SCSI Library in C# - Burn CDs and DVDs, Access Hard Disks, etc.

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using Helper;
using Scsi.Multimedia;

namespace Scsi
{
	/// <summary>Represents a generic Scsi command with a specific operation code. Any derived classes MUST be blittable (that is, contain only primitive types) so that marshaling can be performed. This means that all subclasses must override <see cref="ScsiCommand.Control"/> and make it access the appropriate field.</summary>
	[StructLayout(LayoutKind.Sequential, Pack = 1)]
	public abstract class ScsiCommand : IMarshalable
	{
		protected ScsiCommand(ScsiCommandCode operationCode) : base() { this.OpCode = operationCode; }

		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		internal ScsiCommandCode _OperationCode;  //Internal so we can pin it
		public ScsiCommandCode OpCode { get { return this._OperationCode; } private set { this._OperationCode = value; } }
		public abstract CommandControl Control { get; set; }

		public override string ToString()
		{
#if TO_STRING_OPCODE_ONLY
			return this.OpCode.ToString();
#else
			return Internal.GenericToString(this, true);
#endif
		}
		
		protected virtual void MarshalFrom(BufferWithSize buffer) { Marshaler.DefaultPtrToStructure(buffer, this); }
		protected virtual void MarshalTo(BufferWithSize buffer) { Marshaler.DefaultStructureToPtr((object)this, buffer); }
		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		protected virtual int MarshaledSize { get { return Marshal.SizeOf(this); } }

		public abstract ScsiTimeoutGroup TimeoutGroup { get; }

		void IMarshalable.MarshalFrom(BufferWithSize buffer) { this.MarshalFrom(buffer); }
		void IMarshalable.MarshalTo(BufferWithSize buffer) { this.MarshalTo(buffer); }
		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		int IMarshalable.MarshaledSize { get { return this.MarshaledSize; } }

		public static ScsiCommand CreateInstance(ScsiCommandCode operationCode)
		{
			var result = TryCreateInstance(operationCode);
			if (result == null) { throw new ArgumentOutOfRangeException("operationCode", operationCode, "Unsupported OpCode."); }
			return result;
		}

		public static ScsiCommand TryCreateInstance(ScsiCommandCode operationCode)
		{
			ScsiCommand result;
			switch (operationCode)
			{
				case ScsiCommandCode.Blank:
					result = new BlankCommand();
					break;
				case ScsiCommandCode.CloseSessionOrTrack:
					result = new CloseSessionTrackCommand();
					break;
				case ScsiCommandCode.Erase10:
					result = new Erase10Command();
					break;
				case ScsiCommandCode.Format:
					result = new FormatUnitCommand();
					break;
				case ScsiCommandCode.GetConfiguration:
					result = new GetConfigurationCommand();
					break;
				case ScsiCommandCode.GetEventStatusNotification:
					result = new GetEventStatusNotificationCommand();
					break;
				case ScsiCommandCode.GetPerformance:
					result = new GetPerformanceCommand();
					break;
				case ScsiCommandCode.Inquiry:
					result = new InquiryCommand();
					break;
				case ScsiCommandCode.LoadUnloadMedium:
					result = new LoadUnloadMediumCommand();
					break;
				case ScsiCommandCode.ModeSelect10:
					result = new ModeSelect10Command();
					break;
				case ScsiCommandCode.ModeSense10:
					result = new ModeSense10Command();
					break;
				case ScsiCommandCode.PreventAllowMediumRemoval:
					result = new PreventAllowMediumRemovalCommand();
					break;
				case ScsiCommandCode.Read10:
					result = new Read10Command();
					break;
				case ScsiCommandCode.Read12:
					result = new Read12Command();
					break;
				case ScsiCommandCode.ReadBuffer:
					result = new ReadBufferCommand();
					break;
				case ScsiCommandCode.ReadBufferCapacity:
					result = new ReadBufferCapacityCommand();
					break;
				case ScsiCommandCode.ReadCapacity:
					result = new ReadCapacityCommand();
					break;
				case ScsiCommandCode.ReadCD:
					result = new ReadCDCommand();
					break;
				case ScsiCommandCode.ReadDiscInformation:
					result = new ReadDiscInformationCommand();
					break;
				case ScsiCommandCode.ReadDiscStructure:
					result = new ReadDiscStructureCommand();
					break;
				case ScsiCommandCode.ReadFormatCapacities:
					result = new ReadFormatCapacitiesCommand();
					break;
				case ScsiCommandCode.ReadTocPmaAtip:
					result = new ReadTocPmaAtipCommand();
					break;
				case ScsiCommandCode.ReadTrackInformation:
					result = new ReadTrackInformationCommand();
					break;
				case ScsiCommandCode.Read06:
					result = new Read06Command();
					break;
				case ScsiCommandCode.ReportKey:
					result = new ReportKeyCommand();
					break;
				case ScsiCommandCode.RequestSense:
					result = new RequestSenseCommand();
					break;
				case ScsiCommandCode.ReserveTrack:
					result = new ReserveTrackCommand();
					break;
				case ScsiCommandCode.Seek10:
					result = new Seek10Command();
					break;
				case ScsiCommandCode.SendCueSheet:
					result = new SendCueSheetCommand();
					break;
				case ScsiCommandCode.SendDiagnostic:
					result = new SendDiagnosticCommand();
					break;
				case ScsiCommandCode.SendOpcInformation:
					result = new SendOpcInformationCommand();
					break;
				case ScsiCommandCode.SetCDSpeed:
					result = new SetCDSpeedCommand();
					break;
				case ScsiCommandCode.SetReadAhead:
					result = new SetReadAheadCommand();
					break;
				case ScsiCommandCode.SetRemovableMediaBit:
					result = new SetRemovableMediaBitCommand();
					break;
				case ScsiCommandCode.SetStreaming:
					result = new SetStreamingCommand();
					break;
				case ScsiCommandCode.StartStopUnit:
					result = new StartStopUnitCommand();
					break;
				case ScsiCommandCode.SynchronizeCache10:
					result = new SynchronizeCache10Command();
					break;
				case ScsiCommandCode.TestUnitReady:
					result = new TestUnitReadyCommand();
					break;
				case ScsiCommandCode.Verify10:
					result = new Verify10Command();
					break;
				case ScsiCommandCode.Write10:
					result = new Write10Command();
					break;
				case ScsiCommandCode.Write12:
					result = new Write12Command();
					break;
				case ScsiCommandCode.WriteBuffer:
					result = new WriteBufferCommand();
					break;
				default:
					result = null;
					break;
			}
			return result;
		}

		public static ScsiCommand FromBuffer(IntPtr pBuffer, int bufferLength)
		{
			var buffer = new BufferWithSize(pBuffer, bufferLength);
			var instance = CreateInstance(buffer.Read<ScsiCommandCode>());
			Marshaler.PtrToStructure(buffer, ref instance);
			return instance;
		}

		public static ScsiCommand TryFromBuffer(IntPtr pBuffer, int bufferLength)
		{
			var buffer = new BufferWithSize(pBuffer, bufferLength);
			var instance = TryCreateInstance(buffer.Read<ScsiCommandCode>());
			if (instance != null) { Marshaler.PtrToStructure(buffer, ref instance); }
			return instance;
		}

		public static ScsiCommandCode ReadOperationCode(IntPtr cdb, int cdbLength) { return new BufferWithSize(cdb, cdbLength).Read<ScsiCommandCode>(); }
	}

	public enum ScsiCommandCode : byte
	{
		AtaPassThrough12 = 0xA1,
		Blank = 0xA1,
		CloseSessionOrTrack = 0x5B,
		CloseTrack = 0x5B,
		Copy = 0x18,
		Erase06 = 0x19,
		Erase10 = 0x2C,
		Format = 0x04,
		GetConfiguration = 0x46,
		GetEventStatusNotification = 0x4A,
		GetPerformance = 0xAC,
		Inquiry = 0x12,
		LoadUnloadMedium = 0xA6,
		MechanismStatus = 0xBD,
		ModeSelect06 = 0x15,
		ModeSelect10 = 0x55,
		ModeSense10 = 0x5A,
		Pause = 0x4B,
		PlayAudio10 = 0x45,
		PlayAudio12 = 0xA5,
		PlayAudioMinuteSecondFrame = 0x47,
		PreventAllowMediumRemoval = 0x1E,
		Read06 = 0x08,
		Read10 = 0x28,
		Read12 = 0xA8,
		Read16 = 0x88,
		Read32 = 0x7F,
		ReadBlockLimits = 0x05,
		ReadBuffer = 0x3C,
		ReadBufferCapacity = 0x5C,
		ReadCapacity = 0x25,
		ReadCD = 0xBE,
		ReadCDMinuteSecondFrame = 0xB9,
		ReadDiscInformation = 0x51,
		ReadDiscStructure = 0xAD,
		ReadFormatCapacities = 0x23,
		ReadReverse06 = 0x0F,
		ReadSubChannel = 0x42,
		ReadTocPmaAtip = 0x43,
		ReadTrackInformation = 0x52,
		ReassignBlocks = 0x07,
		RecoverBufferedData = 0x14,
		Release06 = 0x17,
		RepairTrack = 0x58,
		ReportKey = 0xA4,
		RequestSense = 0x03,
		Reserve06 = 0x16,
		ReserveTrack = 0x53,
		Resume = 0x4B,
		Rewind = 0x01,
		RezeroUnit = 0x01,
		Scan = 0xBA,
		Seek = 0x0B,
		Seek10 = 0x2B,
		SendCueSheet = 0x5D,
		SendDiagnostic = 0x1D,
		SendDiscStructure = 0xBF,
		SendKey = 0xA3,
		SendOpcInformation = 0x54,
		SetCDSpeed = 0xBB,
		SetReadAhead = 0xA7,
		SetRemovableMediaBit = 0xD2,
		SetStreaming = 0xB6,
		Space06 = 0x11,
		StartStopUnit = 0x1B,
		StopPlayScan = 0x4E,
		SynchronizeCache10 = 0x35,
		TestUnitReady = 0x00,
		Verify06 = 0x13,
		Verify10 = 0x2F,
		Write06 = 0x0A,
		Write10 = 0x2A,
		Write12 = 0xAA,
		WriteAndVerify10 = 0x2E,
		WriteBuffer = 0x3B,
		WriteFilemarks06 = 0x10,

		//Vendor-specific: 0x0C, 0x0D, 0x0E
	}

	[StructLayout(LayoutKind.Sequential, Pack = 1, Size = 1)]
	public struct CommandControl
	{
		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		private byte byte0;
		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		public bool Link { get { return Bits.GetBit(this.byte0, 0); } set { this.byte0 = Bits.SetBit(this.byte0, 0, value); } }
		[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		public bool NormalACA { get { return Bits.GetBit(this.byte0, 2); } set { this.byte0 = Bits.SetBit(this.byte0, 2, value); } }
		public override string ToString() { return string.Format("Lined = {0}, NACA = {1}", this.Link, this.NormalACA); }
	}
}