add comments and minor refactor

SessionMessagingKit/Database/Models/DisappearingMessageConfiguration.swift

@@ -219,6 +219,7 @@ public extension DisappearingMessagesConfiguration {
 // MARK: - UI Constraints
 
 extension DisappearingMessagesConfiguration {
+    // TODO: Remove this when disappearing messages V2 is up and running
     public static var validDurationsSeconds: [TimeInterval] {
         return [
             5,

SessionMessagingKit/Messages/Control Messages/ExpirationTimerUpdate.swift

@@ -4,6 +4,7 @@ import Foundation
 import GRDB
 import SessionUtilitiesKit
 
+// TODO: Refactor this when disappearing messages V2 is up and running
 public final class ExpirationTimerUpdate: ControlMessage {
     private enum CodingKeys: String, CodingKey {
         case syncTarget

SessionMessagingKit/Sending & Receiving/Message Handling/MessageReceiver+ExpirationTimers.swift

@@ -5,6 +5,7 @@ import GRDB
 import SessionUtilitiesKit
 
 extension MessageReceiver {
+    // TODO: Remove this when disappearing messages V2 is up and running
     internal static func handleExpirationTimerUpdate(
         _ db: Database,
         threadId: String,

SessionMessagingKit/Sending & Receiving/MessageSender.swift

@@ -963,8 +963,24 @@ public final class MessageSender {
                         openGroupServerMessageId: message.openGroupServerMessageId.map { Int64($0) }
                     ).update(db)
                     
+                    if interaction.isExpiringMessage {
+                        // Start disappearing messages job after a message is successfully sent.
+                        // For DAR and DAS outgoing messages, the expiration start time are the
+                        // same as message sentTimestamp. So do this once, DAR and DAS messages
+                        // should all be covered.
+                        dependencies.jobRunner.upsert(
+                            db,
+                            job: DisappearingMessagesJob.updateNextRunIfNeeded(
+                                db,
+                                interaction: interaction,
+                                startedAtMs: Double(interaction.timestampMs)
+                            ),
+                            canStartJob: true,
+                            using: dependencies
+                        )
+                        
                         if
-                        interaction.isExpiringMessage && isSyncMessage,
+                            isSyncMessage,
                             let startedAtMs: Double = interaction.expiresStartedAtMs,
                             let expiresInSeconds: TimeInterval = interaction.expiresInSeconds,
                             let serverHash: String = message.serverHash
@@ -985,18 +1001,7 @@ public final class MessageSender {
                                 using: dependencies
                             )
                         }
-                    
-                    dependencies.jobRunner.upsert(
-                        db,
-                        job: DisappearingMessagesJob.updateNextRunIfNeeded(
-                            db,
-                            interaction: interaction,
-                            startedAtMs: Double(interaction.timestampMs)
-                        ),
-                        canStartJob: true,
-                        using: dependencies
-                    )
-                                            
+                    }
                 }
                 
                 // Mark the message as sent