using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Input;
using System.Windows.Threading;
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; }
}