import SwiftUI
import Network

// MARK: - Downloads View
struct DownloadsView: View {
    @EnvironmentObject var offlineManager: OfflineManager
    @EnvironmentObject var audioPlayer: AudioPlayer
    @ObservedObject private var watchManager = WatchConnectivityManager.shared
    
    @State private var selectedTab: DownloadTab = .offline
    
    enum DownloadTab: String, CaseIterable {
        case offline = "Offline"
        case watch = "Watch"
    }
    
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                // Tab picker
                Picker("", selection: $selectedTab) {
                    ForEach(DownloadTab.allCases, id: \.self) { tab in
                        Text(tab.rawValue).tag(tab)
                    }
                }
                .pickerStyle(.segmented)
                .padding(.horizontal, 16)
                .padding(.vertical, 10)
                
                switch selectedTab {
                case .offline:
                    offlineTab
                case .watch:
                    watchTab
                }
            }
            .background(Color(white: 0.06))
            .navigationTitle("Downloads")
        }
    }
    
    // MARK: - Offline Tab
    
    private var offlineTab: some View {
        List {
            // Storage info
            Section {
                HStack {
                    Image(systemName: "internaldrive")
                        .foregroundColor(accentPink)
                    Text("Storage Used")
                    Spacer()
                    Text(offlineManager.formattedSize)
                        .foregroundColor(.gray)
                }
                
                HStack {
                    Image(systemName: "music.note")
                        .foregroundColor(accentPink)
                    Text("Downloaded Songs")
                    Spacer()
                    Text("\(offlineManager.downloadedSongs.count)")
                        .foregroundColor(.gray)
                }
            }
            
            // Downloaded songs
            Section("Offline Songs") {
                if offlineManager.downloadedSongs.isEmpty {
                    VStack(spacing: 12) {
                        Image(systemName: "arrow.down.circle")
                            .font(.system(size: 36))
                            .foregroundColor(.gray)
                        Text("No downloads yet")
                            .font(.system(size: 14))
                            .foregroundColor(.gray)
                        Text("Download songs from albums or playlists to listen offline")
                            .font(.system(size: 12))
                            .foregroundColor(.gray.opacity(0.7))
                            .multilineTextAlignment(.center)
                    }
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 20)
                } else {
                    ForEach(offlineManager.downloadedSongs) { downloaded in
                        Button(action: {
                            audioPlayer.play(
                                song: downloaded.song,
                                fromQueue: offlineManager.downloadedSongs.map { $0.song }
                            )
                        }) {
                            HStack(spacing: 12) {
                                AsyncCoverArt(
                                    coverArtId: downloaded.song.coverArt,
                                    size: 44
                                )
                                .frame(width: 44, height: 44)
                                .cornerRadius(3)
                                
                                VStack(alignment: .leading, spacing: 2) {
                                    Text(downloaded.song.title)
                                        .font(.system(size: 15))
                                        .foregroundColor(
                                            audioPlayer.currentSong?.id == downloaded.id ? accentPink : .white
                                        )
                                        .lineLimit(1)
                                    Text(downloaded.song.artist ?? "")
                                        .font(.system(size: 12))
                                        .foregroundColor(.gray)
                                }
                                
                                Spacer()
                                
                                VStack(alignment: .trailing, spacing: 2) {
                                    Text(downloaded.song.durationFormatted)
                                        .font(.system(size: 12))
                                        .foregroundColor(.gray)
                                    Text(ByteCountFormatter.string(fromByteCount: downloaded.fileSize, countStyle: .file))
                                        .font(.system(size: 10))
                                        .foregroundColor(.gray.opacity(0.7))
                                }
                            }
                        }
                    }
                    .onDelete { offsets in
                        for idx in offsets {
                            offlineManager.removeSong(offlineManager.downloadedSongs[idx].id)
                        }
                    }
                }
            }
            
            // Remove all
            if !offlineManager.downloadedSongs.isEmpty {
                Section {
                    Button("Remove All Downloads", role: .destructive) {
                        offlineManager.removeAll()
                    }
                }
            }
        }
    }
    
    // MARK: - Watch Tab
    
    private var watchTab: some View {
        List {
            if !watchManager.isWatchPaired {
                Section {
                    VStack(spacing: 12) {
                        Image(systemName: "applewatch.slash")
                            .font(.system(size: 36))
                            .foregroundColor(.gray)
                        Text("No Apple Watch Paired")
                            .font(.system(size: 15, weight: .medium))
                            .foregroundColor(.white)
                        Text("Pair an Apple Watch and install the app to send music")
                            .font(.system(size: 12))
                            .foregroundColor(.gray)
                            .multilineTextAlignment(.center)
                    }
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 20)
                }
            } else {
                // Watch status
                Section {
                    HStack(spacing: 10) {
                        Image(systemName: watchManager.isReachable ? "applewatch.radiowaves.left.and.right" : "applewatch")
                            .foregroundColor(watchManager.isReachable ? .green : .gray)
                            .font(.system(size: 18))
                        VStack(alignment: .leading, spacing: 2) {
                            Text(watchManager.isReachable ? "Watch App Active" : "Watch App Not Running")
                                .font(.system(size: 14, weight: .medium))
                                .foregroundColor(.white)
                            Text(watchManager.isReachable
                                 ? "Files will transfer immediately"
                                 : "Open the app on your watch to receive files")
                                .font(.system(size: 11))
                                .foregroundColor(.gray)
                        }
                        Spacer()
                        if watchManager.isReachable {
                            Button(action: { watchManager.requestWatchSongList() }) {
                                Image(systemName: "arrow.clockwise")
                                    .font(.system(size: 13))
                                    .foregroundColor(accentPink)
                            }
                        }
                    }
                } header: {
                    Text("Status")
                }
                
                // Pending transfers
                if !watchManager.transferringIds.isEmpty {
                    Section {
                        ForEach(watchManager.pendingTransferList, id: \.id) { item in
                            HStack(spacing: 12) {
                                ZStack {
                                    Circle()
                                        .stroke(Color.white.opacity(0.1), lineWidth: 3)
                                    Circle()
                                        .trim(from: 0, to: item.progress)
                                        .stroke(accentPink, style: StrokeStyle(lineWidth: 3, lineCap: .round))
                                        .rotationEffect(.degrees(-90))
                                    Text("\(Int(item.progress * 100))")
                                        .font(.system(size: 9, weight: .bold, design: .monospaced))
                                        .foregroundColor(.gray)
                                }
                                .frame(width: 32, height: 32)
                                
                                VStack(alignment: .leading, spacing: 2) {
                                    Text(item.title)
                                        .font(.system(size: 14))
                                        .foregroundColor(.white)
                                        .lineLimit(1)
                                    GeometryReader { geo in
                                        ZStack(alignment: .leading) {
                                            Capsule().fill(Color.white.opacity(0.1)).frame(height: 3)
                                            Capsule().fill(accentPink)
                                                .frame(width: geo.size.width * item.progress, height: 3)
                                        }
                                    }
                                    .frame(height: 3)
                                }
                                Spacer()
                            }
                        }
                        .onDelete { indexSet in
                            let list = watchManager.pendingTransferList
                            for idx in indexSet {
                                if idx < list.count {
                                    watchManager.cancelTransfer(songId: list[idx].id)
                                }
                            }
                        }
                        
                        if watchManager.transferringIds.count > 1 {
                            Button(role: .destructive, action: { watchManager.cancelAllTransfers() }) {
                                HStack {
                                    Image(systemName: "xmark.circle")
                                    Text("Cancel All (\(watchManager.transferringIds.count))")
                                }
                                .font(.system(size: 13))
                            }
                        }
                    } header: {
                        Text("Pending Transfers (\(watchManager.transferringIds.count))")
                    }
                }
                
                // Completed
                if !watchManager.transferredIds.isEmpty {
                    Section {
                        HStack(spacing: 8) {
                            Image(systemName: "checkmark.circle.fill")
                                .foregroundColor(.green)
                            Text("\(watchManager.transferredIds.count) songs sent")
                                .font(.system(size: 14))
                                .foregroundColor(.white)
                            Spacer()
                            Button("Clear") { watchManager.transferredIds.removeAll() }
                                .font(.system(size: 13))
                                .foregroundColor(accentPink)
                        }
                    } header: {
                        Text("Recently Sent")
                    }
                }
                
                // Songs on watch
                Section {
                    if watchManager.isLoadingWatchSongs {
                        HStack {
                            ProgressView().tint(accentPink)
                            Text("Loading watch library...")
                                .font(.system(size: 13))
                                .foregroundColor(.gray)
                                .padding(.leading, 8)
                        }
                    } else if watchManager.watchSongs.isEmpty {
                        VStack(spacing: 8) {
                            Image(systemName: "applewatch")
                                .font(.system(size: 24))
                                .foregroundColor(.gray)
                            Text(watchManager.isReachable ? "No songs on Watch" : "Connect watch to view songs")
                                .font(.system(size: 13))
                                .foregroundColor(.gray)
                        }
                        .frame(maxWidth: .infinity)
                        .padding(.vertical, 12)
                    } else {
                        HStack {
                            Text("\(watchManager.watchSongs.count) songs")
                                .font(.system(size: 13, weight: .medium))
                                .foregroundColor(.white)
                            Spacer()
                            let totalSize = watchManager.watchSongs.reduce(0) { $0 + $1.fileSize }
                            Text(ByteCountFormatter.string(fromByteCount: totalSize, countStyle: .file))
                                .font(.system(size: 13))
                                .foregroundColor(.gray)
                        }
                        
                        ForEach(watchManager.watchSongs) { song in
                            HStack(spacing: 12) {
                                Image(systemName: "music.note")
                                    .font(.system(size: 12))
                                    .foregroundColor(accentPink)
                                    .frame(width: 24)
                                VStack(alignment: .leading, spacing: 2) {
                                    Text(song.title)
                                        .font(.system(size: 14))
                                        .foregroundColor(.white)
                                        .lineLimit(1)
                                    Text("\(song.artist) · \(song.album)")
                                        .font(.system(size: 11))
                                        .foregroundColor(.gray)
                                        .lineLimit(1)
                                }
                                Spacer()
                                Text(ByteCountFormatter.string(fromByteCount: song.fileSize, countStyle: .file))
                                    .font(.system(size: 11))
                                    .foregroundColor(.gray)
                            }
                        }
                        .onDelete { indexSet in
                            for idx in indexSet {
                                if idx < watchManager.watchSongs.count {
                                    watchManager.requestWatchDeleteSong(watchManager.watchSongs[idx].id)
                                }
                            }
                        }
                        
                        Button(role: .destructive, action: { watchManager.requestWatchDeleteAll() }) {
                            HStack {
                                Image(systemName: "trash")
                                Text("Remove All from Watch")
                            }
                            .font(.system(size: 13))
                        }
                    }
                } header: {
                    Text("On Watch")
                }
                
                // Send all offline songs to watch
                if !offlineManager.downloadedSongs.isEmpty {
                    Section {
                        Button(action: {
                            watchManager.syncOfflineSongsToWatch(songs: offlineManager.downloadedSongs)
                        }) {
                            Label("Send All Offline Songs to Watch", systemImage: "applewatch.and.arrow.forward")
                        }
                    }
                }
            }
        }
        .onAppear {
            if watchManager.isReachable && watchManager.watchSongs.isEmpty {
                watchManager.requestWatchSongList()
            }
        }
        .onChange(of: watchManager.isReachable) { _, reachable in
            if reachable { watchManager.requestWatchSongList() }
        }
    }
}

// MARK: - Streaming Quality Manager (shared)
class StreamingQuality: ObservableObject {
    static let shared = StreamingQuality()
    
    // WiFi
    @Published var wifiFormat: String { didSet { UserDefaults.standard.set(wifiFormat, forKey: "wifi_format") } }
    @Published var wifiBitRate: String { didSet { UserDefaults.standard.set(wifiBitRate, forKey: "wifi_bitrate") } }
    
    // Cellular
    @Published var cellularFormat: String { didSet { UserDefaults.standard.set(cellularFormat, forKey: "cell_format") } }
    @Published var cellularBitRate: String { didSet { UserDefaults.standard.set(cellularBitRate, forKey: "cell_bitrate") } }
    
    // Cache / Downloads
    @Published var cacheFormat: String { didSet { UserDefaults.standard.set(cacheFormat, forKey: "cache_format") } }
    @Published var cacheBitRate: String { didSet { UserDefaults.standard.set(cacheBitRate, forKey: "cache_bitrate") } }
    
    // Scrobbling
    @Published var scrobbleEnabled: Bool { didSet { UserDefaults.standard.set(scrobbleEnabled, forKey: "scrobble_enabled") } }
    
    /// Formats supported by Navidrome's stream endpoint
    static let formatOptions: [(value: String, label: String)] = [
        ("raw", "Raw/Original"),
        ("mp3", "MP3"),
        ("opus", "Opus"),
        ("aac", "AAC"),
        ("ogg", "OGG Vorbis"),
    ]
    
    /// Bitrate options for transcoded formats
    static let bitrateOptions: [(value: String, label: String)] = [
        ("0", "No Limit (default)"),
        ("320", "320 kbps"),
        ("256", "256 kbps"),
        ("192", "192 kbps"),
        ("128", "128 kbps"),
        ("96", "96 kbps"),
        ("64", "64 kbps"),
    ]
    
    /// Active format based on current connection
    var format: String? {
        let fmt = isOnCellular ? cellularFormat : wifiFormat
        return fmt == "raw" ? nil : fmt  // nil = no format param = original
    }
    
    /// Active bitrate based on current connection
    var maxBitRate: Int? {
        let br = isOnCellular ? cellularBitRate : wifiBitRate
        if br == "0" { return nil }
        return Int(br)
    }
    
    /// Format for downloads/cache
    var downloadFormat: String? {
        return cacheFormat == "raw" ? nil : cacheFormat
    }
    
    var downloadBitRate: Int? {
        if cacheBitRate == "0" { return nil }
        return Int(cacheBitRate)
    }
    
    /// Summary string for current WiFi config
    var wifiSummary: String {
        if wifiFormat == "raw" { return "Raw/Original" }
        let br = wifiBitRate == "0" ? "No limit" : "\(wifiBitRate) kbps"
        return "\(wifiFormat.uppercased()) · \(br)"
    }
    
    /// Summary string for current Cellular config
    var cellularSummary: String {
        if cellularFormat == "raw" { return "Raw/Original" }
        let br = cellularBitRate == "0" ? "No limit" : "\(cellularBitRate) kbps"
        return "\(cellularFormat.uppercased()) · \(br)"
    }
    
    /// Summary string for cache config
    var cacheSummary: String {
        if cacheFormat == "raw" { return "Raw/Original" }
        let br = cacheBitRate == "0" ? "No limit" : "\(cacheBitRate) kbps"
        return "\(cacheFormat.uppercased()) · \(br)"
    }
    
    // Legacy compat
    var streamBitRate: String {
        get { isOnCellular ? cellularBitRate : wifiBitRate }
        set { if isOnCellular { cellularBitRate = newValue } else { wifiBitRate = newValue } }
    }
    var streamFormat: String {
        get { isOnCellular ? cellularFormat : wifiFormat }
        set { if isOnCellular { cellularFormat = newValue } else { wifiFormat = newValue } }
    }
    var downloadOriginal: Bool {
        get { cacheFormat == "raw" }
        set { cacheFormat = newValue ? "raw" : "mp3" }
    }
    
    private var isOnCellular: Bool {
        return !isOnWiFi
    }
    
    private var isOnWiFi: Bool {
        var result = true
        let monitor = NWPathMonitor(requiredInterfaceType: .wifi)
        let semaphore = DispatchSemaphore(value: 0)
        monitor.pathUpdateHandler = { path in
            result = (path.status == .satisfied)
            semaphore.signal()
        }
        let queue = DispatchQueue(label: "wifi.check")
        monitor.start(queue: queue)
        _ = semaphore.wait(timeout: .now() + 0.1)
        monitor.cancel()
        return result
    }
    
    private init() {
        let d = UserDefaults.standard
        wifiFormat = d.string(forKey: "wifi_format") ?? "raw"
        wifiBitRate = d.string(forKey: "wifi_bitrate") ?? "0"
        cellularFormat = d.string(forKey: "cell_format") ?? "mp3"
        cellularBitRate = d.string(forKey: "cell_bitrate") ?? "320"
        cacheFormat = d.string(forKey: "cache_format") ?? "raw"
        cacheBitRate = d.string(forKey: "cache_bitrate") ?? "0"
        scrobbleEnabled = d.object(forKey: "scrobble_enabled") as? Bool ?? true
    }
}

// MARK: - Settings View
struct SettingsView: View {
    @EnvironmentObject var serverManager: ServerManager
    @ObservedObject var quality = StreamingQuality.shared
    @ObservedObject var debugLogger = DebugLogger.shared

    @State private var showVisualizerSettings = false
    @State private var cacheSizeText = "..."
    @State private var conflictErrorCount = 0
    @State private var conflictTotalCount = 0

    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    let streamOptions = StreamingQuality.formatOptions
    let bitrateOptions = StreamingQuality.bitrateOptions
    
    var body: some View {
        NavigationStack {
            List {
                // Active Server
                Section("Server") {
                    if let server = serverManager.activeServer {
                        VStack(alignment: .leading, spacing: 4) {
                            Text(server.name)
                                .font(.system(size: 16, weight: .medium))
                            Text(server.url)
                                .font(.system(size: 13))
                                .foregroundColor(.gray)
                            Text("Logged in as \(server.username)")
                                .font(.system(size: 12))
                                .foregroundColor(.gray)
                        }
                    }
                    
                    NavigationLink("Manage Servers") {
                        ManageServersView()
                    }
                    
                    NavigationLink {
                        CompanionSettingsView()
                    } label: {
                        HStack {
                            Text("Companion API")
                            Spacer()
                            if CompanionSettings.shared.isEnabled {
                                Image(systemName: "checkmark.circle.fill")
                                    .font(.system(size: 12))
                                    .foregroundColor(.green)
                            }
                        }
                    }

                    if CompanionSettings.shared.isEnabled {
                        NavigationLink {
                            LibraryConflictsView()
                        } label: {
                            HStack {
                                Text("Issues & Conflicts")
                                Spacer()
                                if conflictErrorCount > 0 {
                                    Text("\(conflictErrorCount)")
                                        .font(.system(size: 12, weight: .bold))
                                        .foregroundColor(.white)
                                        .padding(.horizontal, 7)
                                        .padding(.vertical, 2)
                                        .background(Color(red: 1, green: 0.176, blue: 0.333))
                                        .clipShape(Capsule())
                                } else if conflictTotalCount > 0 {
                                    Text("\(conflictTotalCount)")
                                        .font(.system(size: 12))
                                        .foregroundColor(.gray)
                                }
                            }
                        }
                    }
                }
                
                // WiFi Streaming
                Section {
                    Picker("Format (Transcoding)", selection: $quality.wifiFormat) {
                        ForEach(streamOptions, id: \.value) { opt in
                            Text(opt.label).tag(opt.value)
                        }
                    }
                    
                    if quality.wifiFormat != "raw" {
                        Picker("Bitrate Limit", selection: $quality.wifiBitRate) {
                            ForEach(bitrateOptions, id: \.value) { opt in
                                Text(opt.label).tag(opt.value)
                            }
                        }
                    }
                } header: {
                    Text("WiFi Streaming")
                } footer: {
                    if quality.wifiFormat == "raw" {
                        Text("Streams your files as-is (FLAC, ALAC, etc). Uses the Subsonic 'download' action — no transcoding.")
                    } else {
                        Text("Select a transcoding format for WiFi streaming. Uses the Subsonic 'stream' action with server-side transcoding.")
                    }
                }
                
                // Cellular Streaming
                Section {
                    Picker("Format (Transcoding)", selection: $quality.cellularFormat) {
                        ForEach(streamOptions, id: \.value) { opt in
                            Text(opt.label).tag(opt.value)
                        }
                    }
                    
                    if quality.cellularFormat != "raw" {
                        Picker("Bitrate Limit", selection: $quality.cellularBitRate) {
                            ForEach(bitrateOptions, id: \.value) { opt in
                                Text(opt.label).tag(opt.value)
                            }
                        }
                    }
                } header: {
                    Text("Cellular Streaming")
                } footer: {
                    Text("Transcoding is recommended on cellular to reduce data usage. Default: MP3 320 kbps.")
                }
                
                // Cache / Downloads
                Section {
                    Picker("Format (Transcoding)", selection: $quality.cacheFormat) {
                        ForEach(streamOptions, id: \.value) { opt in
                            Text(opt.label).tag(opt.value)
                        }
                    }
                    
                    if quality.cacheFormat != "raw" {
                        Picker("Bitrate Limit", selection: $quality.cacheBitRate) {
                            ForEach(bitrateOptions, id: \.value) { opt in
                                Text(opt.label).tag(opt.value)
                            }
                        }
                    }
                } header: {
                    Text("Cache Format (Downloads)")
                } footer: {
                    Text("For 'Raw/Original', uses the Subsonic 'download' action which skips transcoding. Other formats use 'stream' with server transcoding. Changes won't apply to already downloaded songs; clear cache and redownload if needed.")
                }
                
                // Watch
                Section {
                    HStack {
                        Text("Watch Transfer Quality")
                        Spacer()
                        Text("MP3 192 kbps")
                            .foregroundColor(.gray)
                    }
                } header: {
                    Text("Apple Watch")
                } footer: {
                    Text("Songs sent to Apple Watch are always transcoded to MP3 192 kbps for fast transfer and storage efficiency.")
                }
                
                // Scrobbling
                Section("Activity") {
                    Toggle("Scrobble Plays", isOn: $quality.scrobbleEnabled)
                        .tint(accentPink)
                }
                
                // Visualizer & Smart DJ
                Section("Audio & Visualizer") {
                    NavigationLink {
                        SmartDJVisualizerSettingsView()
                    } label: {
                        Text("Crossfade & Visualizer Analyzer")
                    }
                    Button(action: { showVisualizerSettings = true }) {
                        HStack {
                            Text("Visualizer Appearance")
                                .foregroundColor(.white)
                            Spacer()
                            Text(VisualizerSettings.shared.nowPlaying.style.rawValue)
                                .foregroundColor(.gray)
                            Image(systemName: "chevron.right")
                                .font(.system(size: 12))
                                .foregroundColor(.gray)
                        }
                    }
                }
                
                // Storage
                Section {
                    Button(action: {
                        ImageCache.shared.clearAll()
                        cacheSizeText = "0 MB"
                    }) {
                        HStack {
                            Text("Clear Image Cache").foregroundColor(.white)
                            Spacer()
                            Text(cacheSizeText).foregroundColor(.gray)
                        }
                    }
                    Button(action: { LibraryCache.shared.clearAll() }) {
                        HStack {
                            Text("Clear Library Cache").foregroundColor(.white)
                            Spacer()
                        }
                    }
                } header: { Text("Storage") }
                
                // About
                Section {
                    Toggle("Debug Console", isOn: $debugLogger.isEnabled)
                        .tint(accentPink)
                } header: {
                    Text("Developer")
                } footer: {
                    Text("Shows a debug panel above the tab bar with real-time logs for Watch transfers, audio engine, network, and more. Drag to resize.")
                }
                
                Section("About") {
                    HStack {
                        Text("Version")
                        Spacer()
                        Text("1.0.0").foregroundColor(.gray)
                    }
                    HStack {
                        Text("API Version")
                        Spacer()
                        Text("1.16.1").foregroundColor(.gray)
                    }
                }
                
                // Logout
                Section {
                    Button("Disconnect", role: .destructive) {
                        serverManager.disconnect()
                    }
                }
            }
            .navigationTitle("Settings")
            .sheet(isPresented: $showVisualizerSettings) {
                VisualizerSettingsView()
            }
            .onAppear {
                cacheSizeText = computeCacheSize()
                conflictErrorCount = ConflictManager.shared.badgeCount
                conflictTotalCount = ConflictManager.shared.totalCount
            }
            .onReceive(NotificationCenter.default.publisher(for: .companionConflictsUpdated)) { _ in
                conflictErrorCount = ConflictManager.shared.badgeCount
                conflictTotalCount = ConflictManager.shared.totalCount
            }
        }
    }
    
    private func computeCacheSize() -> String {
        let fm = FileManager.default
        let caches = fm.urls(for: .cachesDirectory, in: .userDomainMask).first!
        let cacheDir = caches.appendingPathComponent("ImageCache", isDirectory: true)
        guard let files = try? fm.contentsOfDirectory(at: cacheDir, includingPropertiesForKeys: [.fileSizeKey]) else {
            return "0 MB"
        }
        var total: Int64 = 0
        for file in files {
            if let size = try? file.resourceValues(forKeys: [.fileSizeKey]).fileSize {
                total += Int64(size)
            }
        }
        return ByteCountFormatter.string(fromByteCount: total, countStyle: .file)
    }
}

// MARK: - Smart DJ & Visualizer Settings
struct SmartDJVisualizerSettingsView: View {
    @ObservedObject private var crossfade = SmartCrossfadeManager.shared
    @ObservedObject private var compSettings = CompanionSettings.shared
    @State private var visCacheText = "—"
    @State private var smartDJCacheCount = 0
    @State private var isAnalyzing = false
    @State private var analysisProgress = ""

    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)

    var body: some View {
        List {
            // Smart DJ
            Section {
                Toggle("Smart DJ", isOn: $compSettings.smartDJEnabled).tint(accentPink)
                if compSettings.smartDJEnabled {
                    Toggle("Smart Crossfade", isOn: $crossfade.isEnabled).tint(accentPink)
                    if crossfade.isEnabled {
                        HStack {
                            Text("Duration").foregroundColor(.gray)
                            Spacer()
                            Text("\(String(format: "%.1f", crossfade.crossfadeDuration))s").foregroundColor(.white)
                        }
                        Slider(value: $crossfade.crossfadeDuration, in: 1...12, step: 0.5).tint(accentPink)
                        HStack {
                            Text("Target LUFS").foregroundColor(.gray)
                            Spacer()
                            Text("\(String(format: "%.0f", crossfade.targetLUFS)) LUFS").foregroundColor(.white)
                        }
                        Slider(value: $crossfade.targetLUFS, in: -24 ... -8, step: 1).tint(accentPink)
                        Toggle("Skip Silence", isOn: $crossfade.skipSilence).tint(accentPink)
                    }
                }
            } header: { Text("Smart DJ") } footer: {
                Text("Smart DJ uses on-device analysis for downloaded songs (silence detection + loudness). When the Companion API is enabled, server-side BPM data is also used.")
            }

            // Combined Analysis
            Section {
                Button(action: { runAnalysis(force: false) }) {
                    HStack {
                        Image(systemName: isAnalyzing ? "waveform" : "waveform.badge.magnifyingglass")
                            .foregroundColor(accentPink)
                            .symbolEffect(.pulse, isActive: isAnalyzing)
                        VStack(alignment: .leading, spacing: 2) {
                            Text("Pre-Analyze Missing Songs").foregroundColor(.white)
                            Text("Vis frames + Smart DJ profile for un-analyzed songs")
                                .font(.caption).foregroundColor(.gray)
                        }
                        Spacer()
                        if isAnalyzing {
                            Text(analysisProgress).font(.caption).foregroundColor(.gray)
                        }
                    }
                }
                .disabled(isAnalyzing)

                Button(action: { runAnalysis(force: true) }) {
                    HStack {
                        Image(systemName: "arrow.clockwise").foregroundColor(.orange)
                        VStack(alignment: .leading, spacing: 2) {
                            Text("Re-Analyze All Songs").foregroundColor(.white)
                            Text("Clear all caches and rebuild from scratch")
                                .font(.caption).foregroundColor(.gray)
                        }
                    }
                }
                .disabled(isAnalyzing)
            } header: { Text("Analysis (On-Device)") } footer: {
                Text("Each song is read once to produce both its Mitsuha visualizer frames and its Smart DJ profile (silence boundaries + loudness). Results are cached on-device.")
            }

            // Cache management
            Section {
                HStack {
                    Text("Visualizer Cache").foregroundColor(.gray)
                    Spacer()
                    Text(visCacheText).foregroundColor(.white).font(.caption)
                }
                Button(action: {
                    Task {
                        await VisualizerStorageManager.shared.clearCache()
                        await refreshVisCacheText()
                    }
                }) {
                    Text("Clear Visualizer Cache").foregroundColor(.red)
                }
                HStack {
                    Text("Smart DJ Profiles Cached").foregroundColor(.gray)
                    Spacer()
                    Text("\(smartDJCacheCount)").foregroundColor(.white).font(.caption)
                }
                Button(action: {
                    SmartDJCache.shared.clearAll()
                    smartDJCacheCount = 0
                }) {
                    Text("Clear Smart DJ Cache").foregroundColor(.red)
                }
            } header: { Text("Cache") }
        }
        .navigationTitle("Crossfade & Visualizer Analyzer")
        .navigationBarTitleDisplayMode(.inline)
        .onAppear {
            smartDJCacheCount = SmartDJCache.shared.cachedCount
            Task { await refreshVisCacheText() }
        }
    }

    private func refreshVisCacheText() async {
        let size = await VisualizerStorageManager.shared.cacheSize()
        let count = await VisualizerStorageManager.shared.cachedTrackCount()
        await MainActor.run {
            visCacheText = "\(count) tracks · \(ByteCountFormatter.string(fromByteCount: size, countStyle: .file))"
        }
    }

    private func runAnalysis(force: Bool) {
        guard !isAnalyzing else { return }
        isAnalyzing = true
        analysisProgress = "Scanning..."

        let downloaded = OfflineManager.shared.downloadedSongs
        let points = VisualizerSettings.shared.nowPlaying.numberOfPoints
        let fps = VisualizerSettings.shared.effectiveFPS
        let cutoff = VisualizerSettings.shared.frequencyCutoff

        Task {
            let storage = VisualizerStorageManager.shared
            if force {
                await storage.clearCache()
                SmartDJCache.shared.clearAll()
            }

            var toAnalyze: [(songId: String, path: String?, url: URL)] = []
            for dl in downloaded {
                if let url = OfflineManager.shared.localURL(for: dl.id) {
                    let hasVis = await storage.hasCache(for: dl.id)
                    let hasProfile = dl.song.path.map { SmartDJCache.shared.get($0) != nil } ?? false
                    if !hasVis || !hasProfile || force {
                        toAnalyze.append((songId: dl.id, path: dl.song.path, url: url))
                    }
                }
            }

            if toAnalyze.isEmpty {
                await MainActor.run { analysisProgress = "All up to date"; isAnalyzing = false }
                try? await Task.sleep(for: .seconds(2))
                await MainActor.run { analysisProgress = "" }
                return
            }

            for (idx, item) in toAnalyze.enumerated() {
                await MainActor.run { analysisProgress = "\(idx + 1)/\(toAnalyze.count)" }
                do {
                    let result = try await OfflineAudioAnalyzer.shared.analyzeWithSmartDJ(
                        url: item.url, pointsCount: points, fps: fps,
                        cutoff: cutoff, extractSmartDJ: true)
                    try? await storage.saveCache(frames: result.visFrames, for: item.songId)
                    if let path = item.path {
                        SmartDJCache.shared.store(SmartDJProfile(
                            bpm: nil, silenceStart: result.silenceStart,
                            silenceEnd: result.silenceEnd, loudnessLUFS: result.loudnessLUFS
                        ), for: path)
                    }
                } catch {
                    DebugLogger.shared.log("Analysis failed: \(item.songId) — \(error.localizedDescription)", category: "FFT")
                }
            }

            await MainActor.run {
                analysisProgress = "Done — \(toAnalyze.count) songs"
                isAnalyzing = false
                smartDJCacheCount = SmartDJCache.shared.cachedCount
            }
            Task { await refreshVisCacheText() }
        }
    }
}

// MARK: - Manage Servers View
struct ManageServersView: View {
    @EnvironmentObject var serverManager: ServerManager
    @State private var showAddServer = false
    
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    var body: some View {
        List {
            ForEach(serverManager.servers) { server in
                HStack {
                    VStack(alignment: .leading, spacing: 3) {
                        Text(server.name)
                            .font(.system(size: 16, weight: .medium))
                        Text(server.url)
                            .font(.system(size: 12))
                            .foregroundColor(.gray)
                        Text(server.username)
                            .font(.system(size: 11))
                            .foregroundColor(.gray.opacity(0.7))
                    }
                    
                    Spacer()
                    
                    if serverManager.activeServer?.id == server.id {
                        Image(systemName: "checkmark.circle.fill")
                            .foregroundColor(accentPink)
                    }
                }
                .contentShape(Rectangle())
                .onTapGesture {
                    Task { _ = await serverManager.switchServer(server) }
                }
            }
            .onDelete { offsets in
                serverManager.removeServer(at: offsets)
            }
            
            Button(action: { showAddServer = true }) {
                HStack {
                    Image(systemName: "plus.circle.fill")
                        .foregroundColor(accentPink)
                    Text("Add Server")
                        .foregroundColor(accentPink)
                }
            }
        }
        .navigationTitle("Servers")
        .sheet(isPresented: $showAddServer) {
            AddServerSheet(isPresented: $showAddServer)
        }
    }
}

// =============================================================================
// MARK: - Library Conflicts UI
// Appended here so no new file is needed — avoids Xcode project registration issues.
// =============================================================================

extension LibraryConflict {
    var severityColor: Color {
        severity == "error" ? Color(red: 1, green: 0.176, blue: 0.333) : .yellow
    }
    var severityIcon: String {
        severity == "error" ? "xmark.circle.fill" : "exclamationmark.triangle.fill"
    }
    var typeIcon: String {
        switch type {
        case "duplicate_album":       return "rectangle.on.rectangle.fill"
        case "missing_files":         return "doc.badge.questionmark"
        case "picard_legacy_tags":    return "tag.slash.fill"
        case "orphaned_tracks":       return "link.badge.plus"
        case "duplicate_track":       return "music.note.list"
        case "stale_companion_paths": return "externaldrive.badge.xmark"
        default:                      return "exclamationmark.circle"
        }
    }
}

struct LibraryConflictsView: View {
    @StateObject private var manager = ConflictManager.shared
    @State private var selectedTab = 0  // 0 = Active, 1 = Ignored
    @AppStorage("ignoredConflictIDs") private var ignoredIDsRaw = ""
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)

    private var ignoredIDs: Set<String> {
        Set(ignoredIDsRaw.split(separator: "|||").map(String.init))
    }

    private func ignore(_ conflict: LibraryConflict) {
        var ids = ignoredIDs
        ids.insert(conflict.id)
        ignoredIDsRaw = ids.joined(separator: "|||")
    }

    private func restore(_ conflict: LibraryConflict) {
        var ids = ignoredIDs
        ids.remove(conflict.id)
        ignoredIDsRaw = ids.joined(separator: "|||")
    }

    private var activeIssues: [LibraryConflict] {
        guard let all = manager.conflicts?.issues else { return [] }
        return all
            .filter { !ignoredIDs.contains($0.id) }
            .sorted { ($0.severity == "error" ? 0 : 1) < ($1.severity == "error" ? 0 : 1) }
    }

    private var ignoredIssues: [LibraryConflict] {
        guard let all = manager.conflicts?.issues else { return [] }
        return all.filter { ignoredIDs.contains($0.id) }
    }

    var body: some View {
        List {
            // Tab picker
            Section {
                Picker("", selection: $selectedTab) {
                    Text("Active (\(activeIssues.count))").tag(0)
                    Text("Ignored (\(ignoredIssues.count))").tag(1)
                }
                .pickerStyle(.segmented)
                .padding(.vertical, 4)
            }

            if manager.isLoading {
                Section {
                    HStack {
                        ProgressView().tint(accentPink)
                        Text("Scanning library for issues…")
                            .font(.system(size: 14))
                            .foregroundColor(.gray)
                            .padding(.leading, 8)
                    }
                    .padding(.vertical, 4)
                }
            } else if let error = manager.lastError {
                Section {
                    Text(error)
                        .font(.system(size: 13))
                        .foregroundColor(.red)
                }
            } else if selectedTab == 0 {
                // ── Active tab ──────────────────────────────────────────────
                if activeIssues.isEmpty {
                    Section {
                        HStack(spacing: 12) {
                            Image(systemName: "checkmark.seal.fill")
                                .font(.system(size: 28))
                                .foregroundColor(.green)
                            VStack(alignment: .leading, spacing: 2) {
                                Text("No active issues")
                                    .font(.system(size: 15, weight: .medium))
                                Text("Your library looks clean.")
                                    .font(.system(size: 13))
                                    .foregroundColor(.gray)
                            }
                        }
                        .padding(.vertical, 6)
                    }
                } else {
                    let errors   = activeIssues.filter { $0.severity == "error" }.count
                    let warnings = activeIssues.filter { $0.severity == "warning" }.count
                    Section {
                        HStack(spacing: 16) {
                            summaryBadge(count: errors,   label: "Errors",   color: accentPink)
                            summaryBadge(count: warnings, label: "Warnings", color: .yellow)
                            Spacer()
                        }
                        .padding(.vertical, 4)
                    } header: { Text("Summary") }

                    ForEach(activeIssues) { conflict in
                        conflictRow(conflict)
                            .swipeActions(edge: .trailing, allowsFullSwipe: true) {
                                Button {
                                    withAnimation { ignore(conflict) }
                                } label: {
                                    Label("Ignore", systemImage: "eye.slash")
                                }
                                .tint(.gray)
                            }
                    }
                }
            } else {
                // ── Ignored tab ─────────────────────────────────────────────
                if ignoredIssues.isEmpty {
                    Section {
                        Text("No ignored issues.")
                            .font(.system(size: 14))
                            .foregroundColor(.gray)
                    }
                } else {
                    Section {
                        Text("Swipe left to restore an issue to the Active list.")
                            .font(.system(size: 12))
                            .foregroundColor(.gray)
                    }
                    ForEach(ignoredIssues) { conflict in
                        conflictRow(conflict, dimmed: true)
                            .swipeActions(edge: .trailing, allowsFullSwipe: true) {
                                Button {
                                    withAnimation { restore(conflict) }
                                } label: {
                                    Label("Restore", systemImage: "arrow.uturn.left")
                                }
                                .tint(accentPink)
                            }
                    }
                }
            }
        }
        .navigationTitle("Issues & Conflicts")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button(action: { Task { await manager.refresh() } }) {
                    if manager.isLoading {
                        ProgressView().tint(accentPink).scaleEffect(0.8)
                    } else {
                        Image(systemName: "arrow.clockwise").foregroundColor(accentPink)
                    }
                }
                .disabled(manager.isLoading)
            }
        }
        .task {
            if manager.conflicts == nil { await manager.refresh() }
        }
    }

    // MARK: - Conflict Row

    @ViewBuilder
    private func conflictRow(_ conflict: LibraryConflict, dimmed: Bool = false) -> some View {
        Section {
            VStack(alignment: .leading, spacing: 8) {
                HStack(spacing: 8) {
                    Image(systemName: conflict.typeIcon)
                        .font(.system(size: 16))
                        .foregroundColor(dimmed ? .gray : conflict.severityColor)
                    Text(conflict.title)
                        .font(.system(size: 14, weight: .semibold))
                        .foregroundColor(dimmed ? .gray : .white)
                    Spacer()
                    Image(systemName: conflict.severityIcon)
                        .font(.system(size: 12))
                        .foregroundColor(dimmed ? .gray : conflict.severityColor)
                }
                Text(conflict.detail)
                    .font(.system(size: 12))
                    .foregroundColor(.gray)
                    .fixedSize(horizontal: false, vertical: true)
                if !conflict.affected_paths.isEmpty {
                    VStack(alignment: .leading, spacing: 2) {
                        ForEach(conflict.affected_paths.prefix(3), id: \.self) { path in
                            Text(path)
                                .font(.system(size: 10, design: .monospaced))
                                .foregroundColor(.white.opacity(0.45))
                                .lineLimit(1)
                        }
                        if conflict.affected_paths.count > 3 {
                            Text("+ \(conflict.affected_paths.count - 3) more")
                                .font(.system(size: 10))
                                .foregroundColor(.gray.opacity(0.6))
                        }
                    }
                    .padding(6)
                    .background(Color.white.opacity(0.05))
                    .cornerRadius(6)
                }
                if !dimmed, let action = conflict.fix_action {
                    HStack {
                        Spacer()
                        Button(action: { Task { await manager.fix(conflict) } }) {
                            if manager.isFixing == conflict.id {
                                HStack(spacing: 6) {
                                    ProgressView().tint(.white).scaleEffect(0.75)
                                    Text("Fixing…").font(.system(size: 13))
                                }
                                .padding(.horizontal, 16).padding(.vertical, 7)
                                .background(Color.gray.opacity(0.3))
                                .cornerRadius(8)
                            } else {
                                Text(fixButtonLabel(action))
                                    .font(.system(size: 13, weight: .medium))
                                    .padding(.horizontal, 16).padding(.vertical, 7)
                                    .background(conflict.severityColor.opacity(0.25))
                                    .foregroundColor(conflict.severityColor)
                                    .cornerRadius(8)
                            }
                        }
                        .buttonStyle(.plain)
                        .disabled(manager.isFixing != nil)
                    }
                }
            }
            .padding(.vertical, 4)
        }
    }

    // MARK: - Helpers

    private func summaryBadge(count: Int, label: String, color: Color) -> some View {
        VStack(spacing: 2) {
            Text("\(count)")
                .font(.system(size: 24, weight: .bold))
                .foregroundColor(count > 0 ? color : .gray)
            Text(label)
                .font(.system(size: 11))
                .foregroundColor(.gray)
        }
    }

    private func fixButtonLabel(_ action: String) -> String {
        switch action {
        case "fix_duplicate_album":  return "Merge Duplicate"
        case "fix_missing_files":    return "Remove from DB"
        case "fix_picard_tags":      return "Fix Tags"
        case "fix_stale_paths":      return "Rescan Library"
        case "fix_orphaned_tracks":  return "Trigger Rescan"
        default:                     return "Fix"
        }
    }
}