using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Security;

namespace demo.ClassHelper.TimeOperate
{
    class TimerHelper
    {
        /// <summary>
        ///  获取时间的精度
        /// </summary>
        /// <param name="PerformanceFrequency"></param>
        /// <returns></returns>
        [SuppressUnmanagedCodeSecurity]
        [DllImport("kernel32")]
        private static extern bool QueryPerformanceFrequency(ref long PerformanceFrequency);

        /// <summary>
        ///  获取时间计数
        /// </summary>
        /// <param name="PerformanceCount"></param>
        /// <returns></returns>
        [SuppressUnmanagedCodeSecurity]
        [DllImport("kernel32")]
        private static extern bool QueryPerformanceCounter(ref long PerformanceCount);

        [DllImport("kernel32")]
        static extern IntPtr GetCurrentThread();

        [DllImport("kernel32")]
        static extern IntPtr SetThreadAffinityMask(IntPtr hThread, IntPtr dwThreadAffinityMask);

        [DllImport("Kernel32")]
        private extern static Boolean CloseHandle(IntPtr handle);

        private long ticksPerSecond = 0;
        private long Time = 0;
        private long baseTime = 0;
        private IntPtr handle;
        private bool disposed = false;

        /// <summary>
        /// 获取毫秒数
        /// </summary>
        private long duration;
        public long Duration
        {
            get
            {
                QueryPerformanceCounter(ref Time);
                return duration = (long)(((double)(Time - baseTime) / (double)ticksPerSecond) * 1000);
            }
            private set
            {
                duration = value;
            }
        }

        /// <summary>
        /// 
        /// </summary>
        public TimerHelper()
        {
            if (QueryPerformanceFrequency(ref ticksPerSecond) == false)
            {
                // 不支持高性能计数器
                throw new ApplicationException("Timer: Performance Frequency Unavailable");
            }

            Reset();
        }

        /// <summary>
        /// 复位
        /// </summary>
        public void Reset()
        {
            long time = 0;
            IntPtr threadId = GetCurrentThread();
            IntPtr previous = SetThreadAffinityMask(threadId, new IntPtr(1));
            QueryPerformanceCounter(ref time);
            SetThreadAffinityMask(threadId, previous);
            baseTime = time;
            Time = 0;
        }

        // 开始计时器
        public void Start()
        {
            // 来让等待线程工作
            IntPtr threadId = GetCurrentThread();
            IntPtr previous = SetThreadAffinityMask(threadId, new IntPtr(1));
            SetThreadAffinityMask(threadId, previous);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!disposed)
            {
                CloseHandle(handle);
                handle = IntPtr.Zero;
            }

            disposed = true;
        }

        ~TimerHelper()
        {
            Dispose(false);
        }

        // 返回计时器经过时间(单位：秒)
    }
}