// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved. import Foundation import GRDB import DifferenceKit import SessionMessagingKit import SessionUtilitiesKit public class ConversationViewModel: OWSAudioPlayerDelegate { public typealias SectionModel = ArraySection // MARK: - Action public enum Action { case none case compose case audioCall case videoCall } // MARK: - Section public enum Section: Differentiable, Equatable, Comparable, Hashable { case loadOlder case messages case loadNewer } // MARK: - Variables public static let pageSize: Int = 50 private var threadId: String public let initialThreadVariant: SessionThread.Variant public var sentMessageBeforeUpdate: Bool = false public var lastSearchedText: String? public let focusedInteractionId: Int64? // Note: This is used for global search public lazy var blockedBannerMessage: String = { switch self.threadData.threadVariant { case .contact: let name: String = Profile.displayName( id: self.threadData.threadId, threadVariant: self.threadData.threadVariant ) return "\(name) is blocked. Unblock them?" default: return "Thread is blocked. Unblock it?" } }() // MARK: - Initialization init(threadId: String, threadVariant: SessionThread.Variant, focusedInteractionId: Int64?) { // If we have a specified 'focusedInteractionId' then use that, otherwise retrieve the oldest // unread interaction and start focused around that one let targetInteractionId: Int64? = { if let focusedInteractionId: Int64 = focusedInteractionId { return focusedInteractionId } return Storage.shared.read { db in let interaction: TypedTableAlias = TypedTableAlias() return try Interaction .select(.id) .filter(interaction[.wasRead] == false) .filter(interaction[.threadId] == threadId) .order(interaction[.timestampMs].asc) .asRequest(of: Int64.self) .fetchOne(db) } }() self.threadId = threadId self.initialThreadVariant = threadVariant self.focusedInteractionId = targetInteractionId self.pagedDataObserver = nil // Note: Since this references self we need to finish initializing before setting it, we // also want to skip the initial query and trigger it async so that the push animation // doesn't stutter (it should load basically immediately but without this there is a // distinct stutter) self.pagedDataObserver = self.setupPagedObserver( for: threadId, userPublicKey: getUserHexEncodedPublicKey() ) // Run the initial query on a background thread so we don't block the push transition DispatchQueue.global(qos: .userInitiated).async { [weak self] in // If we don't have a `initialFocusedId` then default to `.pageBefore` (it'll query // from a `0` offset) guard let initialFocusedId: Int64 = targetInteractionId else { self?.pagedDataObserver?.load(.pageBefore) return } self?.pagedDataObserver?.load(.initialPageAround(id: initialFocusedId)) } } // MARK: - Thread Data /// This value is the current state of the view public private(set) lazy var threadData: SessionThreadViewModel = SessionThreadViewModel( threadId: self.threadId, threadVariant: self.initialThreadVariant, currentUserIsClosedGroupMember: (self.initialThreadVariant != .closedGroup ? nil : Storage.shared.read { db in try GroupMember .filter(GroupMember.Columns.groupId == self.threadId) .filter(GroupMember.Columns.profileId == getUserHexEncodedPublicKey(db)) .filter(GroupMember.Columns.role == GroupMember.Role.standard) .isNotEmpty(db) } ) ) /// This is all the data the screen needs to populate itself, please see the following link for tips to help optimise /// performance https://github.com/groue/GRDB.swift#valueobservation-performance /// /// **Note:** The 'trackingConstantRegion' is optimised in such a way that the request needs to be static /// otherwise there may be situations where it doesn't get updates, this means we can't have conditional queries /// /// **Note:** This observation will be triggered twice immediately (and be de-duped by the `removeDuplicates`) /// this is due to the behaviour of `ValueConcurrentObserver.asyncStartObservation` which triggers it's own /// fetch (after the ones in `ValueConcurrentObserver.asyncStart`/`ValueConcurrentObserver.syncStart`) /// just in case the database has changed between the two reads - unfortunately it doesn't look like there is a way to prevent this public lazy var observableThreadData: ValueObservation>> = setupObservableThreadData(for: self.threadId) private func setupObservableThreadData(for threadId: String) -> ValueObservation>> { return ValueObservation .trackingConstantRegion { db -> SessionThreadViewModel? in let userPublicKey: String = getUserHexEncodedPublicKey(db) let recentReactionEmoji: [String] = try Emoji.getRecent(db, withDefaultEmoji: true) let threadViewModel: SessionThreadViewModel? = try SessionThreadViewModel .conversationQuery(threadId: threadId, userPublicKey: userPublicKey) .fetchOne(db) return threadViewModel .map { $0.with(recentReactionEmoji: recentReactionEmoji) } } .removeDuplicates() } public func updateThreadData(_ updatedData: SessionThreadViewModel) { self.threadData = updatedData } // MARK: - Interaction Data private var lastInteractionIdMarkedAsRead: Int64? public private(set) var unobservedInteractionDataChanges: ([SectionModel], StagedChangeset<[SectionModel]>)? public private(set) var interactionData: [SectionModel] = [] public private(set) var reactionExpandedInteractionIds: Set = [] public private(set) var pagedDataObserver: PagedDatabaseObserver? public var onInteractionChange: (([SectionModel], StagedChangeset<[SectionModel]>) -> ())? { didSet { // When starting to observe interaction changes we want to trigger a UI update just in case the // data was changed while we weren't observing if let unobservedInteractionDataChanges: ([SectionModel], StagedChangeset<[SectionModel]>) = self.unobservedInteractionDataChanges { onInteractionChange?(unobservedInteractionDataChanges.0, unobservedInteractionDataChanges.1) self.unobservedInteractionDataChanges = nil } } } private func setupPagedObserver(for threadId: String, userPublicKey: String) -> PagedDatabaseObserver { return PagedDatabaseObserver( pagedTable: Interaction.self, pageSize: ConversationViewModel.pageSize, idColumn: .id, observedChanges: [ PagedData.ObservedChanges( table: Interaction.self, columns: Interaction.Columns .allCases .filter { $0 != .wasRead } ), PagedData.ObservedChanges( table: Contact.self, columns: [.isTrusted], joinToPagedType: { let interaction: TypedTableAlias = TypedTableAlias() let contact: TypedTableAlias = TypedTableAlias() return SQL("LEFT JOIN \(Contact.self) ON \(contact[.id]) = \(interaction[.threadId])") }() ), PagedData.ObservedChanges( table: Profile.self, columns: [.profilePictureFileName], joinToPagedType: { let interaction: TypedTableAlias = TypedTableAlias() let profile: TypedTableAlias = TypedTableAlias() return SQL("LEFT JOIN \(Profile.self) ON \(profile[.id]) = \(interaction[.authorId])") }() ) ], filterSQL: MessageViewModel.filterSQL(threadId: threadId), groupSQL: MessageViewModel.groupSQL, orderSQL: MessageViewModel.orderSQL, dataQuery: MessageViewModel.baseQuery( userPublicKey: userPublicKey, orderSQL: MessageViewModel.orderSQL, groupSQL: MessageViewModel.groupSQL ), associatedRecords: [ AssociatedRecord( trackedAgainst: Attachment.self, observedChanges: [ PagedData.ObservedChanges( table: Attachment.self, columns: [.state] ) ], dataQuery: MessageViewModel.AttachmentInteractionInfo.baseQuery, joinToPagedType: MessageViewModel.AttachmentInteractionInfo.joinToViewModelQuerySQL, associateData: MessageViewModel.AttachmentInteractionInfo.createAssociateDataClosure() ), AssociatedRecord( trackedAgainst: Reaction.self, observedChanges: [ PagedData.ObservedChanges( table: Reaction.self, columns: [.count] ) ], dataQuery: MessageViewModel.ReactionInfo.baseQuery, joinToPagedType: MessageViewModel.ReactionInfo.joinToViewModelQuerySQL, associateData: MessageViewModel.ReactionInfo.createAssociateDataClosure() ), AssociatedRecord( trackedAgainst: ThreadTypingIndicator.self, observedChanges: [ PagedData.ObservedChanges( table: ThreadTypingIndicator.self, events: [.insert, .delete], columns: [] ) ], dataQuery: MessageViewModel.TypingIndicatorInfo.baseQuery, joinToPagedType: MessageViewModel.TypingIndicatorInfo.joinToViewModelQuerySQL, associateData: MessageViewModel.TypingIndicatorInfo.createAssociateDataClosure() ) ], onChangeUnsorted: { [weak self] updatedData, updatedPageInfo in PagedData.processAndTriggerUpdates( updatedData: self?.process(data: updatedData, for: updatedPageInfo), currentDataRetriever: { self?.interactionData }, onDataChange: self?.onInteractionChange, onUnobservedDataChange: { updatedData, changeset in self?.unobservedInteractionDataChanges = (updatedData, changeset) } ) } ) } private func process(data: [MessageViewModel], for pageInfo: PagedData.PageInfo) -> [SectionModel] { let typingIndicator: MessageViewModel? = data.first(where: { $0.isTypingIndicator == true }) let sortedData: [MessageViewModel] = data .filter { $0.isTypingIndicator != true } .sorted { lhs, rhs -> Bool in lhs.timestampMs < rhs.timestampMs } // We load messages from newest to oldest so having a pageOffset larger than zero means // there are newer pages to load return [ (!data.isEmpty && (pageInfo.pageOffset + pageInfo.currentCount) < pageInfo.totalCount ? [SectionModel(section: .loadOlder)] : [] ), [ SectionModel( section: .messages, elements: sortedData .enumerated() .map { index, cellViewModel -> MessageViewModel in cellViewModel.withClusteringChanges( prevModel: (index > 0 ? sortedData[index - 1] : nil), nextModel: (index < (sortedData.count - 1) ? sortedData[index + 1] : nil), isLast: ( // The database query sorts by timestampMs descending so the "last" // interaction will actually have a 'pageOffset' of '0' even though // it's the last element in the 'sortedData' array index == (sortedData.count - 1) && pageInfo.pageOffset == 0 ), currentUserBlindedPublicKey: threadData.currentUserBlindedPublicKey ) } .reduce([]) { result, message in guard message.shouldShowDateHeader else { return result.appending(message) } return result .appending( MessageViewModel( timestampMs: message.timestampMs, cellType: .dateHeader ) ) .appending(message) } .appending(typingIndicator) ) ], (!data.isEmpty && pageInfo.pageOffset > 0 ? [SectionModel(section: .loadNewer)] : [] ) ].flatMap { $0 } } public func updateInteractionData(_ updatedData: [SectionModel]) { self.interactionData = updatedData } public func expandReactions(for interactionId: Int64) { reactionExpandedInteractionIds.insert(interactionId) } public func collapseReactions(for interactionId: Int64) { reactionExpandedInteractionIds.remove(interactionId) } // MARK: - Mentions public func mentions(for query: String = "") -> [MentionInfo] { let threadData: SessionThreadViewModel = self.threadData return Storage.shared .read { db -> [MentionInfo] in let userPublicKey: String = getUserHexEncodedPublicKey(db) let pattern: FTS5Pattern? = try? SessionThreadViewModel.pattern(db, searchTerm: query, forTable: Profile.self) let capabilities: Set = (threadData.threadVariant != .openGroup ? nil : try? Capability .select(.variant) .filter(Capability.Columns.openGroupServer == threadData.openGroupServer) .asRequest(of: Capability.Variant.self) .fetchSet(db) ) .defaulting(to: []) let targetPrefix: SessionId.Prefix = (capabilities.contains(.blind) ? .blinded : .standard ) return (try MentionInfo .query( userPublicKey: userPublicKey, threadId: threadData.threadId, threadVariant: threadData.threadVariant, targetPrefix: targetPrefix, pattern: pattern )? .fetchAll(db)) .defaulting(to: []) } .defaulting(to: []) } // MARK: - Functions public func updateDraft(to draft: String) { let threadId: String = self.threadId let currentDraft: String = Storage.shared .read { db in try SessionThread .select(.messageDraft) .filter(id: threadId) .asRequest(of: String.self) .fetchOne(db) } .defaulting(to: "") // Only write the updated draft to the database if it's changed (avoid unnecessary writes) guard draft != currentDraft else { return } Storage.shared.writeAsync { db in try SessionThread .filter(id: threadId) .updateAll(db, SessionThread.Columns.messageDraft.set(to: draft)) } } /// This method will mark all interactions as read before the specified interaction id, if no id is provided then all interactions for /// the thread will be marked as read public func markAsRead(beforeInclusive interactionId: Int64?) { /// Since this method now gets triggered when scrolling we want to try to optimise it and avoid busying the database /// write queue when it isn't needed, in order to do this we: /// /// - Don't bother marking anything as read if there are no unread interactions (we can rely on the /// `threadData.threadUnreadCount` to always be accurate) /// - Don't bother marking anything as read if this was called with the same `interactionId` that we /// previously marked as read (ie. when scrolling and the last message hasn't changed) guard (self.threadData.threadUnreadCount ?? 0) > 0, let targetInteractionId: Int64 = (interactionId ?? self.threadData.interactionId), self.lastInteractionIdMarkedAsRead != targetInteractionId else { return } let threadId: String = self.threadData.threadId let trySendReadReceipt: Bool = (self.threadData.threadIsMessageRequest == false) self.lastInteractionIdMarkedAsRead = targetInteractionId Storage.shared.writeAsync { db in try Interaction.markAsRead( db, interactionId: targetInteractionId, threadId: threadId, includingOlder: true, trySendReadReceipt: trySendReadReceipt ) } } public func swapToThread(updatedThreadId: String) { let oldestMessageId: Int64? = self.interactionData .filter { $0.model == .messages } .first? .elements .first? .id self.threadId = updatedThreadId self.observableThreadData = self.setupObservableThreadData(for: updatedThreadId) self.pagedDataObserver = self.setupPagedObserver( for: updatedThreadId, userPublicKey: getUserHexEncodedPublicKey() ) // Try load everything up to the initial visible message, fallback to just the initial page of messages // if we don't have one switch oldestMessageId { case .some(let id): self.pagedDataObserver?.load(.untilInclusive(id: id, padding: 0)) case .none: self.pagedDataObserver?.load(.pageBefore) } } public func trustContact() { guard self.threadData.threadVariant == .contact else { return } let threadId: String = self.threadId Storage.shared.writeAsync { db in try Contact .filter(id: threadId) .updateAll(db, Contact.Columns.isTrusted.set(to: true)) // Start downloading any pending attachments for this contact (UI will automatically be // updated due to the database observation) try Attachment .stateInfo(authorId: threadId, state: .pendingDownload) .fetchAll(db) .forEach { attachmentDownloadInfo in JobRunner.add( db, job: Job( variant: .attachmentDownload, threadId: threadId, interactionId: attachmentDownloadInfo.interactionId, details: AttachmentDownloadJob.Details( attachmentId: attachmentDownloadInfo.attachmentId ) ) ) } } } public func unblockContact() { guard self.threadData.threadVariant == .contact else { return } let threadId: String = self.threadId Storage.shared.writeAsync { db in try Contact .filter(id: threadId) .updateAll(db, Contact.Columns.isBlocked.set(to: false)) try MessageSender .syncConfiguration(db, forceSyncNow: true) .sinkUntilComplete() } } // MARK: - Audio Playback public struct PlaybackInfo { let state: AudioPlaybackState let progress: TimeInterval let playbackRate: Double let oldPlaybackRate: Double let updateCallback: (PlaybackInfo?, Error?) -> () public func with( state: AudioPlaybackState? = nil, progress: TimeInterval? = nil, playbackRate: Double? = nil, updateCallback: ((PlaybackInfo?, Error?) -> ())? = nil ) -> PlaybackInfo { return PlaybackInfo( state: (state ?? self.state), progress: (progress ?? self.progress), playbackRate: (playbackRate ?? self.playbackRate), oldPlaybackRate: self.playbackRate, updateCallback: (updateCallback ?? self.updateCallback) ) } } private var audioPlayer: Atomic = Atomic(nil) private var currentPlayingInteraction: Atomic = Atomic(nil) private var playbackInfo: Atomic<[Int64: PlaybackInfo]> = Atomic([:]) public func playbackInfo(for viewModel: MessageViewModel, updateCallback: ((PlaybackInfo?, Error?) -> ())? = nil) -> PlaybackInfo? { // Use the existing info if it already exists (update it's callback if provided as that means // the cell was reloaded) if let currentPlaybackInfo: PlaybackInfo = playbackInfo.wrappedValue[viewModel.id] { let updatedPlaybackInfo: PlaybackInfo = currentPlaybackInfo .with(updateCallback: updateCallback) playbackInfo.mutate { $0[viewModel.id] = updatedPlaybackInfo } return updatedPlaybackInfo } // Validate the item is a valid audio item guard let updateCallback: ((PlaybackInfo?, Error?) -> ()) = updateCallback, let attachment: Attachment = viewModel.attachments?.first, attachment.isAudio, attachment.isValid, let originalFilePath: String = attachment.originalFilePath, FileManager.default.fileExists(atPath: originalFilePath) else { return nil } // Create the info with the update callback let newPlaybackInfo: PlaybackInfo = PlaybackInfo( state: .stopped, progress: 0, playbackRate: 1, oldPlaybackRate: 1, updateCallback: updateCallback ) // Cache the info playbackInfo.mutate { $0[viewModel.id] = newPlaybackInfo } return newPlaybackInfo } public func playOrPauseAudio(for viewModel: MessageViewModel) { guard let attachment: Attachment = viewModel.attachments?.first, let originalFilePath: String = attachment.originalFilePath, FileManager.default.fileExists(atPath: originalFilePath) else { return } // If the user interacted with the currently playing item guard currentPlayingInteraction.wrappedValue != viewModel.id else { let currentPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[viewModel.id] let updatedPlaybackInfo: PlaybackInfo? = currentPlaybackInfo? .with( state: (currentPlaybackInfo?.state != .playing ? .playing : .paused), playbackRate: 1 ) audioPlayer.wrappedValue?.playbackRate = 1 switch currentPlaybackInfo?.state { case .playing: audioPlayer.wrappedValue?.pause() default: audioPlayer.wrappedValue?.play() } // Update the state and then update the UI with the updated state playbackInfo.mutate { $0[viewModel.id] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, nil) return } // First stop any existing audio audioPlayer.wrappedValue?.stop() // Then setup the state for the new audio currentPlayingInteraction.mutate { $0 = viewModel.id } audioPlayer.mutate { [weak self] player in // Note: We clear the delegate and explicitly set to nil here as when the OWSAudioPlayer // gets deallocated it triggers state changes which cause UI bugs when auto-playing player?.delegate = nil player = nil let audioPlayer: OWSAudioPlayer = OWSAudioPlayer( mediaUrl: URL(fileURLWithPath: originalFilePath), audioBehavior: .audioMessagePlayback, delegate: self ) audioPlayer.play() audioPlayer.setCurrentTime(playbackInfo.wrappedValue[viewModel.id]?.progress ?? 0) player = audioPlayer } } public func speedUpAudio(for viewModel: MessageViewModel) { // If we aren't playing the specified item then just start playing it guard viewModel.id == currentPlayingInteraction.wrappedValue else { playOrPauseAudio(for: viewModel) return } let updatedPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[viewModel.id]? .with(playbackRate: 1.5) // Speed up the audio player audioPlayer.wrappedValue?.playbackRate = 1.5 playbackInfo.mutate { $0[viewModel.id] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, nil) } public func stopAudio() { audioPlayer.wrappedValue?.stop() currentPlayingInteraction.mutate { $0 = nil } audioPlayer.mutate { // Note: We clear the delegate and explicitly set to nil here as when the OWSAudioPlayer // gets deallocated it triggers state changes which cause UI bugs when auto-playing $0?.delegate = nil $0 = nil } } // MARK: - OWSAudioPlayerDelegate public func audioPlaybackState() -> AudioPlaybackState { guard let interactionId: Int64 = currentPlayingInteraction.wrappedValue else { return .stopped } return (playbackInfo.wrappedValue[interactionId]?.state ?? .stopped) } public func setAudioPlaybackState(_ state: AudioPlaybackState) { guard let interactionId: Int64 = currentPlayingInteraction.wrappedValue else { return } let updatedPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[interactionId]? .with(state: state) playbackInfo.mutate { $0[interactionId] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, nil) } public func setAudioProgress(_ progress: CGFloat, duration: CGFloat) { guard let interactionId: Int64 = currentPlayingInteraction.wrappedValue else { return } let updatedPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[interactionId]? .with(progress: TimeInterval(progress)) playbackInfo.mutate { $0[interactionId] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, nil) } public func audioPlayerDidFinishPlaying(_ player: OWSAudioPlayer, successfully: Bool) { guard let interactionId: Int64 = currentPlayingInteraction.wrappedValue else { return } guard successfully else { return } let updatedPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[interactionId]? .with( state: .stopped, progress: 0, playbackRate: 1 ) // Safe the changes and send one final update to the UI playbackInfo.mutate { $0[interactionId] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, nil) // Clear out the currently playing record currentPlayingInteraction.mutate { $0 = nil } audioPlayer.mutate { // Note: We clear the delegate and explicitly set to nil here as when the OWSAudioPlayer // gets deallocated it triggers state changes which cause UI bugs when auto-playing $0?.delegate = nil $0 = nil } // If the next interaction is another voice message then autoplay it guard let messageSection: SectionModel = self.interactionData .first(where: { $0.model == .messages }), let currentIndex: Int = messageSection.elements .firstIndex(where: { $0.id == interactionId }), currentIndex < (messageSection.elements.count - 1), messageSection.elements[currentIndex + 1].cellType == .audio, Storage.shared[.shouldAutoPlayConsecutiveAudioMessages] == true else { return } let nextItem: MessageViewModel = messageSection.elements[currentIndex + 1] playOrPauseAudio(for: nextItem) } public func showInvalidAudioFileAlert() { guard let interactionId: Int64 = currentPlayingInteraction.wrappedValue else { return } let updatedPlaybackInfo: PlaybackInfo? = playbackInfo.wrappedValue[interactionId]? .with( state: .stopped, progress: 0, playbackRate: 1 ) currentPlayingInteraction.mutate { $0 = nil } playbackInfo.mutate { $0[interactionId] = updatedPlaybackInfo } updatedPlaybackInfo?.updateCallback(updatedPlaybackInfo, AttachmentError.invalidData) } }