#include <windows.h>
#include <stdio.h>
#include <dinput.h>

HWND		g_hWnd;
HINSTANCE	g_hInst;

#define		WNDWIDTH 400
#define		WNDHEIGHT 400
#define		WNDTYPE WS_OVERLAPPEDWINDOW

const char	g_szClass[] = "EnumClass";
const char	g_szCaption[] = "Enumeration Demo";

int WINAPI	WinMain(HINSTANCE hInst, HINSTANCE hPrev, LPSTR szCmdLine, int nCmdShow);
void		AppError(BOOL Fatal, char *Text, ...);
LRESULT		CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
BOOL		RegisterWindowClasses(HINSTANCE hInst);
BOOL		UnregisterWindowClasses(HINSTANCE hInst);
HWND		CreateMainWindow(HINSTANCE hInst);
BOOL		CALLBACK EnumDevices(LPCDIDEVICEINSTANCE pdInst, LPVOID pvRef);

BOOL		DoInit();
BOOL		DoShutdown();
BOOL		DoPreFrame();
BOOL		DoFrame();
BOOL		DoPostFrame();

IDirectInputDevice8 *InitMouse(HWND hWnd, IDirectInput8 *pDI);
BOOL ReadDevice(IDirectInputDevice8 *pDIDevice, void *DataBuffer, long BufferSize);

IDirectInput8		*g_pDI;
IDirectInputDevice8	*g_pDIDevice;

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrev, LPSTR szCmdLine, int nCmdShow)
{
	MSG Msg;
	DIMOUSESTATE MouseState;
	char KeyStateBuffer[256];
	long XPos = 0, YPos = 0;

	g_hInst = hInst;

	if(RegisterWindowClasses(hInst) == FALSE) { return FALSE; }

	if((g_hWnd = CreateMainWindow(hInst)) == NULL) { return FALSE; }

	DirectInput8Create(g_hInst, DIRECTINPUT_VERSION, IID_IDirectInput8, (void**)&g_pDI, NULL);
	g_pDIDevice = InitMouse(g_hWnd, g_pDI);

	if(DoInit() == TRUE)
	{
		ZeroMemory(&Msg, sizeof(MSG));
		while(Msg.message != WM_QUIT)
		{
			if(PeekMessage(&Msg, NULL, 0, 0, PM_REMOVE))
			{
				TranslateMessage(&Msg);
				DispatchMessage(&Msg);
			}
			ReadDevice(g_pDIDevice, (void*)&MouseState, sizeof(DIMOUSESTATE));
			XPos += MouseState.lX;
			YPos += MouseState.lY;
		}
	}

	g_pDIDevice->Unacquire();
	g_pDIDevice->Release();
	g_pDI->Release();

	DoShutdown();
	UnregisterWindowClasses(hInst);

	return TRUE;
}

BOOL RegisterWindowClasses(HINSTANCE hInst)
{
	WNDCLASSEX wcex;
	wcex.cbSize        = sizeof(wcex);
	wcex.style         = CS_CLASSDC;
	wcex.lpfnWndProc   = WindowProc;
	wcex.cbClsExtra    = 0;
	wcex.cbWndExtra    = 0;
	wcex.hInstance     = hInst;
	wcex.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
	wcex.hCursor       = LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground = NULL;
	wcex.lpszMenuName  = NULL;
	wcex.lpszClassName = g_szClass;
	wcex.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

	if(!RegisterClassEx(&wcex)) { return FALSE; }

	return TRUE;
}

BOOL UnregisterWindowClasses(HINSTANCE hInst)
{
	UnregisterClass(g_szClass, hInst);
	return TRUE;
}

HWND CreateMainWindow(HINSTANCE hInst)
{
	HWND hWnd;

	hWnd = CreateWindow(g_szClass, g_szCaption, WNDTYPE, 0, 0, WNDWIDTH, WNDHEIGHT, NULL, NULL, hInst, NULL);

	if(!hWnd) { return NULL; }

	ShowWindow(hWnd, SW_SHOWNORMAL);
	UpdateWindow(hWnd);

	return hWnd;
}

void AppError(BOOL Fatal, char *Text, ...)
{
	char CaptionText[12];
	char ErrorText[2048];
	va_list valist;

	if(Fatal == FALSE)
	{
		strcpy(CaptionText, "Error");
	} else {
		strcpy(CaptionText, "Fatal Error");
	}

	va_start(valist, Text);
	vsprintf(ErrorText, Text, valist);
	va_end(valist);

	MessageBox(NULL, ErrorText, CaptionText, MB_OK | MB_ICONEXCLAMATION);

	if(Fatal == TRUE)
	{
		PostQuitMessage(0);
	}
}

HRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch(uMsg)
	{
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}

	return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

BOOL DoInit()
{
	return TRUE;
}

BOOL DoShutdown()
{
	return TRUE;
}

BOOL DoPreFrame()
{
	return TRUE;
}

BOOL DoFrame()
{
	return TRUE;
}

BOOL DoPostFrame()
{
	return TRUE;
}

IDirectInputDevice8 *InitMouse(HWND hWnd, IDirectInput8 *pDI)
{
	IDirectInputDevice8		*pDIDevice;

	if(FAILED(pDI->CreateDevice(GUID_SysMouse, &pDIDevice, NULL))) { return NULL; }
	if(FAILED(pDIDevice->SetDataFormat(&c_dfDIMouse)))
	{
		pDIDevice->Release();
		return NULL;
	}
	if(FAILED(pDIDevice->SetCooperativeLevel(hWnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE)))
	{
		pDIDevice->Release();
		return NULL;
	}
	if(FAILED(pDIDevice->Acquire()))
	{
		pDIDevice->Release();
		return NULL;
	}

	return pDIDevice;
}
BOOL ReadDevice(IDirectInputDevice8 *pDIDevice, void *DataBuffer, long BufferSize)
{
	while(1)
	{
		HRESULT hr;

		g_pDIDevice->Poll();

		if(SUCCEEDED(hr = pDIDevice->GetDeviceState(BufferSize, (LPVOID)DataBuffer))) { break; }
		if(hr != DIERR_INPUTLOST && hr != DIERR_NOTACQUIRED) { return FALSE; }
		if(FAILED(g_pDIDevice->Acquire())) { return FALSE; }
	}

	return TRUE;
}