#include <windows.h>
#include <wchar.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow)
{
    // Register the window class.
    const wchar_t CLASS_NAME[]  = L"Sample Window Class";

    WNDCLASS wc = { };

    wc.lpfnWndProc   = WindowProc;
    wc.hInstance     = hInstance;
    wc.lpszClassName = CLASS_NAME;

    RegisterClass(&wc);

    // Create the window.

    HWND hwnd = CreateWindowEx(
        0,                              // Optional window styles.
        CLASS_NAME,                     // Window class
        L"Learn to Program Windows",    // Window text
        WS_OVERLAPPEDWINDOW,            // Window style

        // Size and position
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,

        NULL,       // Parent window
        NULL,       // Menu
        hInstance,  // Instance handle
        NULL        // Additional application data
        );

    if (hwnd == NULL)
    {
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);

    // Run the message loop.

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

    return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    wchar_t msg[32];
    switch (uMsg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hwnd, &ps);

        FillRect(hdc, &ps.rcPaint, (HBRUSH) (COLOR_WINDOW+1));

        EndPaint(hwnd, &ps);
    }
        return 0;
    case WM_SYSKEYDOWN:
        swprintf_s(msg, L"WM_SYSKEYDOWN: 0x%x\n", wParam);
        OutputDebugString(msg);
        break;

    case WM_SYSCHAR:
        swprintf_s(msg, L"WM_SYSCHAR: %c\n", (wchar_t)wParam);
        OutputDebugString(msg);
        break;

    case WM_SYSKEYUP:
        swprintf_s(msg, L"WM_SYSKEYUP: 0x%x\n", wParam);
        OutputDebugString(msg);
        break;

    case WM_KEYDOWN:
        swprintf_s(msg, L"WM_KEYDOWN: 0x%x\n", wParam);
        OutputDebugString(msg);
        break;

    case WM_KEYUP:
        swprintf_s(msg, L"WM_KEYUP: 0x%x\n", wParam);
        OutputDebugString(msg);
        break;

    case WM_CHAR:
        swprintf_s(msg, L"WM_CHAR: %c\n", (wchar_t)wParam);
        OutputDebugString(msg);
        break;
    }

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