using System;
using System.Text;
using System.Runtime.InteropServices;

namespace testVoice
{
	[Flags]
	public enum DMD
	{
		DMDO_0      =0,
		DMDO_90     =1,
		DMDO_180    =2,
		DMDO_270    =4,
	}

	public enum DM_Fields
	{
		DM_DISPLAYORIENTATION = 0x00800000,
		DM_DISPLAYQUERYORIENTATION =0x01000000,
	}

	public enum DM_Orient
	{
		DMORIENT_PORTRAIT   =1,
		DMORIENT_LANDSCAPE  =2,
	}

	/* Flags for ChangeDisplaySettings */
	enum CDSFlags
	{
		CDS_TEST            =0x00000002,
		CDS_VIDEOPARAMETERS =0x00000020,
		CDS_RESET           =0x40000000,
	}

	/* Return values for ChangeDisplaySettings */
	enum CDSRet
	{
		DISP_CHANGE_SUCCESSFUL       =0,
		DISP_CHANGE_RESTART          =1,
		DISP_CHANGE_FAILED          =-1,
		DISP_CHANGE_BADMODE         =-2,
		DISP_CHANGE_NOTUPDATED      =-3,
		DISP_CHANGE_BADFLAGS        =-4,
		DISP_CHANGE_BADPARAM        =-5,
	}

	public class SelfMarshalledStruct
	{
		public SelfMarshalledStruct(int size)
		{
			data = new byte[size];
		}

		public Char GetChar( int offset )
		{
			return BitConverter.ToChar(data, offset);
		}

		public void SetChar( int offset, Char val )
		{
			Buffer.BlockCopy(BitConverter.GetBytes( val ), 0, data, offset, 2 );
		}

		public Int32 GetInt32( int offset )
		{
			return BitConverter.ToInt32(data, offset);
		}

		public void SetInt32( int offset, Int32 val )
		{
			Buffer.BlockCopy(BitConverter.GetBytes( val ), 0, data, offset, 4 );
		}

		public UInt32 GetUInt32( int offset )
		{
			return BitConverter.ToUInt32(data, offset);
		}

		public void SetUInt32( int offset, UInt32 val )
		{
			Buffer.BlockCopy(BitConverter.GetBytes( val ), 0, data, offset, 4 );
		}

		public Int16 GetInt16( int offset )
		{
			return BitConverter.ToInt16(data, offset);
		}

		public void SetInt16( int offset, Int16 val )
		{
			Buffer.BlockCopy(BitConverter.GetBytes( val ), 0, data, offset, 2 );
		}

		public UInt16 GetUInt16( int offset )
		{
			return BitConverter.ToUInt16(data, offset);
		}

		public void SetUInt16( int offset, UInt16 val )
		{
			Buffer.BlockCopy(BitConverter.GetBytes( val ), 0, data, offset, 2 );
		}

		public string GetStringUni(int offset, int len)
		{
			return Encoding.Unicode.GetString(data, offset, len).TrimEnd('\0');
		}

		public void SetStringUni(string str, int offset, int len)
		{
			Encoding.Unicode.GetBytes(str, 0, Math.Min(str.Length, len), data, offset);
		}

		public byte this[int offset]
		{
			get { return data[offset]; }
			set { data[offset] = value; }
		}

		public object Get(Type t, int offset)
		{
			if ( t.IsPrimitive )
			{
				if ( t.BaseType == typeof(Int32) || t == typeof(Int32))
					return GetInt32(offset);
				else if ( t.BaseType == typeof(Int16) || t == typeof(Int16) )
					return GetInt16(offset);
				else if ( t.BaseType == typeof(UInt32) || t == typeof(UInt32) )
					return GetInt32(offset);
				else if ( t.BaseType == typeof(UInt16) || t == typeof(UInt16) )
					return GetUInt16(offset);
				else if ( t.BaseType == typeof(byte)|| t == typeof(byte) )
					return this[offset];
			}
			return null;
		}

		public void Set(Type t, int offset, object Val)
		{
			if ( t.IsPrimitive )
			{
				if ( t.BaseType == typeof(Int32) || t == typeof(Int32))
					SetInt32(offset, (int)Val);
				else if ( t.BaseType == typeof(Int16) || t == typeof(Int16) )
					SetInt16(offset, (short)Val);
				else if ( t.BaseType == typeof(UInt32) || t == typeof(UInt32) )
					SetUInt32(offset, (UInt32)Val);
				else if ( t.BaseType == typeof(UInt16) || t == typeof(UInt16) )
					SetUInt16(offset, (ushort)Val);
				else if ( t.BaseType == typeof(byte)|| t == typeof(byte) )
					this[offset] = (byte)Val;
			}
			else if ( t == typeof(string) )
			{
				SetStringUni((string)Val, offset, ((string)Val).Length);
			}
		}

		protected byte[] data;
		public byte[] Data { get { return data; } }
	}

	public class devicemodeW: SelfMarshalledStruct
	{
		public devicemodeW():base(192)
		{
			dmSize = (ushort)Data.Length;
		}
		public string dmDeviceName
		{
			get { return GetStringUni( 0, 64 ); }


			set { SetStringUni( value, 0, 64 ); }
		}
		public ushort dmSpecVersion
		{
			get { return GetUInt16( 64 ); }


			set { SetUInt16( 64, value ); }
		}
		public ushort dmDriverVersion
		{
			get { return GetUInt16( 66 ); }


			set { SetUInt16( 66, value ); }
		}
		public ushort dmSize
		{
			get { return GetUInt16( 68 ); }


			set { SetUInt16( 68, value ); }
		}
		public ushort dmDriverExtra
		{
			get { return GetUInt16( 70 ); }


			set { SetUInt16( 70, value ); }
		}
		public DM_Fields dmFields
		{
			get { return (DM_Fields)GetUInt32( 72 ); }


			set { SetUInt32( 72, (uint)value ); }
		}
		public DM_Orient dmOrientation
		{
			get { return (DM_Orient)GetInt16( 76 ); }


			set { SetInt16( 76, (short)value ); }
		}
		public short dmPaperSize
		{
			get { return GetInt16( 78 ); }


			set { SetInt16( 78, value ); }
		}
		public short dmPaperLength
		{
			get { return GetInt16( 80 ); }


			set { SetInt16( 80, value ); }
		}
		public short dmPaperWidth
		{
			get { return GetInt16( 82 ); }


			set { SetInt16( 82, value ); }
		}
		public short dmScale
		{
			get { return GetInt16( 84 ); }


			set { SetInt16( 84, value ); }
		}
		public short dmCopies
		{
			get { return GetInt16( 86 ); }


			set { SetInt16( 86, value ); }
		}
		public short dmDefaultSource
		{
			get { return GetInt16( 88 ); }


			set { SetInt16( 88, value ); }
		}
		public short dmPrintQuality
		{
			get { return GetInt16( 90 ); }


			set { SetInt16( 90, value ); }
		}
		public short dmColor
		{
			get { return GetInt16( 92 ); }


			set { SetInt16( 92, value ); }
		}
		public short dmDuplex
		{
			get { return GetInt16( 94 ); }


			set { SetInt16( 94, value ); }
		}
		public short dmYResolution
		{
			get { return GetInt16( 96 ); }


			set { SetInt16( 96, value ); }
		}
		public short dmTTOption
		{
			get { return GetInt16( 98 ); }


			set { SetInt16( 98, value ); }
		}
		public short dmCollate
		{
			get { return GetInt16( 100 ); }


			set { SetInt16( 100, value ); }
		}
		public string dmFormName
		{
			get { return GetStringUni( 102, 64 ); }


			set { SetStringUni( value, 102, 64 ); }
		}
		public ushort dmLogPixels
		{
			get { return GetUInt16( 166 ); }


			set { SetUInt16( 166, value ); }
		}
		public uint dmBitsPerPel
		{
			get { return GetUInt32( 168 ); }


			set { SetUInt32( 168, value ); }
		}
		public uint dmPelsWidth
		{
			get { return GetUInt32( 172 ); }


			set { SetUInt32( 172, value ); }
		}
		public uint dmPelsHeight
		{
			get { return GetUInt32( 176 ); }


			set { SetUInt32( 176, value ); }
		}
		public uint dmDisplayFlags
		{
			get { return GetUInt32( 180 ); }


			set { SetUInt32( 180, value ); }
		}
		public uint dmDisplayFrequency
		{
			get { return GetUInt32( 184 ); }


			set { SetUInt32( 184, value ); }
		}
		public DMD dmDisplayOrientation
		{
			get { return (DMD)GetUInt32( 188 ); }


			set { SetUInt32( 188, (uint)value ); }
		}
	}

	public class ScreenMode 
	{

		[DllImport("coredll.dll")]
		internal static extern CDSRet ChangeDisplaySettingsEx(
			string lpszDeviceName,
			/*DEVICEMODE*/ byte[] lpDevMode,
			IntPtr hwnd,
			CDSFlags dwflags,
			IntPtr lParam);

		public string ChangeMode(int degree)
		{
			devicemodeW devMode = new devicemodeW();
			devMode.dmFields = DM_Fields.DM_DISPLAYORIENTATION;
			if ( degree==0 )
				devMode.dmDisplayOrientation = DMD.DMDO_0;
			else if ( degree==90 )
				devMode.dmDisplayOrientation = DMD.DMDO_90;
			else if ( degree==180 )
				devMode.dmDisplayOrientation = DMD.DMDO_180;
			else if ( degree==270 )
				devMode.dmDisplayOrientation = DMD.DMDO_270;
         
			CDSRet ret = ChangeDisplaySettingsEx(null, devMode.Data, IntPtr.Zero, 0, IntPtr.Zero);
			return (ret.ToString());
   
		}

	}
}