#if UNITY_5_3_OR_NEWER
using System.Diagnostics;
using UnityEngine;
using Debug = UnityEngine.Debug;

namespace RocketUtils
{
    public abstract class SingletonBehaviour<T> : MonoBehaviour where T : MonoBehaviour
    {
        [SerializeField]
        protected bool DisableDebugLabels = false;
        private static DebugInfoBehaviour _debugInfoBehaviour;
        
        private static T _instance;

        private void Awake()
        {
            if (Instance == null)
            {
                Instance = (T)FindObjectOfType(typeof(T));
                if (Instance == null)
                {
                    Debug.LogWarning("An instance of " + typeof(T) +
                                     " is needed in the scene, but there is none.");
                }
                else
                {
                    OnAwake();
                }
            }
            else if (Instance != this)
            {
                Destroy(gameObject); // On reload, singleton already set, so destroy duplicate.
            }
#if ROC_DEBUG_MODE || ROC_LOG_MODE
            if (!_debugInfoBehaviour && !FindObjectOfType(typeof(DebugInfoBehaviour)))
            {
                _debugInfoBehaviour = new GameObject(nameof(DebugInfoBehaviour))
                    .AddComponent<DebugInfoBehaviour>();
                DebugInfoBehaviour.DisableDebugLabels = DisableDebugLabels;
            }
#endif
        }        

        protected abstract void OnAwake();
        
        public static bool IsInstantiated => _instance;

        public static T Instance
        {
            get
            {
                if (!_instance)
                {
                    _instance = (T)FindObjectOfType(typeof(T));
                    if (!_instance)
                    {
                        Debug.LogWarning("An instance of " + typeof(T) +
                                         " is needed in the scene, but there is none.");
                    }
                    else
                    {
                        SingletonBehaviour<T> instance = _instance as SingletonBehaviour<T>;
                        instance.OnAwake();
                    }
                }

                return _instance;
            }
            set
            {
                _instance = value;
            }
        }

#if ROC_DEBUG_MODE || ROC_LOG_MODE
        protected bool DrawDebugLabel
        {
            get => DebugInfoBehaviour.DrawDebugLabel;
            set => DebugInfoBehaviour.DrawDebugLabel = value;
        }
        protected bool DrawTimeLabel
        {
            get => DebugInfoBehaviour.DrawTimeLabel;
            set => DebugInfoBehaviour.DrawTimeLabel = value;
        }
        protected bool DrawFPSLabel
        {
            get => DebugInfoBehaviour.DrawFPSLabel;
            set => DebugInfoBehaviour.DrawFPSLabel = value;
        }
#endif

    }
}
#endif