using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SKMC.Api.Common.Types
{
    /// <summary>
    /// 边界队列
    /// 添加新元素时检查是否达到上限, 如果达到则先移除最早的一个元素
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class BoundedQueue<T>
    {
        private readonly Queue<T> queue;
        private readonly int maxSize;

        public BoundedQueue(int size)
        {
            maxSize = size;
            queue = new Queue<T>();
        }

        public void Enqueue(T item)
        {
            if (queue.Count >= maxSize)
            {
                queue.Dequeue();
            }
            queue.Enqueue(item);
        }

        public T Dequeue()
        {
            return queue.Dequeue();
        }

        public T Peek()
        {
            return queue.Peek();
        }

        public int Count
        {
            get { return queue.Count; }
        }

        public T[] ToArray() => queue.ToArray();
    }
}