 33) {
@@ -97,7 +97,7 @@ public final class LokiGroupChatAPI : NSObject {
             // The challenge is prefixed by the 16 bit IV
             guard let tokenAsData = try? DiffieHellman.decrypt(challenge, publicKey: serverPublicKey, privateKey: userKeyPair.privateKey),
                 let token = String(bytes: tokenAsData, encoding: .utf8) else {
-                throw Error.tokenDecryptionFailed
+                throw Error.decryptionFailed
             }
             return token
         }
@@ -136,7 +136,7 @@ public final class LokiGroupChatAPI : NSObject {
         return TSNetworkManager.shared().makePromise(request: request).map { $0.responseObject }.map { rawResponse in
             guard let json = rawResponse as? JSON, let rawMessages = json["data"] as? [JSON] else {
                 print("[Loki] Couldn't parse messages for group chat with ID: \(group) on server: \(server) from: \(rawResponse).")
-                throw Error.messageParsingFailed
+                throw Error.parsingFailed
             }
             return rawMessages.flatMap { message in
                 guard let annotations = message["annotations"] as? [JSON], let annotation = annotations.first, let value = annotation["value"] as? JSON,
@@ -145,7 +145,6 @@ public final class LokiGroupChatAPI : NSObject {
                         print("[Loki] Couldn't parse message for group chat with ID: \(group) on server: \(server) from: \(message).")
                         return nil
                 }
-                guard hexEncodedPublicKey != userHexEncodedPublicKey else { return nil }
                 let lastMessageServerID = getLastMessageServerID(for: group, on: server)
                 if serverID > (lastMessageServerID ?? 0) { setLastMessageServerID(for: group, on: server, to: serverID) }
                 return LokiGroupMessage(serverID: serverID, hexEncodedPublicKey: hexEncodedPublicKey, displayName: displayName, body: body, type: publicChatMessageType, timestamp: timestamp)
@@ -168,7 +167,7 @@ public final class LokiGroupChatAPI : NSObject {
                 guard let json = rawResponse as? JSON, let messageAsJSON = json["data"] as? JSON, let serverID = messageAsJSON["id"] as? UInt64, let body = messageAsJSON["text"] as? String,
                     let dateAsString = messageAsJSON["created_at"] as? String, let date = dateFormatter.date(from: dateAsString) else {
                     print("[Loki] Couldn't parse message for group chat with ID: \(group) on server: \(server) from: \(rawResponse).")
-                    throw Error.messageParsingFailed
+                    throw Error.parsingFailed
                 }
                 let timestamp = UInt64(date.timeIntervalSince1970) * 1000
                 return LokiGroupMessage(serverID: serverID, hexEncodedPublicKey: userHexEncodedPublicKey, displayName: displayName, body: body, type: publicChatMessageType, timestamp: timestamp)
@@ -195,7 +194,7 @@ public final class LokiGroupChatAPI : NSObject {
         return TSNetworkManager.shared().makePromise(request: request).map { $0.responseObject }.map { rawResponse in
             guard let json = rawResponse as? JSON, let deletions = json["data"] as? [JSON] else {
                 print("[Loki] Couldn't parse deleted messages for group chat with ID: \(group) on server: \(server) from: \(rawResponse).")
-                throw Error.deletionParsingFailed
+                throw Error.parsingFailed
             }
             return deletions.flatMap { deletion in
                 guard let serverID = deletion["id"] as? UInt64, let messageServerID = deletion["message_id"] as? UInt64 else {
@@ -209,6 +208,35 @@ public final class LokiGroupChatAPI : NSObject {
         }
     }
     
+    public static func deleteMessage(with messageID: UInt, for group: UInt64, on server: String, isSentByUser: Bool) -> Promise<Void> {
+        return getAuthToken(for: server).then { token -> Promise<Void> in
+            let isModerationRequest = !isSentByUser
+            print("[Loki] Deleting message with ID: \(messageID) for group chat with ID: \(group) on server: \(server) (isModerationRequest = \(isModerationRequest)).")
+            let urlAsString = isSentByUser ? "\(server)/channels/\(group)/messages/\(messageID)" : "\(server)/loki/v1/moderation/message/\(messageID)"
+            let url = URL(string: urlAsString)!
+            let request = TSRequest(url: url, method: "DELETE", parameters: [:])
+            request.allHTTPHeaderFields = [ "Content-Type" : "application/json", "Authorization" : "Bearer \(token)" ]
+            return TSNetworkManager.shared().makePromise(request: request).done { result -> Void in
+                print("[Loki] Deleted message with ID: \(messageID) on server: \(server).")
+            }
+        }
+    }
+    
+    public static func userHasModerationPermission(for group: UInt64, on server: String) -> Promise<Bool> {
+        return getAuthToken(for: server).then { token -> Promise<Bool> in
+            let url = URL(string: "\(server)/loki/v1/user_info")!
+            let request = TSRequest(url: url)
+            request.allHTTPHeaderFields = [ "Content-Type" : "application/json", "Authorization" : "Bearer \(token)" ]
+            return TSNetworkManager.shared().makePromise(request: request).map { $0.responseObject }.map { rawResponse in
+                guard let json = rawResponse as? JSON, let data = json["data"] as? JSON else {
+                    print("[Loki] Couldn't parse moderation permission for group chat with ID: \(group) on server: \(server) from: \(rawResponse).")
+                    throw Error.parsingFailed
+                }
+                return data["moderator_status"] as? Bool ?? false
+            }
+        }
+    }
+    
     // MARK: Public API (Obj-C)
     @objc(getMessagesForGroup:onServer:)
     public static func objc_getMessages(for group: UInt64, on server: String) -> AnyPromise {
@@ -219,4 +247,9 @@ public final class LokiGroupChatAPI : NSObject {
     public static func objc_sendMessage(_ message: LokiGroupMessage, to group: UInt64, on server: String) -> AnyPromise {
         return AnyPromise.from(sendMessage(message, to: group, on: server))
     }
+    
+    @objc (deleteMessageWithID:forGroup:onServer:isSentByUser:)
+    public static func objc_deleteMessage(with messageID: UInt, for group: UInt64, on server: String, isSentByUser: Bool) -> AnyPromise {
+        return AnyPromise.from(deleteMessage(with: messageID, for: group, on: server, isSentByUser: isSentByUser))
+    }
 }

SignalServiceKit/src/Loki/Crypto/OWSPrimaryStorage+Loki.h

@@ -72,7 +72,7 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)removePreKeyBundleForContact:(NSString *)pubKey transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
-# pragma mark - Last Hash Handling
+# pragma mark - Last Hash
 
 /**
  Get the last message hash for the given service node.
@@ -95,8 +95,12 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)setLastMessageHashForServiceNode:(NSString *)serviceNode hash:(NSString *)hash expiresAt:(u_int64_t)expiresAt transaction:(YapDatabaseReadWriteTransaction *)transaction NS_SWIFT_NAME(setLastMessageHash(forServiceNode:hash:expiresAt:transaction:));
 
+# pragma mark - Group Chat
+
 - (void)setIDForMessageWithServerID:(NSUInteger)serverID to:(NSString *)messageID in:(YapDatabaseReadWriteTransaction *)transaction;
-- (NSString *)getIDForMessageWithServerID:(NSUInteger)serverID in:(YapDatabaseReadTransaction *)transaction;
+- (NSString *_Nullable)getIDForMessageWithServerID:(NSUInteger)serverID in:(YapDatabaseReadTransaction *)transaction;
+- (void)setIsModerator:(BOOL)isModerator forGroup:(NSUInteger)group onServer:(NSString *)server in:(YapDatabaseReadWriteTransaction *)transaction NS_SWIFT_NAME(setIsModerator(_:for:on:in:));
+- (BOOL)isModeratorForGroup:(NSUInteger)group onServer:(NSString *)server in:(YapDatabaseReadTransaction *)transaction NS_SWIFT_NAME(isModerator(for:on:in:));
 
 @end
 

SignalServiceKit/src/Loki/Crypto/OWSPrimaryStorage+Loki.m

@@ -19,6 +19,7 @@
 #define LKReceivedMessageHashesKey @"LKReceivedMessageHashesKey"
 #define LKReceivedMessageHashesCollection @"LKReceivedMessageHashesCollection"
 #define LKMessageIDCollection @"LKMessageIDCollection"
+#define LKModerationPermissionCollection @"LKModerationPermissionCollection"
 
 @implementation OWSPrimaryStorage (Loki)
 
@@ -163,14 +164,26 @@
     [transaction removeObjectForKey:serviceNode inCollection:LKLastMessageHashCollection];
 }
 
+# pragma mark - Group Chat
+
 - (void)setIDForMessageWithServerID:(NSUInteger)serverID to:(NSString *)messageID in:(YapDatabaseReadWriteTransaction *)transaction {
     NSString *key = [NSString stringWithFormat:@"%@", @(serverID)];
     [transaction setObject:messageID forKey:key inCollection:LKMessageIDCollection];
 }
 
-- (NSString *)getIDForMessageWithServerID:(NSUInteger)serverID in:(YapDatabaseReadTransaction *)transaction {
+- (NSString *_Nullable)getIDForMessageWithServerID:(NSUInteger)serverID in:(YapDatabaseReadTransaction *)transaction {
     NSString *key = [NSString stringWithFormat:@"%@", @(serverID)];
     return [transaction objectForKey:key inCollection:LKMessageIDCollection];
 }
 
+- (void)setIsModerator:(BOOL)isModerator forGroup:(NSUInteger)group onServer:(NSString *)server in:(YapDatabaseReadWriteTransaction *)transaction {
+    NSString *key = [NSString stringWithFormat:@"%@.%@", server, @(group)];
+    [transaction setBool:isModerator forKey:key inCollection:LKModerationPermissionCollection];
+}
+
+- (BOOL)isModeratorForGroup:(NSUInteger)group onServer:(NSString *)server in:(YapDatabaseReadTransaction *)transaction NS_SWIFT_NAME(isModerator(for:on:in:)) {
+    NSString *key = [NSString stringWithFormat:@"%@.%@", server, @(group)];
+    return [transaction boolForKey:key inCollection:LKModerationPermissionCollection defaultValue:false];
+}
+
 @end

SignalServiceKit/src/Messages/Interactions/TSMessage.h

@@ -39,14 +39,15 @@ typedef NS_ENUM(NSInteger, LKMessageFriendRequestStatus) {
 @property (nonatomic, readonly, nullable) OWSContact *contactShare;
 @property (nonatomic, readonly, nullable) OWSLinkPreview *linkPreview;
 // Loki friend request handling
-// ========
 @property (nonatomic) LKMessageFriendRequestStatus friendRequestStatus;
 @property (nonatomic, readonly) NSString *friendRequestStatusDescription;
 @property (nonatomic) uint64_t friendRequestExpiresAt;
 @property (nonatomic, readonly) BOOL isFriendRequest;
 @property (nonatomic, readonly) BOOL hasFriendRequestStatusMessage;
 @property (nonatomic) BOOL isP2P;
-// ========
+// Group chat
+@property (nonatomic) uint64_t groupChatMessageID;
+@property (nonatomic, readonly) BOOL isGroupChatMessage;
 
 - (instancetype)initInteractionWithTimestamp:(uint64_t)timestamp inThread:(TSThread *)thread NS_UNAVAILABLE;
 
@@ -92,6 +93,10 @@ typedef NS_ENUM(NSInteger, LKMessageFriendRequestStatus) {
 - (void)saveFriendRequestStatus:(LKMessageFriendRequestStatus)friendRequestStatus withTransaction:(YapDatabaseReadWriteTransaction *_Nullable)transaction;
 - (void)saveFriendRequestExpiresAt:(u_int64_t)expiresAt withTransaction:(YapDatabaseReadWriteTransaction *_Nullable)transaction;
 
+#pragma mark - Group Chat
+
+- (void)saveGroupChatMessageID:(uint64_t)serverMessageID in:(YapDatabaseReadWriteTransaction *_Nullable)transaction;
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Messages/Interactions/TSMessage.m

@@ -84,6 +84,7 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
     _linkPreview = linkPreview;
     _friendRequestStatus = LKMessageFriendRequestStatusNone;
     _friendRequestExpiresAt = 0;
+    _groupChatMessageID = -1;
 
     return self;
 }
@@ -490,6 +491,23 @@ static const NSUInteger OWSMessageSchemaVersion = 4;
     return self.isFriendRequest && self.friendRequestStatus != LKMessageFriendRequestStatusSendingOrFailed;
 }
 
+#pragma mark - Group Chat
+
+- (BOOL) isGroupChatMessage {
+    return self.groupChatMessageID > 0;
+}
+
+- (void)saveGroupChatMessageID:(uint64_t)serverMessageID in:(YapDatabaseReadWriteTransaction *_Nullable)transaction {
+    self.groupChatMessageID = serverMessageID;
+    if (transaction == nil) {
+        [self save];
+        [self.dbReadWriteConnection flushTransactionsWithCompletionQueue:dispatch_get_main_queue() completionBlock:^{}];
+    } else {
+        [self saveWithTransaction:transaction];
+        [transaction.connection flushTransactionsWithCompletionQueue:dispatch_get_main_queue() completionBlock:^{}];
+    }
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

SignalServiceKit/src/Messages/OWSMessageManager.m

@@ -1360,7 +1360,7 @@ NS_ASSUME_NONNULL_BEGIN
                     envelopeAddress(envelope),
                     groupId,
                     (unsigned long)timestamp);
-
+                
                 // Legit usage of senderTimestamp when creating an incoming group message record
                 TSIncomingMessage *incomingMessage =
                     [[TSIncomingMessage alloc] initIncomingMessageWithTimestamp:timestamp
@@ -1377,6 +1377,7 @@ NS_ASSUME_NONNULL_BEGIN
                                                                 wasReceivedByUD:wasReceivedByUD];
                 
                 if (envelope.isPtpMessage) { incomingMessage.isP2P = YES; }
+                if (dataMessage.publicChatInfo && dataMessage.publicChatInfo.hasServerID) { incomingMessage.groupChatMessageID = dataMessage.publicChatInfo.serverID; }
 
                 NSArray<TSAttachmentPointer *> *attachmentPointers =
                     [TSAttachmentPointer attachmentPointersFromProtos:dataMessage.attachments

SignalServiceKit/src/Messages/OWSMessageSender.m

@@ -1117,6 +1117,7 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
         [[LKGroupChatAPI sendMessage:groupMessage toGroup:LKGroupChatAPI.publicChatServerID onServer:LKGroupChatAPI.publicChatServer]
         .thenOn(OWSDispatch.sendingQueue, ^(LKGroupMessage *groupMessage) {
             [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+                [message saveGroupChatMessageID:groupMessage.serverID in:transaction];
                 [OWSPrimaryStorage.sharedManager setIDForMessageWithServerID:groupMessage.serverID to:message.uniqueId in:transaction];
             }];
             [self messageSendDidSucceed:messageSend deviceMessages:deviceMessages wasSentByUD:false wasSentByWebsocket:false];