import CoreMedia
import Defaults
import Foundation
import SDWebImageSwiftUI
import SwiftUI

struct VideoBanner: View {
    var id: String?
    let video: Video?
    var playbackTime: CMTime?
    var videoDuration: TimeInterval?
    var watch: Watch?

    @Default(.saveHistory) private var saveHistory
    @Default(.watchedVideoStyle) private var watchedVideoStyle
    @Default(.watchedVideoBadgeColor) private var watchedVideoBadgeColor

    @Environment(\.inChannelView) private var inChannelView
    @Environment(\.inNavigationView) private var inNavigationView
    @Environment(\.navigationStyle) private var navigationStyle

    init(
        id: String? = nil,
        video: Video? = nil,
        playbackTime: CMTime? = nil,
        videoDuration: TimeInterval? = nil,
        watch: Watch? = nil
    ) {
        self.id = id
        self.video = video
        self.playbackTime = playbackTime
        self.videoDuration = videoDuration
        self.watch = watch
    }

    var body: some View {
        HStack(alignment: .top, spacing: 12) {
            VStack(spacing: 2) {
                smallThumbnail

                #if !os(tvOS)
                    progressView
                #endif
            }
            VStack(alignment: .leading, spacing: 2) {
                Group {
                    if let video {
                        HStack(alignment: .top) {
                            Text(video.displayTitle)
                            if video.isLocal, let fileExtension = video.localStreamFileExtension {
                                Spacer()
                                Text(fileExtension)
                                    .foregroundColor(.secondary)
                            }
                        }
                    } else {
                        Text("Loading contents of the video, please wait")
                            .redacted(reason: .placeholder)
                    }
                }
                .truncationMode(.middle)
                .lineLimit(5)
                .font(.headline)

                Spacer()

                HStack {
                    Group {
                        if let video {
                            if !inChannelView, !video.isLocal || video.localStreamIsRemoteURL {
                                channelControl
                            } else {
                                #if os(iOS)
                                    if DocumentsModel.shared.isDocument(video) {
                                        HStack(spacing: 6) {
                                            if let date = DocumentsModel.shared.formattedCreationDate(video) {
                                                Text(date)
                                            }
                                            if let size = DocumentsModel.shared.formattedSize(video) {
                                                Text("•")
                                                Text(size)
                                            }

                                            Spacer()
                                        }
                                        .frame(maxWidth: .infinity)
                                    }
                                #endif
                            }
                        } else {
                            Text("Video Author")
                                .redacted(reason: .placeholder)
                        }
                    }
                    .lineLimit(1)

                    #if os(tvOS)
                        extraAttributes
                    #endif
                }
                .foregroundColor(.secondary)

                #if !os(tvOS)
                    extraAttributes
                #endif
            }
            .frame(maxWidth: .infinity, alignment: .leading)
            .frame(maxHeight: .infinity)
            #if os(tvOS)
                .padding(.vertical)
            #endif
        }
        .fixedSize(horizontal: false, vertical: true)
        .contentShape(Rectangle())
        #if os(tvOS)
            .buttonStyle(.card)
        #else
            .buttonStyle(.plain)
        #endif
        #if os(tvOS)
        .padding(.trailing, 10)
        #endif
        .opacity(contentOpacity)
        .id(id ?? video?.videoID ?? video?.id)
    }

    private var extraAttributes: some View {
        HStack(spacing: 16) {
            if let video {
                if let date = video.publishedDate {
                    HStack(spacing: 2) {
                        Text(date)
                            .allowsTightening(true)
                    }
                }

                if video.views > 0 {
                    HStack(spacing: 2) {
                        Image(systemName: "eye")
                        Text(video.viewsCount!)
                    }
                }
            }

            if timeInfo {
                Spacer()

                #if os(tvOS)
                    progressView
                #endif

                timeLabel
                    .layoutPriority(1)
            }
        }
        .font(.caption)
        .lineLimit(1)
        .foregroundColor(.secondary)
    }

    @ViewBuilder private var smallThumbnail: some View {
        ZStack(alignment: .bottomLeading) {
            ZStack {
                Color("PlaceholderColor")
                if let video {
                    if let thumbnail = video.thumbnailURL(quality: .medium) {
                        ThumbnailView(url: thumbnail)
                    } else if video.isLocal {
                        Image(systemName: video.localStreamImageSystemName)
                    }
                } else {
                    Image(systemName: "ellipsis")
                }
            }

            if saveHistory,
               watchedVideoStyle.isShowingBadge,
               watch?.finished ?? false
            {
                Image(systemName: "checkmark.circle.fill")
                    .foregroundColor(Color(
                        watchedVideoBadgeColor == .colorSchemeBased ? "WatchProgressBarColor" :
                            watchedVideoBadgeColor == .red ? "AppRedColor" : "AppBlueColor"
                    ))
                    .background(Color.white)
                    .clipShape(Circle())
                    .imageScale(.medium)
                    .offset(x: 5, y: -5)
            }
        }
        #if os(tvOS)
        .frame(width: thumbnailWidth, height: thumbnailHeight)
        .mask(RoundedRectangle(cornerRadius: 12))
        #else
        .frame(width: thumbnailWidth, height: thumbnailHeight)
        .mask(RoundedRectangle(cornerRadius: 6))
        #endif
    }

    private var contentOpacity: Double {
        guard saveHistory,
              !watch.isNil,
              watchedVideoStyle == .decreasedOpacity || watchedVideoStyle == .both
        else {
            return 1
        }

        return watch!.finished ? 0.5 : 1
    }

    private var thumbnailWidth: Double {
        #if os(tvOS)
            250
        #else
            100
        #endif
    }

    private var thumbnailHeight: Double {
        #if os(tvOS)
            140
        #else
            60
        #endif
    }

    private var videoDurationLabel: String? {
        guard videoDuration != 0 else { return nil }
        return (videoDuration ?? video?.length)?.formattedAsPlaybackTime()
    }

    private var watchStoppedAtLabel: String? {
        guard let watch else { return nil }

        return watch.stoppedAt.formattedAsPlaybackTime(allowZero: true)
    }

    var timeInfo: Bool {
        videoDurationLabel != nil && (video == nil || !video!.localStreamIsDirectory)
    }

    @ViewBuilder private var timeLabel: some View {
        Group {
            if let watch, let watchStoppedAtLabel, let videoDurationLabel, !watch.finished {
                Text("\(watchStoppedAtLabel) / \(videoDurationLabel)")
            } else if let videoDurationLabel {
                Text(videoDurationLabel)
            } else {
                EmptyView()
            }
        }
    }

    private var progressView: some View {
        ProgressView(value: watchValue, total: progressViewTotal)
            .progressViewStyle(.linear)
            .frame(maxWidth: thumbnailWidth)
            .opacity(showProgressView ? 1 : 0)
            .frame(height: 12)
    }

    private var showProgressView: Bool {
        guard playbackTime != nil,
              let video,
              !video.live
        else {
            return false
        }

        return true
    }

    private var watchValue: Double {
        if finished { return progressViewTotal }

        return progressViewValue
    }

    private var progressViewValue: Double {
        guard videoDuration != 0 else { return 1 }
        return [playbackTime?.seconds, videoDuration].compactMap { $0 }.min() ?? 0
    }

    private var progressViewTotal: Double {
        guard videoDuration != 0 else { return 1 }
        return videoDuration ?? video?.length ?? 1
    }

    private var finished: Bool {
        (progressViewValue / progressViewTotal) * 100 > Double(Defaults[.watchedThreshold])
    }

    @ViewBuilder private var channelControl: some View {
        if let video, !video.displayAuthor.isEmpty {
            #if os(tvOS)
                displayAuthor
            #else
                if navigationStyle == .tab, inNavigationView {
                    channelNavigationLink
                } else {
                    channelButton
                }
            #endif
        }
    }

    @ViewBuilder private var channelNavigationLink: some View {
        if let channel = video?.channel {
            NavigationLink(destination: ChannelVideosView(channel: channel)) {
                displayAuthor
            }
        }
    }

    @ViewBuilder private var channelButton: some View {
        if let video {
            Button {
                guard !inChannelView else { return }

                NavigationModel.shared.openChannel(
                    video.channel,
                    navigationStyle: navigationStyle
                )
            } label: {
                displayAuthor
            }
            #if os(tvOS)
            .buttonStyle(.card)
            #else
            .buttonStyle(.plain)
            #endif
            .help("\(video.channel.name) Channel")
        }
    }

    @ViewBuilder private var displayAuthor: some View {
        if let video, !video.displayAuthor.isEmpty {
            Text(video.displayAuthor)
                .fontWeight(.semibold)
                .foregroundColor(.secondary)
        }
    }
}

struct VideoBanner_Previews: PreviewProvider {
    static var previews: some View {
        VStack(spacing: 2) {
            VideoBanner(video: Video.fixture, playbackTime: CMTime(seconds: 400, preferredTimescale: 10000))
            VideoBanner(video: Video.fixtureUpcomingWithoutPublishedOrViews)
            VideoBanner(video: .local(URL(string: "https://apple.com/a/directory/of/video+that+has+very+long+title+that+will+likely.mp4")!))
            VideoBanner(video: .local(URL(string: "file://a/b/c/d/e/f.mkv")!))
            VideoBanner()
        }
        .frame(maxWidth: 1300)
    }
}