using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using NetLibrary.Log;
using DirectShowLib;
using System.Drawing;
using System.Drawing.Imaging;

namespace NetLibrary
{
    public class Camera : ISampleGrabberCB, IDisposable
    {
        #region Member variables

        /// <summary> graph builder interface. </summary>
        private IFilterGraph2 m_FilterGraph = null;
        private IMediaControl m_mediaCtrl = null;

        /// <summary> so we can wait for the async job to finish </summary>
        private ManualResetEvent m_PictureReady = null;

        /// <summary> Set by async routine when it captures an image </summary>
        private volatile bool m_bGotOne = false;

        /// <summary> Indicates the status of the graph </summary>
        private bool m_bRunning = false;

        /// <summary> Dimensions of the image, calculated once in constructor. </summary>
        private IntPtr m_handle = IntPtr.Zero;
        private int m_videoWidth;
        private int m_videoHeight;
        private int m_stride;
        public int m_Dropped = 0;

        #endregion

        #region API

        [DllImport("Kernel32.dll", EntryPoint = "RtlMoveMemory")]
        private static extern void CopyMemory(IntPtr Destination, IntPtr Source, int Length);

        #endregion

        /// <summary> Use capture device zero, default frame rate and size</summary>
        public Camera()
        {
            _Capture(0, 0, 0, 0);
        }
        /// <summary> Use specified capture device, default frame rate and size</summary>
        public Camera(int iDeviceNum)
        {
            _Capture(iDeviceNum, 0, 0, 0);
        }
        /// <summary> Use specified capture device, specified frame rate and default size</summary>
        public Camera(int iDeviceNum, int iFrameRate)
        {
            _Capture(iDeviceNum, iFrameRate, 0, 0);
        }
        /// <summary> Use specified capture device, specified frame rate and size</summary>
        public Camera(int iDeviceNum, int iFrameRate, int iWidth, int iHeight)
        {
            _Capture(iDeviceNum, iFrameRate, iWidth, iHeight);
        }

        #region 初始化线程
        private AutoResetEvent AutoReset = new AutoResetEvent(false);
        Thread CameraThread = null;
        public bool IsScreenImage = false;
        public event Action<Bitmap> OutImage;
        public void StartScreenImage()
        {
            CameraThread = new Thread(ScreenImage);
            CameraThread.Start();
        }
        #endregion
        #region 停止录像
        public void StopScreenImage()
        {
            IsScreenImage = false;
            if (CameraThread == null) return;
            while (CameraThread.IsAlive)
            {
                System.Threading.Thread.Sleep(500);
            }
            //System.Threading.Thread.Sleep(1000);
            //CameraThread.Abort();
            //CameraThread = null;
        }
        #endregion

        #region 录像
        void ScreenImage()
        {
            IsScreenImage = true;
            while (this.IsScreenImage)
            {
                try
                {
                    Bitmap image = null;
                    IntPtr ip = IntPtr.Zero;
                    ip = this.GetBitMap();
                    image = new Bitmap(this.Width, this.Height, this.Stride, PixelFormat.Format24bppRgb, ip);
                    //旋转
                    image.RotateFlip(RotateFlipType.RotateNoneFlipY);
                    //释放指针ip
                    Marshal.FreeCoTaskMem(ip);
                    //回收垃圾
                    GC.Collect();
                    //不安全的刷新
                    if (this.OutImage != null) this.OutImage(image);
                    AutoReset.WaitOne(100);
                }
                catch (Exception ex)
                {
                    ErrorFollow.TraceWrite(ex.TargetSite.Name, ex.StackTrace, ex.Message);
                }
            }
        }
        #endregion
        #region 截图
        public Bitmap GrabImage()
        {
            try
            {
                StopScreenImage();
               
                Bitmap image = null;
                IntPtr ip = IntPtr.Zero;
                ip = this.GetBitMap();
                image = new Bitmap(this.Width, this.Height, this.Stride, PixelFormat.Format24bppRgb, ip);
                //旋转
                image.RotateFlip(RotateFlipType.RotateNoneFlipY);
                //释放指针ip
                Marshal.FreeCoTaskMem(ip);
                //回收垃圾
                GC.Collect();
                StartScreenImage();
                return image;
            }
            catch (Exception ex)
            {
                ErrorFollow.TraceWrite(ex.TargetSite.Name, ex.StackTrace, ex.Message);
            }
            return null;
        }
        #endregion
        #region 截图
        public void GrabImage(string filePath)
        {
            try
            {
                StopScreenImage();
                Bitmap image = null;
                IntPtr ip = IntPtr.Zero;
                ip = this.GetBitMap();
                image = new Bitmap(this.Width, this.Height, this.Stride, PixelFormat.Format24bppRgb, ip);
                //旋转
                image.RotateFlip(RotateFlipType.RotateNoneFlipY);
                //释放指针ip
                Marshal.FreeCoTaskMem(ip);
                //回收垃圾
                GC.Collect();
                image.Save(filePath, ImageFormat.Jpeg);
                StartScreenImage();
            }
            catch (Exception ex)
            {
                ErrorFollow.TraceWrite(ex.TargetSite.Name, ex.StackTrace, ex.Message);
            }
        }
        #endregion
        #region 截图并转成数组
        public byte[] GrabImageToByte()
        {
            try
            {
                StopScreenImage();
                Bitmap image = null;
                IntPtr ip = IntPtr.Zero;
                ip = this.GetBitMap();
                image = new Bitmap(this.Width, this.Height, this.Stride, PixelFormat.Format24bppRgb, ip);
                //旋转
                image.RotateFlip(RotateFlipType.RotateNoneFlipY);
                //释放指针ip
                Marshal.FreeCoTaskMem(ip);
                //回收垃圾
                GC.Collect();
                byte[] bytes=CustomIO.GetPhoto(image);
                image.Dispose();
                image = null;
                StartScreenImage();
                return bytes;
            }
            catch (Exception ex)
            {
                ErrorFollow.TraceWrite(ex.TargetSite.Name, ex.StackTrace, ex.Message);
            }
            return null;
        }
        #endregion


        #region 读取所有摄像头设备
        public static DsDevice[] GetDevices()
        { 
            DsDevice[] capDevices = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);
            return capDevices;
        }
        #endregion
        #region 是否存在摄像头
        public static bool IsCamera()
        {
            DsDevice[] capDevices = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);
            if (capDevices.Length == 0) return false;
            return true;
        }
        #endregion



        /// <summary> release everything. </summary>
        public void Dispose()
        {
            this.m_bRunning = false;
            CloseInterfaces();
            if (m_PictureReady != null)
            {
                m_PictureReady.Close();
                m_PictureReady = null;
            }
        }
        // Destructor
        ~Camera()
        {
            Dispose();
        }

        public int Width
        {
            get
            {
                return m_videoWidth;
            }
        }
        public int Height
        {
            get
            {
                return m_videoHeight;
            }
        }
        public int Stride
        {
            get
            {
                return m_stride;
            }
        }
        /// <summary> capture the next image </summary>
        public IntPtr GetBitMap()
        {
            m_handle = Marshal.AllocCoTaskMem(m_stride * m_videoHeight);

            try
            {
                // get ready to wait for new image
                m_PictureReady.Reset();
                m_bGotOne = false;

                // If the graph hasn't been started, start it.
                Start();

                // Start waiting
                if (!m_PictureReady.WaitOne(5000, false))
                {
                    throw new Exception("Timeout waiting to get picture");
                }
            }
            catch
            {
                Marshal.FreeCoTaskMem(m_handle);
                throw;
            }
            return m_handle;
        }
        // Start the capture graph
        public void Start()
        {
            if (!m_bRunning)
            {
                int hr = m_mediaCtrl.Run();
                DsError.ThrowExceptionForHR(hr);
                m_bRunning = true;
            }
        }
        // Pause the capture graph.
        // Running the graph takes up a lot of resources.  Pause it when it
        // isn't needed.
        public void Pause()
        {
            if (m_bRunning)
            {
                int hr = m_mediaCtrl.Pause();
                DsError.ThrowExceptionForHR(hr);

                m_bRunning = false;
            }
        }


        // Internal capture
        private void _Capture(int iDeviceNum, int iFrameRate, int iWidth, int iHeight)
        {
            DsDevice[] capDevices;

            // Get the collection of video devices
            capDevices = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);

            if (iDeviceNum + 1 > capDevices.Length)
            {
                throw new Exception("No video capture devices found at that index!");
            }

            try
            {
                // Set up the capture graph
                SetupGraph(capDevices[iDeviceNum], iFrameRate, iWidth, iHeight);

                // tell the callback to ignore new images
                m_PictureReady = new ManualResetEvent(false);
                m_bGotOne = true;
                m_bRunning = false;
            }
            catch
            {
                Dispose();
                throw;
            }
        }

        /// <summary> build the capture graph for grabber. </summary>
        private void SetupGraph(DsDevice dev, int iFrameRate, int iWidth, int iHeight)
        {
            int hr;

            ISampleGrabber sampGrabber = null;
            IBaseFilter capFilter = null;
            ICaptureGraphBuilder2 capGraph = null;

            // Get the graphbuilder object
            m_FilterGraph = (IFilterGraph2)new FilterGraph();
            m_mediaCtrl = m_FilterGraph as IMediaControl;
            try
            {
                // Get the ICaptureGraphBuilder2
                capGraph = (ICaptureGraphBuilder2)new CaptureGraphBuilder2();

                // Get the SampleGrabber interface
                sampGrabber = (ISampleGrabber)new SampleGrabber();

                // Start building the graph
                hr = capGraph.SetFiltergraph(m_FilterGraph);
                DsError.ThrowExceptionForHR(hr);

                // Add the video device
                hr = m_FilterGraph.AddSourceFilterForMoniker(dev.Mon, null, "Video input", out capFilter);
                DsError.ThrowExceptionForHR(hr);

                IBaseFilter baseGrabFlt = (IBaseFilter)sampGrabber;
                ConfigureSampleGrabber(sampGrabber);

                // Add the frame grabber to the graph
                hr = m_FilterGraph.AddFilter(baseGrabFlt, "Ds.NET Grabber");
                DsError.ThrowExceptionForHR(hr);

                // If any of the default config items are set
                if (iFrameRate + iHeight + iWidth > 0)
                {
                    SetConfigParms(capGraph, capFilter, iFrameRate, iWidth, iHeight);
                }

                hr = capGraph.RenderStream(PinCategory.Capture, MediaType.Video, capFilter, null, baseGrabFlt);
                DsError.ThrowExceptionForHR(hr);

                SaveSizeInfo(sampGrabber);
            }
            finally
            {
                if (capFilter != null)
                {
                    Marshal.ReleaseComObject(capFilter);
                    capFilter = null;
                }
                if (sampGrabber != null)
                {
                    Marshal.ReleaseComObject(sampGrabber);
                    sampGrabber = null;
                }
                if (capGraph != null)
                {
                    Marshal.ReleaseComObject(capGraph);
                    capGraph = null;
                }
            }
        }

        private void SaveSizeInfo(ISampleGrabber sampGrabber)
        {
            int hr;

            // Get the media type from the SampleGrabber
            AMMediaType media = new AMMediaType();
            hr = sampGrabber.GetConnectedMediaType(media);
            DsError.ThrowExceptionForHR(hr);

            if ((media.formatType != FormatType.VideoInfo) || (media.formatPtr == IntPtr.Zero))
            {
                throw new NotSupportedException("Unknown Grabber Media Format");
            }

            // Grab the size info
            VideoInfoHeader videoInfoHeader = (VideoInfoHeader)Marshal.PtrToStructure(media.formatPtr, typeof(VideoInfoHeader));
            m_videoWidth = videoInfoHeader.BmiHeader.Width;
            m_videoHeight = videoInfoHeader.BmiHeader.Height;
            m_stride = m_videoWidth * (videoInfoHeader.BmiHeader.BitCount / 8);

            DsUtils.FreeAMMediaType(media);
            media = null;
        }
        private void ConfigureSampleGrabber(ISampleGrabber sampGrabber)
        {
            AMMediaType media;
            int hr;

            // Set the media type to Video/RBG24
            media = new AMMediaType();
            media.majorType = MediaType.Video;
            media.subType = MediaSubType.RGB24;
            media.formatType = FormatType.VideoInfo;
            hr = sampGrabber.SetMediaType(media);
            DsError.ThrowExceptionForHR(hr);

            DsUtils.FreeAMMediaType(media);
            media = null;

            // Configure the samplegrabber
            hr = sampGrabber.SetCallback(this, 1);
            DsError.ThrowExceptionForHR(hr);
        }

        // Set the Framerate, and video size
        private void SetConfigParms(ICaptureGraphBuilder2 capGraph, IBaseFilter capFilter, int iFrameRate, int iWidth, int iHeight)
        {
            int hr;
            object o;
            AMMediaType media;

            // Find the stream config interface
            hr = capGraph.FindInterface(
                PinCategory.Capture, MediaType.Video, capFilter, typeof(IAMStreamConfig).GUID, out o);

            IAMStreamConfig videoStreamConfig = o as IAMStreamConfig;
            if (videoStreamConfig == null)
            {
                throw new Exception("Failed to get IAMStreamConfig");
            }

            // Get the existing format block
            hr = videoStreamConfig.GetFormat(out media);
            DsError.ThrowExceptionForHR(hr);

            // copy out the videoinfoheader
            VideoInfoHeader v = new VideoInfoHeader();
            Marshal.PtrToStructure(media.formatPtr, v);

            // if overriding the framerate, set the frame rate
            if (iFrameRate > 0)
            {
                v.AvgTimePerFrame = 10000000 / iFrameRate;
            }

            // if overriding the width, set the width
            if (iWidth > 0)
            {
                v.BmiHeader.Width = iWidth;
            }

            // if overriding the Height, set the Height
            if (iHeight > 0)
            {
                v.BmiHeader.Height = iHeight;
            }

            // Copy the media structure back
            Marshal.StructureToPtr(v, media.formatPtr, false);

            // Set the new format
            hr = videoStreamConfig.SetFormat(media);
            DsError.ThrowExceptionForHR(hr);

            DsUtils.FreeAMMediaType(media);
            media = null;
        }

        /// <summary> Shut down capture </summary>
        private void CloseInterfaces()
        {
            int hr;

            try
            {
                if (m_mediaCtrl != null)
                {
                    // Stop the graph
                    hr = m_mediaCtrl.Stop();
                    m_bRunning = false;
                }
            }
            catch (Exception ex)
            {
                ErrorFollow.TraceWrite(ex.TargetSite.Name, ex.StackTrace, ex.Message);
            }

            if (m_FilterGraph != null)
            {
                Marshal.ReleaseComObject(m_FilterGraph);
                m_FilterGraph = null;
            }
        }

        /// <summary> sample callback, NOT USED. </summary>
        int ISampleGrabberCB.SampleCB(double SampleTime, IMediaSample pSample)
        {
            if (!m_bGotOne)
            {
                // Set bGotOne to prevent further calls until we
                // request a new bitmap.
                m_bGotOne = true;
                IntPtr pBuffer;

                pSample.GetPointer(out pBuffer);
                int iBufferLen = pSample.GetSize();

                if (pSample.GetSize() > m_stride * m_videoHeight)
                {
                    throw new Exception("Buffer is wrong size");
                }

                CopyMemory(m_handle, pBuffer, m_stride * m_videoHeight);

                // Picture is ready.
                m_PictureReady.Set();
            }

            Marshal.ReleaseComObject(pSample);
            return 0;
        }

        /// <summary> buffer callback, COULD BE FROM FOREIGN THREAD. </summary>
        int ISampleGrabberCB.BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen)
        {
            if (!m_bGotOne)
            {
                // The buffer should be long enought
                if (BufferLen <= m_stride * m_videoHeight)
                {
                    // Copy the frame to the buffer
                    CopyMemory(m_handle, pBuffer, m_stride * m_videoHeight);
                }
                else
                {
                    throw new Exception("Buffer is wrong size");
                }

                // Set bGotOne to prevent further calls until we
                // request a new bitmap.
                m_bGotOne = true;

                // Picture is ready.
                m_PictureReady.Set();
            }
            else
            {
                m_Dropped++;
            }
            return 0;
        }
    }
}