using System.Collections.Generic;
using UnityEngine;

public interface IGlobalUISectionController { }

public sealed class GlobalUIController : MonoBehaviour
{
    public static GlobalUIController Instance { get; private set; }

    private readonly HashSet<IGlobalUISectionController> sectionControllers = new();

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        Instance = this;

        foreach (MonoBehaviour behaviour in FindObjectsByType<MonoBehaviour>(
                     FindObjectsInactive.Include,
                     FindObjectsSortMode.None))
        {
            if (behaviour is IGlobalUISectionController controller)
                Register(controller);
        }
    }

    public void Register(IGlobalUISectionController controller)
    {
        if (controller != null)
            sectionControllers.Add(controller);
    }

    public void Unregister(IGlobalUISectionController controller)
    {
        if (controller != null)
            sectionControllers.Remove(controller);
    }

    public IEnumerable<T> GetControllers<T>() where T : class, IGlobalUISectionController
    {
        foreach (IGlobalUISectionController controller in sectionControllers)
        {
            if (controller is T typedController)
                yield return typedController;
        }
    }

    private void OnDestroy()
    {
        if (Instance == this)
        {
            sectionControllers.Clear();
            Instance = null;
        }
    }
}