using System.Collections.ObjectModel;
using System.IO;
using System.Windows;
using System.Windows.Input;
using System.Windows.Threading;
using Microsoft.Win32;
using ytLive.Helpers;
using ytLive.Models;
using ytLive.Services;
using ytLive.Services.Encoder;

namespace ytLive.ViewModels;

public partial class MainViewModel : ViewModelBase
{

    private readonly DispatcherTimer _liveTimer;
    private readonly DispatcherTimer _healthPollTimer;

    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 readonly FramePump _framePump;

    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 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);
    }

    // ─── 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; }

    // ─── 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 ICommand StartStreamCommand { get; }
    public ICommand EndStreamCommand { get; }
    public ICommand ChooseRecordFolderCommand { get; }
    public ICommand ResetRecordFolderCommand { get; }

    /// <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);
    }

    // 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));
    }

    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));
    }
}