//--------------------------------------------------------
//    [Author]:           玩个游戏
//    [  Date ]:           Tuesday, March 19, 2019
//--------------------------------------------------------
using Cysharp.Threading.Tasks;
using UnityEngine;

[ExecuteAlways]
[RequireComponent(typeof(RectTransform))]
public class UIPrefabLoader : MonoBehaviour
{
    [SerializeField] protected string m_PrefabName;
    public virtual string prefabName { get { return m_PrefabName; } }

    protected GameObject instance;

    [ExecuteAlways]
    private void Awake()
    {
        Create().Forget();
    }
    public void Reload()
    {
        instance = null;
        this.transform.ClearAllChilds();
        Create().Forget();
    }

    [ContextMenu("Create")]
    public virtual async UniTask Create()
    {
        if (instance != null)
            return;

        if (string.IsNullOrEmpty(prefabName))
            return;

        var find = this.transform.Find(prefabName);
        if (find)
        {
            instance = find.gameObject;
            return;
        }
        var inst = await UIUtility.CreateWidget(prefabName, prefabName);
        if (this == null || inst == null)
        {
            if (null != inst) DestroyImmediate(inst);
            return;
        }
        if (instance != null)
        {
            DestroyImmediate(inst);
            return;
        }
        instance = inst;
        instance.transform.SetParentEx(this.transform, Vector3.zero, Quaternion.identity, Vector3.one);
    }

}