//
//  ChatView.swift
//  SimpleX
//
//  Created by Evgeny Poberezkin on 27/01/2022.
//  Copyright © 2022 SimpleX Chat. All rights reserved.
//

import SwiftUI
import SimpleXChat
import SwiftyGif
import Combine

private let memberImageSize: CGFloat = 34

struct ChatView: View {
    @EnvironmentObject var chatModel: ChatModel
    @State var theme: AppTheme = buildTheme()
    @Environment(\.dismiss) var dismiss
    @Environment(\.colorScheme) var colorScheme
    @Environment(\.presentationMode) var presentationMode
    @Environment(\.scenePhase) var scenePhase
    @State @ObservedObject var chat: Chat
    @StateObject private var scrollModel = ReverseListScrollModel<ChatItem>()
    @StateObject private var floatingButtonModel = FloatingButtonModel()
    @State private var showChatInfoSheet: Bool = false
    @State private var showAddMembersSheet: Bool = false
    @State private var composeState = ComposeState()
    @State private var keyboardVisible = false
    @State private var connectionStats: ConnectionStats?
    @State private var customUserProfile: Profile?
    @State private var connectionCode: String?
    @State private var loadingItems = false
    @State private var firstPage = false
    @State private var revealedChatItem: ChatItem?
    @State private var searchMode = false
    @State private var searchText: String = ""
    @FocusState private var searchFocussed
    // opening GroupMemberInfoView on member icon
    @State private var selectedMember: GMember? = nil
    // opening GroupLinkView on link button (incognito)
    @State private var showGroupLinkSheet: Bool = false
    @State private var groupLink: String?
    @State private var groupLinkMemberRole: GroupMemberRole = .member

    var body: some View {
        if #available(iOS 16.0, *) {
            viewBody
            .scrollDismissesKeyboard(.immediately)
            .keyboardPadding()
        } else {
            viewBody
        }
    }

    private var viewBody: some View {
        let cInfo = chat.chatInfo
        return VStack(spacing: 0) {
            if searchMode {
                searchToolbar()
                Divider()
            }
            ZStack(alignment: .bottomTrailing) {
                let wallpaperImage = theme.wallpaper.type.image
                let wallpaperType = theme.wallpaper.type
                let backgroundColor = theme.wallpaper.background ?? wallpaperType.defaultBackgroundColor(theme.base, theme.colors.background)
                let tintColor = theme.wallpaper.tint ?? wallpaperType.defaultTintColor(theme.base)
                chatItemsList()
                    .if(wallpaperImage != nil) { view in
                        view.modifier(
                            ChatViewBackground(image: wallpaperImage!, imageType: wallpaperType, background: backgroundColor, tint: tintColor)
                        )
                }
                floatingButtons(counts: floatingButtonModel.unreadChatItemCounts)
            }
            connectingText()
            ComposeView(
                chat: chat,
                composeState: $composeState,
                keyboardVisible: $keyboardVisible
            )
            .disabled(!cInfo.sendMsgEnabled)
        }
        .padding(.top, 1)
        .navigationTitle(cInfo.chatViewName)
        .background(theme.colors.background)
        .navigationBarTitleDisplayMode(.inline)
        .environmentObject(theme)
        .onAppear {
            loadChat(chat: chat)
            initChatView()
        }
        .onChange(of: chatModel.chatId) { cId in
            showChatInfoSheet = false
            if let cId {
                if let c = chatModel.getChat(cId) {
                    chat = c
                }
                initChatView()
                theme = buildTheme()
            } else {
                dismiss()
            }
        }
        .onChange(of: revealedChatItem) { _ in
            NotificationCenter.postReverseListNeedsLayout()
        }
        .onChange(of: chatModel.reversedChatItems) { reversedChatItems in
            if reversedChatItems.count <= loadItemsPerPage && filtered(reversedChatItems).count < 10 {
                loadChatItems(chat.chatInfo)
            }
        }
        .environmentObject(scrollModel)
        .onDisappear {
            VideoPlayerView.players.removeAll()
            if chatModel.chatId == cInfo.id && !presentationMode.wrappedValue.isPresented {
                chatModel.chatId = nil
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.35) {
                    if chatModel.chatId == nil {
                        chatModel.chatItemStatuses = [:]
                        chatModel.reversedChatItems = []
                        chatModel.groupMembers = []
                        chatModel.groupMembersIndexes.removeAll()
                        chatModel.membersLoaded = false
                    }
                }
            }
        }
        .onChange(of: colorScheme) { _ in
            theme = buildTheme()
        }
        .toolbar {
            ToolbarItem(placement: .principal) {
                if case let .direct(contact) = cInfo {
                    Button {
                        Task {
                            do {
                                let (stats, profile) = try await apiContactInfo(chat.chatInfo.apiId)
                                let (ct, code) = try await apiGetContactCode(chat.chatInfo.apiId)
                                await MainActor.run {
                                    connectionStats = stats
                                    customUserProfile = profile
                                    connectionCode = code
                                    if contact.activeConn?.connectionCode != ct.activeConn?.connectionCode {
                                        chat.chatInfo = .direct(contact: ct)
                                    }
                                }
                            } catch let error {
                                logger.error("apiContactInfo or apiGetContactCode error: \(responseError(error))")
                            }
                            await MainActor.run { showChatInfoSheet = true }
                        }
                    } label: {
                        ChatInfoToolbar(chat: chat)
                    }
                    .appSheet(isPresented: $showChatInfoSheet, onDismiss: {
                        connectionStats = nil
                        customUserProfile = nil
                        connectionCode = nil
                        theme = buildTheme()
                    }) {
                        ChatInfoView(chat: chat, contact: contact, connectionStats: $connectionStats, customUserProfile: $customUserProfile, localAlias: chat.chatInfo.localAlias, connectionCode: $connectionCode)
                    }
                } else if case let .group(groupInfo) = cInfo {
                    Button {
                        Task { await chatModel.loadGroupMembers(groupInfo) { showChatInfoSheet = true } }
                    } label: {
                        ChatInfoToolbar(chat: chat)
                            .tint(theme.colors.primary)
                    }
                    .appSheet(isPresented: $showChatInfoSheet, onDismiss: { theme = buildTheme() }) {
                        GroupChatInfoView(
                            chat: chat,
                            groupInfo: Binding(
                                get: { groupInfo },
                                set: { gInfo in
                                    chat.chatInfo = .group(groupInfo: gInfo)
                                    chat.created = Date.now
                                }
                            )
                        )
                    }
                } else if case .local = cInfo {
                    ChatInfoToolbar(chat: chat)
                }
            }
            ToolbarItem(placement: .navigationBarTrailing) {
                switch cInfo {
                case let .direct(contact):
                    HStack {
                        let callsPrefEnabled = contact.mergedPreferences.calls.enabled.forUser
                        if callsPrefEnabled {
                            if chatModel.activeCall == nil {
                                callButton(contact, .audio, imageName: "phone")
                                    .disabled(!contact.ready || !contact.active)
                            } else if let call = chatModel.activeCall, call.contact.id == cInfo.id {
                                endCallButton(call)
                            }
                        }
                        Menu {
                            if callsPrefEnabled && chatModel.activeCall == nil {
                                Button {
                                    CallController.shared.startCall(contact, .video)
                                } label: {
                                    Label("Video call", systemImage: "video")
                                }
                                .disabled(!contact.ready || !contact.active)
                            }
                            searchButton()
                            ToggleNtfsButton(chat: chat)
                                .disabled(!contact.ready || !contact.active)
                        } label: {
                            Image(systemName: "ellipsis")
                        }
                    }
                case let .group(groupInfo):
                    HStack {
                        if groupInfo.canAddMembers {
                            if (chat.chatInfo.incognito) {
                                groupLinkButton()
                                    .appSheet(isPresented: $showGroupLinkSheet) {
                                        GroupLinkView(
                                            groupId: groupInfo.groupId,
                                            groupLink: $groupLink,
                                            groupLinkMemberRole: $groupLinkMemberRole,
                                            showTitle: true,
                                            creatingGroup: false
                                        )
                                    }
                            } else {
                                addMembersButton()
                                    .appSheet(isPresented: $showAddMembersSheet) {
                                        AddGroupMembersView(chat: chat, groupInfo: groupInfo)
                                    }
                            }
                        }
                        Menu {
                            searchButton()
                            ToggleNtfsButton(chat: chat)
                        } label: {
                            Image(systemName: "ellipsis")
                        }
                    }
                case .local:
                    searchButton()
                default:
                    EmptyView()
                }
            }
        }
    }
    
    private func initChatView() {
        let cInfo = chat.chatInfo
        // This check prevents the call to apiContactInfo after the app is suspended, and the database is closed.
        if case .active = scenePhase,
           case let .direct(contact) = cInfo {
            Task {
                do {
                    let (stats, _) = try await apiContactInfo(chat.chatInfo.apiId)
                    await MainActor.run {
                        if let s = stats {
                            chatModel.updateContactConnectionStats(contact, s)
                        }
                    }
                } catch let error {
                    logger.error("apiContactInfo error: \(responseError(error))")
                }
            }
        }
        if chatModel.draftChatId == cInfo.id && !composeState.forwarding,
           let draft = chatModel.draft {
            composeState = draft
        }
        if chat.chatStats.unreadChat {
            Task {
                await markChatUnread(chat, unreadChat: false)
            }
        }
    }

    private func searchToolbar() -> some View {
        HStack(spacing: 12) {
            HStack(spacing: 4) {
                Image(systemName: "magnifyingglass")
                TextField("Search", text: $searchText)
                    .focused($searchFocussed)
                    .foregroundColor(theme.colors.onBackground)
                    .frame(maxWidth: .infinity)

                Button {
                    searchText = ""
                } label: {
                    Image(systemName: "xmark.circle.fill").opacity(searchText == "" ? 0 : 1)
                }
            }
            .padding(EdgeInsets(top: 7, leading: 7, bottom: 7, trailing: 7))
            .foregroundColor(theme.colors.secondary)
            .background(Color(.tertiarySystemFill))
            .cornerRadius(10.0)

            Button ("Cancel") {
                searchText = ""
                searchMode = false
                searchFocussed = false
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.35) {
                    loadChat(chat: chat)
                }
            }
        }
        .padding(.horizontal)
        .padding(.vertical, 8)
    }

    private func voiceWithoutFrame(_ ci: ChatItem) -> Bool {
        ci.content.msgContent?.isVoice == true && ci.content.text.count == 0 && ci.quotedItem == nil && ci.meta.itemForwarded == nil
    }

    private func filtered(_ reversedChatItems: Array<ChatItem>) -> Array<ChatItem> {
        reversedChatItems
            .enumerated()
            .filter { (index, chatItem) in
                if let mergeCategory = chatItem.mergeCategory, index > .zero {
                    mergeCategory != reversedChatItems[index - 1].mergeCategory
                } else {
                    true
                }
            }
            .map { $0.element }
    }


    private func chatItemsList() -> some View {
        let cInfo = chat.chatInfo
        let mergedItems = filtered(chatModel.reversedChatItems)
        return GeometryReader { g in
            ReverseList(items: mergedItems, scrollState: $scrollModel.state) { ci in
                let voiceNoFrame = voiceWithoutFrame(ci)
                let maxWidth = cInfo.chatType == .group
                                ? voiceNoFrame
                                    ? (g.size.width - 28) - 42
                                    : (g.size.width - 28) * 0.84 - 42
                                : voiceNoFrame
                                    ? (g.size.width - 32)
                                    : (g.size.width - 32) * 0.84
                return chatItemView(ci, maxWidth)
                    .onAppear {
                        floatingButtonModel.appeared(viewId: ci.viewId)
                    }
                    .onDisappear {
                        floatingButtonModel.disappeared(viewId: ci.viewId)
                    }
                    .id(ci.id) // Required to trigger `onAppear` on iOS15
            } loadPage: {
                loadChatItems(cInfo)
            }
                .onTapGesture { hideKeyboard() }
                .onChange(of: searchText) { _ in
                    loadChat(chat: chat, search: searchText)
                }
                .onChange(of: chatModel.chatId) { chatId in
                    if let chatId, let c = chatModel.getChat(chatId) {
                        chat = c
                        showChatInfoSheet = false
                        loadChat(chat: c)
                    }
                }
                .onChange(of: chatModel.reversedChatItems) { _ in
                    floatingButtonModel.chatItemsChanged()
                }
        }
    }

    @ViewBuilder private func connectingText() -> some View {
        if case let .direct(contact) = chat.chatInfo,
           !contact.ready,
           contact.active,
           !contact.nextSendGrpInv {
            Text("connecting…")
                .font(.caption)
                .foregroundColor(theme.colors.secondary)
                .padding(.top)
        } else {
            EmptyView()
        }
    }

    class FloatingButtonModel: ObservableObject {
        private enum Event {
            case appeared(String)
            case disappeared(String)
            case chatItemsChanged
        }

        @Published var unreadChatItemCounts: UnreadChatItemCounts

        private let events = PassthroughSubject<Event, Never>()
        private var bag = Set<AnyCancellable>()

        init() {
            unreadChatItemCounts = UnreadChatItemCounts(
                isNearBottom: true,
                unreadBelow: .zero
            )
            events
                .receive(on: DispatchQueue.global(qos: .background))
                .scan(Set<String>()) { itemsInView, event in
                    return switch event {
                    case let .appeared(viewId):
                        itemsInView.union([viewId])
                    case let .disappeared(viewId):
                        itemsInView.subtracting([viewId])
                    case .chatItemsChanged:
                        itemsInView
                    }
                }
                .map { ChatModel.shared.unreadChatItemCounts(itemsInView: $0) }
                .removeDuplicates()
                .throttle(for: .seconds(0.2), scheduler: DispatchQueue.main, latest: true)
                .assign(to: \.unreadChatItemCounts, on: self)
                .store(in: &bag)
        }

        func appeared(viewId: String) {
            events.send(.appeared(viewId))
        }

        func disappeared(viewId: String) {
            events.send(.disappeared(viewId))
        }

        func chatItemsChanged() {
            events.send(.chatItemsChanged)
        }
    }

    private func floatingButtons(counts: UnreadChatItemCounts) -> some View {
        VStack {
            let unreadAbove = chat.chatStats.unreadCount - counts.unreadBelow
            if unreadAbove > 0 {
                circleButton {
                    unreadCountText(unreadAbove)
                        .font(.callout)
                        .foregroundColor(theme.colors.primary)
                }
                .onTapGesture {
                    scrollModel.scrollToNextPage()
                }
                .contextMenu {
                    Button {
                        Task {
                            await markChatRead(chat)
                        }
                    } label: {
                        Label("Mark read", systemImage: "checkmark")
                    }
                }
            }
            Spacer()
            if counts.unreadBelow > 0 {
                circleButton {
                    unreadCountText(counts.unreadBelow)
                        .font(.callout)
                        .foregroundColor(theme.colors.primary)
                }
                .onTapGesture {
                    scrollModel.scrollToBottom()
                }
            } else if !counts.isNearBottom {
                circleButton {
                    Image(systemName: "chevron.down")
                        .foregroundColor(theme.colors.primary)
                }
                .onTapGesture { scrollModel.scrollToBottom() }
            }
        }
        .padding()
    }

    private func circleButton<Content: View>(_ content: @escaping () -> Content) -> some View {
        ZStack {
            Circle()
                .foregroundColor(Color(uiColor: .tertiarySystemGroupedBackground))
                .frame(width: 44, height: 44)
            content()
        }
    }

    private func callButton(_ contact: Contact, _ media: CallMediaType, imageName: String) -> some View {
        Button {
            CallController.shared.startCall(contact, media)
        } label: {
            Image(systemName: imageName)
        }
    }

    private func endCallButton(_ call: Call) -> some View {
        Button {
            if let uuid = call.callkitUUID {
                CallController.shared.endCall(callUUID: uuid)
            } else {
                CallController.shared.endCall(call: call) {}
            }
        } label: {
            Image(systemName: "phone.down.fill").tint(.red)
        }
    }

    private func searchButton() -> some View {
        Button {
            searchMode = true
            searchFocussed = true
            searchText = ""
        } label: {
            Label("Search", systemImage: "magnifyingglass")
        }
    }

    private func addMembersButton() -> some View {
        Button {
            if case let .group(gInfo) = chat.chatInfo {
                Task { await chatModel.loadGroupMembers(gInfo) { showAddMembersSheet = true } }
            }
        } label: {
            Image(systemName: "person.crop.circle.badge.plus")
        }
    }

    private func groupLinkButton() -> some View {
        Button {
            if case let .group(gInfo) = chat.chatInfo {
                Task {
                    do {
                        if let link = try apiGetGroupLink(gInfo.groupId) {
                            (groupLink, groupLinkMemberRole) = link
                        }
                    } catch let error {
                        logger.error("ChatView apiGetGroupLink: \(responseError(error))")
                    }
                    showGroupLinkSheet = true
                }
            }
        } label: {
            Image(systemName: "link.badge.plus")
        }
    }

    private func loadChatItems(_ cInfo: ChatInfo) {
        Task {
            if loadingItems || firstPage { return }
            loadingItems = true
            do {
                var reversedPage = Array<ChatItem>()
                var chatItemsAvailable = true
                // Load additional items until the page is +50 large after merging
                while chatItemsAvailable && filtered(reversedPage).count < loadItemsPerPage {
                    let pagination: ChatPagination =
                        if let lastItem = reversedPage.last ?? chatModel.reversedChatItems.last {
                            .before(chatItemId: lastItem.id, count: loadItemsPerPage)
                        } else {
                            .last(count: loadItemsPerPage)
                        }
                    let chatItems = try await apiGetChatItems(
                        type: cInfo.chatType,
                        id: cInfo.apiId,
                        pagination: pagination,
                        search: searchText
                    )
                    chatItemsAvailable = !chatItems.isEmpty
                    reversedPage.append(contentsOf: chatItems.reversed())
                }
                await MainActor.run {
                    if reversedPage.count == 0 {
                        firstPage = true
                    } else {
                        chatModel.reversedChatItems.append(contentsOf: reversedPage)
                    }
                    loadingItems = false
                }
            } catch let error {
                logger.error("apiGetChat error: \(responseError(error))")
                await MainActor.run { loadingItems = false }
            }
        }
    }

    @ViewBuilder private func chatItemView(_ ci: ChatItem, _ maxWidth: CGFloat) -> some View {
        ChatItemWithMenu(
            chat: chat,
            chatItem: ci,
            maxWidth: maxWidth,
            composeState: $composeState,
            selectedMember: $selectedMember,
            revealedChatItem: $revealedChatItem
        )
    }

    private struct ChatItemWithMenu: View {
        @EnvironmentObject var m: ChatModel
        @EnvironmentObject var theme: AppTheme
        @ObservedObject var chat: Chat
        let chatItem: ChatItem
        let maxWidth: CGFloat
        @Binding var composeState: ComposeState
        @Binding var selectedMember: GMember?
        @Binding var revealedChatItem: ChatItem?

        @State private var deletingItem: ChatItem? = nil
        @State private var showDeleteMessage = false
        @State private var deletingItems: [Int64] = []
        @State private var showDeleteMessages = false
        @State private var showChatItemInfoSheet: Bool = false
        @State private var chatItemInfo: ChatItemInfo?
        @State private var showForwardingSheet: Bool = false

        @State private var allowMenu: Bool = true

        @State private var audioPlayer: AudioPlayer?
        @State private var playbackState: VoiceMessagePlaybackState = .noPlayback
        @State private var playbackTime: TimeInterval?

        var revealed: Bool { chatItem == revealedChatItem }

        var body: some View {
            let (currIndex, _) = m.getNextChatItem(chatItem)
            let ciCategory = chatItem.mergeCategory
            let (prevHidden, prevItem) = m.getPrevShownChatItem(currIndex, ciCategory)
            let range = itemsRange(currIndex, prevHidden)
            Group {
                if revealed, let range = range {
                    let items = Array(zip(Array(range), m.reversedChatItems[range]))
                    ForEach(items, id: \.1.viewId) { (i, ci) in
                        let prev = i == prevHidden ? prevItem : m.reversedChatItems[i + 1]
                        chatItemView(ci, nil, prev)
                    }
                } else {
                    chatItemView(chatItem, range, prevItem)
                }
            }
            .onAppear {
                markRead(
                    chatItems: range.flatMap { m.reversedChatItems[$0] }
                    ?? [chatItem]
                )
            }
        }

        private func markRead(chatItems: Array<ChatItem>.SubSequence) {
            let unreadItems = chatItems.filter { $0.isRcvNew }
            if unreadItems.isEmpty { return }
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.6) {
                if m.chatId == chat.chatInfo.id {
                    Task {
                        for unreadItem in unreadItems {
                            await apiMarkChatItemRead(chat.chatInfo, unreadItem)
                        }
                    }
                }
            }
        }

        @ViewBuilder func chatItemView(_ ci: ChatItem, _ range: ClosedRange<Int>?, _ prevItem: ChatItem?) -> some View {
            if case let .groupRcv(member) = ci.chatDir,
               case let .group(groupInfo) = chat.chatInfo {
                let (prevMember, memCount): (GroupMember?, Int) =
                    if let range = range {
                        m.getPrevHiddenMember(member, range)
                    } else {
                        (nil, 1)
                    }
                if prevItem == nil || showMemberImage(member, prevItem) || prevMember != nil {
                    VStack(alignment: .leading, spacing: 4) {
                        if ci.content.showMemberName {
                            Text(memberNames(member, prevMember, memCount))
                                .font(.caption)
                                .foregroundStyle(.secondary)
                                .lineLimit(2)
                                .padding(.leading, memberImageSize + 14)
                                .padding(.top, 7)
                        }
                        HStack(alignment: .top, spacing: 8) {
                            ProfileImage(imageStr: member.memberProfile.image, size: memberImageSize, backgroundColor: theme.colors.background)
                                .onTapGesture {
                                    if m.membersLoaded {
                                        selectedMember = m.getGroupMember(member.groupMemberId)
                                    } else {
                                        Task {
                                            await m.loadGroupMembers(groupInfo) {
                                                selectedMember = m.getGroupMember(member.groupMemberId)
                                            }
                                        }
                                    }
                                }
                                .appSheet(item: $selectedMember) { member in
                                    GroupMemberInfoView(groupInfo: groupInfo, groupMember: member, navigation: true)
                                }
                            chatItemWithMenu(ci, range, maxWidth)
                        }
                    }
                    .padding(.top, 5)
                    .padding(.trailing)
                    .padding(.leading, 12)
                } else {
                    chatItemWithMenu(ci, range, maxWidth)
                        .padding(.top, 5)
                        .padding(.trailing)
                        .padding(.leading, memberImageSize + 8 + 12)
                }
            } else {
                chatItemWithMenu(ci, range, maxWidth)
                    .padding(.horizontal)
                    .padding(.top, 5)
            }
        }

        private func memberNames(_ member: GroupMember, _ prevMember: GroupMember?, _ memCount: Int) -> LocalizedStringKey {
            let name = member.displayName
            return if let prevName = prevMember?.displayName {
                memCount > 2
                ? "\(name), \(prevName) and \(memCount - 2) members"
                : "\(name) and \(prevName)"
            } else {
                "\(name)"
            }
        }

        @ViewBuilder func chatItemWithMenu(_ ci: ChatItem, _ range: ClosedRange<Int>?, _ maxWidth: CGFloat) -> some View {
            let alignment: Alignment = ci.chatDir.sent ? .trailing : .leading
            VStack(alignment: alignment.horizontal, spacing: 3) {
                ChatItemView(
                    chat: chat,
                    chatItem: ci,
                    maxWidth: maxWidth,
                    revealed: .constant(revealed),
                    allowMenu: $allowMenu,
                    audioPlayer: $audioPlayer,
                    playbackState: $playbackState,
                    playbackTime: $playbackTime
                )
                .modifier(ChatItemClipped(ci))
                .contextMenu { menu(ci, range, live: composeState.liveMessage != nil) }
                .accessibilityLabel("")
                if ci.content.msgContent != nil && (ci.meta.itemDeleted == nil || revealed) && ci.reactions.count > 0 {
                    chatItemReactions(ci)
                        .padding(.bottom, 4)
                }
            }
                .confirmationDialog("Delete message?", isPresented: $showDeleteMessage, titleVisibility: .visible) {
                    Button("Delete for me", role: .destructive) {
                        deleteMessage(.cidmInternal)
                    }
                    if let di = deletingItem, di.meta.deletable && !di.localNote {
                        Button(broadcastDeleteButtonText, role: .destructive) {
                            deleteMessage(.cidmBroadcast)
                        }
                    }
                }
                .confirmationDialog(deleteMessagesTitle, isPresented: $showDeleteMessages, titleVisibility: .visible) {
                    Button("Delete for me", role: .destructive) {
                        deleteMessages()
                    }
                }
                .frame(maxWidth: maxWidth, maxHeight: .infinity, alignment: alignment)
                .frame(minWidth: 0, maxWidth: .infinity, alignment: alignment)
                .onDisappear {
                    if ci.content.msgContent?.isVoice == true {
                        allowMenu = true
                        audioPlayer?.stop()
                        playbackState = .noPlayback
                        playbackTime = TimeInterval(0)
                    }
                }
                .sheet(isPresented: $showChatItemInfoSheet, onDismiss: {
                    chatItemInfo = nil
                }) {
                    ChatItemInfoView(ci: ci, chatItemInfo: $chatItemInfo)
                }
                .sheet(isPresented: $showForwardingSheet) {
                    if #available(iOS 16.0, *) {
                        ChatItemForwardingView(ci: ci, fromChatInfo: chat.chatInfo, composeState: $composeState)
                            .presentationDetents([.fraction(0.8)])
                    } else {
                        ChatItemForwardingView(ci: ci, fromChatInfo: chat.chatInfo, composeState: $composeState)
                    }
                }
        }

        private func showMemberImage(_ member: GroupMember, _ prevItem: ChatItem?) -> Bool {
            switch (prevItem?.chatDir) {
            case .groupSnd: return true
            case let .groupRcv(prevMember): return prevMember.groupMemberId != member.groupMemberId
            default: return false
            }
        }

        private func chatItemReactions(_ ci: ChatItem) -> some View {
            HStack(spacing: 4) {
                ForEach(ci.reactions, id: \.reaction) { r in
                    let v = HStack(spacing: 4) {
                        switch r.reaction {
                        case let .emoji(emoji): Text(emoji.rawValue).font(.caption)
                        case .unknown: EmptyView()
                        }
                        if r.totalReacted > 1 {
                            Text("\(r.totalReacted)")
                                .font(.caption)
                                .fontWeight(r.userReacted ? .bold : .light)
                                .foregroundColor(r.userReacted ? theme.colors.primary : theme.colors.secondary)
                        }
                    }
                    .padding(.horizontal, 6)
                    .padding(.vertical, 4)

                    if chat.chatInfo.featureEnabled(.reactions) && (ci.allowAddReaction || r.userReacted) {
                        v.onTapGesture {
                            setReaction(ci, add: !r.userReacted, reaction: r.reaction)
                        }
                    } else {
                        v
                    }
                }
            }
        }

        @ViewBuilder
        private func menu(_ ci: ChatItem, _ range: ClosedRange<Int>?, live: Bool) -> some View {
            if let mc = ci.content.msgContent, ci.meta.itemDeleted == nil || revealed {
                if chat.chatInfo.featureEnabled(.reactions) && ci.allowAddReaction,
                   availableReactions.count > 0 {
                    reactionsGroup
                }
                if ci.meta.itemDeleted == nil && !ci.isLiveDummy && !live && !ci.localNote {
                    replyButton
                }
                let fileSource = getLoadedFileSource(ci.file)
                let fileExists = if let fs = fileSource, FileManager.default.fileExists(atPath: getAppFilePath(fs.filePath).path) { true } else { false }
                let copyAndShareAllowed = !ci.content.text.isEmpty || (ci.content.msgContent?.isImage == true && fileExists)
                if copyAndShareAllowed {
                    shareButton(ci)
                    copyButton(ci)
                }
                if let fileSource = fileSource, fileExists {
                    if case .image = ci.content.msgContent, let image = getLoadedImage(ci.file) {
                        if image.imageData != nil {
                            saveButton(file: fileSource)
                        } else {
                            saveButton(image: image)
                        }
                    } else {
                        saveButton(file: fileSource)
                    }
                } else if let file = ci.file, case .rcvInvitation = file.fileStatus, fileSizeValid(file) {
                    downloadButton(file: file)
                }
                if ci.meta.editable && !mc.isVoice && !live {
                    editButton(chatItem)
                }
                if ci.meta.itemDeleted == nil
                    && (ci.file == nil || (fileSource != nil && fileExists))
                    && !ci.isLiveDummy && !live {
                    forwardButton
                }
                if !ci.isLiveDummy {
                    viewInfoButton(ci)
                }
                if revealed {
                   hideButton()
                }
                if ci.meta.itemDeleted == nil && !ci.localNote,
                   let file = ci.file,
                   let cancelAction = file.cancelAction {
                    cancelFileButton(file.fileId, cancelAction)
                }
                if !live || !ci.meta.isLive {
                    deleteButton(ci)
                }
                if let (groupInfo, _) = ci.memberToModerate(chat.chatInfo) {
                    moderateButton(ci, groupInfo)
                }
            } else if ci.meta.itemDeleted != nil {
                if revealed {
                    hideButton()
                } else if !ci.isDeletedContent {
                    revealButton(ci)
                } else if range != nil {
                    expandButton()
                }
                viewInfoButton(ci)
                deleteButton(ci)
            } else if ci.isDeletedContent {
                viewInfoButton(ci)
                deleteButton(ci)
            } else if ci.mergeCategory != nil && ((range?.count ?? 0) > 1 || revealed) {
                if revealed { shrinkButton() } else { expandButton() }
                deleteButton(ci)
            } else if ci.showLocalDelete {
                deleteButton(ci)
            } else {
                EmptyView()
            }
        }

        var replyButton: Button<some View> {
            Button {
                withAnimation {
                    if composeState.editing {
                        composeState = ComposeState(contextItem: .quotedItem(chatItem: chatItem))
                    } else {
                        composeState = composeState.copy(contextItem: .quotedItem(chatItem: chatItem))
                    }
                }
            } label: {
                Label(
                    NSLocalizedString("Reply", comment: "chat item action"),
                    systemImage: "arrowshape.turn.up.left"
                )
            }
        }

        var forwardButton: Button<some View> {
            Button {
                showForwardingSheet = true
            } label: {
                Label(
                    NSLocalizedString("Forward", comment: "chat item action"),
                    systemImage: "arrowshape.turn.up.forward"
                )
            }
        }

        private var reactionsGroup: some View {
            if #available(iOS 16.4, *) {
                return ControlGroup {
                    if availableReactions.count > 4 {
                        reactions(till: 3)
                        Menu {
                            reactions(from: 3)
                        } label: {
                            Image(systemName: "ellipsis")
                        }
                    } else { reactions() }
                }.controlGroupStyle(.compactMenu)
            } else {
                return Menu {
                    reactions()
                } label: {
                    Label(
                        NSLocalizedString("React…", comment: "chat item menu"),
                        systemImage: "face.smiling"
                    )
                }
            }
        }

        func reactions(from: Int? = nil, till: Int? = nil) -> some View {
            ForEach(availableReactions[(from ?? .zero)..<(till ?? availableReactions.count)]) { reaction in
                Button(reaction.text) {
                    setReaction(chatItem, add: true, reaction: reaction)
                }
            }
        }

        /// Reactions, which has not been used yet
        private var availableReactions: Array<MsgReaction> {
            MsgReaction.values
                .filter { reaction in
                    !chatItem.reactions.contains {
                        $0.userReacted && $0.reaction == reaction
                    }
                }
        }

        private func setReaction(_ ci: ChatItem, add: Bool, reaction: MsgReaction) {
            Task {
                do {
                    let cInfo = chat.chatInfo
                    let chatItem = try await apiChatItemReaction(
                        type: cInfo.chatType,
                        id: cInfo.apiId,
                        itemId: ci.id,
                        add: add,
                        reaction: reaction
                    )
                    await MainActor.run {
                        m.updateChatItem(chat.chatInfo, chatItem)
                    }
                } catch let error {
                    logger.error("apiChatItemReaction error: \(responseError(error))")
                }
            }
        }

        private func shareButton(_ ci: ChatItem) -> Button<some View> {
            Button {
                var shareItems: [Any] = [ci.content.text]
                if case .image = ci.content.msgContent, let image = getLoadedImage(ci.file) {
                    shareItems.append(image)
                }
                showShareSheet(items: shareItems)
            } label: {
                Label(
                    NSLocalizedString("Share", comment: "chat item action"),
                    systemImage: "square.and.arrow.up"
                )
            }
        }

        private func copyButton(_ ci: ChatItem) -> Button<some View> {
            Button {
                if case let .image(text, _) = ci.content.msgContent,
                   text == "",
                   let image = getLoadedImage(ci.file) {
                    UIPasteboard.general.image = image
                } else {
                    UIPasteboard.general.string = ci.content.text
                }
            } label: {
                Label("Copy", systemImage: "doc.on.doc")
            }
        }

        func saveButton(image: UIImage) -> Button<some View> {
            Button {
                UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
            } label: {
                Label(
                    NSLocalizedString("Save", comment: "chat item action"),
                    systemImage: "square.and.arrow.down"
                )
            }
        }

        func saveButton(file: CryptoFile) -> Button<some View> {
            Button {
                saveCryptoFile(file)
            } label: {
                Label(
                    NSLocalizedString("Save", comment: "chat item action"),
                    systemImage: file.cryptoArgs == nil ? "square.and.arrow.down" : "lock.open"
                )
            }
        }

        func downloadButton(file: CIFile) -> Button<some View> {
            Button {
                Task {
                    logger.debug("ChatView downloadFileAction, in Task")
                    if let user = m.currentUser {
                        await receiveFile(user: user, fileId: file.fileId)
                    }
                }
            } label: {
                Label(
                    NSLocalizedString("Download", comment: "chat item action"),
                    systemImage: "arrow.down.doc"
                )
            }
        }

        private func editButton(_ ci: ChatItem) -> Button<some View> {
            Button {
                withAnimation {
                    composeState = ComposeState(editingItem: ci)
                }
            } label: {
                Label(
                    NSLocalizedString("Edit", comment: "chat item action"),
                    systemImage: "square.and.pencil"
                )
            }
        }

        private func viewInfoButton(_ ci: ChatItem) -> Button<some View> {
            Button {
                Task {
                    do {
                        let cInfo = chat.chatInfo
                        let ciInfo = try await apiGetChatItemInfo(type: cInfo.chatType, id: cInfo.apiId, itemId: ci.id)
                        await MainActor.run {
                            chatItemInfo = ciInfo
                        }
                        if case let .group(gInfo) = chat.chatInfo {
                            await m.loadGroupMembers(gInfo)
                        }
                    } catch let error {
                        logger.error("apiGetChatItemInfo error: \(responseError(error))")
                    }
                    await MainActor.run { showChatItemInfoSheet = true }
                }
            } label: {
                Label(
                    NSLocalizedString("Info", comment: "chat item action"),
                    systemImage: "info.circle"
                )
            }
        }

        private func cancelFileButton(_ fileId: Int64, _ cancelAction: CancelAction) -> Button<some View> {
            Button {
                AlertManager.shared.showAlert(Alert(
                    title: Text(cancelAction.alert.title),
                    message: Text(cancelAction.alert.message),
                    primaryButton: .destructive(Text(cancelAction.alert.confirm)) {
                        Task {
                            if let user = m.currentUser {
                                await cancelFile(user: user, fileId: fileId)
                            }
                        }
                    },
                    secondaryButton: .cancel()
                ))
            } label: {
                Label(
                    cancelAction.uiAction,
                    systemImage: "xmark"
                )
            }
        }

        private func hideButton() -> Button<some View> {
            Button {
                withConditionalAnimation {
                    revealedChatItem = nil
                }
            } label: {
                Label(
                    NSLocalizedString("Hide", comment: "chat item action"),
                    systemImage: "eye.slash"
                )
            }
        }

        private func deleteButton(_ ci: ChatItem) -> Button<some View> {
            Button(role: .destructive) {
                if !revealed,
                   let currIndex = m.getChatItemIndex(ci),
                   let ciCategory = ci.mergeCategory {
                    let (prevHidden, _) = m.getPrevShownChatItem(currIndex, ciCategory)
                    if let range = itemsRange(currIndex, prevHidden) {
                        var itemIds: [Int64] = []
                        for i in range {
                            itemIds.append(m.reversedChatItems[i].id)
                        }
                        showDeleteMessages = true
                        deletingItems = itemIds
                    } else {
                        showDeleteMessage = true
                        deletingItem = ci
                    }
                } else {
                    showDeleteMessage = true
                    deletingItem = ci
                }
            } label: {
                Label(
                    NSLocalizedString("Delete", comment: "chat item action"),
                    systemImage: "trash"
                )
            }
        }

        private func itemsRange(_ currIndex: Int?, _ prevHidden: Int?) -> ClosedRange<Int>? {
            if let currIndex = currIndex,
               let prevHidden = prevHidden,
               prevHidden > currIndex {
                currIndex...prevHidden
            } else {
                nil
            }
        }

        private func moderateButton(_ ci: ChatItem, _ groupInfo: GroupInfo) -> Button<some View> {
            Button(role: .destructive) {
                AlertManager.shared.showAlert(Alert(
                    title: Text("Delete member message?"),
                    message: Text(
                                groupInfo.fullGroupPreferences.fullDelete.on
                                ? "The message will be deleted for all members."
                                : "The message will be marked as moderated for all members."
                            ),
                    primaryButton: .destructive(Text("Delete")) {
                        deletingItem = ci
                        deleteMessage(.cidmBroadcast)
                    },
                    secondaryButton: .cancel()
                ))
            } label: {
                Label(
                    NSLocalizedString("Moderate", comment: "chat item action"),
                    systemImage: "flag"
                )
            }
        }

        private func revealButton(_ ci: ChatItem) -> Button<some View> {
            Button {
                withConditionalAnimation {
                    revealedChatItem = ci
                }
            } label: {
                Label(
                    NSLocalizedString("Reveal", comment: "chat item action"),
                    systemImage: "eye"
                )
            }
        }

        private func expandButton() -> Button<some View> {
            Button {
                withConditionalAnimation {
                    revealedChatItem = chatItem
                }
            } label: {
                Label(
                    NSLocalizedString("Expand", comment: "chat item action"),
                    systemImage: "arrow.up.and.line.horizontal.and.arrow.down"
                )
            }
        }

        private func shrinkButton() -> Button<some View> {
            Button {
                withConditionalAnimation {
                    revealedChatItem = nil
                }
            } label: {
                Label (
                    NSLocalizedString("Hide", comment: "chat item action"),
                    systemImage: "arrow.down.and.line.horizontal.and.arrow.up"
                )
            }
        }

        private var broadcastDeleteButtonText: LocalizedStringKey {
            chat.chatInfo.featureEnabled(.fullDelete) ? "Delete for everyone" : "Mark deleted for everyone"
        }

        var deleteMessagesTitle: LocalizedStringKey {
            let n = deletingItems.count
            return n == 1 ? "Delete message?" : "Delete \(n) messages?"
        }

        private func deleteMessages() {
            let itemIds = deletingItems
            if itemIds.count > 0 {
                let chatInfo = chat.chatInfo
                Task {
                    var deletedItems: [ChatItem] = []
                    for itemId in itemIds {
                        do {
                            let (di, _) = try await apiDeleteChatItem(
                                type: chatInfo.chatType,
                                id: chatInfo.apiId,
                                itemId: itemId,
                                mode: .cidmInternal
                            )
                            deletedItems.append(di)
                        } catch {
                            logger.error("ChatView.deleteMessage error: \(error.localizedDescription)")
                        }
                    }
                    await MainActor.run {
                        for di in deletedItems {
                            m.removeChatItem(chatInfo, di)
                        }
                    }
                }
            }
        }

        private func deleteMessage(_ mode: CIDeleteMode) {
            logger.debug("ChatView deleteMessage")
            Task {
                logger.debug("ChatView deleteMessage: in Task")
                do {
                    if let di = deletingItem {
                        var deletedItem: ChatItem
                        var toItem: ChatItem?
                        if case .cidmBroadcast = mode,
                           let (groupInfo, groupMember) = di.memberToModerate(chat.chatInfo) {
                            (deletedItem, toItem) = try await apiDeleteMemberChatItem(
                                groupId: groupInfo.apiId,
                                groupMemberId: groupMember.groupMemberId,
                                itemId: di.id
                            )
                        } else {
                            (deletedItem, toItem) = try await apiDeleteChatItem(
                                type: chat.chatInfo.chatType,
                                id: chat.chatInfo.apiId,
                                itemId: di.id,
                                mode: mode
                            )
                        }
                        DispatchQueue.main.async {
                            deletingItem = nil
                            if let toItem = toItem {
                                _ = m.upsertChatItem(chat.chatInfo, toItem)
                            } else {
                                m.removeChatItem(chat.chatInfo, deletedItem)
                            }
                        }
                    }
                } catch {
                    logger.error("ChatView.deleteMessage error: \(error.localizedDescription)")
                }
            }
        }
    }
}

private func buildTheme() -> AppTheme {
    if let cId = ChatModel.shared.chatId, let chat = ChatModel.shared.getChat(cId) {
        let perChatTheme = if case let .direct(contact) = chat.chatInfo {
            contact.uiThemes?.preferredMode(!AppTheme.shared.colors.isLight)
        } else if case let .group(groupInfo) = chat.chatInfo {
            groupInfo.uiThemes?.preferredMode(!AppTheme.shared.colors.isLight)
        } else {
            nil as ThemeModeOverride?
        }
        let overrides = if perChatTheme != nil {
            ThemeManager.currentColors(nil, perChatTheme, ChatModel.shared.currentUser?.uiThemes, themeOverridesDefault.get())
        } else {
            nil as ThemeManager.ActiveTheme?
        }
        let theme = overrides ?? CurrentColors
        return AppTheme(name: theme.name, base: theme.base, colors: theme.colors, appColors: theme.appColors, wallpaper: theme.wallpaper)
    } else {
        return AppTheme.shared
    }
}

struct ToggleNtfsButton: View {
    @ObservedObject var chat: Chat

    var body: some View {
        Button {
            toggleNotifications(chat, enableNtfs: !chat.chatInfo.ntfsEnabled)
        } label: {
            if chat.chatInfo.ntfsEnabled {
                Label("Mute", systemImage: "speaker.slash")
            } else {
                Label("Unmute", systemImage: "speaker.wave.2")
            }
        }
    }
}

func toggleNotifications(_ chat: Chat, enableNtfs: Bool) {
    var chatSettings = chat.chatInfo.chatSettings ?? ChatSettings.defaults
    chatSettings.enableNtfs = enableNtfs ? .all : .none
    updateChatSettings(chat, chatSettings: chatSettings)
}

func toggleChatFavorite(_ chat: Chat, favorite: Bool) {
    var chatSettings = chat.chatInfo.chatSettings ?? ChatSettings.defaults
    chatSettings.favorite = favorite
    updateChatSettings(chat, chatSettings: chatSettings)
}

func updateChatSettings(_ chat: Chat, chatSettings: ChatSettings) {
    Task {
        do {
            try await apiSetChatSettings(type: chat.chatInfo.chatType, id: chat.chatInfo.apiId, chatSettings: chatSettings)
            await MainActor.run {
                switch chat.chatInfo {
                case var .direct(contact):
                    contact.chatSettings = chatSettings
                    ChatModel.shared.updateContact(contact)
                case var .group(groupInfo):
                    groupInfo.chatSettings = chatSettings
                    ChatModel.shared.updateGroup(groupInfo)
                default: ()
                }
            }
        } catch let error {
            logger.error("apiSetChatSettings error \(responseError(error))")
        }
    }
}

struct ChatView_Previews: PreviewProvider {
    static var previews: some View {
        let chatModel = ChatModel()
        chatModel.chatId = "@1"
        chatModel.reversedChatItems = [
            ChatItem.getSample(1, .directSnd, .now, "hello"),
            ChatItem.getSample(2, .directRcv, .now, "hi"),
            ChatItem.getSample(3, .directRcv, .now, "hi there"),
            ChatItem.getDeletedContentSample(4),
            ChatItem.getSample(5, .directRcv, .now, "hello again"),
            ChatItem.getSample(6, .directSnd, .now, "hi there!!!"),
            ChatItem.getSample(7, .directSnd, .now, "how are you?"),
            ChatItem.getSample(8, .directSnd, .now, "👍👍👍👍"),
            ChatItem.getSample(9, .directSnd, .now, "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.")
        ]
        @State var showChatInfo = false
        return ChatView(chat: Chat(chatInfo: ChatInfo.sampleData.direct, chatItems: []))
            .environmentObject(chatModel)
    }
}