import AVFoundation
import AVKit
import Combine
import SwiftUI

struct AVMediaOptionItem: Identifiable, Hashable {
    let id: String
    let name: String
}

/// Native AVPlayer voor ClearKey-live via lokale clear-HLS proxy (on-device decrypt).
@MainActor
final class AVLivePlayerController: NSObject, ObservableObject {
    @Published var isPlaying = false
    @Published var stateText = "Laden…"
    @Published var hasError = false
    @Published var errorMessage: String?
    /// True als AVPlayer minstens één video-track / presentatiegrootte heeft.
    @Published var hasVideo = false
    @Published var audioOptions: [AVMediaOptionItem] = []
    @Published var subtitleOptions: [AVMediaOptionItem] = []
    @Published var currentAudioId: String?
    @Published var currentSubtitleId: String?
    /// True zodra we minstens één keer echt speelden — timeout mag dan niet meer afbreken.
    private var everPlayed = false

    let player = AVPlayer()
    private var proxySession = 0
    private var proxyActive = false
    private var timeControlObs: NSKeyValueObservation?
    private var itemStatusObs: NSKeyValueObservation?
    private var endObs: NSObjectProtocol?
    private var errorLogObs: NSObjectProtocol?
    private var stopping = false
    private var generation = 0
    private var audioGroup: AVMediaSelectionGroup?
    private var subtitleGroup: AVMediaSelectionGroup?
    private var audioOptionById: [String: AVMediaSelectionOption] = [:]
    private var subtitleOptionById: [String: AVMediaSelectionOption] = [:]

    override init() {
        super.init()
        configureAudioSession()
    }

    func play(
        url: URL,
        fallback: URL? = nil,
        format: String? = nil,
        clearKeys: [ClearKeyEntry] = []
    ) async {
        generation &+= 1
        let gen = generation
        stopping = false
        hasError = false
        errorMessage = nil
        hasVideo = false
        everPlayed = false
        audioOptions = []
        subtitleOptions = []
        currentAudioId = nil
        currentSubtitleId = nil
        audioGroup = nil
        subtitleGroup = nil
        audioOptionById = [:]
        subtitleOptionById = [:]
        stateText = "Live laden…"

        stopProxyIfNeeded()
        player.pause()
        player.replaceCurrentItem(with: nil)

        var playURL = url

        if !clearKeys.isEmpty {
            do {
                stateText = "ClearKey laden…"
                let started = try await ClearKeyDashProxy.shared.start(
                    manifestURL: url,
                    keys: clearKeys,
                    preferHlsForAVPlayer: true
                )
                guard gen == generation, !stopping else { return }
                playURL = started.url
                proxySession = started.session
                proxyActive = true
                proxyLogState("proxy ok \(playURL.absoluteString)")
            } catch {
                hasError = true
                errorMessage = "ClearKey-proxy: \(error.localizedDescription)"
                stateText = "Fout"
                return
            }
        } else {
            let fmt = (format ?? "").lowercased()
            let isHls = fmt == "hls" || ClearKeyDashProxy.isHlsURL(url)
            if !isHls, let fallback, ClearKeyDashProxy.isHlsURL(fallback) {
                playURL = fallback
            } else if !isHls {
                hasError = true
                errorMessage = "AVPlayer vereist HLS voor deze stream."
                stateText = "Fout"
                return
            }
        }

        guard gen == generation, !stopping else { return }
        await startItem(url: playURL, gen: gen)
    }

    func stop() {
        guard !stopping else { return }
        stopping = true
        generation &+= 1
        clearObservers()
        player.pause()
        // Eerst item loskoppelen, daarna proxy — voorkomt crash op half-open sockets.
        player.replaceCurrentItem(with: nil)
        stopProxyIfNeeded()
        isPlaying = false
        hasVideo = false
        audioOptions = []
        subtitleOptions = []
        stateText = "Gestopt"
    }

    func togglePlay() {
        if player.timeControlStatus == .playing {
            player.pause()
        } else {
            player.play()
        }
    }

    func refreshMediaOptions() {
        // ClearKey live: sporen uit de proxy (niet HLS multi-rendition — dat gaf -12312).
        let tracks = ClearKeyDashProxy.shared.availableAudioTracks()
        if !tracks.isEmpty {
            audioOptions = tracks.map { AVMediaOptionItem(id: $0.id, name: $0.name) }
            currentAudioId = ClearKeyDashProxy.shared.preferredAudioId ?? tracks.first?.id
        }
        guard let item = player.currentItem else { return }
        Task { await loadMediaOptions(for: item) }
    }

    func selectAudio(id: String) {
        // Proxy-spoor wisselen + item herladen (geen seamless HLS AUDIO switch).
        if ClearKeyDashProxy.shared.setPreferredAudio(id: id) {
            currentAudioId = id
            hasError = false
            errorMessage = nil
            Task { await reloadCurrentItemKeepingProxy() }
            return
        }
        guard let item = player.currentItem, let group = audioGroup,
              let option = audioOptionById[id] else { return }
        item.select(option, in: group)
        currentAudioId = id
    }

    func selectSubtitle(id: String?) {
        guard let item = player.currentItem, let group = subtitleGroup else { return }
        if let id, let option = subtitleOptionById[id] {
            item.select(option, in: group)
            currentSubtitleId = id
        } else {
            item.select(nil, in: group)
            currentSubtitleId = nil
        }
    }

    /// Herlaad dezelfde lokale HLS-URL na audio-wissel zonder proxy te stoppen.
    private func reloadCurrentItemKeepingProxy() async {
        guard let asset = player.currentItem?.asset as? AVURLAsset else { return }
        let url = asset.url
        let gen = generation
        stateText = "Audio wisselen…"
        await startItem(url: url, gen: gen)
    }

    // MARK: - Private

    private func startItem(url: URL, gen: Int) async {
        stateText = "Openen…"
        let asset = AVURLAsset(url: url, options: [
            AVURLAssetAllowsCellularAccessKey: true,
            AVURLAssetAllowsExpensiveNetworkAccessKey: true,
            AVURLAssetAllowsConstrainedNetworkAccessKey: true,
        ])
        let item = AVPlayerItem(asset: asset)
        item.preferredForwardBufferDuration = 6
        clearObservers()

        itemStatusObs = item.observe(\.status, options: [.new, .initial]) { [weak self] item, _ in
            Task { @MainActor in
                guard let self, self.generation == gen, !self.stopping else { return }
                switch item.status {
                case .readyToPlay:
                    self.stateText = "Afspelen"
                    self.hasError = false
                    self.refreshHasVideo(from: item)
                    // Eerst play — loadMediaOptions mag start niet blokkeren (Prime/HBO voelde traag).
                    self.player.play()
                    self.everPlayed = true
                    await self.loadMediaOptions(for: item)
                case .failed:
                    self.fail(from: item.error, gen: gen)
                default:
                    break
                }
            }
        }

        timeControlObs = player.observe(\.timeControlStatus, options: [.new]) { [weak self] player, _ in
            Task { @MainActor in
                guard let self, self.generation == gen, !self.stopping else { return }
                switch player.timeControlStatus {
                case .playing:
                    self.isPlaying = true
                    self.everPlayed = true
                    self.stateText = "Afspelen"
                    self.hasError = false
                    if let item = player.currentItem {
                        self.refreshHasVideo(from: item)
                    }
                case .waitingToPlayAtSpecifiedRate:
                    self.isPlaying = false
                    // Na first-play: bufferen is normaal — geen "Fout"-timeout.
                    self.stateText = self.everPlayed ? "Bufferen…" : "Bufferen…"
                case .paused:
                    self.isPlaying = false
                    if !self.hasError { self.stateText = "Pauze" }
                @unknown default:
                    break
                }
            }
        }

        endObs = NotificationCenter.default.addObserver(
            forName: .AVPlayerItemFailedToPlayToEndTime,
            object: item,
            queue: .main
        ) { [weak self] note in
            Task { @MainActor in
                guard let self, self.generation == gen, !self.stopping else { return }
                let err = note.userInfo?[AVPlayerItemFailedToPlayToEndTimeErrorKey] as? Error
                self.fail(from: err, gen: gen)
            }
        }

        errorLogObs = NotificationCenter.default.addObserver(
            forName: .AVPlayerItemNewErrorLogEntry,
            object: item,
            queue: .main
        ) { [weak self] _ in
            Task { @MainActor in
                guard let self, self.generation == gen else { return }
                if let events = item.errorLog()?.events, let last = events.last {
                    let comment = last.errorComment ?? last.errorDomain
                    self.proxyLogState("AV errorLog: \(last.errorStatusCode) \(comment ?? "")")
                    // -12312 bij audio-wissel: niet meteen als fatale UI-fout tonen.
                    if last.errorStatusCode == -12312 { return }
                }
            }
        }

        player.replaceCurrentItem(with: item)
        player.automaticallyWaitsToMinimizeStalling = true
        player.play()

        // Timeout alleen als er NOOIT iets speelde — nooit een werkende/bufferende stream afbreken.
        Task { @MainActor in
            try? await Task.sleep(nanoseconds: 20_000_000_000)
            guard self.generation == gen, !self.stopping else { return }
            if let item = self.player.currentItem {
                self.refreshHasVideo(from: item)
            }
            if self.everPlayed || self.isPlaying { return }
            if !self.hasError {
                if let err = item.error {
                    self.fail(from: err, gen: gen)
                } else {
                    self.hasError = true
                    self.errorMessage = self.bestErrorMessage(for: item)
                        ?? "Stream opende niet binnen 20s (ClearKey/HLS)."
                    self.stateText = "Fout"
                }
            }
        }
    }

    private func refreshHasVideo(from item: AVPlayerItem) {
        if item.presentationSize.height > 1 {
            hasVideo = true
            return
        }
        let video = item.tracks.contains { track in
            track.assetTrack?.mediaType == .video
        }
        hasVideo = video
    }

    private func loadMediaOptions(for item: AVPlayerItem) async {
        let asset = item.asset
        do {
            let proxyTracks = ClearKeyDashProxy.shared.availableAudioTracks()
            if !proxyTracks.isEmpty {
                audioOptions = proxyTracks.map { AVMediaOptionItem(id: $0.id, name: $0.name) }
                audioOptionById = [:]
                audioGroup = nil
                currentAudioId = ClearKeyDashProxy.shared.preferredAudioId ?? proxyTracks.first?.id
            } else {
                let audible = try await asset.loadMediaSelectionGroup(for: .audible)
                audioGroup = audible
                if let audible {
                    var opts: [AVMediaOptionItem] = []
                    var map: [String: AVMediaSelectionOption] = [:]
                    for (i, opt) in audible.options.enumerated() {
                        let id = "a-\(i)-\(opt.displayName)"
                        let name = opt.displayName.isEmpty ? "Audio \(i + 1)" : opt.displayName
                        opts.append(AVMediaOptionItem(id: id, name: name))
                        map[id] = opt
                    }
                    audioOptions = opts
                    audioOptionById = map
                    if let selected = item.selectedMediaOption(in: audible),
                       let match = map.first(where: { $0.value == selected })?.key {
                        currentAudioId = match
                    } else {
                        currentAudioId = opts.first?.id
                    }
                } else {
                    audioOptions = []
                    audioOptionById = [:]
                }
            }

            let legible = try await asset.loadMediaSelectionGroup(for: .legible)
            subtitleGroup = legible
            if let legible {
                var opts: [AVMediaOptionItem] = [AVMediaOptionItem(id: "off", name: "Uit")]
                var map: [String: AVMediaSelectionOption] = [:]
                for (i, opt) in legible.options.enumerated() where !opt.hasMediaCharacteristic(.containsOnlyForcedSubtitles) {
                    let id = "s-\(i)-\(opt.displayName)"
                    let name = opt.displayName.isEmpty ? "Ondertitel \(i + 1)" : opt.displayName
                    opts.append(AVMediaOptionItem(id: id, name: name))
                    map[id] = opt
                }
                subtitleOptions = opts
                subtitleOptionById = map
                if let selected = item.selectedMediaOption(in: legible),
                   let match = map.first(where: { $0.value == selected })?.key {
                    currentSubtitleId = match
                } else {
                    currentSubtitleId = "off"
                }
            } else {
                subtitleOptions = [AVMediaOptionItem(id: "off", name: "Uit")]
                subtitleOptionById = [:]
                currentSubtitleId = "off"
            }
        } catch {
            proxyLogState("media options: \(error.localizedDescription)")
        }
    }

    private func fail(from error: Error?, gen: Int) {
        guard generation == gen, !stopping else { return }
        let ns = (error as NSError?)
        // Playlist-mismatch tijdens live/audio-wissel — negeren als we nog (opnieuw) laden.
        if let ns, ns.domain == "CoreMediaErrorDomain", ns.code == -12312 {
            proxyLogState("ignore -12312: \(ns.localizedDescription)")
            return
        }
        hasError = true
        if let error {
            errorMessage = dutchAVError(error)
        } else if let item = player.currentItem {
            errorMessage = bestErrorMessage(for: item) ?? "Kon stream niet openen"
        } else {
            errorMessage = "Kon stream niet openen"
        }
        // Toon geen -12312 als enige melding.
        if let msg = errorMessage, msg.contains("-12312") {
            errorMessage = nil
            hasError = false
            return
        }
        stateText = "Fout"
        isPlaying = false
    }

    private func bestErrorMessage(for item: AVPlayerItem) -> String? {
        if let err = item.error {
            let ns = err as NSError
            if ns.domain == "CoreMediaErrorDomain", ns.code == -12312 { return nil }
            return dutchAVError(err)
        }
        if let events = item.errorLog()?.events, let last = events.last {
            if last.errorStatusCode == -12312 { return nil }
            let code = last.errorStatusCode
            let comment = last.errorComment ?? last.errorDomain
            return "Afspeelfout (\(code)): \(comment)"
        }
        return nil
    }

    private func dutchAVError(_ error: Error) -> String {
        let ns = error as NSError
        if ns.domain == "CoreMediaErrorDomain" {
            return "Mediafout (\(ns.code)). Vaak ongeldige HLS of decrypt. Probeer opnieuw."
        }
        return error.localizedDescription
    }

    private func stopProxyIfNeeded() {
        if proxyActive {
            let session = proxySession
            proxyActive = false
            proxySession = 0
            ClearKeyDashProxy.shared.stop(session: session)
        }
    }

    private func clearObservers() {
        timeControlObs?.invalidate()
        timeControlObs = nil
        itemStatusObs?.invalidate()
        itemStatusObs = nil
        if let endObs {
            NotificationCenter.default.removeObserver(endObs)
            self.endObs = nil
        }
        if let errorLogObs {
            NotificationCenter.default.removeObserver(errorLogObs)
            self.errorLogObs = nil
        }
    }

    private func configureAudioSession() {
        let session = AVAudioSession.sharedInstance()
        do {
            try session.setCategory(.playback, mode: .moviePlayback, options: [])
            try session.setActive(true)
        } catch {}
    }

    private func proxyLogState(_ msg: String) {
        #if DEBUG
        print("[AVLive] \(msg)")
        #endif
    }
}

/// AVPlayerLayer i.p.v. AVPlayerViewController:
/// - schaalt mee bij rotatie zonder seek/rebind (geen haperen)
/// - voorkomt ESPN “alleen audio” na landscape (AVPlayerViewController-compositor-bug)
struct AVLivePlayerView: UIViewRepresentable {
    let controller: AVLivePlayerController

    func makeUIView(context: Context) -> AVLivePlayerLayerView {
        let view = AVLivePlayerLayerView()
        view.player = controller.player
        return view
    }

    func updateUIView(_ uiView: AVLivePlayerLayerView, context: Context) {
        if uiView.player !== controller.player {
            uiView.player = controller.player
        }
    }

    static func dismantleUIView(_ uiView: AVLivePlayerLayerView, coordinator: ()) {
        uiView.player = nil
    }
}

final class AVLivePlayerLayerView: UIView {
    override class var layerClass: AnyClass { AVPlayerLayer.self }

    private var playerLayer: AVPlayerLayer { layer as! AVPlayerLayer }

    var player: AVPlayer? {
        get { playerLayer.player }
        set {
            playerLayer.player = newValue
            playerLayer.videoGravity = .resizeAspect
        }
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .black
        isUserInteractionEnabled = false
        playerLayer.videoGravity = .resizeAspect
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        playerLayer.frame = bounds
    }
}