namespace labelUtility
{


using UnityEditor;
using UnityEngine;

using System;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Collections;
using System.Collections.Generic;
using System.Text.RegularExpressions;

public class InstanceUtility
{
    private class RelativeObject
    {
        public int EnumerableIndex;
        public bool IsEnumerable;
        public string FieldName;

        public RelativeObject(string fieldName, string enumerableIndex = null)
        {
            FieldName = fieldName;

            if (enumerableIndex == null)
            {
                IsEnumerable = false;
            }
            else
            {
                EnumerableIndex = int.Parse(enumerableIndex.Substring(5, 1));
                IsEnumerable = true;
            }
        }

        public object GetObject(object originObject)
        {
            object relativeObject = originObject.GetType().GetField(FieldName).GetValue(originObject);

            if (IsEnumerable)
            {
                int index = 0;
                
                foreach (var obj in relativeObject as IEnumerable)
                {
                    if (index == EnumerableIndex)
                        return obj;
                    else
                        index++;
                }
            }
            else
            {
                return relativeObject;
            }

            throw new Exception($"{FieldName} {IsEnumerable} {EnumerableIndex}");
        }
    }

    public static object GetObject(FieldInfo fieldInfo, SerializedProperty property)
    {
        List<string> infos = property.propertyPath.Split('.').ToList();

        List<RelativeObject> relativeObjects = new List<RelativeObject>();

        for (int i = 0; i < infos.Count; i++)
        {
            if (i < infos.Count - 1 && infos[i + 1] == "Array")
            {
                relativeObjects.Add(new RelativeObject(infos[i], infos[i + 2]));
                i += 2;
            }
            else
            {
                relativeObjects.Add(new RelativeObject(infos[i]));
            }
        }

        object obj = property.serializedObject.targetObject;

        foreach (var relativeObject in relativeObjects)
        {
            obj = relativeObject.GetObject(obj);
        }

        return obj;
    }

    public static T GetPropertyDrawerInstance<T>(FieldInfo fieldInfo, SerializedProperty property) where T : class
    {
        return GetObject(fieldInfo, property) as T;
    }
}


}