import SwiftSignalKit
import Postbox

public typealias EngineExportedPeerInvitation = ExportedInvitation
public typealias EngineSecretChatKeyFingerprint = SecretChatKeyFingerprint

public enum EnginePeerCachedInfoItem<T> {
    case known(T)
    case unknown
    
    public var knownValue: T? {
        switch self {
        case let .known(value):
            return value
        case .unknown:
            return nil
        }
    }
}

extension EnginePeerCachedInfoItem: Equatable where T: Equatable {
    public static func ==(lhs: EnginePeerCachedInfoItem<T>, rhs: EnginePeerCachedInfoItem<T>) -> Bool {
        switch lhs {
        case let .known(value):
            if case .known(value) = rhs {
                return true
            } else {
                return false
            }
        case .unknown:
            if case .unknown = rhs {
                return true
            } else {
                return false
            }
        }
    }
}

public enum EngineChannelParticipant: Equatable {
    case creator(id: EnginePeer.Id, adminInfo: ChannelParticipantAdminInfo?, rank: String?)
    case member(id: EnginePeer.Id, invitedAt: Int32, adminInfo: ChannelParticipantAdminInfo?, banInfo: ChannelParticipantBannedInfo?, rank: String?)
    
    public var peerId: EnginePeer.Id {
        switch self {
        case let .creator(id, _, _):
            return id
        case let .member(id, _, _, _, _):
            return id
        }
    }
}

public extension EngineChannelParticipant {
    init(_ participant: ChannelParticipant) {
        switch participant {
        case let .creator(id, adminInfo, rank):
            self = .creator(id: id, adminInfo: adminInfo, rank: rank)
        case let .member(id, invitedAt, adminInfo, banInfo, rank):
            self = .member(id: id, invitedAt: invitedAt, adminInfo: adminInfo, banInfo: banInfo, rank: rank)
        }
    }
    
    func _asParticipant() -> ChannelParticipant {
        switch self {
        case let .creator(id, adminInfo, rank):
            return .creator(id: id, adminInfo: adminInfo, rank: rank)
        case let .member(id, invitedAt, adminInfo, banInfo, rank):
            return .member(id: id, invitedAt: invitedAt, adminInfo: adminInfo, banInfo: banInfo, rank: rank)
        }
    }
}

public enum EngineLegacyGroupParticipant: Equatable {
    case member(id: EnginePeer.Id, invitedBy: EnginePeer.Id, invitedAt: Int32)
    case creator(id: EnginePeer.Id)
    case admin(id: EnginePeer.Id, invitedBy: EnginePeer.Id, invitedAt: Int32)
    
    public var peerId: EnginePeer.Id {
        switch self {
        case let .member(id, _, _):
            return id
        case let .creator(id):
            return id
        case let .admin(id, _, _):
            return id
        }
    }
}

public extension EngineLegacyGroupParticipant {
    init(_ participant: GroupParticipant) {
        switch participant {
        case let .member(id, invitedBy, invitedAt):
            self = .member(id: id, invitedBy: invitedBy, invitedAt: invitedAt)
        case let .creator(id):
            self = .creator(id: id)
        case let .admin(id, invitedBy, invitedAt):
            self = .admin(id: id, invitedBy: invitedBy, invitedAt: invitedAt)
        }
    }
    
    func _asParticipant() -> GroupParticipant {
        switch self {
        case let .member(id, invitedBy, invitedAt):
            return .member(id: id, invitedBy: invitedBy, invitedAt: invitedAt)
        case let .creator(id):
            return .creator(id: id)
        case let .admin(id, invitedBy, invitedAt):
            return .admin(id: id, invitedBy: invitedBy, invitedAt: invitedAt)
        }
    }
}

public extension TelegramEngine.EngineData.Item {
    enum NotificationSettings {
        public struct Global: TelegramEngineDataItem, PostboxViewDataItem {
            public typealias Result = EngineGlobalNotificationSettings

            public init() {
            }

            var key: PostboxViewKey {
                return .preferences(keys: Set([PreferencesKeys.globalNotifications]))
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PreferencesView else {
                    preconditionFailure()
                }
                guard let notificationSettings = view.values[PreferencesKeys.globalNotifications]?.get(GlobalNotificationSettings.self) else {
                    return EngineGlobalNotificationSettings(GlobalNotificationSettings.defaultSettings.effective)
                }
                return EngineGlobalNotificationSettings(notificationSettings.effective)
            }
        }
    }
    
    enum Peer {
        public struct Peer: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<EnginePeer>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .basicPeer(self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? BasicPeerView else {
                    preconditionFailure()
                }
                guard let peer = view.peer else {
                    return nil
                }
                return EnginePeer(peer)
            }
        }

        public struct RenderedPeer: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<EngineRenderedPeer>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peer(peerId: self.id, components: [])
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerView else {
                    preconditionFailure()
                }
                var peers: [EnginePeer.Id: EnginePeer] = [:]
                guard let peer = view.peers[self.id] else {
                    return nil
                }
                peers[peer.id] = EnginePeer(peer)

                if let secretChat = peer as? TelegramSecretChat {
                    guard let mainPeer = view.peers[secretChat.regularPeerId] else {
                        return nil
                    }
                    peers[mainPeer.id] = EnginePeer(mainPeer)
                }

                return EngineRenderedPeer(peerId: self.id, peers: peers, associatedMedia: view.media)
            }
        }

        public struct Presence: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<EnginePeer.Presence>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peer(peerId: self.id, components: [])
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerView else {
                    preconditionFailure()
                }
                var presencePeerId = self.id
                if let secretChat = view.peers[self.id] as? TelegramSecretChat {
                    presencePeerId = secretChat.regularPeerId
                }
                guard let presence = view.peerPresences[presencePeerId] else {
                    return nil
                }
                return EnginePeer.Presence(presence)
            }
        }

        public struct NotificationSettings: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeer.NotificationSettings

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peer(peerId: self.id, components: [])
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerView else {
                    preconditionFailure()
                }
                guard let notificationSettings = view.notificationSettings as? TelegramPeerNotificationSettings else {
                    return EnginePeer.NotificationSettings(TelegramPeerNotificationSettings.defaultSettings)
                }
                return EnginePeer.NotificationSettings(notificationSettings)
            }
        }
        
        public struct ThreadNotificationSettings: TelegramEngineDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeer.NotificationSettings

            fileprivate var id: EnginePeer.Id
            fileprivate var threadId: Int64

            public init(id: EnginePeer.Id, threadId: Int64) {
                self.id = id
                self.threadId = threadId
            }

            var key: PostboxViewKey {
                return .messageHistoryThreadInfo(peerId: self.id, threadId: self.threadId)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? MessageHistoryThreadInfoView else {
                    preconditionFailure()
                }
                guard let data = view.info?.data.get(MessageHistoryThreadData.self) else {
                    return EnginePeer.NotificationSettings(TelegramPeerNotificationSettings.defaultSettings)
                }
                return EnginePeer.NotificationSettings(data.notificationSettings)
            }
        }

        public struct ParticipantCount: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<Int>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                switch cachedPeerData {
                case let channel as CachedChannelData:
                    return channel.participantsSummary.memberCount.flatMap(Int.init)
                case let group as CachedGroupData:
                    return group.participants?.participants.count
                default:
                    return nil
                }
            }
        }
        
        public struct Wallpaper: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<TelegramWallpaper>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                switch cachedPeerData {
                case let user as CachedUserData:
                    return user.wallpaper
                case let channel as CachedChannelData:
                    return channel.wallpaper
                default:
                    return nil
                }
            }
        }

        public struct GroupCallDescription: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<EngineGroupCallDescription>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                switch cachedPeerData {
                case let channel as CachedChannelData:
                    return channel.activeCall.flatMap(EngineGroupCallDescription.init)
                case let group as CachedGroupData:
                    return group.activeCall.flatMap(EngineGroupCallDescription.init)
                default:
                    return nil
                }
            }
        }

        public struct ExportedInvitation: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<EngineExportedPeerInvitation>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                switch cachedPeerData {
                case let channel as CachedChannelData:
                    return channel.exportedInvitation
                case let group as CachedGroupData:
                    return group.exportedInvitation
                default:
                    return nil
                }
            }
        }
        
        public struct StatsDatacenterId: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<Int32>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                switch cachedPeerData {
                case let channel as CachedChannelData:
                    return channel.statsDatacenterId
                default:
                    return nil
                }
            }
        }
        
        public struct ThemeEmoticon: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Optional<String>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedPeerData = view.cachedPeerData else {
                    return nil
                }
                if let cachedData = cachedPeerData as? CachedUserData {
                    return cachedData.themeEmoticon
                } else if let cachedData = cachedPeerData as? CachedGroupData {
                    return cachedData.themeEmoticon
                } else if let cachedData = cachedPeerData as? CachedChannelData {
                    return cachedData.themeEmoticon
                } else {
                    return nil
                }
            }
        }
        
        public struct IsContact: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .isContact(id: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? IsContactView else {
                    preconditionFailure()
                }
                return view.isContact
            }
        }
        
        public struct StickerPack: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = StickerPackCollectionInfo?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                guard let cachedData = view.cachedPeerData as? CachedChannelData else {
                    return nil
                }
                return cachedData.stickerPack
            }
        }
        
        public struct AllowedReactions: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<PeerAllowedReactions>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.allowedReactions
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return cachedData.allowedReactions
                } else {
                    return .unknown
                }
            }
        }
        
        public struct CallJoinAsPeerId: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeer.Id?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.callJoinPeerId
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return cachedData.callJoinPeerId
                } else {
                    return nil
                }
            }
        }
        
        public struct LinkedDiscussionPeerId: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<EnginePeer.Id?>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    switch cachedData.linkedDiscussionPeerId {
                    case let .known(value):
                        return .known(value)
                    case .unknown:
                        return .unknown
                    }
                } else {
                    return .unknown
                }
            }
        }
        
        public struct StatusSettings: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeer.StatusSettings?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return cachedData.peerStatusSettings.flatMap(EnginePeer.StatusSettings.init)
                } else if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.peerStatusSettings.flatMap(EnginePeer.StatusSettings.init)
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return cachedData.peerStatusSettings.flatMap(EnginePeer.StatusSettings.init)
                } else {
                    return nil
                }
            }
        }
        
        public struct AreVideoCallsAvailable: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return cachedData.videoCallsAvailable
                } else {
                    return false
                }
            }
        }
        
        public struct AreVoiceCallsAvailable: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return !cachedData.callsPrivate
                } else {
                    return true
                }
            }
        }
        
        public struct AreVoiceMessagesAvailable: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return cachedData.voiceMessagesAvailable
                } else {
                    return true
                }
            }
        }
        
        public struct AboutText: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<String?>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return .known(cachedData.about)
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return .known(cachedData.about)
                } else if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return .known(cachedData.about)
                } else {
                    return .unknown
                }
            }
        }
        
        public struct Photo: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<TelegramMediaImage?>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    if case let .known(value) = cachedData.photo {
                        return .known(value)
                    } else {
                        return .unknown
                    }
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return .known(cachedData.photo)
                } else if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return .known(cachedData.photo)
                } else {
                    return .unknown
                }
            }
        }
        
        public struct CanViewStats: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.flags.contains(.canViewStats)
                } else {
                    return false
                }
            }
        }
        
        public struct CanDeleteHistory: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.flags.contains(.canDeleteHistory)
                } else {
                    return false
                }
            }
        }
        
        public struct AntiSpamEnabled: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.flags.contains(.antiSpamEnabled)
                } else {
                    return false
                }
            }
        }
        
        public struct IsBlocked: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<Bool>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return .known(cachedData.isBlocked)
                } else {
                    return .unknown
                }
            }
        }
        
        public struct IsBlockedFromStories: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<Bool>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return .known(cachedData.flags.contains(.isBlockedFromStories))
                } else {
                    return .unknown
                }
            }
        }
        
        public struct TranslationHidden: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Bool

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedUserData {
                    return cachedData.flags.contains(.translationHidden)
                } else if let cachedData = view.cachedPeerData as? CachedGroupData {
                    return cachedData.flags.contains(.translationHidden)
                } else if let cachedData = view.cachedPeerData as? CachedChannelData {
                    return cachedData.flags.contains(.translationHidden)
                } else {
                    return false
                }
            }
        }
        
        public struct LegacyGroupParticipants: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EnginePeerCachedInfoItem<[EngineLegacyGroupParticipant]>

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .cachedPeerData(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? CachedPeerDataView else {
                    preconditionFailure()
                }
                if let cachedData = view.cachedPeerData as? CachedGroupData {
                    if let participants = cachedData.participants {
                        return .known(participants.participants.map(EngineLegacyGroupParticipant.init))
                    } else {
                        return .unknown
                    }
                } else {
                    return .unknown
                }
            }
        }
        
        public struct SecretChatKeyFingerprint: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = EngineSecretChatKeyFingerprint?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peerChatState(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerChatStateView else {
                    preconditionFailure()
                }
                
                if let peerChatState = view.chatState?.getLegacy() as? SecretChatState {
                    return peerChatState.keyFingerprint
                } else {
                    return nil
                }
            }
        }
        
        public struct SecretChatLayer: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = Int?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peerChatState(peerId: self.id)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerChatStateView else {
                    preconditionFailure()
                }
                
                if let peerChatState = view.chatState?.getLegacy() as? SecretChatState {
                    switch peerChatState.embeddedState {
                    case .terminated:
                        return nil
                    case .handshake:
                        return nil
                    case .basicLayer:
                        return 7
                    case let .sequenceBasedLayer(secretChatSequenceBasedLayerState):
                        return Int(secretChatSequenceBasedLayerState.layerNegotiationState.activeLayer.rawValue)
                    }
                } else {
                    return nil
                }
            }
        }
        
        public struct ThreadData: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public struct Key: Hashable {
                public var id: EnginePeer.Id
                public var threadId: Int64
                
                public init(id: EnginePeer.Id, threadId: Int64) {
                    self.id = id
                    self.threadId = threadId
                }
            }
            
            public typealias Result = MessageHistoryThreadData?

            fileprivate var id: EnginePeer.Id
            fileprivate var threadId: Int64
            
            public var mapKey: Key {
                return Key(id: self.id, threadId: self.threadId)
            }

            public init(id: EnginePeer.Id, threadId: Int64) {
                self.id = id
                self.threadId = threadId
            }

            var key: PostboxViewKey {
                return .messageHistoryThreadInfo(peerId: self.id, threadId: self.threadId)
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? MessageHistoryThreadInfoView else {
                    preconditionFailure()
                }
                
                return view.info?.data.get(MessageHistoryThreadData.self)
            }
        }
        
        public struct StoryStats: TelegramEngineDataItem, TelegramEngineMapKeyDataItem, PostboxViewDataItem {
            public typealias Result = PeerStoryStats?

            fileprivate var id: EnginePeer.Id
            public var mapKey: EnginePeer.Id {
                return self.id
            }

            public init(id: EnginePeer.Id) {
                self.id = id
            }

            var key: PostboxViewKey {
                return .peerStoryStats(peerIds: Set([self.id]))
            }

            func extract(view: PostboxView) -> Result {
                guard let view = view as? PeerStoryStatsView else {
                    preconditionFailure()
                }
                
                if let result = view.storyStats[self.id] {
                    return result
                } else {
                    return nil
                }
            }
        }
        
    }
}