#include <Windows.h>

const wchar_t text[50] = L"Enter text and click the button.";

static HWND textField;
static HWND button;
static HWND field1;
static HWND field2;

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int CALLBACK wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR szCmdLine, int nCmdShow)
{
    // структура, содержащая информацию о сообщениях
    MSG msg{};
    // структура, в которой хранитс¤ дескриптор окна (указатель на область пам¤ти в ¤дре)
    HWND hwnd{};
    // структура, отвечающа¤ за параметры окна
    WNDCLASSEX wc{ sizeof(WNDCLASSEX) };
    // параметры окна
    wc.hbrBackground = CreateSolidBrush(RGB(240, 240, 240));
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    wc.hInstance = hInstance;
    wc.lpfnWndProc = WndProc;
    wc.lpszClassName = L"MyClass";
    wc.style = CS_VREDRAW | CS_HREDRAW;
    // проверка регистрации окна
    if (!RegisterClassEx(&wc))
        return EXIT_FAILURE;
    // создание окна
    if (hwnd = CreateWindowW(wc.lpszClassName, L"Lab_1", WS_OVERLAPPEDWINDOW, 0, 0, 500, 200, NULL, NULL, wc.hInstance, NULL); hwnd == INVALID_HANDLE_VALUE)
        return EXIT_FAILURE;
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
    // цикл сообщений
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return EXIT_SUCCESS;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_DESTROY:
        PostQuitMessage(EXIT_SUCCESS);
        break;
    case WM_CREATE:
        textField = CreateWindowW(L"STATIC", text, WS_CHILD | WS_VISIBLE | SS_CENTER, 50, 20, 350, 70, hWnd, NULL, NULL, NULL);
        button = CreateWindowW(L"BUTTON", L"Click!", WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 180, 40, 100, 20, hWnd, (HMENU) 1, NULL, NULL);
        field1 = CreateWindowW(L"EDIT", L"", WS_BORDER | WS_CHILD | WS_VISIBLE | !ES_READONLY, 50, 70, 350, 20, hWnd, NULL, NULL, NULL);
        field2 = CreateWindowW(L"EDIT", L"", WS_BORDER | WS_CHILD | WS_VISIBLE | ES_READONLY, 50, 100, 350, 20, hWnd, NULL, NULL, NULL);
        break;
    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case 1:
            WCHAR* buffer = new WCHAR[150];
            GetWindowText(field1, buffer, 150);
            // изменяет название окна
            SetWindowText(hWnd, buffer);
            // изменяет значение поля field2
            SetWindowText(field2, buffer);
            break;
        }
        break;
    }
    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}