using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace ytLive.Models;

public class Scene : INotifyPropertyChanged
{
    public string Id { get; init; } = Guid.NewGuid().ToString();

    private string _name = string.Empty;
    private bool _isEditing;
    private bool _isHidden;
    private bool _hasBackdrop;

    public string Name
    {
        get => _name;
        set => Set(ref _name, value);
    }

    public bool IsEditing
    {
        get => _isEditing;
        set => Set(ref _isEditing, value);
    }

    public bool IsHidden
    {
        get => _isHidden;
        set => Set(ref _isHidden, value);
    }

    /// <summary>
    /// Whether the scene has a live desktop/game backdrop layer. Enforced by
    /// policy: only the canonical Live scene ever has one (see SceneCatalog).
    /// </summary>
    public bool HasBackdrop
    {
        get => _hasBackdrop;
        set => Set(ref _hasBackdrop, value);
    }

    /// <summary>
    /// The scene's rendered elements in z-order (back to front): multi-instance
    /// Sources plus this scene's webcam usage (<see cref="WebcamConfig"/>), if any.
    /// </summary>
    public ObservableCollection<SceneElement> Elements { get; } = new();

    /// <summary>This scene's webcam usage, or null if the creator hasn't added the webcam here.</summary>
    public WebcamSceneConfig? WebcamConfig => Elements.OfType<WebcamSceneConfig>().FirstOrDefault();

    public bool IsChatScene { get; init; }

    public event PropertyChangedEventHandler? PropertyChanged;

    private void Set<T>(ref T field, T value, [CallerMemberName] string? propertyName = null)
    {
        if (EqualityComparer<T>.Default.Equals(field, value)) return;
        field = value;
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}