#include <windows.h>
#include <stdio.h>

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

    POINT rectExPoint;
    typedef struct rect {
             int a;
             int b;
    };
    rect sides;
    int edge = 0;

bool Inside (POINT mouse, POINT rectMidd, rect a_sides) {  
    if (mouse.x > rectMidd.x-a_sides.a & mouse.x < rectMidd.x+a_sides.a & mouse.y > rectMidd.y-a_sides.b & mouse.y < rectMidd.y+a_sides.b) {
       return true;
    } else {
      return false;       
    }
} 

int OnEdge (POINT mouse, POINT rectMidd, rect a_sides) { 
    int l_sides = 0;  
    if (abs(mouse.x - rectMidd.x) == a_sides.a & mouse.y >= rectMidd.y-a_sides.b & mouse.y <= rectMidd.y+a_sides.b) l_sides = l_sides + 10;
    if (abs(mouse.y - rectMidd.y) == a_sides.b & mouse.x >= rectMidd.x-a_sides.a & mouse.x <= rectMidd.x+a_sides.a) l_sides = l_sides + 1;
    return l_sides;
}

rect Stretch (POINT mouse, POINT rectMidd, rect a_sides, int a_edge) {   
    rect l_sides; 
    l_sides.a = a_sides.a;
    l_sides.b = a_sides.b;
    if (a_edge % 10) l_sides.b = abs(mouse.y - rectMidd.y);
    if (a_edge >= 10) l_sides.a = abs(mouse.x - rectMidd.x); 
    return l_sides;        
} 

int DrawRect(HDC hdc, POINT a_center, rect a_sides, COLORREF color) {      
    HPEN hNPen=CreatePen(PS_SOLID,1, color);
    HPEN hOPen=(HPEN)SelectObject(hdc,hNPen);    
    Rectangle(hdc, a_center.x-a_sides.a , a_center.y-a_sides.b, a_center.x+a_sides.a, a_center.y+a_sides.b);  
    DeleteObject(SelectObject(hdc,hOPen));     
    return 0;
} 

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow) {
    static TCHAR szAppName[] = TEXT ("Connect") ;
    HWND hwnd ;
    MSG msg ;
    WNDCLASS wndclass ;
    
    wndclass.style = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc = WndProc ;
    wndclass.cbClsExtra = 0 ;
    wndclass.cbWndExtra = 0 ;
    wndclass.hInstance = hInstance ;
    wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
    wndclass.hCursor = LoadCursor (NULL, IDC_CROSS) ;
    wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
    wndclass.lpszMenuName = NULL ;
    wndclass.lpszClassName = szAppName ;
    
    rectExPoint.x = -1;
    rectExPoint.y = -1;
    sides.a = 10;
    sides.b = 20;
    
    if (!RegisterClass (&wndclass)) {
        MessageBox (NULL, TEXT (""),
        szAppName, MB_ICONERROR) ;
        return 0 ;
    }    


    hwnd = CreateWindow (szAppName, TEXT (""),
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT,
    CW_USEDEFAULT, CW_USEDEFAULT,
    NULL, NULL, hInstance, NULL) ;

    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;

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

    return (int)msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {

    static int iPrevX,iPrevY,cxClient,cyClient;
    static HDC hdc, hdcMem;
    static HBITMAP hBitmap , oldBitmap;
    PAINTSTRUCT ps;
    POINT rectPoint; 
    TCHAR chText[30];
    
    switch(message) {

        
        case WM_RBUTTONUP:
            hdc=GetDC(hwnd);       
            rectExPoint.x = 100;
            rectExPoint.y = 100;              
            DrawRect(hdc, rectExPoint, sides, RGB(0, 0, 0));     
            ReleaseDC(hwnd,hdc);                 
        return 0 ;
        
        case WM_LBUTTONUP:
            rectPoint.x = LOWORD (lParam);
            rectPoint.y = HIWORD (lParam);  
            edge = 0;    
            sprintf(chText, "x=%d, y=%d, x=%d, y=%d, a=%d, b=%d, e=%d", rectExPoint.x, rectExPoint.y, rectPoint.x, rectPoint.y, sides.a, sides.b, edge);                                     
            SetWindowText(hwnd, chText);            
        return 0 ;
        
        case WM_LBUTTONDOWN:
            rectPoint.x = LOWORD (lParam);
            rectPoint.y = HIWORD (lParam);  
            if (!edge) edge = OnEdge(rectPoint, rectExPoint, sides);   
            sprintf(chText, "x=%d, y=%d, x=%d, y=%d, a=%d, b=%d, e=%d", rectExPoint.x, rectExPoint.y, rectPoint.x, rectPoint.y, sides.a, sides.b, edge);                                     
            SetWindowText(hwnd, chText);            
        return 0 ;
        
        case WM_MOUSEWHEEL:
            if (GET_WHEEL_DELTA_WPARAM(wParam) > 0) {
                hdc=GetDC(hwnd);             
                DrawRect(hdc, rectExPoint, sides, RGB(255, 255, 255));  
                sides.a ++;
                sides.b ++; 
                DrawRect(hdc, rectExPoint, sides, RGB(0, 0, 0));     
                ReleaseDC(hwnd,hdc);                 
            };
            if (GET_WHEEL_DELTA_WPARAM(wParam) < 0) {
                hdc=GetDC(hwnd);             
                DrawRect(hdc, rectExPoint, sides, RGB(255, 255, 255));  
                sides.a --;
                sides.b --;                 
                DrawRect(hdc, rectExPoint, sides, RGB(0, 0, 0));     
                ReleaseDC(hwnd,hdc);                 
            };
        return 0 ;
        
        
        case WM_MOUSEMOVE:    
            rectPoint.x = LOWORD (lParam);
            rectPoint.y = HIWORD (lParam);  
            hdc=GetDC(hwnd);                   
             if((wParam & MK_LBUTTON)) {   
                if (edge) {            
                    DrawRect(hdc, rectExPoint, sides, RGB(255, 255, 255));   
                    sides = Stretch (rectPoint, rectExPoint, sides, edge);
                    DrawRect(hdc, rectExPoint, sides, RGB(0, 0, 0));     
                    ReleaseDC(hwnd,hdc);  
                } else if (Inside(rectPoint, rectExPoint, sides)) {
                    DrawRect(hdc, rectExPoint, sides, RGB(255, 255, 255));   
                    rectExPoint = rectPoint;
                    DrawRect(hdc, rectPoint, sides, RGB(0, 0, 0));  
                } 
                            
            ReleaseDC(hwnd,hdc); 
 
            }            
            sprintf(chText, "x=%d, y=%d, x=%d, y=%d, a=%d, b=%d, e=%d", rectExPoint.x, rectExPoint.y, rectPoint.x, rectPoint.y, sides.a, sides.b, edge);                                     
            SetWindowText(hwnd, chText); 
        return 0;

        case WM_CLOSE:
            SelectObject(hdcMem,hBitmap);
            DeleteObject (hBitmap);
            DeleteObject(hdcMem);
            PostQuitMessage (0);
        return 0 ;
    }
    return DefWindowProc (hwnd, message, wParam, lParam) ;
}