using UnityEditor;
using UnityEditor.ShortcutManagement;
using UnityEngine;

public class ConvertToMeshAsset : EditorWindow
{

    [Shortcut("Convert To Mesh Asset", KeyCode.Z, ShortcutModifiers.Shift)]
    private static void Shortcut() => OpenWindow();

    private static void CreateAsset(Transform child, Transform parent, string path, string selectionName)
    {
        // TODO: do some error handling here
        MeshFilter mf = child.GetComponent<MeshFilter>();
        Mesh m = mf.sharedMesh;
        Mesh meshToSave = UnityEngine.Object.Instantiate(m);

        GameObject childObject = new GameObject(mf.name, typeof(MeshFilter), typeof(MeshRenderer));
        childObject.GetComponent<MeshFilter>().mesh = meshToSave;
        childObject.GetComponent<MeshRenderer>().material = child.GetComponent<Renderer>().sharedMaterial;
        childObject.transform.parent = parent;

        AssetDatabase.CreateAsset(meshToSave, path + "/" + selectionName + "/mesh/" + selectionName + "_" + mf.name + ".asset");
        AssetDatabase.SaveAssets();
    }
    private static void OpenWindow()
    {
        // var selection = Selection.activeObject;
        var selections = Selection.gameObjects;
        
        // TODO: do some error handling here

        string path = EditorUtility.SaveFolderPanel("Save Separate Mesh Asset", 
            "Assets/", "");

        if (string.IsNullOrEmpty(path)) return;
        path = FileUtil.GetProjectRelativePath(path);

        foreach (var selection in selections)
        {
            // TODO: do some error handling here
            AssetDatabase.CreateFolder(path, selection.name);
            AssetDatabase.CreateFolder(path + "/" + selection.name , "mesh");

            GameObject prefabObject = new GameObject(selection.name);

            foreach(Transform item in ((GameObject)selection).transform)
            {
                if (item.childCount > 0)
                {
                    GameObject childObject = new GameObject(item.name);
                    childObject.transform.parent = prefabObject.transform;
                    foreach (Transform child in item)
                    {
                        CreateAsset(child, childObject.transform, path, selection.name);
                    }
                } else {
                    CreateAsset(item, prefabObject.transform, path, selection.name);
                }
            }

            PrefabUtility.SaveAsPrefabAsset(prefabObject, path + "/" + selection.name + "/" + selection.name + ".prefab");
            foreach(Transform child in prefabObject.transform)
            {
                DestroyImmediate(child.gameObject);
            }
            DestroyImmediate(prefabObject);
        }
    }


}