/// <summary>
/// MIT License - Copyright(c) 2019 Ugo Belfiore
/// </summary>

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

public static class ExtTransform
{
    /// <summary>
    /// Remove every childs in a transform
    /// use: someTransform.ClearChild();
    /// someTransform.ClearChild(true); //can destroy immediatly in editor
    /// </summary>
    public static Transform ClearChild(this Transform transform, bool immediate = false)
	{
        if (Application.isPlaying)
        {
            foreach (Transform child in transform)
            {
                GameObject.Destroy(child.gameObject);
            }
        }
#if UNITY_EDITOR
        else if (immediate)
        {
            if (UnityEditor.PrefabUtility.IsPartOfPrefabInstance(transform))
            {
                Debug.Log("here we are in a prefabs !!!!!");
                GameObject rootPrefabs = UnityEditor.PrefabUtility.GetOutermostPrefabInstanceRoot(transform);


                if (rootPrefabs == null)
                {
                    return (transform);
                }
                string pathRootPrefabs = UnityEditor.PrefabUtility.GetPrefabAssetPathOfNearestInstanceRoot(rootPrefabs);
                Debug.Log(pathRootPrefabs);

                UnityEditor.PrefabUtility.UnpackPrefabInstanceAndReturnNewOutermostRoots(rootPrefabs, UnityEditor.PrefabUnpackMode.Completely);

                var tempList = transform.Cast<Transform>().ToList();
                foreach (var child in tempList)
                {
                    GameObject.DestroyImmediate(child.gameObject);
                }
                UnityEditor.PrefabUtility.SaveAsPrefabAssetAndConnect(rootPrefabs, pathRootPrefabs, UnityEditor.InteractionMode.UserAction);
            }
            else
            {
                var tempList = transform.Cast<Transform>().ToList();
                foreach (var child in tempList)
                {
                    GameObject.DestroyImmediate(child.gameObject);
                }
            }
        }
#endif
        return (transform);
	}

    /// <summary>
    /// return a list of all child in a transform (not recursive)
    /// use: List<Transform>() newList = someTransform.GetAllChild();
    /// </summary>
    /// <param name="transform"></param>
    /// <returns></returns>
    public static List<Transform> GetAllChild(this Transform transform)
    {
        List<Transform> allChild = new List<Transform>();
        foreach (Transform child in transform)
        {
            allChild.Add(child);
        }
        return (allChild);
    }
}