#include <windows.h>

LRESULT CALLBACK windowProcedure(HWND, UINT, WPARAM, LPARAM);
void initialize(WNDCLASS&, HINSTANCE&, HWND&, int);

HINSTANCE mainInstance;

int APIENTRY WinMain(HINSTANCE instance, HINSTANCE previousInstance,
					 LPSTR commandParam, int commandShow)
{
	HWND hwnd;
	MSG message;
	WNDCLASS wndclass;
	
	mainInstance = instance;
	
	initialize(wndclass, instance, hwnd, commandShow);

	while (GetMessage(&message, 0, 0, 0)) {
		TranslateMessage(&message);
		DispatchMessage(&message);
	}

	return message.wParam;
}

HWND input, output, from, to, ok;

struct WindowSize
{
	int x, y, width, height;
};

LRESULT CALLBACK windowProcedure(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
{
	enum { ID_INPUT=100, ID_OUTPUT, ID_FROM, ID_TO, ID_OK };
	enum { OPTION_DEFAULT = WS_CHILD | WS_VISIBLE };
	enum {
		EDIT_OPTION = OPTION_DEFAULT | WS_BORDER | ES_AUTOHSCROLL,
		COMBO_OPTION = OPTION_DEFAULT| CBS_DROPDOWNLIST,
		OK_OPTION = OPTION_DEFAULT | BS_PUSHBUTTON | BS_NOTIFY
	};

	char ItemList[][8] = {"2 &#51652;&#48277;", "8 &#51652;&#48277;", "10 &#51652;&#48277;", "16 &#51652;&#48277;"};
	enum { ITEM_LENGTH = 4, BI = 0, OCT, TEN, HEXA };

	const char * const OK_TITLE = "&#48320;       &#54872;";

	WindowSize
		inputSize = { 10, 10, 200, 25 },
		fromSize = { 220, 10, 80, 100 },
		toSize = { 300, 10, 80, 100 },
		okSize = { 220, 40, 158, 25 },
		outputSize = {5, 70, 373, 190 };

	int i;

	switch(message) {
	case WM_CREATE:
		input = CreateWindow("edit", NULL, EDIT_OPTION,
			inputSize.x, inputSize.y, inputSize.width, inputSize.height,
			hwnd, (HMENU) ID_INPUT, mainInstance, NULL);

		from = CreateWindow("combobox", NULL, COMBO_OPTION,
			fromSize.x, fromSize.y, fromSize.width, fromSize.height,
			hwnd, (HMENU) ID_FROM, mainInstance, NULL);

		to = CreateWindow("combobox", NULL, COMBO_OPTION,
			toSize.x, toSize.y, toSize.width, toSize.height,
			hwnd, (HMENU) ID_TO, mainInstance, NULL);

		ok = CreateWindow("button", OK_TITLE, OK_OPTION,
			okSize.x, okSize.y, okSize.width, okSize.height,
			hwnd, (HMENU) ID_OK, mainInstance, NULL);

		output = CreateWindow("edit", NULL, EDIT_OPTION,
			outputSize.x, outputSize.y, outputSize.width, outputSize.height,
			hwnd, (HMENU) ID_OUTPUT, mainInstance, NULL);

		for(i = 0; i < ITEM_LENGTH; ++i)
			SendMessage(from, CB_ADDSTRING,  0, (LPARAM)ItemList[i]);

		SendMessage(from, CB_SETCURSEL, (WPARAM) TEN, 0);

		for(i = 0; i < ITEM_LENGTH; ++i)
			SendMessage(to, CB_ADDSTRING,  0, (LPARAM)ItemList[i]);

		SendMessage(to, CB_SETCURSEL, (WPARAM) HEXA, 0);

    	return 0;

	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}

	return DefWindowProc(hwnd, message, wparam, lparam);
}

void initialize(WNDCLASS& wndclass, HINSTANCE& instance,
						  HWND &hwnd, int commandShow)
{
	const LPSTR NAME = "&#49345;&#48512;&#49345;&#51312;";
	enum { WIN_WIDTH = 390, WIN_HEIGHT= 300 };

	wndclass.cbClsExtra = 0;
	wndclass.cbWndExtra = 0;
	wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	wndclass.hInstance = instance;
	wndclass.lpfnWndProc = (WNDPROC) windowProcedure;
	wndclass.lpszClassName = NAME;
	wndclass.lpszMenuName = NULL;
	wndclass.style = CS_HREDRAW | CS_VREDRAW;

	RegisterClass(&wndclass);

	hwnd = CreateWindow(NAME, NAME, WS_OVERLAPPEDWINDOW,
		CW_USEDEFAULT, CW_USEDEFAULT, WIN_WIDTH, WIN_HEIGHT,
		NULL, (HMENU)NULL, instance, NULL);

	ShowWindow(hwnd, commandShow);
}