using System; 
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.IO;
using System.Net.Sockets;
using System.Collections.Generic;

namespace BigEyes.Server
{
	public class UserCapture
	{
		[DllImport("user32.dll")]
		private static extern uint MapVirtualKey(uint uCode, uint uMapType);
		[DllImport("user32.dll")]
		private static extern IntPtr GetDesktopWindow();
		[DllImport("gdi32.dll")]
		private static extern bool BitBlt(IntPtr hdcDest,int nXDest,int nYDest,int nWidth,int nHeight,IntPtr hdcSrc,int nXSrc,int nYSrc,int dwRop);
		[DllImport("user32.dll")]
		private static extern int GetSystemMetrics(int nIndex);
		[DllImport("user32.dll")]
		private static extern uint SendInput(uint nInputs,ref INPUT input,int cbSize);
		[DllImport("user32.dll")]
		private static extern void SetCursorPos(int x, int y);
		private const int SM_CXSCREEN = 0;
		private const int SM_CYSCREEN = 1;
		private const uint MOUSEEVENTF_MOVE       = 0x0001;
		private const uint MOUSEEVENTF_LEFTDOWN   = 0x0002;
		private const uint MOUSEEVENTF_LEFTUP     = 0x0004;
		private const uint MOUSEEVENTF_RIGHTDOWN  = 0x0008;
		private const uint MOUSEEVENTF_RIGHTUP    = 0x0010;
		private const uint MOUSEEVENTF_MIDDLEDOWN = 0x0020;
		private const uint MOUSEEVENTF_MIDDLEUP   = 0x0040;
		private const uint MOUSEEVENTF_WHEEL      = 0x0800;
		private const uint MOUSEEVENTF_ABSOLUTE   = 0x8000;
		private const uint KEYEVENTF_EXTENDEDKEY = 0x0001;
		private const uint KEYEVENTF_KEYUP       = 0x0002;
		private const uint INPUT_MOUSE    = 0;
		private const uint INPUT_KEYBOARD = 1;
		private const int SRCCOPY = 0xCC0020;
		struct MOUSE_INPUT
		{
			public uint dx;
			public uint dy;
			public uint mouseData;
			public uint dwFlags;
			public uint time;
			public uint dwExtraInfo;
		}
		struct KEYBD_INPUT
		{
			public ushort wVk;
			public ushort wScan;
			public uint   dwFlags;
			public uint   time;
			public uint   dwExtraInfo;
		}
		[StructLayout(LayoutKind.Explicit)]
		struct INPUT
		{
			[FieldOffset(0)]
			public uint type;
			[FieldOffset(4)]
			public MOUSE_INPUT mi;
			[FieldOffset(4)]
			public KEYBD_INPUT ki;
		}
		private static byte[] _previousBitmapBytes = null;
		private int _scaleSize;
		public UserCapture(int scalesize)
		{
			_scaleSize = scalesize;
		}
		public void PressOrReleaseMouseButton(bool press, bool left, int x, int y)
		{
			INPUT input = new INPUT();
			input.type           = INPUT_MOUSE;
			input.mi.dx          = (uint) x;
			input.mi.dy          = (uint) y;
			input.mi.mouseData   = 0;
			input.mi.dwFlags     = 0;
			input.mi.time        = 0;
			input.mi.dwExtraInfo = 0;
			if (left)
			{
				input.mi.dwFlags = press ? MOUSEEVENTF_LEFTDOWN : MOUSEEVENTF_LEFTUP;
			}
			else
			{
				input.mi.dwFlags = press ? MOUSEEVENTF_RIGHTDOWN : MOUSEEVENTF_RIGHTUP;
			}
			SendInput(1, ref input, Marshal.SizeOf(input));
		}
		public void MoveMouse(int x, int y)
		{
			double w = GetSystemMetrics(SM_CXSCREEN);
			double h = GetSystemMetrics(SM_CYSCREEN);
			SetCursorPos((int)Math.Round((w/(double)_scaleSize) * (double)x,0),(int)Math.Round((h/((h * (double)_scaleSize) / w)) * (double)y,0));
		}
		public void SendKeystroke(byte virtualKeyCode, bool keyDown, bool extendedKey)
		{
			INPUT input = new INPUT();
			input.type           = INPUT_KEYBOARD;
			input.ki.wVk         = virtualKeyCode;
			input.ki.wScan       = (byte)MapVirtualKey((uint) virtualKeyCode, 0);
			input.ki.dwExtraInfo = 0;
			input.ki.time        = 0;
			if (!keyDown)
			{
				input.ki.dwFlags |= KEYEVENTF_KEYUP;
			}
			if (extendedKey)
			{
				input.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;
			}
			SendInput(1, ref input, Marshal.SizeOf(input));
		}
		private Bitmap GetDesktopBitmap()
		{
			Size desktopBitmapSize = new Size(GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN));
			Graphics graphic = Graphics.FromHwnd(GetDesktopWindow());
			Bitmap memImage = new Bitmap(desktopBitmapSize.Width, desktopBitmapSize.Height, graphic);
			Graphics memGraphic = Graphics.FromImage(memImage);
			IntPtr dc1 = graphic.GetHdc();
			IntPtr dc2 = memGraphic.GetHdc();
			BitBlt(dc2, 0, 0, desktopBitmapSize.Width, desktopBitmapSize.Height, dc1, 0, 0, SRCCOPY);
			graphic.ReleaseHdc(dc1);
			memGraphic.ReleaseHdc(dc2);
			graphic.Dispose();
			memGraphic.Dispose();
			return memImage;
		}
		public byte[] GetDesktopBitmapBytes()
		{
			Bitmap currentBitmap = GetDesktopBitmap();
			currentBitmap = new Bitmap(currentBitmap.GetThumbnailImage(_scaleSize,currentBitmap.Height * _scaleSize / currentBitmap.Width,null,IntPtr.Zero));
			MemoryStream ms = new MemoryStream();
			currentBitmap.Save(ms,ImageFormat.Jpeg);
			byte[] currentBitmapBytes = ms.ToArray();
			ms.Close();
			byte[] b = compBytes(_previousBitmapBytes, currentBitmapBytes);
			_previousBitmapBytes = currentBitmapBytes;
			return b;
		}
		private byte[] compBytes(byte[] old, byte[] now)
		{
			if (old == null)
			{
				byte[] b = new byte[now.Length + 1];
				b[0] = 0;
				Array.Copy(now, 0, b, 1, now.Length);
				return b;
			}
			MemoryStream ms = new MemoryStream();
			BinaryWriter bw = new BinaryWriter(ms);
			bool equality = true;
			int min = Math.Min(old.Length, now.Length);
			for (int i = 0; i < min; i++)
			{
				if (old[i] != now[i])
				{
					bw.Write(i);
					bw.Write(now[i]);
					equality = false;
				}
			}
			if (equality)
			{
				return new byte[0];
			}
			for (int i = min + 1; i < now.Length; i++)
			{
				bw.Write(i);
				bw.Write(now[i]);
			}
			if (ms.Length >= now.Length)
			{
				byte[] b = new byte[now.Length + 1];
				b[0] = 0;
				Array.Copy(now, 0, b, 1, now.Length);
				return b;
			}
			else
			{
				System.Diagnostics.Debug.WriteLine("Partial image.");
				byte[] r =  ms.ToArray();
				byte[] b = new byte[r.Length + 1];
				b[0] = 1;
				Array.Copy(r, 0, b, 1, r.Length);
				return b;
			}
		}

	}
}