session-ios/SessionMessagingKit/Database/Migrations/_003_YDBToGRDBMigration.swift

// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import Foundation
import AVKit
import GRDB
import YapDatabase
import Curve25519Kit
import SessionUtilitiesKit
import SessionSnodeKit

// Note: Looks like the oldest iOS device we support (min iOS 13.0) has 2Gb of RAM, processing
// ~250k messages and ~1000 threads seems to take up
enum _003_YDBToGRDBMigration: Migration {
    static let target: TargetMigrations.Identifier = .messagingKit
    static let identifier: String = "YDBToGRDBMigration"
    static let needsConfigSync: Bool = true
    static let minExpectedRunDuration: TimeInterval = 20
    
    static func migrate(_ db: Database) throws {
        guard let dbConnection: YapDatabaseConnection = SUKLegacy.newDatabaseConnection() else {
            // We want this setting to be on by default (even if there isn't a legacy database)
            db[.trimOpenGroupMessagesOlderThanSixMonths] = true
            
            SNLog("[Migration Warning] No legacy database, skipping \(target.key(with: self))")
            return
        }
        
        // MARK: - Read from Legacy Database
        
        let timestampNow: TimeInterval = Date().timeIntervalSince1970
        var shouldFailMigration: Bool = false
        var legacyMigrations: Set<SMKLegacy._DBMigration> = []
        var contacts: Set<SMKLegacy._Contact> = []
        var legacyBlockedSessionIds: Set<String> = []
        var validProfileIds: Set<String> = []
        var contactThreadIds: Set<String> = []
        
        var legacyThreadIdToIdMap: [String: String] = [:]
        var legacyThreads: Set<SMKLegacy._Thread> = []
        var disappearingMessagesConfiguration: [String: SMKLegacy._DisappearingMessagesConfiguration] = [:]
        
        var closedGroupKeys: [String: [TimeInterval: SUKLegacy.KeyPair]] = [:]
        var closedGroupName: [String: String] = [:]
        var closedGroupFormation: [String: UInt64] = [:]
        var closedGroupModel: [String: SMKLegacy._GroupModel] = [:]
        var closedGroupZombieMemberIds: [String: Set<String>] = [:]
        
        var openGroupServer: [String: String] = [:]
        var openGroupInfo: [String: SMKLegacy._OpenGroup] = [:]
        var openGroupUserCount: [String: Int64] = [:]
        var openGroupImage: [String: Data] = [:]
        
        var interactions: [String: [SMKLegacy._DBInteraction]] = [:]
        var attachments: [String: SMKLegacy._Attachment] = [:]
        var processedAttachmentIds: Set<String> = []
        var outgoingReadReceiptsTimestampsMs: [String: Set<Int64>] = [:]
        var receivedMessageTimestamps: Set<UInt64> = []
        var receivedCallUUIDs: [String: Set<String>] = [:]
        
        var notifyPushServerJobs: Set<SMKLegacy._NotifyPNServerJob> = []
        var messageReceiveJobs: Set<SMKLegacy._MessageReceiveJob> = []
        var messageSendJobs: Set<SMKLegacy._MessageSendJob> = []
        var attachmentUploadJobs: Set<SMKLegacy._AttachmentUploadJob> = []
        var attachmentDownloadJobs: Set<SMKLegacy._AttachmentDownloadJob> = []
        
        var legacyPreferences: [String: Any] = [:]
        
        // Map the Legacy types for the NSKeyedUnarchivez
        self.mapLegacyTypesForNSKeyedUnarchiver()
        
        dbConnection.read { transaction in
            // MARK: --Migrations
            
            // Process the migrations (we don't want to bother running the old migrations as it would be
            // a waste of time, rather we include the logic from the old migrations in here and make the
            // same changes if the migration hasn't already run)
            transaction.enumerateKeys(inCollection: SMKLegacy.databaseMigrationCollection) { key, _ in
                guard let legacyMigration: SMKLegacy._DBMigration = SMKLegacy._DBMigration(rawValue: key) else {
                    SNLog("[Migration Error] Found unknown migration")
                    shouldFailMigration = true
                    return
                }
                
                legacyMigrations.insert(legacyMigration)
            }
            Storage.update(progress: 0.01, for: self, in: target)
            
            // MARK: --Contacts
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Contacts")
            
            transaction.enumerateRows(inCollection: SMKLegacy.contactCollection) { _, object, _, _ in
                guard let contact = object as? SMKLegacy._Contact else { return }
                
                contacts.insert(contact)
                
                /// Store a record of the all valid profiles (so we can create dummy entries if we need to for closed group members)
                validProfileIds.insert(contact.sessionID)
            }
            
            legacyBlockedSessionIds = Set(transaction.object(
                forKey: SMKLegacy.blockedPhoneNumbersKey,
                inCollection: SMKLegacy.blockListCollection
            ) as? [String] ?? [])
            Storage.update(progress: 0.02, for: self, in: target)
            
            // MARK: --Threads
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Threads")
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.threadCollection) { key, object, _ in
                guard let thread: SMKLegacy._Thread = object as? SMKLegacy._Thread else { return }
                
                legacyThreads.insert(thread)
                
                // Want to exclude threads which aren't visible (ie. threads which we started
                // but the user never ended up sending a message)
                if key.starts(with: SMKLegacy.contactThreadPrefix) && thread.shouldBeVisible {
                    contactThreadIds.insert(key)
                }
             
                // Get the disappearing messages config
                disappearingMessagesConfiguration[thread.uniqueId] = transaction
                    .object(forKey: thread.uniqueId, inCollection: SMKLegacy.disappearingMessagesCollection)
                    .asType(SMKLegacy._DisappearingMessagesConfiguration.self)
                
                // Process group-specific info
                guard let groupThread: SMKLegacy._GroupThread = thread as? SMKLegacy._GroupThread else {
                    legacyThreadIdToIdMap[thread.uniqueId] = thread.uniqueId.substring(
                        from: SMKLegacy.contactThreadPrefix.count
                    )
                    return
                }
                
                if groupThread.isClosedGroup {
                    // The old threadId for closed groups was in the below format, we don't
                    // really need the unnecessary complexity so process the key and extract
                    // the publicKey from it
                    // `g{base64String(Data(__textsecure_group__!{publicKey}))}
                    let base64GroupId: String = String(thread.uniqueId.suffix(from: thread.uniqueId.index(after: thread.uniqueId.startIndex)))
                    guard
                        let groupIdData: Data = Data(base64Encoded: base64GroupId),
                        let groupId: String = String(data: groupIdData, encoding: .utf8),
                        let publicKey: String = groupId.split(separator: "!").last.map({ String($0) })
                    else {
                        SNLog("[Migration Error] Unable to decode Closed Group")
                        shouldFailMigration = true
                        return
                    }
                    
                    legacyThreadIdToIdMap[thread.uniqueId] = publicKey
                    closedGroupName[thread.uniqueId] = groupThread.groupModel.groupName
                    closedGroupModel[thread.uniqueId] = groupThread.groupModel
                    closedGroupFormation[thread.uniqueId] = ((transaction.object(forKey: publicKey, inCollection: SMKLegacy.closedGroupFormationTimestampCollection) as? UInt64) ?? 0)
                    closedGroupZombieMemberIds[thread.uniqueId] = transaction.object(
                        forKey: publicKey,
                        inCollection: SMKLegacy.closedGroupZombieMembersCollection
                    ) as? Set<String>
                    
                    // Note: If the user is no longer in a closed group then the group will still exist but the user
                    // won't have the closed group public key anymore
                    let keyCollection: String = "\(SMKLegacy.closedGroupKeyPairPrefix)\(publicKey)"
                    
                    transaction.enumerateKeysAndObjects(inCollection: keyCollection) { key, object, _ in
                        guard
                            let timestamp: TimeInterval = TimeInterval(key),
                            let keyPair: SUKLegacy.KeyPair = object as? SUKLegacy.KeyPair
                        else { return }
                        
                        closedGroupKeys[thread.uniqueId] = (closedGroupKeys[thread.uniqueId] ?? [:])
                            .setting(timestamp, keyPair)
                    }
                }
                else if groupThread.isOpenGroup {
                    guard let openGroup: SMKLegacy._OpenGroup = transaction.object(forKey: thread.uniqueId, inCollection: SMKLegacy.openGroupCollection) as? SMKLegacy._OpenGroup else {
                        SNLog("[Migration Error] Unable to find open group info")
                        shouldFailMigration = true
                        return
                    }
                    
                    // We want to migrate everyone over to using the domain name for open group
                    // servers rather than the IP, also best to use HTTPS over HTTP where possible
                    // so catch the case where we have the domain with HTTP (the 'defaultServer'
                    // value contains a HTTPS scheme so we get IP HTTP -> HTTPS for free as well)
                    let processedOpenGroupServer: String = {
                        // Check if the server is a Session-run one based on it's
                        guard OpenGroupManager.isSessionRunOpenGroup(server: openGroup.server) else {
                            return openGroup.server
                        }
                        
                        return OpenGroupAPI.defaultServer
                    }()
                    legacyThreadIdToIdMap[thread.uniqueId] = OpenGroup.idFor(
                        roomToken: openGroup.room,
                        server: processedOpenGroupServer
                    )
                    openGroupServer[thread.uniqueId] = processedOpenGroupServer
                    openGroupInfo[thread.uniqueId] = openGroup
                    openGroupUserCount[thread.uniqueId] = ((transaction.object(forKey: openGroup.id, inCollection: SMKLegacy.openGroupUserCountCollection) as? Int64) ?? 0)
                    openGroupImage[thread.uniqueId] = transaction.object(forKey: openGroup.id, inCollection: SMKLegacy.openGroupImageCollection) as? Data
                }
            }
            Storage.update(progress: 0.04, for: self, in: target)
            
            // MARK: --Interactions
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Interactions")
            
            /// **Note:** There is no index on the collection column so unfortunately it takes the same amount of time to enumerate through all
            /// collections as it does to just get the count of collections, due to this, if the database is very large, importing thecollections can be
            /// very slow (~15s with 2,000,000 rows) - we want to show some kind of progress while enumerating so the below code creates a
            /// very rought guess of the number of collections based on the file size of the database (this shouldn't affect most users at all)
            let roughKbPerRow: CGFloat = 2.25
            let oldDatabaseSizeBytes: CGFloat = (try? FileManager.default
                .attributesOfItem(atPath: SUKLegacy.legacyDatabaseFilepath)[.size]
                .asType(CGFloat.self))
                .defaulting(to: 0)
            let roughNumRows: CGFloat = ((oldDatabaseSizeBytes / 1024) / roughKbPerRow)
            let startProgress: CGFloat = 0.04
            let interactionsCompleteProgress: CGFloat = 0.19
            var rowIndex: CGFloat = 0
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.interactionCollection) { _, object, _ in
                guard let interaction: SMKLegacy._DBInteraction = object as? SMKLegacy._DBInteraction else {
                    SNLog("[Migration Error] Unable to process interaction")
                    shouldFailMigration = true
                    return
                }
                
                /// Prune interactions from OpenGroup thread interactions which are older than 6 months
                ///
                /// The old structure for the open group id was `g{base64String(Data(__loki_public_chat_group__!{server.room}))}
                /// so we process the uniqueThreadId to see if it matches that
                if
                    interaction.uniqueThreadId.starts(with: SMKLegacy.groupThreadPrefix),
                    let base64Data: Data = Data(base64Encoded: interaction.uniqueThreadId.substring(from: SMKLegacy.groupThreadPrefix.count)),
                    let groupIdString: String = String(data: base64Data, encoding: .utf8),
                    (
                        groupIdString.starts(with: SMKLegacy.openGroupIdPrefix) ||
                        groupIdString.starts(with: "http")
                    ),
                    interaction.timestamp < UInt64(floor((timestampNow - GarbageCollectionJob.approxSixMonthsInSeconds) * 1000))
                {
                    return
                }
                
                interactions[interaction.uniqueThreadId] = (interactions[interaction.uniqueThreadId] ?? [])
                    .appending(interaction)
                
                rowIndex += 1
                
                Storage.update(
                    progress: min(
                        interactionsCompleteProgress,
                        ((rowIndex / roughNumRows) * (interactionsCompleteProgress - startProgress))
                    ),
                    for: self,
                    in: target
                )
            }
            Storage.update(progress: interactionsCompleteProgress, for: self, in: target)
            
            // MARK: --Attachments
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Attachments")
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.attachmentsCollection) { key, object, _ in
                guard let attachment: SMKLegacy._Attachment = object as? SMKLegacy._Attachment else {
                    SNLog("[Migration Error] Unable to process attachment")
                    shouldFailMigration = true
                    return
                }
                
                attachments[key] = attachment
            }
            Storage.update(progress: 0.21, for: self, in: target)
            
            // MARK: --Read Receipts
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.outgoingReadReceiptManagerCollection) { key, object, _ in
                guard let timestampsMs: Set<Int64> = object as? Set<Int64> else { return }
                
                outgoingReadReceiptsTimestampsMs[key] = (outgoingReadReceiptsTimestampsMs[key] ?? Set())
                    .union(timestampsMs)
            }
            
            // MARK: --De-duping
            
            receivedMessageTimestamps = receivedMessageTimestamps.inserting(
                contentsOf: transaction
                    .object(
                        forKey: SMKLegacy.receivedMessageTimestampsKey,
                        inCollection: SMKLegacy.receivedMessageTimestampsCollection
                    )
                    .asType([UInt64].self)
                    .defaulting(to: [])
                    .asSet()
            )
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.receivedCallsCollection) { key, object, _ in
                guard let uuids: Set<String> = object as? Set<String> else { return }
                
                receivedCallUUIDs[key] = (receivedCallUUIDs[key] ?? Set())
                    .union(uuids)
            }
            
            // MARK: --Jobs
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Jobs")
            
            transaction.enumerateRows(inCollection: SMKLegacy.notifyPushServerJobCollection) { _, object, _, _ in
                guard let job = object as? SMKLegacy._NotifyPNServerJob else { return }
                notifyPushServerJobs.insert(job)
            }
            
            transaction.enumerateRows(inCollection: SMKLegacy.messageReceiveJobCollection) { _, object, _, _ in
                guard let job = object as? SMKLegacy._MessageReceiveJob else { return }
                messageReceiveJobs.insert(job)
            }
            
            transaction.enumerateRows(inCollection: SMKLegacy.messageSendJobCollection) { _, object, _, _ in
                guard let job = object as? SMKLegacy._MessageSendJob else { return }
                messageSendJobs.insert(job)
            }
            
            transaction.enumerateRows(inCollection: SMKLegacy.attachmentUploadJobCollection) { _, object, _, _ in
                guard let job = object as? SMKLegacy._AttachmentUploadJob else { return }
                attachmentUploadJobs.insert(job)
            }
            
            transaction.enumerateRows(inCollection: SMKLegacy.attachmentDownloadJobCollection) { _, object, _, _ in
                guard let job = object as? SMKLegacy._AttachmentDownloadJob else { return }
                attachmentDownloadJobs.insert(job)
            }
            Storage.update(progress: 0.22, for: self, in: target)
            
            // MARK: --Preferences
            
            SNLog("[Migration Info] \(target.key(with: self)) - Processing Preferences")
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.preferencesCollection) { key, object, _ in
                legacyPreferences[key] = object
            }
            
            transaction.enumerateKeysAndObjects(inCollection: SMKLegacy.additionalPreferencesCollection) { key, object, _ in
                legacyPreferences[key] = object
            }
            
            // Note: The 'int(forKey:inCollection:)' defaults to `0` which is an incorrect value
            // for the notification sound so catch it and default
            legacyPreferences[SMKLegacy.soundsGlobalNotificationKey] = (transaction
                .object(
                    forKey: SMKLegacy.soundsGlobalNotificationKey,
                    inCollection: SMKLegacy.soundsStorageNotificationCollection
                )
                .asType(NSNumber.self)?
                .intValue)
                .defaulting(to: Preferences.Sound.defaultNotificationSound.rawValue)
            
            legacyPreferences[SMKLegacy.readReceiptManagerAreReadReceiptsEnabled] = (transaction
                .object(
                    forKey: SMKLegacy.readReceiptManagerAreReadReceiptsEnabled,
                    inCollection: SMKLegacy.readReceiptManagerCollection
                )
                .asType(NSNumber.self)?
                .boolValue)
                .defaulting(to: false)
            
            legacyPreferences[SMKLegacy.typingIndicatorsEnabledKey] = (transaction
                .object(
                    forKey: SMKLegacy.typingIndicatorsEnabledKey,
                    inCollection: SMKLegacy.typingIndicatorsCollection
                )
                .asType(NSNumber.self)?
                .boolValue)
                .defaulting(to: false)
            
            legacyPreferences[SMKLegacy.screenLockIsScreenLockEnabledKey] = (transaction
                .object(
                    forKey: SMKLegacy.screenLockIsScreenLockEnabledKey,
                    inCollection: SMKLegacy.screenLockCollection
                )
                .asType(NSNumber.self)?
                .boolValue)
                .defaulting(to: false)
            
            legacyPreferences[SMKLegacy.screenLockScreenLockTimeoutSecondsKey] = (transaction
                .object(
                    forKey: SMKLegacy.screenLockScreenLockTimeoutSecondsKey,
                    inCollection: SMKLegacy.screenLockCollection)
                .asType(NSNumber.self)?
                .doubleValue)
                .defaulting(to: (15 * 60))
            Storage.update(progress: 0.23, for: self, in: target)
        }
        
        // We can't properly throw within the 'enumerateKeysAndObjects' block so have to throw here
        guard !shouldFailMigration else { throw StorageError.migrationFailed }
        
        // Insert the data into GRDB
        
        let currentUserPublicKey: String = getUserHexEncodedPublicKey(db)
        
        // MARK: - Insert Contacts
        
        SNLog("[Migration Info] \(target.key(with: self)) - Inserting Contacts")
        
        try autoreleasepool {
            // Values for contact progress
            let contactStartProgress: CGFloat = 0.23
            let progressPerContact: CGFloat = (0.05 / CGFloat(contacts.count))
            
            try contacts.enumerated().forEach { index, legacyContact in
                let isCurrentUser: Bool = (legacyContact.sessionID == currentUserPublicKey)
                let contactThreadId: String = SMKLegacy._ContactThread.threadId(from: legacyContact.sessionID)
                
                // Create the "Profile" for the legacy contact
                try Profile(
                    id: legacyContact.sessionID,
                    name: (legacyContact.name ?? legacyContact.sessionID),
                    nickname: legacyContact.nickname,
                    profilePictureUrl: legacyContact.profilePictureURL,
                    profilePictureFileName: legacyContact.profilePictureFileName,
                    profileEncryptionKey: legacyContact.profileEncryptionKey
                ).migrationSafeInsert(db)
                
                /// **Note:** The blow "shouldForce" flags are here to allow us to avoid having to run legacy migrations they
                /// replicate the behaviour of a number of the migrations and perform the changes if the migrations had never run
                
                /// `ContactsMigration` - Marked all existing contacts as trusted
                let shouldForceTrustContact: Bool = (!legacyMigrations.contains(.contactsMigration))
                
                /// `MessageRequestsMigration` - Marked all existing contacts as isApproved and didApproveMe
                let shouldForceApproveContact: Bool = (!legacyMigrations.contains(.messageRequestsMigration))
                
                /// `BlockingManagerRemovalMigration` - Removed the old blocking manager and updated contacts isBlocked flag accordingly
                let shouldForceBlockContact: Bool = (
                    !legacyMigrations.contains(.messageRequestsMigration) &&
                    legacyBlockedSessionIds.contains(legacyContact.sessionID)
                )
                
                /// Looks like there are some cases where conversations would be visible in the old version but wouldn't in the new version
                /// it seems to be related to the `isApproved` and `didApproveMe` not being set correctly somehow, this logic is to
                /// ensure the flags are set correctly based on sent/received messages
                let interactionsForContact: [SMKLegacy._DBInteraction] = (interactions["\(SMKLegacy.contactThreadPrefix)\(legacyContact.sessionID)"] ?? [])
                let shouldForceIsApproved: Bool = interactionsForContact
                    .contains(where: { $0 is SMKLegacy._DBOutgoingMessage })
                let shouldForceDidApproveMe: Bool = interactionsForContact
                    .contains(where: { $0 is SMKLegacy._DBIncomingMessage })
                
                // Determine if this contact is a "real" contact (don't want to create contacts for
                // every user in the new structure but still want profiles for every user)
                if
                    isCurrentUser ||
                    contactThreadIds.contains(contactThreadId) ||
                    legacyContact.isApproved ||
                    legacyContact.didApproveMe ||
                    legacyContact.isBlocked ||
                    legacyContact.hasBeenBlocked ||
                    shouldForceTrustContact ||
                    shouldForceApproveContact ||
                    shouldForceBlockContact ||
                    shouldForceIsApproved ||
                    shouldForceDidApproveMe
                {
                    // Create the contact
                    try Contact(
                        id: legacyContact.sessionID,
                        isTrusted: (
                            isCurrentUser ||
                            legacyContact.isTrusted ||
                            shouldForceTrustContact
                        ),
                        isApproved: (
                            isCurrentUser ||
                            legacyContact.isApproved ||
                            shouldForceApproveContact ||
                            shouldForceIsApproved
                        ),
                        isBlocked: (
                            !isCurrentUser && (
                                legacyContact.isBlocked ||
                                shouldForceBlockContact
                            )
                        ),
                        didApproveMe: (
                            isCurrentUser ||
                            legacyContact.didApproveMe ||
                            shouldForceApproveContact ||
                            shouldForceDidApproveMe
                        ),
                        hasBeenBlocked: (!isCurrentUser && (legacyContact.hasBeenBlocked || legacyContact.isBlocked))
                    ).migrationSafeInsert(db)
                }
                
                // Increment the progress for each contact
                Storage.update(
                    progress: contactStartProgress + (progressPerContact * CGFloat(index + 1)),
                    for: self,
                    in: target
                )
            }
        }
        
        // Clear out processed data (give the memory a change to be freed)
        contacts = []
        legacyBlockedSessionIds = []
        contactThreadIds = []
        
        // MARK: - Insert Threads
        
        SNLog("[Migration Info] \(target.key(with: self)) - Inserting Threads & Interactions")
        
        var legacyInteractionToIdMap: [String: Int64] = [:]
        var legacyInteractionIdentifierToIdMap: [String: Int64] = [:]
        var legacyInteractionIdentifierToIdFallbackMap: [String: Int64] = [:]
        
        func identifier(
            for threadId: String,
            sentTimestamp: UInt64,
            recipients: [String],
            destination: Message.Destination?,
            variant: Interaction.Variant?,
            useFallback: Bool
        ) -> String {
            let recipientString: String = {
                if let destination: Message.Destination = destination {
                    switch destination {
                        case .contact(let publicKey): return publicKey
                        default: break
                    }
                }
                
                return (recipients.first ?? "0")
            }()
            
            return [
                (useFallback ?
                    // Fallback to seconds-based accuracy (instead of milliseconds)
                    String("\(sentTimestamp)".prefix("\(Int(Date().timeIntervalSince1970))".count)) :
                    "\(sentTimestamp)"
                ),
                (useFallback ? variant.map { "\($0)" } : nil),
                recipientString,
                threadId
            ]
            .compactMap { $0 }
            .joined(separator: "-")
        }
        
        // Values for thread progress
        var interactionCounter: CGFloat = 0
        let allInteractionsCount: Int = interactions.map { $0.value.count }.reduce(0, +)
        let threadInteractionsStartProgress: CGFloat = 0.28
        let progressPerInteraction: CGFloat = (0.70 / CGFloat(allInteractionsCount))
        
        // Sort by id just so we can make the migration process more determinstic
        try legacyThreads.sorted(by: { lhs, rhs in lhs.uniqueId < rhs.uniqueId }).forEach { legacyThread in
            guard let threadId: String = legacyThreadIdToIdMap[legacyThread.uniqueId] else {
                SNLog("[Migration Error] Unable to migrate thread with no id mapping")
                throw StorageError.migrationFailed
            }
            
            let threadVariant: SessionThread.Variant
            let onlyNotifyForMentions: Bool
            
            switch legacyThread {
                case let groupThread as SMKLegacy._GroupThread:
                    threadVariant = (groupThread.isOpenGroup ? .openGroup : .closedGroup)
                    onlyNotifyForMentions = groupThread.isOnlyNotifyingForMentions
                    
                default:
                    threadVariant = .contact
                    onlyNotifyForMentions = false
            }
            
            try autoreleasepool {
                try SessionThread(
                    id: threadId,
                    variant: threadVariant,
                    creationDateTimestamp: legacyThread.creationDate.timeIntervalSince1970,
                    shouldBeVisible: legacyThread.shouldBeVisible,
                    isPinned: legacyThread.isPinned,
                    messageDraft: ((legacyThread.messageDraft ?? "").isEmpty ?
                        nil :
                        legacyThread.messageDraft
                    ),
                    mutedUntilTimestamp: legacyThread.mutedUntilDate?.timeIntervalSince1970,
                    onlyNotifyForMentions: onlyNotifyForMentions
                ).migrationSafeInsert(db)
                
                // Disappearing Messages Configuration
                if let config: SMKLegacy._DisappearingMessagesConfiguration = disappearingMessagesConfiguration[threadId] {
                    try DisappearingMessagesConfiguration(
                        threadId: threadId,
                        isEnabled: config.isEnabled,
                        durationSeconds: TimeInterval(config.durationSeconds)
                    ).migrationSafeInsert(db)
                }
                else {
                    try DisappearingMessagesConfiguration
                        .defaultWith(threadId)
                        .migrationSafeInsert(db)
                }
                
                // Closed Groups
                if legacyThread.isClosedGroup {
                    guard
                        let name: String = closedGroupName[legacyThread.uniqueId],
                        let groupModel: SMKLegacy._GroupModel = closedGroupModel[legacyThread.uniqueId],
                        let formationTimestamp: UInt64 = closedGroupFormation[legacyThread.uniqueId]
                    else {
                        SNLog("[Migration Error] Closed group missing required data")
                        throw StorageError.migrationFailed
                    }
                    
                    try ClosedGroup(
                        threadId: threadId,
                        name: name,
                        formationTimestamp: TimeInterval(formationTimestamp)
                    ).migrationSafeInsert(db)
                    
                    // Note: If a user has left a closed group then they won't actually have any keys
                    // but they should still be able to browse the old messages so we do want to allow
                    // this case and migrate the rest of the info
                    try closedGroupKeys[legacyThread.uniqueId]?.forEach { timestamp, legacyKeys in
                        try ClosedGroupKeyPair(
                            threadId: threadId,
                            publicKey: legacyKeys.publicKey,
                            secretKey: legacyKeys.privateKey,
                            receivedTimestamp: timestamp
                        ).migrationSafeInsert(db)
                    }
                    
                    // Create the 'GroupMember' models for the group (even if the current user is no longer
                    // a member as these objects are used to generate the group avatar icon)
                    func createDummyProfile(profileId: String) {
                        SNLog("[Migration Warning] Closed group member with unknown user found - Creating empty profile")
                        
                        // Note: Need to upsert here because it's possible multiple quotes
                        // will use the same invalid 'authorId' value resulting in a unique
                        // constraint violation
                        try? Profile(
                            id: profileId,
                            name: profileId
                        ).migrationSafeSave(db)
                    }
                    
                    try groupModel.groupMemberIds.forEach { memberId in
                        try GroupMember(
                            groupId: threadId,
                            profileId: memberId,
                            role: .standard,
                            isHidden: false // Ignored: Didn't exist at time of migration
                        ).migrationSafeInsert(db)
                        
                        if !validProfileIds.contains(memberId) {
                            createDummyProfile(profileId: memberId)
                        }
                    }
                    
                    try groupModel.groupAdminIds.forEach { adminId in
                        try GroupMember(
                            groupId: threadId,
                            profileId: adminId,
                            role: .admin,
                            isHidden: false // Ignored: Didn't exist at time of migration
                        ).migrationSafeInsert(db)
                        
                        if !validProfileIds.contains(adminId) {
                            createDummyProfile(profileId: adminId)
                        }
                    }
                    
                    try (closedGroupZombieMemberIds[legacyThread.uniqueId] ?? []).forEach { zombieId in
                        try GroupMember(
                            groupId: threadId,
                            profileId: zombieId,
                            role: .zombie,
                            isHidden: false // Ignored: Didn't exist at time of migration
                        ).migrationSafeInsert(db)
                        
                        if !validProfileIds.contains(zombieId) {
                            createDummyProfile(profileId: zombieId)
                        }
                    }
                }
                
                // Open Groups
                if legacyThread.isOpenGroup {
                    guard
                        let openGroup: SMKLegacy._OpenGroup = openGroupInfo[legacyThread.uniqueId],
                        let targetOpenGroupServer: String = openGroupServer[legacyThread.uniqueId]
                    else {
                        SNLog("[Migration Error] Open group missing required data")
                        throw StorageError.migrationFailed
                    }
                    
                    try OpenGroup(
                        server: targetOpenGroupServer,
                        roomToken: openGroup.room,
                        publicKey: openGroup.publicKey,
                        isActive: true,
                        name: openGroup.name,
                        roomDescription: nil,
                        imageId: openGroup.imageID,
                        imageData: openGroupImage[legacyThread.uniqueId],
                        userCount: (openGroupUserCount[legacyThread.uniqueId] ?? 0),  // Will be updated next poll
                        infoUpdates: 0,
                        sequenceNumber: 0,
                        inboxLatestMessageId: 0,
                        outboxLatestMessageId: 0
                    )
                    .migrationSafeInsert(db)
                }
            }
            
            try autoreleasepool {
                try interactions[legacyThread.uniqueId]?
                    .sorted(by: { lhs, rhs in lhs.timestamp < rhs.timestamp }) // Maintain sort order
                    .forEach { legacyInteraction in
                        let serverHash: String?
                        let variant: Interaction.Variant
                        let authorId: String
                        let body: String?
                        let wasRead: Bool
                        let expiresInSeconds: UInt32?
                        let expiresStartedAtMs: UInt64?
                        let openGroupServerMessageId: Int64?
                        let recipientStateMap: [String: SMKLegacy._DBOutgoingMessageRecipientState]?
                        let mostRecentFailureText: String?
                        let quotedMessage: SMKLegacy._DBQuotedMessage?
                        let linkPreview: SMKLegacy._DBLinkPreview?
                        let linkPreviewVariant: LinkPreview.Variant
                        var attachmentIds: [String]
                        
                        // Handle the common 'SMKLegacy._DBMessage' values first
                        if let legacyMessage: SMKLegacy._DBMessage = legacyInteraction as? SMKLegacy._DBMessage {
                            serverHash = legacyMessage.serverHash
                            
                            // The legacy code only considered '!= 0' ids as valid so set those
                            // values to be null to avoid the unique constraint (it's also more
                            // correct for the values to be null)
                            //
                            // Note: Looks like it was also possible for this to be set to the max
                            // value which overflows when trying to convert to a signed version so
                            // we essentially discard the information in those cases)
                            openGroupServerMessageId = (Int64.zeroingOverflow(legacyMessage.openGroupServerMessageID) == 0 ?
                                nil :
                                Int64.zeroingOverflow(legacyMessage.openGroupServerMessageID)
                            )
                            quotedMessage = legacyMessage.quotedMessage
                            
                            // Convert the 'OpenGroupInvitation' into a LinkPreview
                            if let openGroupInvitationName: String = legacyMessage.openGroupInvitationName, let openGroupInvitationUrl: String = legacyMessage.openGroupInvitationURL {
                                linkPreviewVariant = .openGroupInvitation
                                linkPreview = SMKLegacy._DBLinkPreview(
                                    urlString: openGroupInvitationUrl,
                                    title: openGroupInvitationName,
                                    imageAttachmentId: nil
                                )
                            }
                            else {
                                linkPreviewVariant = .standard
                                linkPreview = legacyMessage.linkPreview
                            }
                            
                            // Attachments for deleted messages won't exist
                            attachmentIds = (legacyMessage.isDeleted ?
                                [] :
                                legacyMessage.attachmentIds
                            )
                        }
                        else {
                            serverHash = nil
                            openGroupServerMessageId = nil
                            quotedMessage = nil
                            linkPreviewVariant = .standard
                            linkPreview = nil
                            attachmentIds = []
                        }
                        
                        // Then handle the behaviours for each message type
                        switch legacyInteraction {
                            case let incomingMessage as SMKLegacy._DBIncomingMessage:
                                // Note: We want to distinguish deleted messages from normal ones
                                variant = (incomingMessage.isDeleted ?
                                    .standardIncomingDeleted :
                                    .standardIncoming
                                )
                                authorId = incomingMessage.authorId
                                body = incomingMessage.body
                                wasRead = incomingMessage.wasRead
                                expiresInSeconds = incomingMessage.expiresInSeconds
                                expiresStartedAtMs = incomingMessage.expireStartedAt
                                recipientStateMap = [:]
                                mostRecentFailureText = nil
                                
                            case let outgoingMessage as SMKLegacy._DBOutgoingMessage:
                                variant = .standardOutgoing
                                authorId = currentUserPublicKey
                                body = outgoingMessage.body
                                wasRead = true // Outgoing messages are read by default
                                expiresInSeconds = outgoingMessage.expiresInSeconds
                                expiresStartedAtMs = outgoingMessage.expireStartedAt
                                recipientStateMap = outgoingMessage.recipientStateMap
                                mostRecentFailureText = outgoingMessage.mostRecentFailureText
                                
                            case let infoMessage as SMKLegacy._DBInfoMessage:
                                // Note: The legacy 'TSInfoMessage' didn't store the author id so there is no
                                // way to determine who actually triggered the info message
                                authorId = currentUserPublicKey
                                body = {
                                    // Note: Some message types stored additional info and constructed a string
                                    // at display time, instead we encode the data into the body of the message
                                    // as JSON so we want to continue that behaviour but not change the database
                                    // structure for some edge cases
                                    switch infoMessage.messageType {
                                        case .disappearingMessagesUpdate:
                                            guard
                                                let updateMessage: SMKLegacy._DisappearingConfigurationUpdateInfoMessage = infoMessage as? SMKLegacy._DisappearingConfigurationUpdateInfoMessage,
                                                let infoMessageData: Data = try? JSONEncoder().encode(
                                                    DisappearingMessagesConfiguration.MessageInfo(
                                                        senderName: updateMessage.createdByRemoteName,
                                                        isEnabled: updateMessage.configurationIsEnabled,
                                                        durationSeconds: TimeInterval(updateMessage.configurationDurationSeconds)
                                                    )
                                                ),
                                                let infoMessageString: String = String(data: infoMessageData, encoding: .utf8)
                                            else { break }
                                            
                                            return infoMessageString
                                            
                                        case .call:
                                            let messageInfo: CallMessage.MessageInfo = CallMessage.MessageInfo(
                                                state: {
                                                    switch infoMessage.callState {
                                                        case .incoming: return .incoming
                                                        case .outgoing: return .outgoing
                                                        case .missed: return .missed
                                                        case .permissionDenied: return .permissionDenied
                                                        case .unknown: return .unknown
                                                    }
                                                }()
                                            )
                                            
                                            guard
                                                let messageInfoData: Data = try? JSONEncoder().encode(messageInfo),
                                                let messageInfoDataString: String = String(data: messageInfoData, encoding: .utf8)
                                            else { break }
                                            
                                            return messageInfoDataString
                                            
                                        default: break
                                    }
                                    
                                    return ((infoMessage.body ?? "").isEmpty ?
                                        infoMessage.customMessage :
                                        infoMessage.body
                                    )
                                }()
                                wasRead = infoMessage.wasRead
                                expiresInSeconds = nil    // Info messages don't expire
                                expiresStartedAtMs = nil  // Info messages don't expire
                                recipientStateMap = [:]
                                mostRecentFailureText = nil
                                
                                switch infoMessage.messageType {
                                    case .groupCreated: variant = .infoClosedGroupCreated
                                    case .groupUpdated: variant = .infoClosedGroupUpdated
                                    case .groupCurrentUserLeft: variant = .infoClosedGroupCurrentUserLeft
                                    case .disappearingMessagesUpdate: variant = .infoDisappearingMessagesUpdate
                                    case .screenshotNotification: variant = .infoScreenshotNotification
                                    case .mediaSavedNotification: variant = .infoMediaSavedNotification
                                    case .call: variant = .infoCall
                                    case .messageRequestAccepted: variant = .infoMessageRequestAccepted
                                }
                                
                            default:
                                SNLog("[Migration Error] Unsupported interaction type")
                                throw StorageError.migrationFailed
                        }
                        
                        // Insert the data
                        let interaction: Interaction
                        
                        do {
                            interaction = try Interaction(
                                serverHash: {
                                    switch variant {
                                        // Don't store the 'serverHash' for these so sync messages
                                        // are seen as duplicates
                                        case .infoDisappearingMessagesUpdate: return nil
                                            
                                        default: return serverHash
                                    }
                                }(),
                                messageUuid: {
                                    guard variant == .infoCall else { return nil }
                                    
                                    /// **Note:** Unfortunately there is no good way to properly match this UUID up with the correct
                                    /// interaction (and it was previously stored as a Set so the values will be unsorted anyway); luckily
                                    /// we are only using this value for updating and de-duping purposes at this stage so it _shouldn't_
                                    /// matter if the values end up being assigned to the wrong interactions, we do still want to try and
                                    /// store each value through so mutate the list as we process each UUID
                                    ///
                                    /// **Note:** It looks like these values were stored against the sessionId rather than the legacy
                                    /// thread unique id
                                    return receivedCallUUIDs[threadId]?.popFirst()
                                }(),
                                threadId: threadId,
                                authorId: authorId,
                                variant: variant,
                                body: body,
                                timestampMs: Int64.zeroingOverflow(legacyInteraction.timestamp),
                                receivedAtTimestampMs: Int64.zeroingOverflow(legacyInteraction.receivedAtTimestamp),
                                wasRead: wasRead,
                                hasMention: Interaction.isUserMentioned(
                                    db,
                                    threadId: threadId,
                                    body: body,
                                    quoteAuthorId: quotedMessage?.authorId
                                ),
                                // For both of these '0' used to be equivalent to null
                                expiresInSeconds: ((expiresInSeconds ?? 0) > 0 ?
                                    expiresInSeconds.map { TimeInterval($0) } :
                                    nil
                                ),
                                expiresStartedAtMs: ((expiresStartedAtMs ?? 0) > 0 ?
                                    expiresStartedAtMs.map { Double($0) } :
                                    nil
                                ),
                                linkPreviewUrl: linkPreview?.urlString, // Only a soft link so save to set
                                openGroupServerMessageId: openGroupServerMessageId,
                                openGroupWhisperMods: false,
                                openGroupWhisperTo: nil
                            ).migrationSafeInserted(db)
                        }
                        catch {
                            switch error {
                                // Ignore duplicate interactions
                                case DatabaseError.SQLITE_CONSTRAINT_UNIQUE:
                                    SNLog("[Migration Warning] Found duplicate message of variant: \(variant); skipping")
                                    return
                                
                                default:
                                    SNLog("[Migration Error] Failed to insert interaction")
                                    throw StorageError.migrationFailed
                            }
                        }
                        
                        // Insert a 'ControlMessageProcessRecord' if needed (for duplication prevention)
                        try ControlMessageProcessRecord(
                            threadId: threadId,
                            variant: variant,
                            timestampMs: Int64.zeroingOverflow(legacyInteraction.timestamp)
                        )?.migrationSafeInsert(db)
                        
                        // Remove timestamps we created records for (they will be protected by unique
                        // constraints so don't need legacy process records)
                        receivedMessageTimestamps.remove(legacyInteraction.timestamp)
                        
                        guard let interactionId: Int64 = interaction.id else {
                            SNLog("[Migration Error] Failed to insert interaction")
                            throw StorageError.migrationFailed
                        }
                        
                        // Store the interactionId in the lookup map to simplify job creation later
                        let legacyIdentifier: String = identifier(
                            for: threadId,
                            sentTimestamp: legacyInteraction.timestamp,
                            recipients: ((legacyInteraction as? SMKLegacy._DBOutgoingMessage)?
                                .recipientStateMap?
                                .keys
                                .map { $0 })
                                .defaulting(to: []),
                            destination: (threadVariant == .contact ? .contact(publicKey: threadId) : nil),
                            variant: variant,
                            useFallback: false
                        )
                        let legacyIdentifierFallback: String = identifier(
                            for: threadId,
                            sentTimestamp: legacyInteraction.timestamp,
                            recipients: ((legacyInteraction as? SMKLegacy._DBOutgoingMessage)?
                                .recipientStateMap?
                                .keys
                                .map { $0 })
                                .defaulting(to: []),
                            destination: (threadVariant == .contact ? .contact(publicKey: threadId) : nil),
                            variant: variant,
                            useFallback: true
                        )
                        
                        legacyInteractionToIdMap[legacyInteraction.uniqueId] = interactionId
                        legacyInteractionIdentifierToIdMap[legacyIdentifier] = interactionId
                        legacyInteractionIdentifierToIdFallbackMap[legacyIdentifierFallback] = interactionId
                        
                        // Handle the recipient states
                        
                        // Note: Inserting an Interaction into the database will automatically create a 'RecipientState'
                        // for outgoing messages
                        try recipientStateMap?.forEach { recipientId, legacyState in
                            try RecipientState(
                                interactionId: interactionId,
                                recipientId: recipientId,
                                state: {
                                    switch legacyState.state {
                                        case .failed: return .failed
                                        case .sending: return .sending
                                        case .skipped: return .skipped
                                        case .sent: return .sent
                                    }
                                }(),
                                readTimestampMs: legacyState.readTimestamp,
                                mostRecentFailureText: (legacyState.state == .failed ?
                                    mostRecentFailureText :
                                    nil
                                )
                            ).migrationSafeSave(db)
                        }
                        
                        // Handle any quote
                        
                        if let quotedMessage: SMKLegacy._DBQuotedMessage = quotedMessage {
                            var quoteAttachmentId: String? = quotedMessage.quotedAttachments
                                .flatMap { attachmentInfo in
                                    return [
                                        // Prioritise the thumbnail as it means we won't
                                        // need to generate a new one
                                        attachmentInfo.thumbnailAttachmentStreamId,
                                        attachmentInfo.thumbnailAttachmentPointerId,
                                        attachmentInfo.attachmentId
                                    ]
                                    .compactMap { $0 }
                                }
                                .first { attachmentId -> Bool in attachments[attachmentId] != nil }
                            
                            // It looks like there can be cases where a quote can be quoting an
                            // interaction that isn't associated with a profile we know about (eg.
                            // if you join an open group and one of the first messages is a quote of
                            // an older message not cached to the device) - this will cause a foreign
                            // key constraint violation so in these cases just create an empty profile
                            if !validProfileIds.contains(quotedMessage.authorId) {
                                SNLog("[Migration Warning] Quote with unknown author found - Creating empty profile")
                                
                                // Note: Need to upsert here because it's possible multiple quotes
                                // will use the same invalid 'authorId' value resulting in a unique
                                // constraint violation
                                try Profile(
                                    id: quotedMessage.authorId,
                                    name: quotedMessage.authorId
                                ).migrationSafeSave(db)
                            }
                            
                            // Note: It looks like there is a way for a quote to not have it's
                            // associated attachmentId so let's try our best to track down the
                            // original interaction and re-create the attachment link before
                            // falling back to having no attachment in the quote
                            if quoteAttachmentId == nil && !quotedMessage.quotedAttachments.isEmpty {
                                quoteAttachmentId = interactions[legacyThread.uniqueId]?
                                    .first(where: {
                                        $0.timestamp == quotedMessage.timestamp &&
                                        (
                                            // Outgoing messages don't store the 'authorId' so we
                                            // need to compare against the 'currentUserPublicKey'
                                            // for those or cast to a TSIncomingMessage otherwise
                                            quotedMessage.authorId == currentUserPublicKey ||
                                            quotedMessage.authorId == ($0 as? SMKLegacy._DBIncomingMessage)?.authorId
                                        )
                                    })
                                    .asType(SMKLegacy._DBMessage.self)?
                                    .attachmentIds
                                    .first
                                
                                SNLog([
                                    "[Migration Warning] Quote with invalid attachmentId found",
                                    (quoteAttachmentId == nil ?
                                        "Unable to reconcile, leaving attachment blank" :
                                        "Original interaction found, using source attachment"
                                    )
                                ].joined(separator: " - "))
                            }
                            
                            // Setup the attachment and add it to the lookup (if it exists)
                            let attachmentId: String? = try attachmentId(
                                db,
                                for: quoteAttachmentId,
                                isQuotedMessage: true,
                                attachments: attachments,
                                processedAttachmentIds: &processedAttachmentIds
                            )
                            
                            // Create the quote
                            try Quote(
                                interactionId: interactionId,
                                authorId: quotedMessage.authorId,
                                timestampMs: Int64.zeroingOverflow(quotedMessage.timestamp),
                                body: quotedMessage.body,
                                attachmentId: attachmentId
                            ).migrationSafeInsert(db)
                        }
                        
                        // Handle any LinkPreview
                        
                        if let linkPreview: SMKLegacy._DBLinkPreview = linkPreview, let urlString: String = linkPreview.urlString {
                            // Note: The `legacyInteraction.timestamp` value is in milliseconds
                            let timestamp: TimeInterval = LinkPreview.timestampFor(sentTimestampMs: Double(legacyInteraction.timestamp))
                            
                            // Setup the attachment and add it to the lookup (if it exists - we do actually
                            // support link previews with no image attachments so no need to throw migration
                            // errors in those cases)
                            let attachmentId: String? = try attachmentId(
                                db,
                                for: linkPreview.imageAttachmentId,
                                attachments: attachments,
                                processedAttachmentIds: &processedAttachmentIds
                            )
                            
                            // Note: It's possible for there to be duplicate values here so we use 'save'
                            // instead of insert (ie. upsert)
                            try LinkPreview(
                                url: urlString,
                                timestamp: timestamp,
                                variant: linkPreviewVariant,
                                title: linkPreview.title,
                                attachmentId: attachmentId
                            ).migrationSafeSave(db)
                        }
                        
                        // Handle any attachments
                        
                        try attachmentIds.enumerated().forEach { index, legacyAttachmentId in
                            let maybeAttachmentId: String? = (try attachmentId(
                                db,
                                for: legacyAttachmentId,
                                interactionVariant: variant,
                                attachments: attachments,
                                processedAttachmentIds: &processedAttachmentIds
                            ))
                            .defaulting(
                                // It looks like somehow messages could exist in the old database which
                                // referenced attachments but had no attachments in the database; doing
                                // nothing here results in these messages appearing as empty message
                                // bubbles so instead we want to insert invalid attachments instead
                                to: try invalidAttachmentId(
                                    db,
                                    for: legacyAttachmentId,
                                    attachments: attachments,
                                    processedAttachmentIds: &processedAttachmentIds
                                )
                            )
                            
                            guard let attachmentId: String = maybeAttachmentId else {
                                SNLog("[Migration Warning] Failed to create invalid attachment for missing attachment")
                                return
                            }
                            
                            // Link the attachment to the interaction and add to the id lookup
                            try InteractionAttachment(
                                albumIndex: index,
                                interactionId: interactionId,
                                attachmentId: attachmentId
                            ).migrationSafeInsert(db)
                        }
                        
                        // Increment the progress for each contact
                        Storage.update(
                            progress: (
                                threadInteractionsStartProgress +
                                (progressPerInteraction * (interactionCounter + 1))
                            ),
                            for: self,
                            in: target
                        )
                        interactionCounter += 1
                    }
            }
        }
        
        // Clear out processed data (give the memory a change to be freed)
        legacyThreads = []
        disappearingMessagesConfiguration = [:]
        
        closedGroupKeys = [:]
        closedGroupName = [:]
        closedGroupFormation = [:]
        closedGroupModel = [:]
        closedGroupZombieMemberIds = [:]
        
        openGroupInfo = [:]
        openGroupUserCount = [:]
        openGroupImage = [:]
        
        interactions = [:]
        attachments = [:]
        
        // MARK: --Received Message Timestamps
        
        // Insert a 'ControlMessageProcessRecord' for any remaining 'receivedMessageTimestamp'
        // entries as "legacy"
        try ControlMessageProcessRecord.generateLegacyProcessRecords(
            db,
            receivedMessageTimestamps: receivedMessageTimestamps.map { Int64.zeroingOverflow($0) }
        )
        
        // Clear out processed data (give the memory a change to be freed)
        receivedMessageTimestamps = []
        
        // MARK: - Insert Jobs
        
        SNLog("[Migration Info] \(target.key(with: self)) - Inserting Jobs")
        
        // MARK: --notifyPushServer
        
        try autoreleasepool {
            try notifyPushServerJobs.forEach { legacyJob in
                _ = try Job(
                    failureCount: legacyJob.failureCount,
                    variant: .notifyPushServer,
                    behaviour: .runOnce,
                    nextRunTimestamp: 0,
                    details: NotifyPushServerJob.Details(
                        message: SnodeMessage(
                            recipient: legacyJob.message.recipient,
                            // Note: The legacy type had 'LosslessStringConvertible' so we need
                            // to use '.description' to get it as a basic string
                            data: legacyJob.message.data.description,
                            ttl: legacyJob.message.ttl,
                            timestampMs: legacyJob.message.timestamp
                        )
                    )
                )?.migrationSafeInserted(db)
            }
        }
        
        // MARK: --messageReceive
        
        try autoreleasepool {
            try messageReceiveJobs.forEach { legacyJob in
                // We haven't supported OpenGroup messageReceive jobs for a long time so if
                // we see any then just ignore them
                if legacyJob.openGroupID != nil && legacyJob.openGroupMessageServerID != nil {
                    return
                }
                
                // We have changed how messageReceive jobs work - we now parse the message upon receipt and
                // the MessageReceiveJob only does the handling - as a result we need to do the same behaviour
                // here so we don't need to support the legacy behaviour
                guard let processedMessage: ProcessedMessage = try? Message.processRawReceivedMessage(db, serializedData: legacyJob.data, serverHash: legacyJob.serverHash) else {
                    return
                }
                
                _ = try Job(
                    failureCount: legacyJob.failureCount,
                    variant: .messageReceive,
                    behaviour: .runOnce,
                    nextRunTimestamp: 0,
                    threadId: processedMessage.threadId,
                    details: MessageReceiveJob.Details(
                        messages: [processedMessage.messageInfo],
                        calledFromBackgroundPoller: legacyJob.isBackgroundPoll
                    )
                )?.migrationSafeInserted(db)
            }
        }
        
        // MARK: --messageSend
        
        var messageSendJobLegacyMap: [String: Job] = [:]

        try autoreleasepool {
            try messageSendJobs.forEach { legacyJob in
                // Fetch the threadId and interactionId this job should be associated with
                let threadId: String = {
                    switch legacyJob.destination {
                        case .contact(let publicKey): return publicKey
                        case .closedGroup(let groupPublicKey): return groupPublicKey
                        case .openGroup(let roomToken, let server, _, _, _):
                            return OpenGroup.idFor(roomToken: roomToken, server: server)
                        
                        case .openGroupInbox(_, _, let blindedPublicKey): return blindedPublicKey
                    }
                }()
                let interactionId: Int64? = {
                    // The 'Legacy.Job' 'id' value was "(timestamp)(num jobs for this timestamp)"
                    // so we can reverse-engineer an approximate timestamp by extracting it from
                    // the id (this value is unlikely to match exactly though)
                    let fallbackTimestamp: UInt64 = legacyJob.id
                        .map { UInt64($0.prefix("\(SnodeAPI.currentOffsetTimestampMs())".count)) }
                        .defaulting(to: 0)
                    let legacyIdentifier: String = identifier(
                        for: threadId,
                        sentTimestamp: (legacyJob.message.sentTimestamp ?? fallbackTimestamp),
                        recipients: (legacyJob.message.recipient.map { [$0] } ?? []),
                        destination: legacyJob.destination,
                        variant: nil,
                        useFallback: false
                    )
                    
                    if let matchingId: Int64 = legacyInteractionIdentifierToIdMap[legacyIdentifier] {
                        return matchingId
                    }

                    // If we didn't find the correct interaction then we need to try the "fallback"
                    // identifier which is less accurate (during testing this only happened for
                    // 'ExpirationTimerUpdate' send jobs)
                    let fallbackIdentifier: String = identifier(
                        for: threadId,
                        sentTimestamp: (legacyJob.message.sentTimestamp ?? fallbackTimestamp),
                        recipients: (legacyJob.message.recipient.map { [$0] } ?? []),
                        destination: legacyJob.destination,
                        variant: {
                            switch legacyJob.message {
                                case is SMKLegacy._ExpirationTimerUpdate:
                                    return .infoDisappearingMessagesUpdate
                                default: return nil
                            }
                        }(),
                        useFallback: true
                    )
                    
                    return legacyInteractionIdentifierToIdFallbackMap[fallbackIdentifier]
                }()
                
                // Don't botther adding any 'MessageSend' jobs VisibleMessages which don't have associated
                // interactions
                switch legacyJob.message {
                    case is SMKLegacy._VisibleMessage:
                        guard interactionId != nil else {
                            SNLog("[Migration Warning] Unable to find associated interaction to messageSend job, ignoring.")
                            return
                        }
                        
                        break
                        
                    default: break
                }
                
                let job: Job? = try Job(
                    failureCount: legacyJob.failureCount,
                    variant: .messageSend,
                    behaviour: .runOnce,
                    nextRunTimestamp: 0,
                    threadId: threadId,
                    // Note: There are some cases where there isn't a link between a
                    // 'MessageSendJob' and an interaction (eg. ConfigurationMessage),
                    // in these cases the 'interactionId' value will be nil
                    interactionId: interactionId,
                    details: MessageSendJob.Details(
                        destination: legacyJob.destination,
                        message: legacyJob.message.toNonLegacy()
                    )
                )?.migrationSafeInserted(db)
                
                if let oldId: String = legacyJob.id {
                    messageSendJobLegacyMap[oldId] = job
                }
            }
        }
        
        // MARK: --attachmentUpload

        try autoreleasepool {
            try attachmentUploadJobs.forEach { legacyJob in
                guard let sendJob: Job = messageSendJobLegacyMap[legacyJob.messageSendJobID], let sendJobId: Int64 = sendJob.id else {
                    SNLog("[Migration Error] attachmentUpload job missing associated MessageSendJob")
                    throw StorageError.migrationFailed
                }
                
                let uploadJob: Job? = try Job(
                    failureCount: legacyJob.failureCount,
                    variant: .attachmentUpload,
                    behaviour: .runOnce,
                    threadId: sendJob.threadId,
                    interactionId: sendJob.interactionId,
                    details: AttachmentUploadJob.Details(
                        messageSendJobId: sendJobId,
                        attachmentId: legacyJob.attachmentID
                    )
                )?.migrationSafeInserted(db)
                
                // Add the dependency to the relevant MessageSendJob
                guard let uploadJobId: Int64 = uploadJob?.id else {
                    SNLog("[Migration Error] attachmentUpload job was not created")
                    throw StorageError.migrationFailed
                }
                
                try JobDependencies(
                    jobId: sendJobId,
                    dependantId: uploadJobId
                ).migrationSafeInsert(db)
            }
        }
        
        // MARK: --attachmentDownload
        
        try autoreleasepool {
            try attachmentDownloadJobs.forEach { legacyJob in
                guard let interactionId: Int64 = legacyInteractionToIdMap[legacyJob.tsMessageID] else {
                    // This can happen if an UnsendRequest came before an AttachmentDownloadJob completed
                    SNLog("[Migration Warning] attachmentDownload job with no interaction found - ignoring")
                    return
                }
                guard processedAttachmentIds.contains(legacyJob.attachmentID) else {
                    // Unsure how this case can occur but it seemed to happen when testing internally
                    SNLog("[Migration Warning] attachmentDownload job unable to find attachment - ignoring")
                    return
                }
                
                _ = try Job(
                    failureCount: legacyJob.failureCount,
                    variant: .attachmentDownload,
                    behaviour: .runOnce,
                    nextRunTimestamp: 0,
                    threadId: legacyThreadIdToIdMap[legacyJob.threadID],
                    interactionId: interactionId,
                    details: AttachmentDownloadJob.Details(
                        attachmentId: legacyJob.attachmentID
                    )
                )?.migrationSafeInserted(db)
            }
        }
        
        // MARK: --sendReadReceipts
        
        try autoreleasepool {
            try outgoingReadReceiptsTimestampsMs.forEach { threadId, timestampsMs in
                _ = try Job(
                    variant: .sendReadReceipts,
                    behaviour: .recurring,
                    threadId: threadId,
                    details: SendReadReceiptsJob.Details(
                        destination: .contact(publicKey: threadId),
                        timestampMsValues: timestampsMs
                    )
                )?.migrationSafeInserted(db)
            }
        }
        Storage.update(progress: 0.99, for: self, in: target)
        
        // MARK: - Preferences
        
        SNLog("[Migration Info] \(target.key(with: self)) - Inserting Preferences")
        
        db[.defaultNotificationSound] = Preferences.Sound(rawValue: legacyPreferences[SMKLegacy.soundsGlobalNotificationKey] as? Int ?? -1)
            .defaulting(to: Preferences.Sound.defaultNotificationSound)
        db[.playNotificationSoundInForeground] = (legacyPreferences[SMKLegacy.preferencesKeyNotificationSoundInForeground] as? Bool == true)
        db[.preferencesNotificationPreviewType] = Preferences.NotificationPreviewType(rawValue: legacyPreferences[SMKLegacy.preferencesKeyNotificationPreviewType] as? Int ?? -1)
            .defaulting(to: .defaultPreviewType)
        
        if let lastPushToken: String = legacyPreferences[SMKLegacy.preferencesKeyLastRecordedPushToken] as? String {
            db[.lastRecordedPushToken] = lastPushToken
        }
        
        if let lastVoipToken: String = legacyPreferences[SMKLegacy.preferencesKeyLastRecordedVoipToken] as? String {
            db[.lastRecordedVoipToken] = lastVoipToken
        }
        
        db[.areReadReceiptsEnabled] = (legacyPreferences[SMKLegacy.readReceiptManagerAreReadReceiptsEnabled] as? Bool == true)
        db[.typingIndicatorsEnabled] = (legacyPreferences[SMKLegacy.typingIndicatorsEnabledKey] as? Bool == true)
        db[.isScreenLockEnabled] = (legacyPreferences[SMKLegacy.screenLockIsScreenLockEnabledKey] as? Bool == true)
        // Note: 'screenLockTimeoutSeconds' has been removed, but we want to avoid changing the behaviour
        // of old migrations when possible
        db.unsafeSet(
            key: "screenLockTimeoutSeconds",
            value: (legacyPreferences[SMKLegacy.screenLockScreenLockTimeoutSecondsKey] as? Double)
                .defaulting(to: (15 * 60))
        )
        db[.areLinkPreviewsEnabled] = (legacyPreferences[SMKLegacy.preferencesKeyAreLinkPreviewsEnabled] as? Bool == true)
        db[.areCallsEnabled] = (legacyPreferences[SMKLegacy.preferencesKeyAreCallsEnabled] as? Bool == true)
        db[.hasHiddenMessageRequests] = CurrentAppContext().appUserDefaults()
            .bool(forKey: SMKLegacy.userDefaultsHasHiddenMessageRequests)
        
        // Note: The 'hasViewedSeed' was originally stored on standard user defaults
        db[.hasViewedSeed] = UserDefaults.standard.bool(forKey: SMKLegacy.userDefaultsHasViewedSeedKey)
        db[.hasSavedThread] = (legacyPreferences[SMKLegacy.preferencesKeyHasSavedThreadKey] as? Bool == true)
        db[.hasSentAMessage] = (legacyPreferences[SMKLegacy.preferencesKeyHasSentAMessageKey] as? Bool == true)
        db[.isReadyForAppExtensions] = CurrentAppContext().appUserDefaults().bool(forKey: SMKLegacy.preferencesKeyIsReadyForAppExtensions)
        
        // We want this setting to be on by default
        db[.trimOpenGroupMessagesOlderThanSixMonths] = true
        
        Storage.update(progress: 1, for: self, in: target) // In case this is the last migration
    }
    
    // MARK: - Convenience
    
    private static func attachmentId(
        _ db: Database,
        for legacyAttachmentId: String?,
        interactionVariant: Interaction.Variant? = nil,
        isQuotedMessage: Bool = false,
        attachments: [String: SMKLegacy._Attachment],
        processedAttachmentIds: inout Set<String>
    ) throws -> String? {
        guard let legacyAttachmentId: String = legacyAttachmentId else { return nil }
        guard !processedAttachmentIds.contains(legacyAttachmentId) else {
            guard isQuotedMessage else {
                SNLog("[Migration Error] Attempted to process duplicate attachment")
                throw StorageError.migrationFailed
            }
            
            return legacyAttachmentId
        }
        
        guard let legacyAttachment: SMKLegacy._Attachment = attachments[legacyAttachmentId] else {
            SNLog("[Migration Warning] Missing attachment - interaction will show a \"failed\" attachment")
            return nil
        }

        let processedLocalRelativeFilePath: String? = (legacyAttachment as? SMKLegacy._AttachmentStream)?
            .localRelativeFilePath
            .map { filePath -> String in
                // The old 'localRelativeFilePath' seemed to have a leading forward slash (want
                // to get rid of it so we can correctly use 'appendingPathComponent')
                guard filePath.starts(with: "/") else { return filePath }
                
                return String(filePath.suffix(from: filePath.index(after: filePath.startIndex)))
            }
        let state: Attachment.State = {
            switch legacyAttachment {
                case let stream as SMKLegacy._AttachmentStream:  // Outgoing or already downloaded
                    switch interactionVariant {
                        case .standardOutgoing: return (stream.isUploaded ? .uploaded : .uploading)
                        default: return .downloaded
                    }
                
                // All other cases can just be set to 'pendingDownload'
                default: return .pendingDownload
            }
        }()
        let size: CGSize = {
            switch legacyAttachment {
                case let stream as SMKLegacy._AttachmentStream:
                    // First try to get an image size using the 'localRelativeFilePath' value
                    if
                        let localRelativeFilePath: String = processedLocalRelativeFilePath,
                        let specificImageSize: CGSize = Attachment.imageSize(
                            contentType: stream.contentType,
                            originalFilePath: URL(fileURLWithPath: Attachment.attachmentsFolder)
                                .appendingPathComponent(localRelativeFilePath)
                                .path
                        ),
                        specificImageSize != .zero
                    {
                        return specificImageSize
                    }
                    
                    // Then fallback to trying to get the size from the 'originalFilePath'
                    guard let originalFilePath: String = Attachment.originalFilePath(id: legacyAttachmentId, mimeType: stream.contentType, sourceFilename: stream.sourceFilename) else {
                        return .zero
                    }
                    
                    return Attachment
                        .imageSize(
                            contentType: stream.contentType,
                            originalFilePath: originalFilePath
                        )
                        .defaulting(to: .zero)
                    
                case let pointer as SMKLegacy._AttachmentPointer: return pointer.mediaSize
                default: return CGSize.zero
            }
        }()
        let (isValid, duration): (Bool, TimeInterval?) = {
            guard
                let stream: SMKLegacy._AttachmentStream = legacyAttachment as? SMKLegacy._AttachmentStream,
                let originalFilePath: String = Attachment.originalFilePath(
                    id: legacyAttachmentId,
                    mimeType: stream.contentType,
                    sourceFilename: stream.sourceFilename
                )
            else {
                return (false, nil)
            }
            
            if stream.isAudio {
                if let cachedDuration: TimeInterval = stream.cachedAudioDurationSeconds?.doubleValue, cachedDuration > 0 {
                    return (true, cachedDuration)
                }
                
                let attachmentVailidityInfo = Attachment.determineValidityAndDuration(
                    contentType: stream.contentType,
                    localRelativeFilePath: processedLocalRelativeFilePath,
                    originalFilePath: originalFilePath
                )
                
                return (attachmentVailidityInfo.isValid, attachmentVailidityInfo.duration)
            }
            
            if stream.isVisualMedia {
                let attachmentVailidityInfo = Attachment.determineValidityAndDuration(
                    contentType: stream.contentType,
                    localRelativeFilePath: processedLocalRelativeFilePath,
                    originalFilePath: originalFilePath
                )
                
                return (attachmentVailidityInfo.isValid, attachmentVailidityInfo.duration)
            }
            
            return (true, nil)
        }()
        
        _ = try Attachment(
            // Note: The legacy attachment object used a UUID string for it's id as well
            // and saved files using these id's so just used the existing id so we don't
            // need to bother renaming files as part of the migration
            id: legacyAttachmentId,
            serverId: "\(legacyAttachment.serverId)",
            variant: (legacyAttachment.attachmentType == .voiceMessage ? .voiceMessage : .standard),
            state: state,
            contentType: legacyAttachment.contentType,
            byteCount: UInt(legacyAttachment.byteCount),
            creationTimestamp: (legacyAttachment as? SMKLegacy._AttachmentStream)?
                .creationTimestamp.timeIntervalSince1970,
            sourceFilename: legacyAttachment.sourceFilename,
            downloadUrl: legacyAttachment.downloadURL,
            localRelativeFilePath: processedLocalRelativeFilePath,
            width: (size == .zero ? nil : UInt(size.width)),
            height: (size == .zero ? nil : UInt(size.height)),
            duration: duration,
            isValid: isValid,
            encryptionKey: legacyAttachment.encryptionKey,
            digest: {
                switch legacyAttachment {
                    case let stream as SMKLegacy._AttachmentStream: return stream.digest
                    case let pointer as SMKLegacy._AttachmentPointer: return pointer.digest
                    default: return nil
                }
            }(),
            caption: legacyAttachment.caption
        ).migrationSafeInserted(db)
        
        processedAttachmentIds.insert(legacyAttachmentId)
        
        return legacyAttachmentId
    }
    
    private static func invalidAttachmentId(
        _ db: Database,
        for legacyAttachmentId: String,
        interactionVariant: Interaction.Variant? = nil,
        attachments: [String: SMKLegacy._Attachment],
        processedAttachmentIds: inout Set<String>
    ) throws -> String {
        guard !processedAttachmentIds.contains(legacyAttachmentId) else {
            return legacyAttachmentId
        }
        
        _ = try Attachment(
            // Note: The legacy attachment object used a UUID string for it's id as well
            // and saved files using these id's so just used the existing id so we don't
            // need to bother renaming files as part of the migration
            id: legacyAttachmentId,
            serverId: nil,
            variant: .standard,
            state: .invalid,
            contentType: "",
            byteCount: 0,
            creationTimestamp: (TimeInterval(SnodeAPI.currentOffsetTimestampMs()) / 1000),
            sourceFilename: nil,
            downloadUrl: nil,
            localRelativeFilePath: nil,
            width: nil,
            height: nil,
            duration: nil,
            isValid: false,
            encryptionKey: nil,
            digest: nil,
            caption: nil
        ).migrationSafeInserted(db)
        
        processedAttachmentIds.insert(legacyAttachmentId)
        
        return legacyAttachmentId
    }
    
    private static func mapLegacyTypesForNSKeyedUnarchiver() {
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Thread.self,
            forClassName: "TSThread"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ContactThread.self,
            forClassName: "TSContactThread"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._GroupThread.self,
            forClassName: "TSGroupThread"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._GroupModel.self,
            forClassName: "TSGroupModel"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._OpenGroup.self,
            forClassName: "SNOpenGroupV2"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Contact.self,
            forClassName: "SNContact"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBInteraction.self,
            forClassName: "TSInteraction"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBMessage.self,
            forClassName: "TSMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBQuotedMessage.self,
            forClassName: "TSQuotedMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBQuotedMessage._DBAttachmentInfo.self,
            forClassName: "OWSAttachmentInfo"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBLinkPreview.self,
            forClassName: "SessionServiceKit.OWSLinkPreview"    // Very old legacy name
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBLinkPreview.self,
            forClassName: "SessionMessagingKit.OWSLinkPreview"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBIncomingMessage.self,
            forClassName: "TSIncomingMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBOutgoingMessage.self,
            forClassName: "TSOutgoingMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBOutgoingMessageRecipientState.self,
            forClassName: "TSOutgoingMessageRecipientState"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DBInfoMessage.self,
            forClassName: "TSInfoMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DisappearingConfigurationUpdateInfoMessage.self,
            forClassName: "OWSDisappearingConfigurationUpdateInfoMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DataExtractionNotificationInfoMessage.self,
            forClassName: "SNDataExtractionNotificationInfoMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Attachment.self,
            forClassName: "TSAttachment"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._AttachmentStream.self,
            forClassName: "TSAttachmentStream"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._AttachmentPointer.self,
            forClassName: "TSAttachmentPointer"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._NotifyPNServerJob.self,
            forClassName: "SessionMessagingKit.NotifyPNServerJob"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._NotifyPNServerJob._SnodeMessage.self,
            forClassName: "SessionSnodeKit.SnodeMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._MessageSendJob.self,
            forClassName: "SessionMessagingKit.SNMessageSendJob"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._MessageReceiveJob.self,
            forClassName: "SessionMessagingKit.MessageReceiveJob"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._AttachmentUploadJob.self,
            forClassName: "SessionMessagingKit.AttachmentUploadJob"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._AttachmentDownloadJob.self,
            forClassName: "SessionMessagingKit.AttachmentDownloadJob"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Message.self,
            forClassName: "SNMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._VisibleMessage.self,
            forClassName: "SNVisibleMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Quote.self,
            forClassName: "SNQuote"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._LinkPreview.self,
            forClassName: "SNLinkPreview"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._Profile.self,
            forClassName: "SNProfile"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._OpenGroupInvitation.self,
            forClassName: "SNOpenGroupInvitation"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ControlMessage.self,
            forClassName: "SNControlMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ReadReceipt.self,
            forClassName: "SNReadReceipt"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._TypingIndicator.self,
            forClassName: "SNTypingIndicator"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ClosedGroupControlMessage.self,
            forClassName: "SessionMessagingKit.ClosedGroupControlMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ClosedGroupControlMessage._KeyPairWrapper.self,
            forClassName: "ClosedGroupControlMessage.SNKeyPairWrapper"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._DataExtractionNotification.self,
            forClassName: "SessionMessagingKit.DataExtractionNotification"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ExpirationTimerUpdate.self,
            forClassName: "SNExpirationTimerUpdate"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._ConfigurationMessage.self,
            forClassName: "SNConfigurationMessage"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._CMClosedGroup.self,
            forClassName: "SNClosedGroup"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._CMContact.self,
            forClassName: "SNConfigurationMessage.SNConfigurationMessageContact"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._UnsendRequest.self,
            forClassName: "SNUnsendRequest"
        )
        NSKeyedUnarchiver.setClass(
            SMKLegacy._MessageRequestResponse.self,
            forClassName: "SNMessageRequestResponse"
        )
    }
}

fileprivate extension Int64 {
    static func zeroingOverflow(_ value: UInt64) -> Int64 {
        return (value > UInt64(Int64.max) ? 0 : Int64(value))
    }
}