internal class ComponentManager
    {
        private int _wordsPerEntity;
        private int[] _componentHashCodes;
        private ComponentStore<IComponent>[] _componentStores;
        private OpenBitSet _componentBits;
        private int _componentTypeCount;

        internal ComponentManager(Type[] componentTypes)
        {
            _componentTypeCount = componentTypes.Length;
            _componentStores = new ComponentStore<IComponent>[_componentTypeCount];
            _componentHashCodes = new int[_componentTypeCount];
            _wordsPerEntity = Math.Max(1, _componentTypeCount / 64);
            _componentBits = new OpenBitSet((_wordsPerEntity * 1024) * 64);

            Array.Sort(componentTypes, (x, y) => x.GetHashCode().CompareTo(y.GetHashCode()));

            for (int i = 0; i < _componentTypeCount; i++)
            {
                Type currentType = componentTypes[i];
                Type storeType = typeof(ComponentStore<>).MakeGenericType(currentType);

                _componentHashCodes[i] = currentType.GetHashCode();

                var currentStore = Activator.CreateInstance(storeType, new object[] { _componentBits, _wordsPerEntity, i });
                _componentStores[i] = currentStore as ComponentStore<IComponent>;
            }
        }

        internal ComponentStore<T> GetStoreFor<T>() where T : IComponent
        {
            int index = GetTypeIndex(typeof(T));
            return _componentStores[index] as ComponentStore<T>;
        }

        private int GetTypeIndex(Type componentType)
        {
            return Array.BinarySearch(_componentStores, componentType.GetHashCode());
        }
    }