#include <Windows.h>
#include <sstream>
#include <winuser.h>

LRESULT CALLBACK MainWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

HBRUSH createSolidBrushWithColor(int r, int g, int b) {
    return CreateSolidBrush(RGB(r, g, b));
}

WNDCLASS initWNDCLASS(HINSTANCE hInstance, int nCmdShow, HBRUSH hbrBackground, char *lpszClassName, WNDPROC wndProc) {
    WNDCLASS wndClass = { 0 };
    wndClass.hInstance = hInstance;
    wndClass.lpszClassName = TEXT(lpszClassName);
    wndClass.lpfnWndProc = wndProc;
    wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndClass.hbrBackground = hbrBackground;
    return wndClass;
}

long q = 0;

struct UserInfo {
    bool isLeft, isTop;
    bool isSetted = false;
};

int CALLBACK WinMain(
    _In_ HINSTANCE hInstance,
    _In_ HINSTANCE hPrevInstance,
    _In_ LPSTR lpCmdLine,
    _In_ int nCmdShow
) {
    WNDCLASS mainWndClass = initWNDCLASS(hInstance, nCmdShow, createSolidBrushWithColor(155, 89, 182), "KalyuzhinWin32_MainWindow", MainWindowProc);
    if (!RegisterClass(&mainWndClass)) {
        return 0;
    }
    int screenWeight = GetSystemMetrics(SM_CXSCREEN);
    int screenHeight = GetSystemMetrics(SM_CYSCREEN);
    int mainWindowWeight = screenWeight / 2;
    int mainWindowHeight = screenHeight / 2;

    HWND mainHWND = CreateWindow(
        mainWndClass.lpszClassName,
        TEXT("Main"),
        WS_OVERLAPPEDWINDOW,
        screenWeight / 2 - mainWindowWeight / 2,
        screenHeight / 2 - mainWindowHeight / 2,
        mainWindowWeight,
        mainWindowHeight,
        NULL,
        NULL,
        hInstance,
        NULL);
    UserInfo userInfo = UserInfo();
    SetWindowLongPtr(mainHWND, GWLP_USERDATA, (LONG) &userInfo);

    ShowWindow(mainHWND, nCmdShow);
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0)) {
        DispatchMessage(&msg);
    }
    return 0;
}

void drawWindowsLogo(HDC* hdc, WORD windowHeight, WORD windowWeight, bool isLeft, bool isTop, bool isMouseOutside) {
    RECT rect;
    HBRUSH brush1, brush2, brush3, brush4, brushActive;
    brush1 = createSolidBrushWithColor(231, 76, 60);
    brush2 = createSolidBrushWithColor(41, 128, 185);
    brush3 = createSolidBrushWithColor(46, 204, 113);
    brush4 = createSolidBrushWithColor(241, 196, 15);
    brushActive = createSolidBrushWithColor(255, 255, 255);
    rect.left = 0;
    rect.right = windowWeight / 2;
    rect.top = 0;
    rect.bottom = windowHeight / 2;
    if (isLeft && isTop && !isMouseOutside) {
        FillRect((*hdc), &rect, brushActive);
    }
    else {
        FillRect((*hdc), &rect, brush1);
    }
    rect.left = 0;
    rect.right = windowWeight / 2;
    rect.top = windowHeight / 2;
    rect.bottom = windowHeight;
    if (isLeft && !isTop && !isMouseOutside) {
        FillRect((*hdc), &rect, brushActive);
    }
    else {
        FillRect((*hdc), &rect, brush2);
    }
    rect.left = windowWeight / 2;
    rect.right = windowWeight;
    rect.top = 0;
    rect.bottom = windowHeight / 2;
    if (!isLeft && isTop && !isMouseOutside) {
        FillRect((*hdc), &rect, brushActive);
    }
    else {
        FillRect((*hdc), &rect, brush3);
    }
    rect.left = windowWeight / 2;
    rect.right = windowWeight;
    rect.top = windowHeight / 2;
    rect.bottom = windowHeight;
    if (!isLeft && !isTop && !isMouseOutside) {
        FillRect((*hdc), &rect, brushActive);
    }
    else {
        FillRect((*hdc), &rect, brush4);
    }
    DeleteObject(brush1);
    DeleteObject(brush2);
    DeleteObject(brush3);
    DeleteObject(brush4);
    DeleteObject(brushActive);
}

LRESULT CALLBACK MainWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg) {
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    case WM_ERASEBKGND:
        return (LRESULT)1;
//  case WM_SIZE:
//      InvalidateRect(hwnd, 0, true);
//      return 0;
    case WM_PAINT: {
        q++;
        std::stringstream stream;
        stream << q;
        SetWindowText(hwnd, stream.str().c_str());
        PAINTSTRUCT ps;
        POINT pt;
        RECT rc;
        RECT windowRect;
        bool isLeft, isTop;
        GetClientRect(hwnd, &rc);
        GetCursorPos(&pt);
        WORD windowHeight = rc.bottom - rc.top;
        WORD windowWeight = rc.right - rc.left;
        GetWindowRect(hwnd, &windowRect);
        ScreenToClient(hwnd, &pt);
        bool isMouseOutside = !PtInRect(&rc, pt);

        isLeft = pt.x < (windowWeight / 2);
        isTop = pt.y < (windowHeight / 2);

        BeginPaint(hwnd, &ps);
        HDC hdcMem;
        HBITMAP hbmMem, hbmOld;
        hdcMem = CreateCompatibleDC(ps.hdc); //  создаем совместимый контекст устройства
        hbmMem = CreateCompatibleBitmap(ps.hdc, windowWeight, windowHeight); // создаем совместимую карту (изображение)
        hbmOld = (HBITMAP)SelectObject(hdcMem, hbmMem);
        drawWindowsLogo(&hdcMem, rc.bottom - rc.top, rc.right - rc.left, isLeft, isTop, isMouseOutside);
        BitBlt(ps.hdc, 0, 0, windowWeight, windowHeight, hdcMem, 0, 0, SRCCOPY);
        SelectObject(hdcMem, hbmOld);
        DeleteObject(hbmMem);
        DeleteDC(hdcMem);
        EndPaint(hwnd, &ps);
        return 0;
    }
    case WM_MOUSELEAVE: {
        LONG_PTR lpUserData = GetWindowLongPtr(hwnd, GWLP_USERDATA);
        UserInfo* pUserInfo = (UserInfo*)lpUserData;
        if (pUserInfo->isSetted) {
            pUserInfo->isSetted = false;
            InvalidateRect(hwnd, 0, true);
        }
        return 0;
    }
    case WM_MOUSEMOVE: {
        LONG_PTR lpUserData = GetWindowLongPtr(hwnd, GWLP_USERDATA);
        UserInfo* pUserInfo = (UserInfo*)lpUserData;
        POINT pt;
        RECT rc;
        RECT windowRect;
        bool isLeft, isTop;

        GetClientRect(hwnd, &rc);
        GetCursorPos(&pt);
        WORD windowHeight = rc.bottom - rc.top;
        WORD windowWeight = rc.right - rc.left;
        GetWindowRect(hwnd, &windowRect);
        ScreenToClient(hwnd, &pt);
        bool isMouseOutside = !PtInRect(&rc, pt);

        isLeft = pt.x < (windowWeight / 2);
        isTop = pt.y < (windowHeight / 2);

        if (!pUserInfo->isSetted) {
            InvalidateRect(hwnd, 0, true);
        }
        if (pUserInfo->isSetted && (pUserInfo->isLeft != isLeft || pUserInfo->isTop != isTop)) {
            InvalidateRect(hwnd, 0, true);
        }
        pUserInfo->isLeft = isLeft;
        pUserInfo->isTop = isTop;
        pUserInfo->isSetted = true;
        return 0;
    }

    default:
        TRACKMOUSEEVENT tme;
        tme.cbSize = sizeof(TRACKMOUSEEVENT);
        tme.dwFlags = TME_LEAVE;
        tme.hwndTrack = hwnd;

        TrackMouseEvent(&tme);
        return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}