Entity UUID

Entity.cs

[DisallowMultipleComponent]
[ExecuteAlways]
public class Entity : MonoBehaviour
{
    private static readonly Dictionary<EntityUuid, Entity> Entities = new Dictionary<EntityUuid, Entity>();
    
    public EntityUuid Uuid;

    private void Awake()
    {
        if (Application.isPlaying)
        {
            Uuid = ParseUuidFromName();
            Entities.Add(Uuid, this);
        }
    }
    
    public EntityUuid ParseUuidFromName()
    {
        if (Uuid.IsExplicit)
        {
            return Uuid;
        }

        var entityName = gameObject.name;

        if (entityName.EndsWith("@"))
        {
            var startIndex = entityName.LastIndexOf('@', entityName.Length - 2) + 1;
            var uuidStr = entityName.Substring(startIndex, entityName.Length - startIndex - 1);
            return EntityUuid.Parse(uuidStr);
        }

        var uuid = Uuid;
        if (Entities.ContainsKey(Uuid))
            uuid = new EntityUuid(null);

        gameObject.name = entityName + " @" + uuid + "@";
        return uuid;
    }

#if UNITY_EDITOR
    private void Start()
    {
        if (!Application.isPlaying)
        {
            ValidateName();
            Entities[Uuid] = this;
        }
    }
#endif

    private void ValidateName()
    {
#if UNITY_EDITOR
        if (Application.isPlaying)
            return;

        if (Uuid.IsExplicit)
            return;

        var go = gameObject;
        if (go.IsPrefabObject())
            return;

        var prevName = go.name;
        if (Regex.IsMatch(prevName, @"^.* @[A-Za-z0-9\-]+@ \(\d+\)$"))
        {
            var updatedName = prevName.Substring(0, prevName.LastIndexOf('@',
                                                        prevName.LastIndexOf('@') - 1) - 1) + " @" +
                              new EntityUuid(null) + "@";
            go.name = updatedName;
            UnityEditor.SceneManagement.EditorSceneManager.MarkSceneDirty(go.scene);
        }
        else if (!prevName.EndsWith("@"))
        {
            go.name = prevName + " @" + new EntityUuid(null) + "@";
        }
#endif
    }

    private void OnDestroy()
    {
        if (Application.isPlaying)
        {
            Entities.Remove(Uuid);
        }
        else
        {
            Entities.Remove(ParseUuidFromName());
        }
    }

    public override string ToString()
    {
        return Uuid.ToString();
    }
    
    // ...
}