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

namespace MvvmScaffoldFrame48.DLL.SystemTools
{
    public sealed class RingBuffer<T>
    {
        private readonly T[] _buffer;
        private int _writeIndex;
        private int _readIndex;
        private int _count;
        private readonly int _capacity;
        private readonly object _lock = new object();

        public RingBuffer(int capacity)
        {
            _capacity = capacity;
            _buffer = new T[capacity];
        }

        public bool TryEnqueue(T item)
        {
            lock (_lock)
            {
                if (_count >= _capacity) return false;

                var index = (_readIndex + _count) % _capacity;
                _buffer[index] = item;
                _count++;
                return true;
            }
        }

        public bool TryDequeue(out T result)
        {
            lock (_lock)
            {
                if (_count <= 0)
                {
                    result = default(T);
                    return false;
                }

                result = _buffer[_readIndex];
                _buffer[_readIndex] = default(T); // 避免内存泄漏
                _readIndex = (_readIndex + 1) % _capacity;
                _count--;
                return true;
            }
        }

        public int Count => _count;
    }
}