using System;

 using System.Windows.Forms;

 using System.Runtime.InteropServices;

 using System.Diagnostics;

 using System.Text;

 using Microsoft.Win32.SafeHandles;

 using Win32;

 namespace Hid

 {

     /// <summary>

     /// Represent a HID device.

     /// Rename to RawInputDevice?

     /// </summary>

     public class HidDevice: IDisposable

     {

         public string Name { get; private set; }

         public string Manufacturer { get; private set; }

         public string Product { get; private set; }

         public ushort VendorId { get; private set; }

         public ushort ProductId { get; private set; }

         public ushort Version { get; private set; }

         //Pre-parsed HID descriptor

         public IntPtr PreParsedData {get; private set;}

         //Info

         public RID_DEVICE_INFO Info { get {return iInfo;} }

         private RID_DEVICE_INFO iInfo;

         //Capabilities

         public HIDP_CAPS Capabilities { get { return iCapabilities; } }

         private HIDP_CAPS iCapabilities;

         //Input Button Capabilities

         public HIDP_BUTTON_CAPS[] InputButtonCapabilities { get { return iInputButtonCapabilities; } }

         private HIDP_BUTTON_CAPS[] iInputButtonCapabilities;

         //Input Value Capabilities

         public HIDP_VALUE_CAPS[] InputValueCapabilities { get { return iInputValueCapabilities; } }

         private HIDP_VALUE_CAPS[] iInputValueCapabilities;

         /// <summary>

         /// Class constructor will fetch this object properties from HID sub system.

         /// </summary>

         /// <param name="hRawInputDevice">Device Handle as provided by RAWINPUTHEADER.hDevice, typically accessed as rawinput.header.hDevice</param>

         public HidDevice(IntPtr hRawInputDevice)

         {

             //Try construct and rollback if needed

             try

             {

                 Construct(hRawInputDevice);

             }

             catch (System.Exception ex)

             {

                 //Just rollback and propagate

                 Dispose();

                 throw ex;

             }

         }

         /// <summary>

         /// Make sure dispose is called even if the user forgot about it.

         /// </summary>

         ~HidDevice()

         {

             Dispose();

         }

         /// <summary>

         /// Private constructor.

         /// </summary>

         /// <param name="hRawInputDevice"></param>

         private void Construct(IntPtr hRawInputDevice)

         {

             PreParsedData = IntPtr.Zero;

             iInputButtonCapabilities = null;

             iInputValueCapabilities = null;

             //Fetch various information defining the given HID device

             Name = Win32.RawInput.GetDeviceName(hRawInputDevice);

             //Fetch device info

             iInfo = new RID_DEVICE_INFO();

             if (!Win32.RawInput.GetDeviceInfo(hRawInputDevice, ref iInfo))

             {

                 throw new Exception("HidDevice: GetDeviceInfo failed: " + Marshal.GetLastWin32Error().ToString());

             }

             //Open our device from the device name/path

             SafeFileHandle handle = Win32.Function.CreateFile(Name,

                 Win32.FileAccess.NONE,

                 Win32.FileShare.FILE_SHARE_READ | Win32.FileShare.FILE_SHARE_WRITE,

                 IntPtr.Zero,

                 Win32.CreationDisposition.OPEN_EXISTING,

                 Win32.FileFlagsAttributes.FILE_FLAG_OVERLAPPED,

                 IntPtr.Zero

                 );

             //Check if CreateFile worked

             if (handle.IsInvalid)

             {

                 throw new Exception("HidDevice: CreateFile failed: " + Marshal.GetLastWin32Error().ToString());

             }

             //Get manufacturer string

             StringBuilder manufacturerString = new StringBuilder(256);

             if (Win32.Function.HidD_GetManufacturerString(handle, manufacturerString, manufacturerString.Capacity))

             {

                 Manufacturer = manufacturerString.ToString();

             }

             //Get product string

             StringBuilder productString = new StringBuilder(256);

             if (Win32.Function.HidD_GetProductString(handle, productString, productString.Capacity))

             {

                 Product = productString.ToString();

             }

             //Get attributes

             Win32.HIDD_ATTRIBUTES attributes = new Win32.HIDD_ATTRIBUTES();

             if (Win32.Function.HidD_GetAttributes(handle, ref attributes))

             {

                 VendorId = attributes.VendorID;

                 ProductId = attributes.ProductID;

                 Version = attributes.VersionNumber;

             }

             handle.Close();

             //Get our HID descriptor pre-parsed data

             PreParsedData = Win32.RawInput.GetPreParsedData(hRawInputDevice);

             if (PreParsedData == IntPtr.Zero)

             {

                 //We are done then.

                 //Some devices don't have pre-parsed data.

                 return;

             }

             //Get capabilities

             HidStatus status = Win32.Function.HidP_GetCaps(PreParsedData, ref iCapabilities);

             if (status != HidStatus.HIDP_STATUS_SUCCESS)

             {

                 throw new Exception("HidDevice: HidP_GetCaps failed: " + status.ToString());

             }

             //Get input button caps if needed

             if (Capabilities.NumberInputButtonCaps > 0)

             {

                 iInputButtonCapabilities = new HIDP_BUTTON_CAPS[Capabilities.NumberInputButtonCaps];

                 ushort buttonCapabilitiesLength = Capabilities.NumberInputButtonCaps;

                 status = Win32.Function.HidP_GetButtonCaps(HIDP_REPORT_TYPE.HidP_Input, iInputButtonCapabilities, ref buttonCapabilitiesLength, PreParsedData);

                 if (status != HidStatus.HIDP_STATUS_SUCCESS || buttonCapabilitiesLength != Capabilities.NumberInputButtonCaps)

                 {

                     throw new Exception("HidDevice: HidP_GetButtonCaps failed: " + status.ToString());

                 }

             }

             //Get input value caps if needed

             if (Capabilities.NumberInputValueCaps > 0)

             {

                 iInputValueCapabilities = new HIDP_VALUE_CAPS[Capabilities.NumberInputValueCaps];

                 ushort valueCapabilitiesLength = Capabilities.NumberInputValueCaps;

                 status = Win32.Function.HidP_GetValueCaps(HIDP_REPORT_TYPE.HidP_Input, iInputValueCapabilities, ref valueCapabilitiesLength, PreParsedData);

                 if (status != HidStatus.HIDP_STATUS_SUCCESS || valueCapabilitiesLength != Capabilities.NumberInputValueCaps)

                 {

                     throw new Exception("HidDevice: HidP_GetValueCaps failed: " + status.ToString());

                 }

             }

         }

         /// <summary>

         /// Dispose is just for unmanaged clean-up.

         /// Make sure calling disposed multiple times does not crash.

         /// See: http://stackoverflow.com/questions/538060/proper-use-of-the-idisposable-interface/538238#538238

         /// </summary>

         public void Dispose()

         {

             Marshal.FreeHGlobal(PreParsedData);

             PreParsedData = IntPtr.Zero;

         }

         /// <summary>

         /// Print information about this device to our debug output.

         /// </summary>

         public void DebugWrite()

         {

             Debug.WriteLine("================ HID =========================================================================================");

             Debug.WriteLine("==== Name: " + Name);

             Debug.WriteLine("==== Manufacturer: " + Manufacturer);

             Debug.WriteLine("==== Product: " + Product);

             Debug.WriteLine("==== VendorID: 0x" + VendorId.ToString("X4"));

             Debug.WriteLine("==== ProductID: 0x" + ProductId.ToString("X4"));

             Debug.WriteLine("==== Version: " + Version.ToString());

             Debug.WriteLine("==============================================================================================================");

         }

     }

 }