using System;

 using System.Windows.Forms;

 using System.Runtime.InteropServices;

 using System.Diagnostics;

 using System.Text;

 using Microsoft.Win32.SafeHandles;

 using Win32;

 using System.Collections.Generic;

 namespace Hid

 {

     /// <summary>

     /// Represent a HID event.

     /// </summary>

     class HidEvent

     {

         public bool IsValid { get; private set; }

         public bool IsForeground { get; private set; }

         public bool IsBackground { get{return !IsForeground;} }

         public bool IsMouse { get; private set; }

         public bool IsKeyboard { get; private set; }

         public bool IsGeneric { get; private set; }

         public HidDevice Device { get; private set; }

         public ushort UsagePage { get; private set; }

         public ushort UsageCollection { get; private set; }

         public List<ushort> Usages { get; private set; }

         /// <summary>

         /// Initialize an HidEvent from a WM_INPUT message

         /// </summary>

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

         public HidEvent(Message aMessage)

         {

             IsValid = false;

             IsKeyboard = false;

             IsGeneric = false;

             Usages = new List<ushort>();

             if (aMessage.Msg != Const.WM_INPUT)

             {

                 //Has to be a WM_INPUT message

                 return;

             }

             if (Macro.GET_RAWINPUT_CODE_WPARAM(aMessage.WParam) == Const.RIM_INPUT)

             {

                 IsForeground = true;

             }

             else if (Macro.GET_RAWINPUT_CODE_WPARAM(aMessage.WParam) == Const.RIM_INPUTSINK)

             {

                 IsForeground = false;

             }

             //Declare some pointers

             IntPtr rawInputBuffer = IntPtr.Zero;

             //My understanding is that this is basically our HID descriptor 

             IntPtr preParsedData = IntPtr.Zero;

             try

             {

                 //Fetch raw input

                 RAWINPUT rawInput = new RAWINPUT();

                 if (!RawInput.GetRawInputData(aMessage.LParam, ref rawInput, ref rawInputBuffer))

                 {

                     return;

                 }

                 //Fetch device info

                 RID_DEVICE_INFO deviceInfo = new RID_DEVICE_INFO();

                 if (!RawInput.GetDeviceInfo(rawInput.header.hDevice, ref deviceInfo))

                 {

                     return;

                 }

                 //Get various information about this HID device

                 Device = new Hid.HidDevice(rawInput.header.hDevice);                

                 if (rawInput.header.dwType == Const.RIM_TYPEHID)  //Check that our raw input is HID                        

                 {

                     IsGeneric = true;

                     Debug.WriteLine("WM_INPUT source device is HID.");

                     //Get Usage Page and Usage

                     //Debug.WriteLine("Usage Page: 0x" + deviceInfo.hid.usUsagePage.ToString("X4") + " Usage ID: 0x" + deviceInfo.hid.usUsage.ToString("X4"));

                     UsagePage = deviceInfo.hid.usUsagePage;

                     UsageCollection = deviceInfo.hid.usUsage;

                     preParsedData = RawInput.GetPreParsedData(rawInput.header.hDevice);

                     if (!(rawInput.hid.dwSizeHid > 1     //Make sure our HID msg size more than 1. In fact the first ushort is irrelevant to us for now

                         && rawInput.hid.dwCount > 0))    //Check that we have at least one HID msg

                     {

                         return;

                     }

                     //Allocate a buffer for one HID input

                     byte[] hidInputReport = new byte[rawInput.hid.dwSizeHid];

                     Debug.WriteLine("Raw input contains " + rawInput.hid.dwCount + " HID input report(s)");

                     //For each HID input report in our raw input

                     for (int i = 0; i < rawInput.hid.dwCount; i++)

                     {

                         //Compute the address from which to copy our HID input

                         int hidInputOffset = 0;

                         unsafe

                         {

                             byte* source = (byte*)rawInputBuffer;

                             source += sizeof(RAWINPUTHEADER) + sizeof(RAWHID) + (rawInput.hid.dwSizeHid * i);

                             hidInputOffset = (int)source;

                         }

                         //Copy HID input into our buffer

                         Marshal.Copy(new IntPtr(hidInputOffset), hidInputReport, 0, (int)rawInput.hid.dwSizeHid);

                         //Print HID input report in our debug output

                         string hidDump = "HID input report: ";

                         foreach (byte b in hidInputReport)

                         {

                             hidDump += b.ToString("X2");

                         }

                         Debug.WriteLine(hidDump);

                         //Proper parsing now

                         uint usageCount = 1; //Assuming a single usage per input report. Is that correct?

                         Win32.USAGE_AND_PAGE[] usages = new Win32.USAGE_AND_PAGE[usageCount];

                         Win32.HidStatus status = Win32.Function.HidP_GetUsagesEx(Win32.HIDP_REPORT_TYPE.HidP_Input, 0, usages, ref usageCount, preParsedData, hidInputReport, (uint)hidInputReport.Length);

                         if (status != Win32.HidStatus.HIDP_STATUS_SUCCESS)

                         {

                             Debug.WriteLine("Could not parse HID data!");

                         }

                         else

                         {

                             //Debug.WriteLine("UsagePage: 0x" + usages[0].UsagePage.ToString("X4"));

                             //Debug.WriteLine("Usage: 0x" + usages[0].Usage.ToString("X4"));

                             //Add this usage to our list

                             Usages.Add(usages[0].Usage);

                         }

                     }

                 }

                 else if (rawInput.header.dwType == Const.RIM_TYPEMOUSE)

                 {

                     IsMouse = true;

                     Debug.WriteLine("WM_INPUT source device is Mouse.");                    

                     // do mouse handling...

                 }

                 else if (rawInput.header.dwType == Const.RIM_TYPEKEYBOARD)

                 {

                     IsKeyboard = true;

                     Debug.WriteLine("WM_INPUT source device is Keyboard.");

                     // do keyboard handling...

                     Debug.WriteLine("Type: " + deviceInfo.keyboard.dwType.ToString());

                     Debug.WriteLine("SubType: " + deviceInfo.keyboard.dwSubType.ToString());

                     Debug.WriteLine("Mode: " + deviceInfo.keyboard.dwKeyboardMode.ToString());

                     Debug.WriteLine("Number of function keys: " + deviceInfo.keyboard.dwNumberOfFunctionKeys.ToString());

                     Debug.WriteLine("Number of indicators: " + deviceInfo.keyboard.dwNumberOfIndicators.ToString());

                     Debug.WriteLine("Number of keys total: " + deviceInfo.keyboard.dwNumberOfKeysTotal.ToString());

                 }

             }

             finally

             {

                 //Always executed when leaving our try block

                 Marshal.FreeHGlobal(rawInputBuffer);

                 Marshal.FreeHGlobal(preParsedData);

             }

             IsValid = true;

         }

         /// <summary>

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

         /// </summary>

         public void DebugWrite()

         {

             if (!IsValid)

             {

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

                 return;

             }

             Device.DebugWrite();

             if (IsGeneric) Debug.WriteLine("==== Generic");

             if (IsKeyboard) Debug.WriteLine("==== Keyboard");

             if (IsMouse) Debug.WriteLine("==== Mouse");

             Debug.WriteLine("==== Foreground: " + IsForeground.ToString());

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

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

             foreach (ushort usage in Usages)

             {

                 Debug.WriteLine("==== Usage: 0x" + usage.ToString("X4"));

             }

         }

     }

 }