SaveableEntity.cs

using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

[ExecuteAlways]
public class SaveableEntity : MonoBehaviour
{
    [SerializeField] string uniqueIdentifier = "";
    static Dictionary<string, SaveableEntity> globalLookup = new Dictionary<string, SaveableEntity>();

    public string GetUniqueIdentifier()
    {
        return uniqueIdentifier;
    }

    public object CaptureState()
    {
        Dictionary<string, object> state = new Dictionary<string, object>();
        foreach (ISaveable saveable in GetComponents<ISaveable>())
        {
            state[saveable.GetType().ToString()] = saveable.CaptureState();
        }
        return state;
    }

    public void RestoreState(object state)
    {
        Dictionary<string, object> stateDict = (Dictionary<string, object>)state;
        foreach (ISaveable saveable in GetComponents<ISaveable>())
        {
            string typeString = saveable.GetType().ToString();
            if (stateDict.ContainsKey(typeString))
            {
                saveable.RestoreState(stateDict[typeString]);
            }
        }
    }

#if UNITY_EDITOR
    private void Update()
    {
        if (Application.IsPlaying(gameObject)) return; //Epitrepei na trexei mono sto edit
        if (string.IsNullOrEmpty(gameObject.scene.path)) return; // me ayto dn trexei o kwdikas sta prefabs.. nice tric Yo!!

        SerializedObject serializedObject = new SerializedObject(this);
        SerializedProperty property = serializedObject.FindProperty("uniqueIdentifier");

        if (string.IsNullOrEmpty(property.stringValue) || !IsUnique(property.stringValue))
        {
            property.stringValue = System.Guid.NewGuid().ToString();
            serializedObject.ApplyModifiedProperties();
        }

        globalLookup[property.stringValue] = this;
    }
#endif

    private bool IsUnique(string candidate)
    {
        if (!globalLookup.ContainsKey(candidate)) return true;

        if (globalLookup[candidate] == this) return true;

        if (globalLookup[candidate] == null)
        {
            globalLookup.Remove(candidate);
            return true;
        }

        if (globalLookup[candidate].GetUniqueIdentifier() != candidate)
        {
            globalLookup.Remove(candidate);
            return true;
        }

        return false;
    }
}