using System;
using System.Collections.Generic;

namespace FlowerPower
{
    public class ObjectPool<T> where T : new()
    {
        private Stack<T> m_Stack = new();

        private Action<T> m_ActionOnNew;
        private Action<T> m_ActionOnGet;
        private Action<T> m_ActionOnRelease;

        public int CountAll { get; private set; }

        public ObjectPool()
        {
        }

        public ObjectPool(Action<T> actionOnGet, Action<T> actionOnRelease)
        {
            m_ActionOnGet = actionOnGet;
            m_ActionOnRelease = actionOnRelease;
        }

        public T Get()
        {
            T element;
            if (m_Stack.Count == 0)
            {
                element = new T();
                CountAll++;

                if (m_ActionOnNew != null)
                {
                    m_ActionOnNew(element);
                }
            }
            else
            {
                element = m_Stack.Pop();
            }

            if (m_ActionOnGet != null)
                m_ActionOnGet(element);

            return element;
        }

        public void Release(T element)
        {
            if (m_ActionOnRelease != null)
            {
                m_ActionOnRelease(element);
            }

            m_Stack.Push(element);
        }

        public void Dispose()
        {
            m_Stack.Clear();
            m_Stack = null;

            m_ActionOnNew = null;
            m_ActionOnGet = null;
            m_ActionOnRelease = null;
        }
    }
}