#include <Windows.h>

LPCWSTR g_szClassName = L"MainWindow_Class";


LRESULT CALLBACK WndProc(HWND hwnd, UINT msg , WPARAM wParam, LPARAM lParam)
{
        switch (msg)
        {
        case WM_CLOSE:
                DestroyWindow(hwnd);
                break;
        case WM_DESTROY:
                PostQuitMessage(0);
                break;
        default:
                return DefWindowProc(hwnd, msg, wParam, lParam);
        }
        return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
        WNDCLASSEX wc;
        MSG msg;
        HWND hwnd;

        ZeroMemory(&wc, sizeof(&wc));

        wc.style = 0;
        wc.lpszClassName = g_szClassName;
        wc.lpszMenuName = NULL;
        wc.lpfnWndProc = WndProc;
        wc.hInstance = hInstance;
        wc.hIconSm = LoadIcon(NULL, IDC_ICON);
        wc.hIcon = LoadIcon(NULL, IDC_ICON);
        wc.hCursor = LoadCursor(NULL, IDC_ARROW);
        wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
        wc.cbWndExtra = 0;
        wc.cbSize = sizeof(WNDCLASSEX);
        wc.cbClsExtra = 0;

        if (!RegisterClassEx(&wc))
        {
                LPCWSTR Error01 = L"Could not register class!";
                LPCWSTR Error01_Caption = L"Error";
                MessageBox(NULL, Error01, Error01_Caption, MB_OK | MB_ICONERROR);
        }

        LPCWSTR WindowTitle = L"EXAMPLE WINDOW!";

        hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, g_szClassName, WindowTitle, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 300, NULL, NULL, hInstance, NULL);

        if (hwnd == NULL)
        {
                LPCWSTR Error02 = L"Could not create Window!";
                LPCWSTR Error02_Caption = L"Error";
                MessageBox(NULL, Error02 , Error02_Caption , MB_OK | MB_ICONERROR);
        }

        ShowWindow(hwnd, nCmdShow);
        UpdateWindow(hwnd);

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

        return msg.wParam;
}