using System.Collections.Generic;

namespace PhxhSDK
{
    public class SubSystemManager : IUpdatable, IInitable, IStart, IOnApplicationPause
    {
        private readonly List<IOnApplicationPause> _appPauseList = new(4);
        private readonly List<IInitable> _initables = new(8);
        private readonly List<IStart> _startables = new(4);
        private readonly List<IUpdatable> _updateList = new(4);


        public void Init()
        {
        }


        public void Release()
        {
            for (var i = _initables.Count - 1; i >= 0; i--)
            {
                var initable = _initables[i];
                initable.Release();
            }

            _updateList.Clear();
        }

        public void OnApplicationPause(bool pauseStatus)
        {
            foreach (var appPause in _appPauseList) appPause.OnApplicationPause(pauseStatus);
        }

        public void Start()
        {
            foreach (var st in _startables) st.Start();
        }


        public void Update(float deltaTime)
        {
            foreach (var updatable in _updateList) updatable.Update(deltaTime);
        }

        public void AddSubSystem<T>() where T : class, new()
        {
            // if T is subclass of Singleton, use Instance instead of new
            T subSystem = null;
            if (typeof(T).IsSubclassOf(typeof(Singlenton<T>)))
                subSystem = Singlenton<T>.Instance;
            else
                subSystem = new T();

            var initable = subSystem as IInitable;
            if (initable != null) 
            {
                initable.Init();
                _initables.Add(initable);
            }

            var startable = subSystem as IStart;
            if (startable != null) _startables.Add(startable);

            var globalObj = subSystem as IGlobal;
            if (globalObj != null) globalObj.ToGlobal();

            var updatable = subSystem as IUpdatable;
            if (updatable != null) _updateList.Add(updatable);

            var appPause = subSystem as IOnApplicationPause;
            if (appPause != null) _appPauseList.Add(appPause);
        }
    }
}