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

namespace DetectorUtils.Captures
{
    public class CaptureAuto
    {


        public CaptureAuto(double frameRate, Action<Bitmap> captureCallback)
            :this(frameRate,captureCallback,-1,-1,-1,-1)
        {
        }

        public CaptureAuto(double frameRate, Action<Bitmap> captureCallback, Int32 startX, Int32 startY, Int32 width, Int32 height)
        {
            this.frameRate = frameRate;
            this.captureCallback = captureCallback;
            this.Status = CaptureStatus.Stop;
            this.AreaStartX = startX;
            this.AreaStartY = startY;
            this.AreaWidth = width;
            this.AreaHeight = height;

            Int32 screenWidth;
            Int32 screenHeight;
            Utils.GetWindowSize(out screenWidth, out screenHeight);
            if (startX >= 0 && startY >= 0 && width > 0 && height > 0 && (startX + width) <= screenWidth && (startY + height) <= screenHeight)
            {
                captureArea = true;
            }
            else
            {
                captureArea = false;
            }
        }

        private CancellationTokenSource CancellationSource;//取消源
        private double frameRate = 30d;//30帧
        private Action<Bitmap> captureCallback;//回调
        private DateTime time = DateTime.Now;
        private bool captureArea = false;//是否只截取一部分画面
        public Int32 AreaStartX=0;
        public Int32 AreaStartY=0;
        public Int32 AreaWidth=0;
        public Int32 AreaHeight=0;
        /// <summary>
        /// 状态
        /// </summary>
        public CaptureStatus Status
        {
            get;
            private set;
        }

        public void Start()
        {
            if (this.Status == CaptureStatus.Stop)
            {
                CancellationSource = new CancellationTokenSource();
                ThreadPool.QueueUserWorkItem(AutoCapture, CancellationSource.Token);
                Status = CaptureStatus.Captureing;
            }
        }

        public void Stop()
        {
            if (CancellationSource != null&&Status==CaptureStatus.Captureing)
            {
                CancellationSource.Cancel();
                CancellationSource = null;
                Status = CaptureStatus.Stop;
            }
        }

        /// <summary>
        /// 改变大小
        /// </summary>
        public void Resize(Int32 width,Int32 height)
        {
            Int32 screenWidth = 0;
            Int32 screenHeight = 0;
            Utils.GetWindowSize(out screenWidth, out screenHeight);
            if (width <= 0 || (this.AreaStartX + width) > screenWidth)
            {
                this.AreaWidth = screenWidth - this.AreaStartX;
            }
            else
            {
                this.AreaWidth = width;
            }

            if (height <= 0 || (this.AreaStartY + height) > screenHeight)
            {
                this.AreaHeight = screenHeight - this.AreaStartY;
            }
            else
            {
                this.AreaHeight = height;
            }

        }

        /// <summary>
        /// 移动到指定位置
        /// </summary>
        public void MoveTo(Int32 x,Int32 y)
        {
            Int32 screenWidth = 0;
            Int32 screenHeight = 0;
            Utils.GetWindowSize(out screenWidth, out screenHeight);

            if (x < 0 || x > screenWidth)
            {
                this.AreaStartX = 0;
            }
            else
            {
                this.AreaStartX = x;
            }
            if (y < 0 || y > screenHeight)
            {
                this.AreaStartY = 0;
            }
            else
            {
                this.AreaStartY = y;
            }

            if ((this.AreaStartX + this.AreaWidth) > screenWidth)
            {
                this.AreaStartX = screenWidth - this.AreaWidth;
            }

            if ( (this.AreaStartY + this.AreaHeight) > screenHeight)
            {
                this.AreaStartY = screenHeight - this.AreaHeight;
            }

        }





        /// <summary>
        /// 自动截屏
        /// </summary>
        /// <param name="obj"></param>
        private void AutoCapture(object obj)
        {
            double d = 1000d / frameRate;
            CancellationToken token = (CancellationToken)obj;
            
            while (!token.IsCancellationRequested)
            {
                double ts = (DateTime.Now - time).TotalMilliseconds;
                if (ts < d)
                {
                    Thread.Sleep((Int32)(d - ts));
                    continue;
                }
                Bitmap bitmap = null;
                if (captureArea)
                {
                    bitmap = ScreenCapture.CaptureScreen(this.AreaStartX, this.AreaStartY, this.AreaWidth, this.AreaHeight);
                }
                else
                {
                    bitmap = ScreenCapture.CaptureScreen();
                }
                if (this.captureCallback != null)
                {
                    this.captureCallback(bitmap);
                }
                time = DateTime.Now;
            }

        }

        public enum CaptureStatus : byte
        {
            Stop,//停止状态
            Captureing//截屏状态
        }
    }
}