using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
using Microsoft.Win32;
using NAudio.CoreAudioApi;
using ytLive.Helpers;
using ytLive.Models;
using ytLive.Services;
using ytLive.Services.Audio;
using ytLive.Services.Compositor;
using ytLive.Services.Encoder;

namespace ytLive.ViewModels;

public partial class MainViewModel : ViewModelBase
{
    private readonly YouTubeAuthService _youtubeAuth;
    private readonly YouTubeStreamService _youtubeStream;
    private readonly YouTubeChatService _youtubeChat;
    private readonly DispatcherTimer _liveTimer;
    private readonly DispatcherTimer _healthPollTimer;

    private SceneElement? _selectedElement;

    private StreamStatus _streamStatus = StreamStatus.Offline;
    private StreamHealth _currentHealth = new();
    private string _streamTitle = string.Empty;
    private string _streamDescription = string.Empty;
    private string _streamVisibility = "Private";
    private string? _currentBroadcastId;
    private string? _reusableStreamUrl;
    private ReusableStream? _reusableStream;
    private string? _healthIssueBanner;
    private string _healthIssueBackground = "Transparent";
    private string _windowTitle = "LlamaCasty";
    private string _topBarBackground = "#16213e";
    private string _previewGlowBrush = "Transparent";
    private Thickness _previewGlowThickness = new(0);
    private string _liveElapsedText = "00:00:00";
    private double _recDotPulse = 1.0;
    private TimeSpan _liveElapsed;

    // ─── Recording (TASK 18): independent REC / ON-AIR pills. The pills are
    // ─── intent; IsRecording / IsLive are reality. ON-AIR needs a sign-in.
    private bool _recordPillOn;
    private bool _onAirPillOn;
    private bool _isRecording;
    private string? _recordFolder;

    /// <summary>Resolved record folder — the configured choice, or Downloads (0th case).</summary>
    public string RecordFolderDisplay => _recordFolder ?? DefaultRecordFolder();

    private string? _activeRecordPath;
    private DateTime _recordStartTime;
    private TimeSpan _recordLength;

    private bool _isSettingsOpen;
    private bool _isBugOpen;
    private bool _isFeatureOpen;
    private bool _isAboutOpen;
    private bool _isLicensesOpen;
    private string _overlayTitle = string.Empty;
    private string _bugReportText = string.Empty;
    private string _bugReportEmail = string.Empty;
    private string _featureRequestText = string.Empty;
    private string _featureRequestEmail = string.Empty;

    private LayoutStore _layoutStore;
    private string? _activeLayoutPath;
    private DispatcherTimer? _saveDebounce;
    private bool _isLoading;

    // Toasts (TASK 24): non-blocking user-facing messages. Parameterless ctor
    // news up the real service; the VM is built from XAML so no DI seam exists.
    private readonly INotificationService _notifications = new NotificationService();

    // Live frame pipeline (TASK 4 ship step 5): composites the active scene at the
    // tier's FPS and paces frames into the encoder. The RTMP URL seam stays null
    // until the live-stream create flow (TASK 5) supplies the reusable stream URL.
    private readonly Func<string?> _rtmpUrlProvider;
    private readonly FramePump _framePump;
    private readonly TransitionService _transition = new();

    private readonly ChatBoxRenderer _chatBoxRenderer;
    private WebView2Manager? _webView2Manager;

    // Mock chat messages for the ChatBox preview — branded placeholders so the
    // creator sees where the overlay lands before going live.
    private static readonly IReadOnlyList<ChatMessage> MockChatMessages = new[]
    {
        new ChatMessage { AuthorName = "LlamaCasty", Message = "welcome to the stream!", Timestamp = DateTime.Now.AddMinutes(-4), IsMember = true },
        new ChatMessage { AuthorName = "LlamaCastyFan", Message = "$10 — LlamaCasty is the best!", Timestamp = DateTime.Now.AddMinutes(-3), IsSuperChat = true },
        new ChatMessage { AuthorName = "GamerDude", Message = "what streaming software is this?", Timestamp = DateTime.Now.AddMinutes(-2) },
        new ChatMessage { AuthorName = "LlamaCasty", Message = "thanks for watching! llamacasty.com", Timestamp = DateTime.Now.AddMinutes(-1), IsMember = true },
        new ChatMessage { AuthorName = "LlamaDog", Message = "Subscribe so they can buy the subscription at llamacasty.com!", Timestamp = DateTime.Now, IsMember = true },
    };
    // Chat fade timer: clears chat overlay after N seconds of inactivity.
    private System.Windows.Threading.DispatcherTimer? _chatFadeTimer;

    // Branding flash (monetization): a full-frame "made with LlamaCasty!" shown
    // for ~1s every 300s on the live output, ~25% opacity. Paid unlock sets
    // BrandFlashEnabled = false. See ai.md "Monetization".
    private readonly DispatcherTimer _brandFlashTimer;
    private readonly DispatcherTimer _brandFlashOffTimer;
    private bool _brandFlashEnabled = true;
    private bool _brandFlashActive;

    private const string SupportEmail = "gramps@llamachile.shop";
    // The creator-hub link targets (About overlay) — public so the hub's
    // integration test can assert they point at real destinations.
    public const string ChannelUrl = "https://youtube.com/@llamachileshop";
    public const string MastodonUrl = "https://mastodon.llamachile.tube/@gramps";
    public const string PremiumUrl = "https://buy.polar.sh/polar_cl_ueMy8AyAClO0o0yo19IroZwKTbD587gzUsjEW3bFapw";
    public const string CoffeeUrl = "https://buymeacoffee.com/llamachiley";
    public static string AppVersionLabel => $"Version {typeof(MainViewModel).Assembly.GetName().Version?.ToString(3)}";

    /// <summary>The About hub's Unlock Premium button lights up only once the
    /// billing URL is set (Polar — polar.sh, pending TASK 10 implementation).</summary>
    public bool IsPremiumAvailable => PremiumUrl.Length > 0;

    /// <summary>Full in-app licensing/legal text, loaded on demand from the
    /// shipped THIRD-PARTY-NOTICES.txt (never opens the OS viewer).</summary>
    public string LicensesText { get; private set; } = string.Empty;

    public ObservableCollection<ChatMessage> ChatMessages { get; } = new();

    public SceneElement? SelectedElement
    {
        get => _selectedElement;
        set
        {
            if (_selectedElement != null)
                _selectedElement.PropertyChanged -= OnSelectedElementPropertyChanged;
            if (SetProperty(ref _selectedElement, value))
            {
                OnPropertyChanged(nameof(IsWebcamSelected));
                OnPropertyChanged(nameof(IsElementsPanelEmpty));
                if (_selectedElement != null)
                    _selectedElement.PropertyChanged += OnSelectedElementPropertyChanged;
            }
        }
    }

    private void OnSelectedElementPropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
    {
        if (e.PropertyName == nameof(SceneElement.UseDefaultBackground))
        {
            UpdateBackgroundImage();
            RefreshSnapshotsAsync();
            ScheduleSave();
        }
    }

    /// <summary>The Add → YouTube Chat menu item: enabled only while no chat layer exists
    /// anywhere — one chat overlay per layout.</summary>
    public bool CanAddYouTubeChat
        => StagedScene != null
           && !Scenes.Any(s => s.Elements.OfType<Source>().Any(e => e.Type == SourceType.ChatBox));

    private static readonly SolidColorBrush BarOnBrush = CreateBrush("#2ecc71");
    private static readonly SolidColorBrush BarOffBrush = CreateBrush("#e94560");
    private static SolidColorBrush CreateBrush(string hex)
        => (SolidColorBrush)new BrushConverter().ConvertFromString(hex)!;

    /// <summary>True when the Elements panel should show the "No configurable elements" hint.</summary>
    public bool IsElementsPanelEmpty => SelectedElement is { } el
        && !el.IsDraggable && !el.IsWebcam
        && el is not Source { Type: SourceType.Countdown or SourceType.WebSource or SourceType.ChatBox };

    public StreamStatus StreamStatus
    {
        get => _streamStatus;
        set
        {
            if (SetProperty(ref _streamStatus, value))
            {
                OnPropertyChanged(nameof(IsOffline));
                OnPropertyChanged(nameof(IsLive));
                OnPropertyChanged(nameof(IsEditMode));
                OnPropertyChanged(nameof(RecDotBrush));
                OnPropertyChanged(nameof(RecTextBrush));
                OnPropertyChanged(nameof(RecDotOpacity));
                OnPropertyChanged(nameof(OnAirBrush));
                OnPropertyChanged(nameof(IsLivePrivate));
                OnPropertyChanged(nameof(ShowPrimaryStartButton));
                OnPropertyChanged(nameof(ShowLogInButton));
                OnPropertyChanged(nameof(ShowEndStreamButton));
                OnPropertyChanged(nameof(EndButtonText));
                OnPropertyChanged(nameof(AccountStatusLightToolTip));
                OnPropertyChanged(nameof(ShowChatInactiveMessage));
                OnPropertyChanged(nameof(ShowPreviewPlaceholder));
                UpdateLiveVisuals();
            }
        }
    }

    public bool IsOffline => StreamStatus == StreamStatus.Offline;
    public bool IsLive => StreamStatus == StreamStatus.Streaming;
    public bool IsLivePrivate => IsLive && string.Equals(StreamVisibility, "Private", StringComparison.OrdinalIgnoreCase);
    public string RecDotBrush => !IsRecording ? "#555555" : "#e94560";
    public string RecTextBrush => (IsLive || IsRecording) ? "#ffffff" : "#888888";
    public double RecDotOpacity => IsRecording ? _recDotPulse : 0.55;
    public string OnAirBrush => !IsLive ? "#555555" : IsLivePrivate ? "#22c55e" : "#e94560";

    // ─── REC / ON-AIR pills (TASK 18) ───
    public bool RecordPillOn
    {
        get => _recordPillOn;
        set
        {
            if (!SetProperty(ref _recordPillOn, value)) return;
            OnPropertyChanged(nameof(ShowPrimaryStartButton));
            OnPropertyChanged(nameof(CanStartSession));
        }
    }

    public bool OnAirPillOn
    {
        get => _onAirPillOn;
        set
        {
            if (value && !CanToggleOnAir) return; // needs a sign-in
            if (!SetProperty(ref _onAirPillOn, value)) return;
            OnPropertyChanged(nameof(ShowPrimaryStartButton));
            OnPropertyChanged(nameof(CanStartSession));
        }
    }

    /// <summary>The ON-AIR pill (and thus live streaming) needs a YouTube sign-in.</summary>
    public bool CanToggleOnAir => IsConnected;

    /// <summary>Whether the session is actively recording — the REC status light
    /// turns green only when this is true (the pill is intent, this is reality).</summary>
    public bool IsRecording
    {
        get => _isRecording;
        private set
        {
            if (!SetProperty(ref _isRecording, value)) return;
            OnPropertyChanged(nameof(RecDotBrush));
            OnPropertyChanged(nameof(RecTextBrush));
            OnPropertyChanged(nameof(RecDotOpacity));
            OnPropertyChanged(nameof(IsEditMode));
            OnPropertyChanged(nameof(ShowEndStreamButton));
            OnPropertyChanged(nameof(ShowPrimaryStartButton));
            OnPropertyChanged(nameof(EndButtonText));
            UpdateSessionTimer();
        }
    }

    /// <summary>The primary button shows when there's something to start, but never
    /// while a session is running — once recording/live the ONLY control is the End
    /// button.</summary>
    public bool ShowPrimaryStartButton =>
        IsOffline && !IsRecording && !IsLive
        && (IsConnected || (RecordPillOn && !OnAirPillOn));

    /// <summary>Either output selected makes the button actionable.</summary>
    public bool CanStartSession => RecordPillOn || OnAirPillOn;

    /// <summary>The End button shows while recording OR live.</summary>
    public bool ShowEndStreamButton => IsLive || IsRecording;

    /// <summary>The one button whose label changes: while recording it reads
    /// "Stop Recording", while live "End Stream".</summary>
    public string EndButtonText => IsRecording && !IsLive ? "Stop Recording" : "End Stream";

    public bool ShowLogInButton => !IsConnected && IsOffline && !IsRecording;

    public bool ShowChatInactiveMessage => !IsLive;
    public bool ShowPreviewPlaceholder => !ShowEmptySceneHint && ActiveBackgroundImage == null && BackgroundImage == null;

    // Paid unlock flips this off (see ai.md "Monetization"). When disabled the
    // cadence timer is stopped and any active flash is hidden immediately.
    public bool BrandFlashEnabled
    {
        get => _brandFlashEnabled;
        set
        {
            if (!SetProperty(ref _brandFlashEnabled, value)) return;
            if (value)
            {
                if (IsLive) StartBrandFlashTimer();
            }
            else
            {
                _brandFlashTimer.Stop();
                _brandFlashOffTimer.Stop();
                BrandFlashActive = false;
            }
        }
    }

    public bool BrandFlashActive
    {
        get => _brandFlashActive;
        private set => SetProperty(ref _brandFlashActive, value);
    }

    public StreamHealth CurrentHealth
    {
        get => _currentHealth;
        set => SetProperty(ref _currentHealth, value);
    }

    /// <summary>Report-by-exception YouTube health (TASK 5 item 3): non-null only
    /// while a warning/error configuration issue exists — the banner's text.
    /// good/ok/noData keep it null so nothing renders.</summary>
    public string? HealthIssueBanner
    {
        get => _healthIssueBanner;
        private set => SetProperty(ref _healthIssueBanner, value);
    }

    /// <summary>Banner background: app red (#8f1f1f) for an error issue, amber
    /// (#b8860b) for a warning. Transparent when no banner is shown.</summary>
    public string HealthIssueBackground
    {
        get => _healthIssueBackground;
        private set => SetProperty(ref _healthIssueBackground, value);
    }

    public string StreamTitle
    {
        get => _streamTitle;
        set => SetProperty(ref _streamTitle, value);
    }

    public string StreamDescription
    {
        get => _streamDescription;
        set => SetProperty(ref _streamDescription, value);
    }

    public string StreamVisibility
    {
        get => _streamVisibility;
        set
        {
            if (SetProperty(ref _streamVisibility, value))
            {
                OnPropertyChanged(nameof(RecDotBrush));
                OnPropertyChanged(nameof(RecTextBrush));
                OnPropertyChanged(nameof(OnAirBrush));
                OnPropertyChanged(nameof(IsLivePrivate));
            }
        }
    }

    public string WindowTitle
    {
        get => _windowTitle;
        set => SetProperty(ref _windowTitle, value);
    }

    public string TopBarBackground
    {
        get => _topBarBackground;
        set => SetProperty(ref _topBarBackground, value);
    }

    public string PreviewGlowBrush
    {
        get => _previewGlowBrush;
        set => SetProperty(ref _previewGlowBrush, value);
    }

    public Thickness PreviewGlowThickness
    {
        get => _previewGlowThickness;
        set => SetProperty(ref _previewGlowThickness, value);
    }

    public string LiveElapsedText
    {
        get => _liveElapsedText;
        set => SetProperty(ref _liveElapsedText, value);
    }

    // Overlay panels
    public bool IsSettingsOpen
    {
        get => _isSettingsOpen;
        private set => SetPanel(ref _isSettingsOpen, value);
    }

    public bool IsBugOpen
    {
        get => _isBugOpen;
        private set => SetPanel(ref _isBugOpen, value);
    }

    public bool IsFeatureOpen
    {
        get => _isFeatureOpen;
        private set => SetPanel(ref _isFeatureOpen, value);
    }

    public bool IsAboutOpen
    {
        get => _isAboutOpen;
        private set => SetPanel(ref _isAboutOpen, value);
    }

    /// <summary>About hub sub-view: the full licensing/legal texts panel
    /// (in-app scrolling — no Notepad, no browser tab).</summary>
    public bool IsLicensesOpen
    {
        get => _isLicensesOpen;
        set
        {
            if (SetProperty(ref _isLicensesOpen, value))
                OnPropertyChanged(nameof(IsHubVisible));
        }
    }

    public bool IsAnyOverlayOpen => IsSettingsOpen || IsBugOpen || IsFeatureOpen || IsAboutOpen;

    public string OverlayTitle
    {
        get => _overlayTitle;
        private set => SetProperty(ref _overlayTitle, value);
    }

    // ─── Broadcast metadata pull-out (the "Text" tab on the Live screen) ───

    /// <summary>The broadcast id of the current/last session; null until Go Live
    /// succeeds. Gates the pull-out's Update button (nothing remote to patch).</summary>
    public string? CurrentBroadcastId => _currentBroadcastId;

    public Services.LiveBroadcastFormViewModel BroadcastForm { get; }

    // Window geometry pass-through (code-behind owns the WPF specifics).
    public (double Left, double Top, double Width, double Height, string State)? RestoreWindowState()
        => _layoutStore.LoadWindowState();

    public void PersistWindowState(double left, double top, double width, double height, string state)
        => _layoutStore.SaveWindowState(left, top, width, height, state);

    // ─── Resolution quality dropdown (bottom bar) ───
    // Tiers offered to the creator before going live. First = default. The
    // dropdown is disabled while live because YouTube stream resolution is
    // immutable after stream creation (see TASKS.md compliance notes).

    // The composition master frame. Every tier is an output rect + target
    // resolution over this frame (see ai.md "Resolution tiers"): 16:9 tiers
    // use the full frame; the vertical tier uses a centered 9:16 window and
    // the preview dims the cropped strips (semi-crop).
    private const double MasterFrameWidth = 1920;
    private const double MasterFrameHeight = 1080;

    public QualityOption[] QualityOptions { get; } =
    {
        new("1080p60", 60, 8.0, 1920, 1080),
        new("1080p30", 30, 8.0, 1920, 1080),
        new("720p60", 60, 6.0, 1280, 720),
        new("720p30", 30, 6.0, 1280, 720),
        new("Vertical 1080p60", 60, 8.0, 1080, 1920),
    };

    public string ResolutionHelp { get; } =
        "Pick the highest resolution your upload bandwidth can comfortably sustain. " +
        "Find your upload speed on your ISP plan or with a speed test (e.g. fast.com), " +
        "then choose a tier your upload comfortably exceeds. 1080p60 is the default.";

    private QualityOption _selectedQuality;
    public QualityOption SelectedQuality
    {
        get => _selectedQuality;
        set
        {
            if (SetProperty(ref _selectedQuality, value))
                ApplyStreamQuality(value);
        }
    }

    // Output frame of the selected tier over the 1920x1080 master. The strips
    // outside it are dimmed in the preview so the cropped area stays visible.
    public double OutputRectX { get; private set; }
    public double OutputRectY { get; private set; }
    public double OutputRectWidth { get; private set; }
    public double OutputRectHeight { get; private set; }
    public bool IsOutputCropped { get; private set; }
    public string ResolutionBadgeText { get; private set; } = string.Empty;
    public ObservableCollection<Rect> DimRects { get; } = new();

    private void ApplyStreamQuality(QualityOption quality)
    {
        var health = CurrentHealth;
        health.CurrentBitrate = quality.Bitrate;
        health.FPS = quality.Fps;
        OnPropertyChanged(nameof(CurrentHealth));

        var scale = Math.Min(MasterFrameWidth / quality.Width, MasterFrameHeight / quality.Height);
        var rectW = quality.Width * scale;
        var rectH = quality.Height * scale;
        var rectX = (MasterFrameWidth - rectW) / 2;
        var rectY = (MasterFrameHeight - rectH) / 2;

        OutputRectX = rectX;
        OutputRectY = rectY;
        OutputRectWidth = rectW;
        OutputRectHeight = rectH;

        DimRects.Clear();
        if (rectX > 0) DimRects.Add(new Rect(0, 0, rectX, MasterFrameHeight));
        if (rectX + rectW < MasterFrameWidth)
            DimRects.Add(new Rect(rectX + rectW, 0, MasterFrameWidth - rectX - rectW, MasterFrameHeight));
        if (rectY > 0) DimRects.Add(new Rect(0, 0, MasterFrameWidth, rectY));
        if (rectY + rectH < MasterFrameHeight)
            DimRects.Add(new Rect(0, rectY + rectH, MasterFrameWidth, MasterFrameHeight - rectY - rectH));

        IsOutputCropped = DimRects.Count > 0;
        ResolutionBadgeText = $"{quality.Label} · {quality.Width}×{quality.Height}";

        OnPropertyChanged(nameof(OutputRectX));
        OnPropertyChanged(nameof(OutputRectY));
        OnPropertyChanged(nameof(OutputRectWidth));
        OnPropertyChanged(nameof(OutputRectHeight));
        OnPropertyChanged(nameof(IsOutputCropped));
        OnPropertyChanged(nameof(ResolutionBadgeText));
    }

    public string BugReportText
    {
        get => _bugReportText;
        set => SetProperty(ref _bugReportText, value);
    }

    public string BugReportEmail
    {
        get => _bugReportEmail;
        set => SetProperty(ref _bugReportEmail, value);
    }

    public string FeatureRequestText
    {
        get => _featureRequestText;
        set => SetProperty(ref _featureRequestText, value);
    }

    public string FeatureRequestEmail
    {
        get => _featureRequestEmail;
        set => SetProperty(ref _featureRequestEmail, value);
    }

    // Commands
    public ICommand AddSceneCommand { get; }
    public ICommand AddSourceCommand { get; }
    public ICommand AddImageCommand { get; }
    public ICommand RemoveSourceCommand { get; }
    public ICommand EditElementCommand { get; }
    public ICommand ToggleElementVisibilityCommand { get; }
    public ICommand StartStreamCommand { get; }
    public ICommand EndStreamCommand { get; }
    public ICommand ChooseRecordFolderCommand { get; }
    public ICommand ResetRecordFolderCommand { get; }
    public ICommand OpenSettingsCommand { get; }
    public ICommand OpenBugCommand { get; }
    public ICommand OpenFeatureCommand { get; }
    public ICommand OpenAboutCommand { get; }
    public ICommand CloseOverlayCommand { get; }
    public ICommand SubmitBugCommand { get; }
    public ICommand SubmitFeatureCommand { get; }
    public ICommand OpenChannelCommand { get; }
    public ICommand OpenMastodonCommand { get; }
    public ICommand OpenCoffeeCommand { get; }
    public ICommand OpenPremiumCommand { get; }
    public ICommand OpenLicensesCommand { get; }
    public ICommand ActivateLicenseCommand { get; }
    public ICommand OpenLicenseEntryCommand { get; }
    public ICommand OpenHotkeyConfigCommand { get; }
    public ICommand ChangeAccountCommand { get; }
    public ICommand LogoutCommand { get; }

    public MainViewModel()
    {
        AppLog.Write("MainViewModel ctor begin");
        _youtubeAuth = new YouTubeAuthService(OAuthCredentials.ClientId, OAuthCredentials.ClientSecret,
            sessionChanged: ch => TokenStore.Save(ch));
        _youtubeStream = new YouTubeStreamService(_youtubeAuth);
        _youtubeChat = new YouTubeChatService(_youtubeAuth);
        AppLog.Write("MainViewModel ctor: services created");

        _selectedQuality = QualityOptions[0];
        ApplyStreamQuality(_selectedQuality);

        _youtubeChat.MessageReceived += OnChatMessageReceived;

        _liveTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(1) };
        _liveTimer.Tick += OnLiveTimerTick;
        _volumeFlashTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(300) };
        _volumeFlashTimer.Tick += (_, _) => EndVolumeFlash();

        _gameVolumeFlashTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(300) };
        _gameVolumeFlashTimer.Tick += (_, _) => EndGameVolumeFlash();

        _saveDebounce = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(1500) };
        _saveDebounce.Tick += (_, _) => SaveLayoutNow();

        _brandFlashTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(300) };
        _brandFlashTimer.Tick += OnBrandFlashTimerTick;
        _brandFlashOffTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(750) };
        _brandFlashOffTimer.Tick += (_, _) => { _brandFlashOffTimer.Stop(); BrandFlashActive = false; };

        _healthPollTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(30) };
        _healthPollTimer.Tick += OnHealthPollTick;

        Scenes.CollectionChanged += OnScenesChanged;

        AddSceneCommand = new RelayCommand(name => AddScene(name as string ?? string.Empty));
        AddSourceCommand = new RelayCommand(parameter => AddSource(parameter));
        AddWebcamCommand = new RelayCommand(_ => _ = AddWebcamToStagedSceneAsync());
        AddImageCommand = new RelayCommand(_ => AddImage());
        RemoveSourceCommand = new RelayCommand(element => RemoveElement(element as SceneElement));
        EditElementCommand = new RelayCommand(element => BeginEditElement(element as SceneElement));
        ToggleElementVisibilityCommand = new RelayCommand(element => ToggleElementVisibility(element as SceneElement));
        ChangeWebcamCommand = new RelayCommand(_ => _ = ChangeWebcamAsync(), _ => CanChangeWebcam);
        ShowWebcamCommand = new RelayCommand(_ => ShowWebcamInStagedScene(), _ => CanShowWebcamInStagedScene);
        OpenSocialDialogCommand = new RelayCommand(_ => OpenSocialDialog());
        ChangeCaptureCommand = new RelayCommand(_ => _ = ChangeBackgroundCaptureAsync());
        RefreshCaptureCommand = new RelayCommand(_ => RefreshBackgroundAutoCapture());
        SetBackgroundDisplayCommand = new RelayCommand(display => SetBackgroundCapture(display as DisplayInfo));
        ToggleShowDesktopCommand = new RelayCommand(_ => ToggleBackgroundShowDesktop());
        BrowseBackgroundCommand = new RelayCommand(_ => BrowseBackground());
        ToggleMicMuteCommand = new RelayCommand(_ => ToggleMicMute());
        ToggleGameMuteCommand = new RelayCommand(_ => ToggleGameMute());
        OpenMicPickerCommand = new RelayCommand(_ => PickMicrophone());
        OpenSettingsCommand = new RelayCommand(_ => ShowOverlay(nameof(IsSettingsOpen), "App Settings"));
        OpenBugCommand = new RelayCommand(_ => ShowOverlay(nameof(IsBugOpen), "Report Bug"));
        OpenFeatureCommand = new RelayCommand(_ => ShowOverlay(nameof(IsFeatureOpen), "Feature Request"));
        OpenAboutCommand = new RelayCommand(_ => ShowOverlay(nameof(IsAboutOpen), "About"));
        CloseOverlayCommand = new RelayCommand(_ => ShowOverlay());
        SubmitBugCommand = new RelayCommand(_ => SubmitBug());
        SubmitFeatureCommand = new RelayCommand(_ => SubmitFeature());
        OpenChannelCommand = new RelayCommand(_ => OpenUrl(ChannelUrl));
        OpenMastodonCommand = new RelayCommand(_ => OpenUrl(MastodonUrl));
        OpenCoffeeCommand = new RelayCommand(_ => OpenUrl(CoffeeUrl));
        OpenPremiumCommand = new RelayCommand(_ => OpenUrl(PremiumUrl), _ => IsPremiumAvailable);
        OpenLicensesCommand = new RelayCommand(_ => ShowLicenses());
        StartStreamCommand = new RelayCommand(_ => StartSession());
        EndStreamCommand = new RelayCommand(_ => StopStream(), _ => IsLive || IsRecording);
        ChooseRecordFolderCommand = new RelayCommand(_ => ChooseRecordFolder());
        ResetRecordFolderCommand = new RelayCommand(_ => ResetRecordFolder());
        ActivateLicenseCommand = new RelayCommand(_ => _ = ActivateLicenseAsync(), _ => !IsLicenseValidating);
        OpenLicenseEntryCommand = new RelayCommand(_ => IsLicenseEntryOpen = !IsLicenseEntryOpen);
        OpenHotkeyConfigCommand = new RelayCommand(_ => OpenHotkeyConfig());
        ChangeAccountCommand = new RelayCommand(_ => _ = ChangeAccountAsync());
        LogoutCommand = new RelayCommand(_ => _ = SignOutYouTubeAsync());

        _layoutStore = new LayoutStore(LayoutPathOverride ?? DefaultLayoutPath);
        _activeLayoutPath = _layoutStore.ActivePath;
        _recordFolder = _layoutStore.LoadRecordFolder();

        // Load saved hotkey bindings (filled with defaults for any unbound actions).
        _hotkeyBindings = _layoutStore.LoadHotkeyBindings();

        BroadcastForm = new Services.LiveBroadcastFormViewModel(
            () => _layoutStore,
            () => _youtubeStream,
            () => CurrentBroadcastId,
            () => IsLive);

        // Restore the last picked mic so the mixer's first capture attaches to
        // the same, already-vetted device (green dot) or reports it missing
        // (yellow) instead of silently falling back to the default.
        MicSourceName = _layoutStore.LoadMicSourceName();

        _cameraEnumerator = new MediaCaptureCameraEnumerator();
        _cameraManager = new CameraManager(
            _cameraEnumerator,
            id => new MediaCaptureFrameSource(id),
            System.Windows.Application.Current?.Dispatcher);
        _cameraManager.PreviewBitmapChanged += OnCameraPreviewBitmapChanged;
        _cameraManager.CameraFailed += OnCameraFailed;

        _microphoneEnumerator = new WinRtMicrophoneEnumerator();

        // The mixer consumes these Func seams live each mix tick, so the volume
        // sliders and mute buttons are stream-honest (they also update the
        // meters' display). Before this wiring the gains defaulted to unity and
        // the controls were decorative.
        _gainProvider = new AudioGainProvider(
            () => MicMuted,
            () => MicVolume,
            () => GameMuted,
            () => GameAudioVolume);
        _audioMixer = new AudioMixer(
            new WasapiMicAudioSource(() => MicSourceName),
            new WasapiLoopbackAudioSource(),
            message => AppLog.Write(message),
            micGain: _gainProvider.MicGain,
            loopbackGain: _gainProvider.LoopbackGain);
        _audioMixer.MicLevelChanged += OnMicLevelChanged;
        _audioMixer.LoopbackLevelChanged += OnLoopbackLevelChanged;
        _audioMixer.MicConnected += OnMicConnected;
        _audioMixer.MicFailed += OnMicFailed;
        _musicPlayer.PlaybackEnded += OnTraxPlaybackEnded;
        _ = StartMicCaptureAsync();

        _fullScreenDetector = new Win32FullScreenDetector();
        _fullScreenDetector.FullscreenMonitorChanged += OnFullscreenMonitorChanged;
        foreach (var display in _fullScreenDetector.GetDisplays())
            Displays.Add(display);

        _screenCaptureFactory = new ScreenCaptureSourceFactory(
            () => new WindowInteropHelper(System.Windows.Application.Current?.MainWindow).Handle);
        _screenCaptureManager = new ScreenCaptureManager(
            _screenCaptureFactory.Resolve,
            System.Windows.Application.Current?.Dispatcher);
        _screenCaptureManager.PreviewBitmapChanged += OnScreenPreviewBitmapChanged;
        _screenCaptureManager.CaptureFailed += (key, message) =>
            AppLog.Write($"ScreenCaptureManager: capture '{key}' failed: {message}");

        _chatBoxRenderer = new ChatBoxRenderer();

        _rtmpUrlProvider = () => _reusableStreamUrl; // TASK 5: the reusable stream's ingest URL
        _framePump = new FramePump(
            sceneProvider: () => StagedScene,
            frameResolver: ResolveOutputFrame,
            compositorOptions: BuildCompositorOptions,
            encoderOptions: BuildEncoderOptions,
            encoderFactory: () => new FfmpegEncoder(new FfmpegLocator()),
            log: message => AppLog.Write(message),
            socialBar: () => (_socialBarFrame, _socials?.BarPosition ?? SocialBarPosition.Bottom),
            transition: _transition,
            fromSceneProvider: () => LiveScene);
        _framePump.Failed += OnFramePumpFailed;
        _framePump.HealthUpdated += OnFramePumpHealthUpdated;

        LoadLayout();
        // The cached reusable stream gives the pump its RTMP URL the moment go-live
        // starts (the pump reads the URL once at startup — no waiting on YouTube).
        _reusableStream = _layoutStore.LoadReusableStream();
        _reusableStreamUrl = _reusableStream?.RtmpUrl;
        _ = LoadSavedSessionAsync();
        _ = ValidateLicenseAtStartupAsync();
        AppLog.Write("MainViewModel ctor end");
    }

    private static string DefaultLayoutPath => Path.Combine(
        Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
        "ytLlive",
        "ytLlive.db");

    // Test seam: a real MainWindow test must never read or write the user's
    // real layout DB (it would persist test sources over real ones). Tests set
    // this to a temp path before constructing MainWindow and reset it after.
    internal static string? LayoutPathOverride { get; set; }

    private void LoadLayout()
    {
        _isLoading = true;
        try
        {
            AppLog.Write("LoadLayout begin");
            var scenes = _layoutStore.Load();
            Scenes.Clear();
            foreach (var scene in scenes)
                Scenes.Add(scene);

            if (Scenes.Count == 0)
            {
                foreach (var name in SceneCatalog.All)
                    AddScene(name);
            }
            HealBackgrounds();
            RefreshHotkeyLabels();

            foreach (var scene in Scenes)
                foreach (var config in scene.Elements.OfType<WebcamSceneConfig>())
                {
                    ClampWebcamToBounds(config, scene.Name);
                    HealLegacySquareRect(config);
                }

            // One-time heal: ChatBox layers created before the "YouTube Chat"
            // default still carry the old "Chat" name — creator renames untouched.
            foreach (var scene in Scenes)
                foreach (var source in scene.Elements.OfType<Source>())
                    if (source.Type == SourceType.ChatBox
                        && string.Equals(source.Name, "Chat", StringComparison.OrdinalIgnoreCase))
                        source.Name = "YouTube Chat";

            AppLog.Write($"LoadLayout: {Scenes.Count} scenes loaded");
        }
        finally
        {
            _isLoading = false;
        }
        StagedScene = Scenes.FirstOrDefault();
        UpdateActiveBackground();
        UpdateActiveChatBoxPreviews();
        StartMockChatPreview();
        UpdateBackgroundImage();
        ReacquireWebcam();
        ReacquireScreenCaptures();
        RegisterLoadedWebSources();
        _socials = _layoutStore.Socials;
        RenderSocialBarFrame();
        HealFediverseSoftwareInBackground();
        OnPropertyChanged(nameof(HasSocials));
        OnPropertyChanged(nameof(SocialBarVisible));
        OnPropertyChanged(nameof(SocialBarDotBrush));
        _music = _layoutStore.Music;
        LoadTrax(play: false);

        var (transType, transDur) = _layoutStore.LoadTransitionSettings();
        if (Enum.TryParse<TransitionType>(transType, true, out var parsed))
            SelectedTransitionType = parsed;
        TransitionDurationMs = transDur;

        BroadcastForm.Load();

        ScheduleSave();
        AppLog.Write("LoadLayout end");
    }

    private void RegisterLoadedWebSources()
    {
        if (_webView2Manager == null) return;

        foreach (var source in Scenes.SelectMany(s => s.Elements).OfType<Source>()
                     .Where(s => s.Type == SourceType.WebSource))
        {
            _webView2Manager.Register(source);
            source.PropertyChanged += (_, e) =>
            {
                if (e.PropertyName == nameof(Source.WebUri))
                    _webView2Manager.OnWebUriChanged(source);
            };
        }
    }

    public void InitWebView2(Panel hostPanel)
    {
        _webView2Manager = new WebView2Manager(hostPanel, System.Windows.Application.Current.Dispatcher);
        _webView2Manager.PreviewBitmapChanged += OnWebView2PreviewBitmapChanged;
        RegisterLoadedWebSources();
    }

    private void OnWebView2PreviewBitmapChanged(string sourceId, WriteableBitmap bitmap)
    {
        foreach (var scene in Scenes)
            foreach (var el in scene.Elements.OfType<Source>().Where(s => s.Id == sourceId))
                el.VideoImageSource = bitmap;
    }

    public void Shutdown()
    {
        _saveDebounce?.Stop();
        SaveLayoutNow();
        _audioMixer.Dispose();
        _framePump.Dispose();
        _cameraManager.Dispose();
        _screenCaptureManager.Dispose();
        _webView2Manager?.Dispose();
        _layoutStore.Dispose();
        _musicPlayer.Dispose();
        _youtubeChat.Dispose();
    }

    public void SaveLayoutNow()
    {
        _saveDebounce?.Stop();
        try
        {
            _layoutStore.Save(Scenes, _webcam, _socials, _music);
            _layoutStore.SaveTransitionSettings(
                SelectedTransitionType.ToString(), TransitionDurationMs);
        }
        catch (Exception ex)
        {
            Debug.WriteLine($"Layout save failed: {ex.Message}");
        }
    }

    private void ScheduleSave()
    {
        if (_isLoading || _saveDebounce == null) return;
        _saveDebounce.Stop();
        _saveDebounce.Start();
    }

    private void BeginEditElement(SceneElement? element)
    {
        if (element == null) return;
        element.IsEditing = true;
    }

    private void ToggleElementVisibility(SceneElement? element)
    {
        if (element == null) return;
        element.IsVisible = !element.IsVisible;
        if (element is Source { IsBackground: true })
            OnPropertyChanged(nameof(BackgroundVisible));
    }

    private void AddSource(object? parameter)
    {
        var scene = StagedScene;
        if (scene == null) return;

        var sourceType = parameter is SourceType typed
            ? typed
            : Enum.TryParse<SourceType>(parameter?.ToString(), true, out var parsed) ? parsed : SourceType.Image;
        var baseName = sourceType switch
        {
            SourceType.Image => "Image",
            SourceType.TextOverlay => "Text",
            SourceType.Countdown => "Countdown",
            SourceType.WebSource => "Web Resource",
            SourceType.ChatBox => "YouTube Chat",
            _ => "Layer",
        };

        // The (+) menu only adds regular layers. The Background is a locked
        // per-screen layer managed by EnsureBackground/NormalizeBackgrounds —
        // never user-created, never deleted. YouTube Chat is one-per-layout.
        if (sourceType is SourceType.DisplayCapture or SourceType.WindowCapture or SourceType.Background)
            return;
        if (sourceType == SourceType.ChatBox && !CanAddYouTubeChat)
            return;

        // Web resources use "Web Resource-N" naming (0-indexed per scene)
        var webCount = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.WebSource);
        var source = new Source
        {
            Name = sourceType == SourceType.WebSource
                ? $"{baseName}-{webCount}"
                : NextSourceName(scene, baseName),
            Type = sourceType,
            X = sourceType == SourceType.ChatBox ? 1400 : 0,
            Y = sourceType == SourceType.ChatBox ? 20 : 0,
            Width = sourceType == SourceType.WebSource ? 640 : sourceType == SourceType.ChatBox ? 500 : 0,
            Height = sourceType == SourceType.WebSource ? 480 : sourceType == SourceType.ChatBox ? 648 : 0,
        };
        scene.Elements.Add(source);

        if (sourceType == SourceType.WebSource)
        {
            _webView2Manager?.Register(source);
            source.PropertyChanged += (_, e) =>
            {
                if (e.PropertyName == nameof(Source.WebUri))
                    _webView2Manager?.OnWebUriChanged(source);
            };
        }

        if (sourceType == SourceType.ChatBox)
        {
            source.PropertyChanged += (_, e) =>
            {
                if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
                    or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
                    or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
                    or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
                    or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
                    or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
                    UpdateChatBoxPreview(source);
            };
            UpdateChatBoxPreview(source);
        }

        OnPropertyChanged(nameof(ShowEmptySceneHint));
        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
        UpdateActiveBackground();
    }

    // Duplicate resource names get an incrementing suffix with no space: Image,
    // Image2, Image3… The next free number is derived from the names actually in
    // the scene, so deleting a middle resource never collides with a survivor.
    private static string NextSourceName(Scene scene, string baseName)
    {
        var taken = scene.Elements.OfType<Source>()
            .Select(s => s.Name)
            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
                || (n.Length > baseName.Length
                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
                    && int.TryParse(n.Substring(baseName.Length), out _)))
            .ToHashSet(StringComparer.OrdinalIgnoreCase);
        if (!taken.Contains(baseName)) return baseName;
        for (var i = 2; ; i++)
            if (!taken.Contains($"{baseName}{i}"))
                return $"{baseName}{i}";
    }

    private void AddImage()
    {
        var scene = StagedScene;
        if (scene == null) return;

        var candidates = BuildImageCandidates();
        if (candidates.Count == 0)
        {
            var bytes = PickImageBytes("Choose an image");
            if (bytes != null) AddImageSource(bytes);
            return;
        }

        var dialog = new ReuseImageDialog(new ReuseImageViewModel(candidates))
        {
            Owner = Application.Current.MainWindow
        };
        if (dialog.ShowDialog() != true) return;

        if (dialog.WantsNew)
        {
            var bytes = PickImageBytes("Choose an image");
            if (bytes != null) AddImageSource(bytes);
        }
        else
        {
            AddReusedImage(dialog.PickedAssetId!);
        }
    }

    private List<ReuseImageCandidate> BuildImageCandidates()
    {
        var candidates = new List<ReuseImageCandidate>();
        foreach (var scene in Scenes)
        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.Image && !string.IsNullOrWhiteSpace(s.AssetId)))
        {
            candidates.Add(new ReuseImageCandidate
            {
                SceneName = scene.Name,
                SourceName = source.Name,
                AssetId = source.AssetId!
            });
        }
        return candidates;
    }

    private byte[]? PickImageBytes(string title)
    {
        var dialog = new OpenFileDialog
        {
            Title = title,
            Filter = "Image files (*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp)|*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp|All files (*.*)|*.*"
        };
        if (dialog.ShowDialog() != true) return null;
        try
        {
            return File.ReadAllBytes(dialog.FileName);
        }
        catch (Exception ex)
        {
            _notifications.Warning("Couldn't read that image", ex.Message);
            return null;
        }
    }

    private string? AddAsset(byte[] bytes)
    {
        try
        {
            var image = ImageCache.FromBytes(bytes);
            var id = _layoutStore.UpsertAsset(bytes, image?.PixelWidth ?? 0, image?.PixelHeight ?? 0);
            if (id != null && image != null) ImageCache.Put(id, image);
            return id;
        }
        catch (Exception ex)
        {
            Debug.WriteLine($"Asset store failed: {ex.Message}");
            return null;
        }
    }

    private void AddImageSource(byte[] bytes)
    {
        if (bytes.Length == 0) return;
        var assetId = AddAsset(bytes);
        if (assetId != null) AddReusedImage(assetId);
    }

    private void AddReusedImage(string assetId)
    {
        var scene = StagedScene;
        if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;

        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };

        var image = ImageCache.Get(assetId);
        if (image != null)
        {
            var scale = Math.Min(640.0 / image.PixelWidth, 480.0 / image.PixelHeight);
            source.Width = image.PixelWidth * scale;
            source.Height = image.PixelHeight * scale;
            source.X = (1920 - source.Width) / 2;
            source.Y = (1080 - source.Height) / 2;
        }

        scene.Elements.Add(source);
        SelectedElement = source;
        OnPropertyChanged(nameof(ShowEmptySceneHint));
        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
        UpdateActiveBackground();
    }

    // Removes an element from the active scene. For a webcam config this drops the
    // scene's usage and releases one camera reference (CameraManager stops the
    // session when the last using scene lets go). When the last config anywhere is
    // removed, the webcam identity is cleared too — re-adding opens the picker
    // again instead of silently resurrecting the old camera.
    private void RemoveElement(SceneElement? element)
    {
        var scene = StagedScene;
        if (scene == null || element == null) return;
        if (element is Source { IsBackground: true }) return;
        if (element is WebcamSceneConfig && _webcam != null)
        {
            if (SelectedElement == element)
                SelectedElement = null;
            _ = _cameraManager.ReleaseAsync(_webcam.DeviceId);
        }
        if (element is Source { Type: SourceType.WebSource } webSource)
            _webView2Manager?.Unregister(webSource.Id);
        scene.Elements.Remove(element);

        if (element is WebcamSceneConfig && _webcam != null
            && !Scenes.Any(s => s.Elements.OfType<WebcamSceneConfig>().Any()))
        {
            _webcam = null;
            OnPropertyChanged(nameof(CanChangeWebcam));
            OnPropertyChanged(nameof(CanAddWebcam));
            OnPropertyChanged(nameof(CanShowWebcamInStagedScene));
        }

        OnPropertyChanged(nameof(ShowEmptySceneHint));
        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
        UpdateActiveBackground();
    }

    private void SetPanel(ref bool field, bool value, [System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
    {
        if (SetProperty(ref field, value, propertyName))
            OnPropertyChanged(nameof(IsAnyOverlayOpen));
    }

    private void ShowOverlay(string? panel = null, string title = "")
    {
        IsSettingsOpen = panel == nameof(IsSettingsOpen);
        IsBugOpen = panel == nameof(IsBugOpen);
        IsFeatureOpen = panel == nameof(IsFeatureOpen);
        IsAboutOpen = panel == nameof(IsAboutOpen);
        OverlayTitle = title;
        if (panel != nameof(IsAboutOpen))
            IsLicensesOpen = false;
    }

    /// <summary>Shows the in-app licensing panel, loading the full texts from
    /// the shipped THIRD-PARTY-NOTICES.txt on first open (never the OS viewer).
    /// Falls back to a "not found" note if the file is missing so the panel
    /// never hangs on nothing.</summary>
    private void ShowLicenses()
    {
        if (string.IsNullOrEmpty(LicensesText))
        {
            try
            {
                var path = Path.Combine(AppContext.BaseDirectory, "THIRD-PARTY-NOTICES.txt");
                LicensesText = File.Exists(path)
                    ? File.ReadAllText(path)
                    : "THIRD-PARTY-NOTICES.txt not found next to the executable.";
            }
            catch (Exception ex)
            {
                LicensesText = $"Could not read THIRD-PARTY-NOTICES.txt: {ex.Message}";
            }
        }
        IsLicensesOpen = true;
    }

    private void SubmitBug()
    {
        var body = string.Join(Environment.NewLine,
            BugReportText.Trim(),
            string.Empty,
            $"LlamaCasty {AppVersionLabel}",
            string.IsNullOrWhiteSpace(BugReportEmail) ? string.Empty : $"Reply-to: {BugReportEmail.Trim()}");
        ComposeEmail("[LlamaCasty Bug Report]", body);
        ShowOverlay();
    }

    private void SubmitFeature()
    {
        var body = string.Join(Environment.NewLine,
            FeatureRequestText.Trim(),
            string.Empty,
            $"LlamaCasty {AppVersionLabel}",
            string.IsNullOrWhiteSpace(FeatureRequestEmail) ? string.Empty : $"Reply-to: {FeatureRequestEmail.Trim()}");
        ComposeEmail("[LlamaCasty Feature Request]", body);
        ShowOverlay();
    }

    private static void ComposeEmail(string subject, string body)
    {
        var uri = $"mailto:{SupportEmail}?subject={Uri.EscapeDataString(subject)}&body={Uri.EscapeDataString(body)}";
        OpenUrl(uri);
    }

    private static void OpenUrl(string url)
    {
        Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
    }

    private void OnChatMessageReceived(ChatMessage message)
    {
        System.Windows.Application.Current.Dispatcher.Invoke(() =>
        {
            ChatMessages.Add(message);
            if (ChatMessages.Count > 500)
                ChatMessages.RemoveAt(0);

            // Reset chat fade timer on every message
            ResetChatFadeTimer();

            StopMockChatPreview();

            // Switch ChatBox previews from mock to real messages
            if (StagedScene != null)
                foreach (var chatBox in StagedScene.Elements.OfType<Source>().Where(s => s.Type == SourceType.ChatBox))
                    UpdateChatBoxPreview(chatBox);
        });
    }

    private void ResetChatFadeTimer()
    {
        _chatFadeTimer?.Stop();
        var chatBoxes = Scenes.SelectMany(s => s.Elements).OfType<Source>()
            .Where(s => s.Type == SourceType.ChatBox && s.ChatFadeSeconds > 0).ToList();
        if (chatBoxes.Count == 0) return;

        var delay = chatBoxes.Min(s => s.ChatFadeSeconds);
        _chatFadeTimer = new System.Windows.Threading.DispatcherTimer
        { Interval = TimeSpan.FromSeconds(delay) };
        _chatFadeTimer.Tick += (_, _) =>
        {
            _chatFadeTimer?.Stop();
            _chatFadeTimer = null;
            ChatMessages.Clear();
            foreach (var chatBox in Scenes.SelectMany(s => s.Elements).OfType<Source>()
                         .Where(s => s.Type == SourceType.ChatBox))
                UpdateChatBoxPreview(chatBox);
            StartMockChatPreview();
        };
        _chatFadeTimer.Start();
    }

    /// <summary>Entry point for the primary Start button (and the start/stop hotkey):
    /// routes to a record session or the YouTube go-live dialog by the pill state.</summary>
    private void StartSession()
    {
        if (IsLive || IsRecording) return;
        var streaming = OnAirPillOn;
        var recording = RecordPillOn;
        if (!streaming && !recording) return;

        if (!streaming)
        {
            BeginRecordOnly();
            return;
        }
        BeginGoLive(recording);
    }

    /// <summary>Record-only (REC pill on, ON-AIR off): no YouTube dialog — recording
    /// is local and works signed-out. Generates the auto-named file and starts the
    /// pipeline immediately.</summary>
    private async void BeginRecordOnly()
    {
        var path = StartRecordFile();
        if (path == null)
        {
            _notifications.Error("Couldn't record", "No record output path could be created.");
            return;
        }
        _recordStartTime = DateTime.Now;
        _liveElapsed = TimeSpan.Zero;
        _recordLength = TimeSpan.Zero;
        ResetHealth(StreamStatus.Offline);
        _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
        IsRecording = true;
        await _framePump.StartAsync();
    }

    private void BeginGoLive(bool alsoRecord)
    {
        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
        {
            StreamTitle = BroadcastForm.Title,
            StreamDescription = BroadcastForm.Description,
        };
        var window = new ytLive.GoLiveWindow(dialog) { Owner = System.Windows.Application.Current.MainWindow };
        if (window.ShowDialog() == true)
        {
            StreamTitle = dialog.StreamTitle;
            StreamDescription = dialog.StreamDescription;
            StreamVisibility = dialog.Visibility; // always "Private" (ship step 7)
            BroadcastForm.CaptureGoLive(dialog.StreamTitle, dialog.StreamDescription, DateTime.UtcNow);
            WindowTitle = string.IsNullOrWhiteSpace(dialog.StreamTitle)
                ? "LlamaCasty"
                : $"{dialog.StreamTitle} — LlamaCasty";
            StreamStatus = StreamStatus.Streaming;
            ResetHealth(StreamStatus.Streaming);
            _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
            _liveElapsed = TimeSpan.Zero;
            _recordLength = TimeSpan.Zero;

            var recordStarted = false;
            if (alsoRecord)
            {
                if (StartRecordFile() == null)
                {
                    _notifications.Error("Couldn't record",
                        "No record output path could be created — streaming continues without recording.");
                }
                else
                {
                    _recordStartTime = DateTime.Now;
                    recordStarted = true;
                }
            }
            IsRecording = recordStarted;

            _ = PrepareAndStartLiveAsync();
        }
    }

    /// <summary>Creates the record file (auto-named <c>ty-…-0000.mp4</c> in the record
    /// folder) and returns its path, or null when the folder can't be prepared.</summary>
    private string? StartRecordFile()
    {
        try
        {
            var folder = _recordFolder ?? DefaultRecordFolder();
            Directory.CreateDirectory(folder);
            var name = RecordingFile.BuildStartName(DateTime.Now) + ".mp4";
            var path = Path.Combine(folder, name);
            _activeRecordPath = path;
            return path;
        }
        catch (Exception ex)
        {
            AppLog.Write(ex, "Recording: failed to prepare output path");
            return null;
        }
    }

    /// <summary>One-click go-live (TASK 5): ensure the reusable stream, create a
    /// broadcast bound to it, then start the frame pump. The pump reads the RTMP
    /// URL once at startup (FramePump.StartAsync), so the stream URL must be set
    /// before the pump starts — hence the ordering here. Failures surface as an
    /// error health state, never a crash.</summary>
    private async Task PrepareAndStartLiveAsync()
    {
        try
        {
            var stream = await _youtubeStream.GetOrCreateReusableStreamAsync();
            if (stream == null)
            {
                AppLog.Write("Reusable stream unavailable; check the OAuth session");
                _notifications.Error("Couldn't go live",
                    "The reusable stream is unavailable — check the YouTube sign-in and try again.");
                StreamStatus = StreamStatus.Error;
                return;
            }
            _reusableStream = stream;
            _reusableStreamUrl = stream.RtmpUrl;
            _layoutStore.SaveReusableStream(stream);

            _currentBroadcastId = await _youtubeStream.CreateBroadcast(
                StreamTitle, StreamDescription, DateTime.UtcNow, stream.Id);
            if (_currentBroadcastId == null)
            {
                AppLog.Write("Broadcast creation failed; check the OAuth session");
                _notifications.Error("Couldn't go live", "YouTube rejected the broadcast — check the sign-in and try again.");
                StreamStatus = StreamStatus.Error;
                return;
            }
            AppLog.Write($"Broadcast created: {_currentBroadcastId}");
            OnPropertyChanged(nameof(CurrentBroadcastId));

            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
            {
                BroadcastForm.IsDrawerOpen = true;
                _notifications.Warning("Complete your broadcast details",
                    "Your title and description are empty — fill them in from the Text panel on the right.");
            }

            // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
            // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
            // the stream continues without on-panel chat.
            try
            {
                var liveChatId = await _youtubeStream.GetBroadcastLiveChatIdAsync(_currentBroadcastId);
                if (liveChatId != null)
                {
                    _youtubeChat.Start(liveChatId);
                    AppLog.Write($"Chat polling started: {liveChatId}");
                }
                else
                {
                    AppLog.Write("Could not retrieve liveChatId; chat polling disabled");
                }
            }
            catch (Exception chatEx)
            {
                AppLog.Write($"Chat start failed (non-fatal): {chatEx.Message}");
            }
        }
        catch (Exception ex)
        {
            AppLog.Write($"Go-live preparation failed: {ex.Message}");
            _notifications.Error("Couldn't go live", ex.Message);
            StreamStatus = StreamStatus.Error;
            return;
        }

        await _framePump.StartAsync(); // never throws; failures log + surface via Failed

        // Health polling (TASK 5 item 3): poll immediately, then every 30s while
        // live. Report-by-exception — a banner appears only on warning/error.
        _healthPollTimer.Start();
        _ = PollHealthAsync();
    }

    private void OnHealthPollTick(object? sender, EventArgs e) => _ = PollHealthAsync();

    /// <summary>One liveStreams.list poll (TASK 5 item 3): updates the YouTube
    /// health state + the report-by-exception banner. Never throws — a poll
    /// failure logs and leaves the last state untouched.</summary>
    private async Task PollHealthAsync()
    {
        if (_reusableStream == null || !IsLive) return;
        try
        {
            var health = await _youtubeStream.GetStreamHealthAsync(_reusableStream.Id);
            if (health == null)
            {
                AppLog.Write("Stream health poll failed; check the OAuth session");
                return;
            }
            CurrentHealth.HealthStatus = health.HealthStatus;
            CurrentHealth.HealthMessage = health.HealthStatus;
            CurrentHealth.ConfigurationIssues.Clear();
            CurrentHealth.ConfigurationIssues.AddRange(health.ConfigurationIssues);
            OnPropertyChanged(nameof(CurrentHealth));
            ApplyHealthIssue(health.ConfigurationIssues);
        }
        catch (Exception ex)
        {
            AppLog.Write($"Stream health poll failed: {ex.Message}");
        }
    }

    // Report-by-exception: good/ok/noData (or info-only issues) clear the banner;
    // the first warning/error issue raises it, colored by the worst severity.
    private void ApplyHealthIssue(List<StreamConfigurationIssue> issues)
    {
        var report = StreamHealthReporter.BannerFor(issues);
        if (report.Text == null)
        {
            HealthIssueBanner = null;
            HealthIssueBackground = "Transparent";
            return;
        }

        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
        HealthIssueBanner = report.Text;
    }

    private async void StopStream()
    {
        var wasLive = IsLive;
        var wasRecording = IsRecording;

        StreamStatus = StreamStatus.Offline;
        IsRecording = false;
        WindowTitle = "LlamaCasty";
        ResetHealth(StreamStatus.Offline);
        // Stop chat polling first (TASK 9.4) — no more messages arriving while
        // we're tearing down the stream.
        _youtubeChat.Stop();
        // Close the audio pipe FIRST so ffmpeg sees EOF on the audio input,
        // then stop the pump (stdin EOF) — both inputs end and the encoder
        // finalizes the output. Audio capture itself is always-on (preview
        // monitoring); only the live/report pipe, the pump, and the session stop here.
        _audioMixer.StopLive();
        await _framePump.StopAsync();
        _currentBroadcastId = null;
        OnPropertyChanged(nameof(CurrentBroadcastId));

        if (wasRecording) await FinalizeRecordingAsync();

        // Explicit sign-out only (TASK 18): stopping the stream does NOT clear
        // the session/token — the creator signs out deliberately via the
        // Logout / Change Account commands.
        AppLog.Write(wasLive ? "Stream ended" : "Recording ended");
    }

    /// <summary>On stop the auto-named <c>ty-…-0000.mp4</c> file is renamed to carry
    /// the real recording length (<c>ty-…-hh2mm2.mp4</c>), with a numeric suffix on
    /// name collisions. Runs only after the pump has fully closed the file.</summary>
    private async Task FinalizeRecordingAsync()
    {
        var startPath = _activeRecordPath;
        _activeRecordPath = null;
        if (string.IsNullOrEmpty(startPath)) return;
        try
        {
            while (_framePump.IsRunning) await Task.Delay(50);

            if (!File.Exists(startPath))
            {
                AppLog.Write($"Recording: output not found for rename: {startPath}");
                return;
            }
            _recordLength = _liveElapsed;
            var autoStem = RecordingFile.BuildFinalName(_recordStartTime, _recordLength);
            var dir = Path.GetDirectoryName(startPath)!;

            // Manual rename modal: give the creator a chance to name the recording;
            // null = keep the auto name (or the default recorded above).
            string stem = autoStem;
            var dialog = new RenameRecordingDialog(autoStem);
            if (dialog.ShowDialog() == true && !string.IsNullOrEmpty(dialog.ResultFileName))
                stem = dialog.ResultFileName;

            var finalPath = UniquePath(Path.Combine(dir, stem + ".mp4"));
            File.Move(startPath, finalPath);
            AppLog.Write($"Recording saved: {finalPath}");
            _notifications.Info("Recording saved",
                Path.GetFileName(finalPath) + " — you can rename it in your videos folder at any time.");
        }
        catch (Exception ex)
        {
            AppLog.Write(ex, "Recording: rename-on-stop failed");
            _notifications.Error("Recording saved",
                $"The recording was written but couldn't be renamed: {Path.GetFileName(startPath)}");
        }
    }

    private static string UniquePath(string path)
    {
        if (!File.Exists(path)) return path;
        var dir = Path.GetDirectoryName(path)!;
        var name = Path.GetFileNameWithoutExtension(path);
        var ext = Path.GetExtension(path);
        for (var i = 2; ; i++)
        {
            var candidate = Path.Combine(dir, $"{name}-{i}{ext}");
            if (!File.Exists(candidate)) return candidate;
        }
    }

    private void ChooseRecordFolder()
    {
        var dialog = new Microsoft.Win32.OpenFolderDialog
        {
            Title = "Choose a folder for local recordings",
            InitialDirectory = _recordFolder ?? DefaultRecordFolder(),
        };
        if (dialog.ShowDialog() == true)
        {
            _recordFolder = dialog.FolderName;
            _layoutStore.SaveRecordFolder(_recordFolder);
            OnPropertyChanged(nameof(RecordFolderDisplay));
            _notifications.Info("Record folder set", _recordFolder);
        }
    }

    private void ResetRecordFolder()
    {
        _recordFolder = null;
        _layoutStore.SaveRecordFolder(null);
        OnPropertyChanged(nameof(RecordFolderDisplay));
        _notifications.Info("Record folder reset", RecordFolderDisplay);
    }

    /// <summary>Falls back to the user's Downloads folder when no preference is set;
    /// returns MyVideos if Downloads doesn't exist.</summary>
    internal static string DefaultRecordFolder()
    {
        var downloads = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
        return Directory.Exists(downloads)
            ? downloads
            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
    }


    // Scene-element → latest frame, for the live compositor. The map mirrors the
    // preview: webcam by DeviceId, live captures (the background) by CaptureKey,
    // images/background by AssetId. A null frame leaves the element transparent.
    private VideoFrame? ResolveOutputFrame(SceneElement element)
    {
        return element switch
        {
            WebcamSceneConfig webcam => _cameraManager.GetLatestFrame(webcam.WebcamId),
            Source { IsLiveCapture: true, CaptureKey: not null } live => _screenCaptureManager.GetLatestFrame(live.CaptureKey),
            Source { Type: SourceType.ChatBox } chatBox => RenderChatBox(chatBox),
            Source { Type: SourceType.WebSource } web => _webView2Manager?.GetLatestFrame(web.Id),
            Source { AssetId: not null } image => StaticPixelCache.Get(image.AssetId),
            _ => null,
        };
    }

    private VideoFrame? RenderChatBox(Source chatBox)
    {
        if (ChatMessages.Count == 0) return null;

        var width = (int)Math.Max(1, chatBox.Width);
        var height = (int)Math.Max(1, chatBox.Height);

        return _chatBoxRenderer.Render(
            ChatMessages,
            width,
            height,
            chatBox.ChatFontSize,
            chatBox.ChatFontFamily,
            chatBox.ChatFontColor,
            chatBox.ChatBackgroundColor,
            chatBox.ChatMaxMessages,
            chatBox.ChatShowTimestamps,
            chatBox.ChatShowBadges,
            chatBox.ChatMemberColor,
            chatBox.ChatSuperChatColor);
    }

    /// <summary>
    /// Renders the ChatBox preview: real messages when connected, mock when not.
    /// </summary>
    private void UpdateChatBoxPreview(Source chatBox, IReadOnlyList<ChatMessage>? messages = null)
    {
        try
        {
            messages ??= ChatMessages.Count > 0 ? (IReadOnlyList<ChatMessage>)ChatMessages : MockChatMessages;
            var width = (int)Math.Max(32, chatBox.Width);
            var height = (int)Math.Max(32, chatBox.Height);

            var frame = _chatBoxRenderer.Render(
                messages,
                width,
                height,
                chatBox.ChatFontSize,
                chatBox.ChatFontFamily,
                chatBox.ChatFontColor,
                chatBox.ChatBackgroundColor,
                chatBox.ChatMaxMessages,
                chatBox.ChatShowTimestamps,
                chatBox.ChatShowBadges,
                chatBox.ChatMemberColor,
                chatBox.ChatSuperChatColor);

            var bitmap = new WriteableBitmap(width, height, 96, 96, System.Windows.Media.PixelFormats.Bgra32, null);
            bitmap.WritePixels(new System.Windows.Int32Rect(0, 0, width, height), frame.BgraPixels, frame.Stride, 0);
            chatBox.VideoImageSource = bitmap;
        }
        catch (Exception ex) { AppLog.Write($"UpdateChatBoxPreview failed: {ex.Message}"); }
    }

    private CancellationTokenSource? _mockChatCts;

    private async Task RunMockChatPreviewAsync(Source chatBox, CancellationToken ct)
    {
        var n = 0;
        while (!ct.IsCancellationRequested)
        {
            UpdateChatBoxPreview(chatBox, MockChatMessages.Take(n + 1).ToList());
            await Task.Delay(1000, ct);
            n++;
            if (n == MockChatMessages.Count)
            {
                await Task.Delay(3000, ct);
                n = 0;
            }
        }
    }

    private void StartMockChatPreview()
    {
        StopMockChatPreview();
        _mockChatCts = new CancellationTokenSource();
        var ct = _mockChatCts.Token;
        foreach (var chatBox in Scenes.SelectMany(s => s.Elements).OfType<Source>()
                     .Where(s => s.Type == SourceType.ChatBox && s.ChatPreviewEnabled))
            _ = RunMockChatPreviewAsync(chatBox, ct);
    }

    private void StopMockChatPreview()
    {
        _mockChatCts?.Cancel();
        _mockChatCts?.Dispose();
        _mockChatCts = null;
    }

    /// <summary>
    /// Render previews + wire property-change subscriptions for all ChatBox
    /// sources across every scene. Called after layout load so existing ChatBox
    /// sources show mock content and respond to config changes.
    /// </summary>
    private void UpdateActiveChatBoxPreviews()
    {
        foreach (var scene in Scenes)
            foreach (var chatBox in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.ChatBox))
            {
                chatBox.PropertyChanged += (_, e) =>
                {
                    if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
                        or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
                        or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
                        or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
                        or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
                        or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
                        UpdateChatBoxPreview(chatBox);
                };
                UpdateChatBoxPreview(chatBox);
            }
    }

    // The tier's crop rect over the 1920x1080 master, integer-aligned (the VM's
    // OutputRect* are doubles — the vertical 607.5 half-pixel crop rounds to 608).
    private CompositorOptions BuildCompositorOptions()
    {
        var quality = SelectedQuality;
        return new CompositorOptions
        {
            SourceRectX = (int)Math.Round(OutputRectX),
            SourceRectY = (int)Math.Round(OutputRectY),
            SourceRectWidth = (int)Math.Round(OutputRectWidth),
            SourceRectHeight = (int)Math.Round(OutputRectHeight),
            OutputWidth = quality.Width,
            OutputHeight = quality.Height,
        };
    }

    // Full encoder options for the current tier, or null when no RTMP URL is
    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
    private EncoderOptions? BuildEncoderOptions()
    {
        var url = _rtmpUrlProvider();
        var quality = SelectedQuality;
        return new EncoderOptions
        {
            RtmpUrl = url ?? string.Empty,
            StreamEnabled = OnAirPillOn,
            RecordEnabled = RecordPillOn,
            RecordPath = _activeRecordPath,
            Width = quality.Width,
            Height = quality.Height,
            Fps = quality.Fps,
            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
        };
    }

    private void OnFramePumpFailed(object? sender, string message)
    {
        AppLog.Write($"Frame pump failed: {message}");
        _notifications.Error("The stream pipeline stopped", message);
        if (IsLive) StreamStatus = StreamStatus.Error;
    }

    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
    // duration) lands in the bottom bar. The stderr loop raises on a background
    // thread — marshal to the UI thread like the audio level handlers.
    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
    {
        var dispatcher = System.Windows.Application.Current?.Dispatcher;
        if (dispatcher != null && !dispatcher.CheckAccess())
            dispatcher.BeginInvoke(() => ApplyHealth(health));
        else
            ApplyHealth(health);
    }

    private void ApplyHealth(StreamHealth health)
    {
        CurrentHealth.Status = health.Status;
        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
        CurrentHealth.FPS = health.FPS;
        CurrentHealth.DroppedFrames = health.DroppedFrames;
        CurrentHealth.StreamDuration = health.StreamDuration;
        CurrentHealth.LastError = health.LastError;
        CurrentHealth.HealthMessage = health.HealthMessage;
        OnPropertyChanged(nameof(CurrentHealth));
    }

    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
    // on the tier's targets — ApplyStreamQuality sets them on pick).
    private void ResetHealth(StreamStatus status)
    {
        CurrentHealth.Status = status;
        CurrentHealth.DroppedFrames = 0;
        CurrentHealth.StreamDuration = TimeSpan.Zero;
        CurrentHealth.LastError = null;
        CurrentHealth.HealthStatus = null;
        CurrentHealth.HealthMessage = null;
        CurrentHealth.ConfigurationIssues.Clear();
        HealthIssueBanner = null;
        HealthIssueBackground = "Transparent";
        OnPropertyChanged(nameof(CurrentHealth));
    }

    private void UpdateLiveVisuals()
    {
        var live = IsLive;
        TopBarBackground = live ? "#e94560" : "#16213e";
        PreviewGlowBrush = live ? "#e94560" : "Transparent";
        PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);

        if (live)
        {
            if (BrandFlashEnabled) StartBrandFlashTimer();
        }
        else
        {
            _healthPollTimer.Stop();
            _brandFlashTimer.Stop();
            _brandFlashOffTimer.Stop();
            BrandFlashActive = false;
        }
        UpdateSessionTimer();
    }

    /// <summary>Runs the elapsed/rec-dot-pulse timer while a session is active —
    /// live (Streaming) OR recording. Reset the elapsed when a new session starts.</summary>
    private void UpdateSessionTimer()
    {
        var active = IsLive || IsRecording;
        if (active)
        {
            _recDotPulse = 1.0;
            _liveTimer.Start();
        }
        else
        {
            _liveTimer.Stop();
            LiveElapsedText = "00:00:00";
            _recDotPulse = 1.0;
        }
        OnPropertyChanged(nameof(RecDotOpacity));
        OnPropertyChanged(nameof(LiveElapsedText));
    }

    // First flash shortly after go-live, then every 300s (the cadence resets on
    // the first tick so the interval is 5s only for that one shot).
    private void StartBrandFlashTimer()
    {
        _brandFlashTimer.Stop();
        _brandFlashTimer.Interval = TimeSpan.FromSeconds(5);
        _brandFlashTimer.Start();
    }

    private void OnBrandFlashTimerTick(object? sender, EventArgs e)
    {
        _brandFlashTimer.Stop();
        _brandFlashTimer.Interval = TimeSpan.FromSeconds(300);
        _brandFlashTimer.Start();
        ShowBrandFlash();
    }

    private void ShowBrandFlash()
    {
        if (!IsLive || !BrandFlashEnabled) return;
        BrandFlashActive = true;
        _brandFlashOffTimer.Stop();
        _brandFlashOffTimer.Start();
    }

    private void OnLiveTimerTick(object? sender, EventArgs e)
    {
        _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
        LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
        _recordLength = _liveElapsed;
        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
        OnPropertyChanged(nameof(RecDotOpacity));
    }

    }