//
//  CIVoiceView.swift
//  SimpleX (iOS)
//
//  Created by JRoberts on 22.11.2022.
//  Copyright © 2022 SimpleX Chat. All rights reserved.
//

import SwiftUI
import SimpleXChat

struct CIVoiceView: View {
    @ObservedObject var chat: Chat
    @EnvironmentObject var theme: AppTheme
    var chatItem: ChatItem
    let recordingFile: CIFile?
    let duration: Int
    @State var audioPlayer: AudioPlayer? = nil
    @State var playbackState: VoiceMessagePlaybackState = .noPlayback
    @State var playbackTime: TimeInterval? = nil

    @Binding var allowMenu: Bool
    var smallViewSize: CGFloat?
    @State private var seek: (TimeInterval) -> Void = { _ in }

    var body: some View {
        Group {
            if smallViewSize != nil {
                HStack(spacing: 10) {
                    player()
                    playerTime()
                        .allowsHitTesting(false)
                    if .playing == playbackState || (playbackTime ?? 0) > 0 || !allowMenu {
                        playbackSlider()
                    }
                }
            } else if chatItem.chatDir.sent {
                VStack (alignment: .trailing, spacing: 6) {
                    HStack {
                        if .playing == playbackState || (playbackTime ?? 0) > 0 || !allowMenu {
                            playbackSlider()
                        }
                        playerTime()
                        player()
                    }
                    .frame(alignment: .trailing)
                    metaView().padding(.trailing, 10)
                }
            } else {
                VStack (alignment: .leading, spacing: 6) {
                    HStack {
                        player()
                        playerTime()
                        if .playing == playbackState || (playbackTime ?? 0) > 0 || !allowMenu {
                            playbackSlider()
                        }
                    }
                    .frame(alignment: .leading)
                    metaView().padding(.leading, -6)
                }
            }
        }
        .padding(.top, 4)
        .padding(.bottom, 8)
    }

    private func player() -> some View {
        let sizeMultiplier: CGFloat = if let sz = smallViewSize {
            voiceMessageSizeBasedOnSquareSize(sz) / 56
        } else {
            1
        }
        return VoiceMessagePlayer(
            chat: chat,
            chatItem: chatItem,
            recordingFile: recordingFile,
            recordingTime: TimeInterval(duration),
            showBackground: true,
            seek: $seek,
            audioPlayer: $audioPlayer,
            playbackState: $playbackState,
            playbackTime: $playbackTime,
            allowMenu: $allowMenu,
            sizeMultiplier: sizeMultiplier
        )
    }

    private func playerTime() -> some View {
        VoiceMessagePlayerTime(
            recordingTime: TimeInterval(duration),
            playbackState: $playbackState,
            playbackTime: $playbackTime
        )
        .foregroundColor(theme.colors.secondary)
    }
    
    private func playbackSlider() -> some View {
            ComposeVoiceView.SliderBar(
                length: TimeInterval(duration),
                progress: $playbackTime,
                seek: {
                    let time = max(0.0001, $0)
                    seek(time)
                    playbackTime = time
                })
            .onChange(of: .playing == playbackState || (playbackTime ?? 0) > 0) { show in
                if !show {
                    allowMenu = true
                }
            }
            .tint(theme.colors.primary)
    }

    private func metaView() -> some View {
        CIMetaView(chat: chat, chatItem: chatItem, metaColor: theme.colors.secondary)
    }
}

struct VoiceMessagePlayerTime: View {
    var recordingTime: TimeInterval
    @Binding var playbackState: VoiceMessagePlaybackState
    @Binding var playbackTime: TimeInterval?

    var body: some View {
        ZStack(alignment: .leading) {
            Text(String("66:66")).foregroundColor(.clear)
            switch playbackState {
            case .noPlayback:
                Text(voiceMessageTime(recordingTime))
            case .playing:
                Text(voiceMessageTime_(playbackTime))
            case .paused:
                Text(voiceMessageTime_(playbackTime))
            }
        }
    }
}

struct VoiceMessagePlayer: View {
    @ObservedObject var chat: Chat
    @EnvironmentObject var chatModel: ChatModel
    @EnvironmentObject var theme: AppTheme
    var chatItem: ChatItem
    var recordingFile: CIFile?
    var recordingTime: TimeInterval
    var showBackground: Bool

    @Binding var seek: (TimeInterval) -> Void
    @Binding var audioPlayer: AudioPlayer?
    @Binding var playbackState: VoiceMessagePlaybackState
    @Binding var playbackTime: TimeInterval?

    @Binding var allowMenu: Bool
    var sizeMultiplier: CGFloat

    var body: some View {
        ZStack {
            if let recordingFile = recordingFile {
                switch recordingFile.fileStatus {
                case .sndStored:
                    if recordingFile.fileProtocol == .local {
                        playbackButton()
                    } else {
                        loadingIcon()
                    }
                case .sndTransfer: loadingIcon()
                case .sndComplete: playbackButton()
                case .sndCancelled: playbackButton()
                case let .sndError(sndFileError):
                    fileStatusIcon("multiply", 14)
                        .onTapGesture {
                            AlertManager.shared.showAlert(Alert(
                                title: Text("File error"),
                                message: Text(sndFileError.errorInfo)
                            ))
                        }
                case let .sndWarning(sndFileError):
                    fileStatusIcon("exclamationmark.triangle.fill", 16)
                        .onTapGesture {
                            AlertManager.shared.showAlert(Alert(
                                title: Text("Temporary file error"),
                                message: Text(sndFileError.errorInfo)
                            ))
                        }
                case .rcvInvitation: downloadButton(recordingFile, "play.fill")
                case .rcvAccepted: loadingIcon()
                case .rcvTransfer: loadingIcon()
                case .rcvAborted: downloadButton(recordingFile, "exclamationmark.arrow.circlepath")
                case .rcvComplete: playbackButton()
                case .rcvCancelled: playPauseIcon("play.fill", Color(uiColor: .tertiaryLabel))
                case let .rcvError(rcvFileError):
                    fileStatusIcon("multiply", 14)
                        .onTapGesture {
                            AlertManager.shared.showAlert(Alert(
                                title: Text("File error"),
                                message: Text(rcvFileError.errorInfo)
                            ))
                        }
                case let .rcvWarning(rcvFileError):
                    fileStatusIcon("exclamationmark.triangle.fill", 16)
                        .onTapGesture {
                            AlertManager.shared.showAlert(Alert(
                                title: Text("Temporary file error"),
                                message: Text(rcvFileError.errorInfo)
                            ))
                        }
                case .invalid: playPauseIcon("play.fill", Color(uiColor: .tertiaryLabel))
                }
            } else {
                playPauseIcon("play.fill", Color(uiColor: .tertiaryLabel))
            }
        }
        .onAppear {
            if audioPlayer == nil {
                let small = sizeMultiplier != 1
                audioPlayer = small ? VoiceItemState.smallView[VoiceItemState.id(chat, chatItem)]?.audioPlayer : VoiceItemState.chatView[VoiceItemState.id(chat, chatItem)]?.audioPlayer
                playbackState = (small ? VoiceItemState.smallView[VoiceItemState.id(chat, chatItem)]?.playbackState : VoiceItemState.chatView[VoiceItemState.id(chat, chatItem)]?.playbackState) ?? .noPlayback
                playbackTime = small ? VoiceItemState.smallView[VoiceItemState.id(chat, chatItem)]?.playbackTime : VoiceItemState.chatView[VoiceItemState.id(chat, chatItem)]?.playbackTime
            }
            seek = { to in audioPlayer?.seek(to) }
            let audioPath: URL? = if let recordingSource = getLoadedFileSource(recordingFile) {
                getAppFilePath(recordingSource.filePath)
            } else {
                nil
            }
            let chatId = chatModel.chatId
            let userId = chatModel.currentUser?.userId
            audioPlayer?.onTimer = {
                playbackTime = $0
                notifyStateChange()
                // Manual check here is needed because when this view is not visible, SwiftUI don't react on stopPreviousRecPlay, chatId and current user changes and audio keeps playing when it should stop
                if (audioPath != nil && chatModel.stopPreviousRecPlay != audioPath) || chatModel.chatId != chatId || chatModel.currentUser?.userId != userId {
                    stopPlayback()
                }
            }
            audioPlayer?.onFinishPlayback = {
                playbackState = .noPlayback
                playbackTime = TimeInterval(0)
                notifyStateChange()
            }
            // One voice message was paused, then scrolled far from it, started to play another one, drop to stopped state
            if let audioPath, chatModel.stopPreviousRecPlay != audioPath {
                stopPlayback()
            }
        }
        .onChange(of: chatModel.stopPreviousRecPlay) { it in
            if let recordingFileName = getLoadedFileSource(recordingFile)?.filePath,
               chatModel.stopPreviousRecPlay != getAppFilePath(recordingFileName) {
                stopPlayback()
            }
        }
        .onChange(of: playbackState) { state in
            allowMenu = state == .paused || state == .noPlayback
            // Notify activeContentPreview in ChatPreviewView that playback is finished
            if state == .noPlayback, let recordingFileName = getLoadedFileSource(recordingFile)?.filePath,
               chatModel.stopPreviousRecPlay == getAppFilePath(recordingFileName) {
                chatModel.stopPreviousRecPlay = nil
            }
        }
        .onChange(of: chatModel.chatId) { _ in
            stopPlayback()
        }
        .onDisappear {
            if sizeMultiplier == 1 && chatModel.chatId == nil {
                stopPlayback()
            }
        }
    }

    @ViewBuilder private func playbackButton() -> some View {
        if sizeMultiplier != 1 {
            switch playbackState {
            case .noPlayback:
                playPauseIcon("play.fill", theme.colors.primary)
                    .onTapGesture {
                        if let recordingSource = getLoadedFileSource(recordingFile) {
                            startPlayback(recordingSource)
                        }
                    }
            case .playing:
                playPauseIcon("pause.fill", theme.colors.primary)
                    .onTapGesture {
                        audioPlayer?.pause()
                        playbackState = .paused
                        notifyStateChange()
                    }
            case .paused:
                playPauseIcon("play.fill", theme.colors.primary)
                    .onTapGesture {
                        audioPlayer?.play()
                        playbackState = .playing
                        notifyStateChange()
                    }
            }
        } else {
            switch playbackState {
            case .noPlayback:
                Button {
                    if let recordingSource = getLoadedFileSource(recordingFile) {
                        startPlayback(recordingSource)
                    }
                } label: {
                    playPauseIcon("play.fill", theme.colors.primary)
                }
            case .playing:
                Button {
                    audioPlayer?.pause()
                    playbackState = .paused
                    notifyStateChange()
                } label: {
                    playPauseIcon("pause.fill", theme.colors.primary)
                }
            case .paused:
                Button {
                    audioPlayer?.play()
                    playbackState = .playing
                    notifyStateChange()
                } label: {
                    playPauseIcon("play.fill", theme.colors.primary)
                }
            }
        }
    }

    private func playPauseIcon(_ image: String, _ color: Color/* = .accentColor*/) -> some View {
        ZStack {
            Image(systemName: image)
                .resizable()
                .aspectRatio(contentMode: .fit)
                .frame(width: 20 * sizeMultiplier, height: 20 * sizeMultiplier)
                .foregroundColor(color)
                .padding(.leading, image == "play.fill" ? 4 : 0)
                .frame(width: 56 * sizeMultiplier, height: 56 * sizeMultiplier)
                .background(showBackground ? chatItemFrameColor(chatItem, theme) : .clear)
                .clipShape(Circle())
            if recordingTime > 0 {
                ProgressCircle(length: recordingTime, progress: $playbackTime)
                    .frame(width: 53 * sizeMultiplier, height: 53 * sizeMultiplier) // this + ProgressCircle lineWidth = background circle diameter
            }
        }
    }

    private func downloadButton(_ recordingFile: CIFile, _ icon: String) -> some View {
        Group {
            if sizeMultiplier != 1 {
                playPauseIcon(icon, theme.colors.primary)
                    .onTapGesture {
                        Task {
                            if let user = chatModel.currentUser {
                                await receiveFile(user: user, fileId: recordingFile.fileId)
                            }
                        }
                    }
            } else {
                Button {
                    Task {
                        if let user = chatModel.currentUser {
                            await receiveFile(user: user, fileId: recordingFile.fileId)
                        }
                    }
                } label: {
                    playPauseIcon(icon, theme.colors.primary)
                }
            }
        }
    }

    func notifyStateChange() {
        if sizeMultiplier != 1 {
            VoiceItemState.smallView[VoiceItemState.id(chat, chatItem)] = VoiceItemState(audioPlayer: audioPlayer, playbackState: playbackState, playbackTime: playbackTime)
        } else {
            VoiceItemState.chatView[VoiceItemState.id(chat, chatItem)] = VoiceItemState(audioPlayer: audioPlayer, playbackState: playbackState, playbackTime: playbackTime)
        }
    }

    private struct ProgressCircle: View {
        @EnvironmentObject var theme: AppTheme
        var length: TimeInterval
        @Binding var progress: TimeInterval?

        var body: some View {
            Circle()
                .trim(from: 0, to: ((progress ?? TimeInterval(0)) / length))
                .stroke(
                    theme.colors.primary,
                    style: StrokeStyle(lineWidth: 3)
                )
                .rotationEffect(.degrees(-90))
                .animation(.linear, value: progress)
        }
    }

    private func fileStatusIcon(_ image: String, _ size: CGFloat) -> some View {
        Image(systemName: image)
            .resizable()
            .aspectRatio(contentMode: .fit)
            .frame(width: size * sizeMultiplier, height: size * sizeMultiplier)
            .foregroundColor(Color(uiColor: .tertiaryLabel))
            .frame(width: 56 * sizeMultiplier, height: 56 * sizeMultiplier)
            .background(showBackground ? chatItemFrameColor(chatItem, theme) : .clear)
            .clipShape(Circle())
    }

    private func loadingIcon() -> some View {
        ProgressView()
            .frame(width: 30 * sizeMultiplier, height: 30 * sizeMultiplier)
            .frame(width: 56 * sizeMultiplier, height: 56 * sizeMultiplier)
            .background(showBackground ? chatItemFrameColor(chatItem, theme) : .clear)
            .clipShape(Circle())
    }

    private func startPlayback(_ recordingSource: CryptoFile) {
        let audioPath = getAppFilePath(recordingSource.filePath)
        let chatId = chatModel.chatId
        let userId = chatModel.currentUser?.userId
        chatModel.stopPreviousRecPlay = audioPath
        audioPlayer = AudioPlayer(
            onTimer: {
                playbackTime = $0
                notifyStateChange()
                // Manual check here is needed because when this view is not visible, SwiftUI don't react on stopPreviousRecPlay, chatId and current user changes and audio keeps playing when it should stop
                if chatModel.stopPreviousRecPlay != audioPath || chatModel.chatId != chatId || chatModel.currentUser?.userId != userId {
                    stopPlayback()
                }
            },
            onFinishPlayback: {
                playbackState = .noPlayback
                playbackTime = TimeInterval(0)
                notifyStateChange()
            }
        )
        audioPlayer?.start(fileSource: recordingSource, at: playbackTime)
        playbackState = .playing
        notifyStateChange()
    }

    private func stopPlayback() {
        audioPlayer?.stop()
        playbackState = .noPlayback
        playbackTime = TimeInterval(0)
        notifyStateChange()
    }
}

func voiceMessageSizeBasedOnSquareSize(_ squareSize: CGFloat) -> CGFloat {
    let squareToCircleRatio = 0.935
    return squareSize + squareSize * (1 - squareToCircleRatio)
}

class VoiceItemState {
    var audioPlayer: AudioPlayer?
    var playbackState: VoiceMessagePlaybackState
    var playbackTime: TimeInterval?

    init(audioPlayer: AudioPlayer? = nil, playbackState: VoiceMessagePlaybackState, playbackTime: TimeInterval? = nil) {
        self.audioPlayer = audioPlayer
        self.playbackState = playbackState
        self.playbackTime = playbackTime
    }

    static func id(_ chat: Chat, _ chatItem: ChatItem) -> String {
        "\(chat.id) \(chatItem.id)"
    }

    static func id(_ chatInfo: ChatInfo, _ chatItem: ChatItem) -> String {
        "\(chatInfo.id) \(chatItem.id)"
    }

    static func stopVoiceInSmallView(_ chatInfo: ChatInfo, _ chatItem: ChatItem) {
        let id = id(chatInfo, chatItem)
        if let item = smallView[id] {
            item.audioPlayer?.stop()
            ChatModel.shared.stopPreviousRecPlay = nil
        }
    }

    static func stopVoiceInChatView(_ chatInfo: ChatInfo, _ chatItem: ChatItem) {
        let id = id(chatInfo, chatItem)
        if let item = chatView[id] {
            item.audioPlayer?.stop()
            ChatModel.shared.stopPreviousRecPlay = nil
        }
    }

    static var smallView: [String: VoiceItemState] = [:]
    static var chatView: [String: VoiceItemState] = [:]
}

struct CIVoiceView_Previews: PreviewProvider {
    static var previews: some View {
        let sentVoiceMessage: ChatItem = ChatItem(
            chatDir: .directSnd,
            meta: CIMeta.getSample(1, .now, "", .sndSent(sndProgress: .complete), itemEdited: true),
            content: .sndMsgContent(msgContent: .voice(text: "", duration: 30)),
            quotedItem: nil,
            file: CIFile.getSample(fileStatus: .sndComplete)
        )
        let voiceMessageWtFile = ChatItem(
            chatDir: .directRcv,
            meta: CIMeta.getSample(1, .now, "", .rcvRead),
            content: .rcvMsgContent(msgContent: .voice(text: "", duration: 30)),
            quotedItem: nil,
            file: nil
        )
        Group {
            CIVoiceView(
                chat: Chat.sampleData,
                chatItem: ChatItem.getVoiceMsgContentSample(),
                recordingFile: CIFile.getSample(fileName: "voice.m4a", fileSize: 65536, fileStatus: .rcvComplete),
                duration: 30,
                allowMenu: Binding.constant(true)
            )
            ChatItemView(chat: Chat.sampleData, chatItem: sentVoiceMessage, allowMenu: .constant(true))
            ChatItemView(chat: Chat.sampleData, chatItem: ChatItem.getVoiceMsgContentSample(), allowMenu: .constant(true))
            ChatItemView(chat: Chat.sampleData, chatItem: ChatItem.getVoiceMsgContentSample(fileStatus: .rcvTransfer(rcvProgress: 7, rcvTotal: 10)), allowMenu: .constant(true))
            ChatItemView(chat: Chat.sampleData, chatItem: voiceMessageWtFile, allowMenu: .constant(true))
        }
        .previewLayout(.fixed(width: 360, height: 360))
    }
}