using Engine.Scene.Component;

namespace Engine.Scene;

public sealed class GameObject
{
    public Guid Id { get; } = Guid.NewGuid();
    public Transform Transform { get; }

    private readonly Queue<Action> _componentActions = new();

    private readonly List<Component.Component> _components = new();
    private readonly ISet<Type> _addedComponentTypes = new HashSet<Type>();

    public GameObject()
    {
        AddComponent<Transform>();
        UpdateComponents();
        
        Transform = GetComponent<Transform>()!;
    }

    public T? GetComponent<T>() where T : Component.Component
    {
        if (!_addedComponentTypes.Contains(typeof(T)))
            return null;

        return _components.OfType<T>().FirstOrDefault();
    }

    public void AddComponent<T>(params object?[] args) where T : Component.Component
    {
        if (_addedComponentTypes.Contains(typeof(T)))
            return;
        
        var newArgs = new object?[args.Length + 1];
        newArgs[0] = this;
        for (var i = 0; i < args.Length; i++)
            newArgs[i + 1] = args[i];

        var component = (T?)Activator.CreateInstance(typeof(T), newArgs);
        if (component == null)
            throw new InvalidOperationException($"Failed to create component of type {typeof(T)}");

        _componentActions.Enqueue(() =>
        {
            _components.Add(component);
            _addedComponentTypes.Add(typeof(T));
        });
    }

    public void RemoveComponent<T>() where T : Component.Component
    {
        if (!_addedComponentTypes.Contains(typeof(T)) || typeof(T) == typeof(Transform))
            return;

        var component = GetComponent<T>();
        if (component == null)
            return;

        _componentActions.Enqueue(() =>
        {
            _components.Remove(component);
            _addedComponentTypes.Remove(typeof(T));
        });
    }

    private void UpdateComponents()
    {
        while (_componentActions.TryDequeue(out var action))
            action();
    }
}