#include "stdafx.h"

#define BUFFER_LENGTH 100

void OnError(LPCSTR msg){
	printf("%s", msg);
	exit(0);
}

int main(){

	HANDLE hDevice = INVALID_HANDLE_VALUE;
	GUID guid;
	HMODULE hHidLib;

	//function pointers to HID.DLL addresses
	void (__stdcall *HidD_GetHidGuid)(OUT LPGUID HidGuid);
	bool (__stdcall *HidD_GetProductString)(IN HANDLE HidDeviceObject, OUT PVOID  Buffer, IN ULONG  BufferLength);
	bool (__stdcall *HidD_GetAttributes)(IN HANDLE HidDeviceObject, OUT void* Attributes);
	bool (__stdcall *HidD_SetFeature)(IN HANDLE  HidDeviceObject, IN PVOID  ReportBuffer, IN ULONG  ReportBufferLength);
	bool (__stdcall *HidD_GetFeature)(IN HANDLE  HidDeviceObject, OUT PVOID  ReportBuffer, IN ULONG  ReportBufferLength);
	bool (__stdcall *HidD_GetInputReport)(IN HANDLE  HidDeviceObject, IN OUT  PVOID  ReportBuffer, IN ULONG  ReportBufferLength);

	hHidLib = LoadLibrary("HID.DLL");
	if (!hHidLib) OnError("Failed to load HID.DLL.");

	(FARPROC&) HidD_GetHidGuid = GetProcAddress(hHidLib, "HidD_GetHidGuid");
	(FARPROC&) HidD_GetProductString = GetProcAddress(hHidLib, "HidD_GetProductString");
	(FARPROC&) HidD_GetAttributes =  GetProcAddress(hHidLib, "HidD_GetAttributes");
	(FARPROC&) HidD_SetFeature =  GetProcAddress(hHidLib, "HidD_SetFeature");
	(FARPROC&) HidD_GetFeature =  GetProcAddress(hHidLib, "HidD_GetFeature");
	(FARPROC&) HidD_GetInputReport = GetProcAddress(hHidLib, "HidD_GetInputReport");

	if ( !HidD_GetInputReport || !HidD_GetHidGuid || !HidD_GetAttributes || !HidD_GetProductString || !HidD_SetFeature || !HidD_GetFeature ){
		OnError("Couldn’t find one or more HID entry points.");
		FreeLibrary(hHidLib);
	}


	//get GUID for HID devices
	(HidD_GetHidGuid)(&guid);
	
	HDEVINFO hDevInfo;

	hDevInfo = SetupDiGetClassDevs( &guid, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
	if (hDevInfo == INVALID_HANDLE_VALUE){
		FreeLibrary(hHidLib);
		OnError("Failed to open handle to HID device set.");
	}

	//try all HID devices
	DWORD dwIndex = 0;
	SP_DEVICE_INTERFACE_DATA devData;
	PSP_DEVICE_INTERFACE_DETAIL_DATA devDetailData = NULL;
	devData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);

	DWORD devDetailDataSize;
	DWORD ReqSize;

	while(SetupDiEnumDeviceInterfaces(hDevInfo, NULL, &guid, dwIndex, &devData)){
		dwIndex++;

		//probing for DevicePath helper struct length
		SetupDiGetDeviceInterfaceDetail(hDevInfo, &devData, NULL, 0, &devDetailDataSize, NULL);
		devDetailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA) malloc(devDetailDataSize);
		devDetailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
	
		//getting DevicePath
		if (! SetupDiGetDeviceInterfaceDetail ( hDevInfo, &devData, devDetailData, devDetailDataSize, &ReqSize, NULL)){
                    SetupDiDestroyDeviceInfoList(hDevInfo);
                    return FALSE;
	        }


		//test vid and pid to find our device
		if (NULL != strstr(devDetailData->DevicePath, "vid_099d&pid_ff00")){

			//opening handle for a device
			hDevice = CreateFile(devDetailData->DevicePath,
						GENERIC_READ,
						FILE_SHARE_READ,
						NULL,
						OPEN_EXISTING,
						FILE_ATTRIBUTE_NORMAL,
						NULL);
			break;
		};

		//free allocated
		free(devDetailData);

	}//end of while

	//delete device information set 
	SetupDiDestroyDeviceInfoList(hDevInfo);

	if (hDevice == INVALID_HANDLE_VALUE){
		FreeLibrary(hHidLib);
		OnError("Failed to find or open device");
	}
	


//-------------------
//working with device
	DWORD dwBytes;

	unsigned char pBuf[BUFFER_LENGTH];
	pBuf[0] = 0;
	ReadFile(hDevice, pBuf, BUFFER_LENGTH, , &dwBytes, NULL);

	//another way

	dwBytes=BUFFER_LENGTH;
	pBuf[0] = 0  ;
	(HidD_GetInputReport)(hDevice, pBuf, dwBytes);

//-------------------


	//closing device handle
	CloseHandle(hDevice);

	FreeLibrary(hHidLib);
	return 0;
}