using UnityEngine;

#if UNITY_EDITOR
using UnityEditor.SceneManagement;
using System.Xml.Serialization;
using System.IO;
using System.Text;
using UnityEditor;
#endif

[ExecuteInEditMode]
public class UniqueObject : MonoBehaviour
{

    [System.Serializable]
    public class UniqueIdDatabase
    {

        public long lastIndex = 0;

    }

    public long id = -1;

#if UNITY_EDITOR

    void Awake()
    {

        if (Application.isPlaying) return;

        if (id == -1)
        {

            id = GetUnusedID();

            EditorUtility.SetDirty(this);
            EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
            EditorSceneManager.SaveScene(EditorSceneManager.GetActiveScene());

        }

    }

    public void AssignNewID()
    {

        id = GetUnusedID();

    }

    public void Clear()
    {

        id = -1;

    }

    static XmlSerializer serializer = new XmlSerializer(typeof(UniqueIdDatabase));
    static string path = "IndexDatabase.xml";

    public static long GetUnusedID()
    {

        if (!File.Exists(path))
        {

            using (StreamWriter stream3 = new StreamWriter(path, false, Encoding.UTF8))
            {
                UniqueIdDatabase newDatabase = new UniqueIdDatabase();
                serializer.Serialize(stream3, newDatabase);
            }

        }

        // wczytaj

        var stream = new FileStream(path, FileMode.Open);
        UniqueIdDatabase loadedDatabase = serializer.Deserialize(stream) as UniqueIdDatabase;
        stream.Close();

        // zajmij ID

        UniqueIdDatabase temporaryDatabase = new UniqueIdDatabase();
        temporaryDatabase.lastIndex = loadedDatabase.lastIndex + 1;

        long idd = temporaryDatabase.lastIndex;

        using (StreamWriter stream2 = new StreamWriter(path, false, Encoding.UTF8))
        {
            serializer.Serialize(stream2, temporaryDatabase);
        }

        // zwroc zajete ID

        print("Assigned unique id : " + idd);

        return idd;

    }

#endif

}