#include <windows.h>
#include <vector>

LPCWSTR ClassName = L"WndClass";
MSG msg;

std::vector<HWND> handles;
std::vector<COLORREF> colours;

PAINTSTRUCT ps;
HDC hdc;
RECT wRect;

HBRUSH currentBrush;
HPEN currentPen;

COLORREF menuColor = RGB(135, 135, 135);
COLORREF colBrush;
COLORREF colPen;

RECT menu;

int x, y, x2, y2;

enum {rectangle, ellipse, triangle} object;

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

void IconRect(HDC hdc, int left, int top, int right, int bottom);
void IconEllipse(HDC hdc, int left, int top, int right, int bottom);
void IconTriangle(HDC hdc, int left, int top, int right, int bottom);

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

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

    colours.push_back(RGB(255,255,255));
    colours.push_back(RGB(0,0,0));
    colours.push_back(RGB(127,0,0));
    colours.push_back(RGB(0,127,0));
    colours.push_back(RGB(0,0,127));
    colours.push_back(RGB(127,127,0));
    colours.push_back(RGB(127,0,127));
    colours.push_back(RGB(0,127,127));

    if( !RegisterClassEx( & wc ) )
    {
        MessageBox( NULL, L"Wysoka Komisja odmawia rejestracji tego okna!", L"Niestety...", MB_ICONEXCLAMATION | MB_OK );
        return 1;
    }

    handles.push_back(CreateWindowEx( 0, ClassName, L"MainWnd", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, 0, 0, hInstance, 0 ));

    for(int i = 0; i < handles.size(); ++i)
    {
        if( handles[i] == 0 )
        {
            MessageBox( NULL, L"Okno odmówiło przyjścia na świat!", L"Ale kicha...", MB_ICONEXCLAMATION );
            return 1;
        }
    }

    for(int i = 0; i < handles.size(); ++i)
    {
        ShowWindow( handles[i], nCmdShow );
        UpdateWindow( handles[i] );
    }

    while( GetMessage( & msg, 0, 0, 0 ) )
    {
        TranslateMessage( & msg );
        DispatchMessage( & msg );
    }
    UnregisterClassW(ClassName, hInstance);
    return msg.wParam;
}


LRESULT CALLBACK WndProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
{
    switch( uMsg )
    {
        case WM_CLOSE:
            {
                DestroyWindow( hwnd );
            }
            break;

        case WM_DESTROY:
            if(handles.size() <= 1)
            {
                colours.erase(colours.begin(), colours.end());
                PostQuitMessage( 0 );
            }
            break;

        case WM_PAINT:
            {
                hdc = BeginPaint(hwnd, &ps);
                GetClientRect(hwnd, &wRect);

                menu = wRect;
                menu.left = wRect.right - 220;

                HBRUSH brush = CreateSolidBrush(menuColor);
                SelectObject(hdc, brush);
                Rectangle(hdc, menu.left, menu.top, menu.right, menu.bottom);
                DeleteObject(brush);

                for(int i = 0; i < colours.size(); ++i)
                {
                    HBRUSH brush = CreateSolidBrush(colours[i]);
                    HBRUSH def = (HBRUSH) SelectObject(hdc, brush);

                    if(i % 2)
                    {
                        Rectangle(hdc, wRect.right - 190, wRect.top - 20 + i*40, wRect.right - 140, wRect.top + (30 + i*40));
                    }
                    else
                    {
                        Rectangle(hdc, wRect.right - 90, wRect.top + (20 + i*40), wRect.right - 40, wRect.top + (70 + i*40));
                    }

                    SelectObject(hdc, def);
                    DeleteObject(brush);
                }

                IconRect(hdc, wRect.right - 190, wRect.top + 400, wRect.right - 140, wRect.top + 450);
                IconEllipse(hdc, wRect.right - 90, wRect.top + 400, wRect.right - 40, wRect.top + 450);
                IconTriangle(hdc, wRect.right - 190, wRect.top + 470, wRect.right - 140, wRect.top + 520);

                switch(object)
                {
                    case rectangle:
                        {
                            HPEN defPen = (HPEN) SelectObject(hdc, currentPen);
                            Rectangle(hdc, x, y, x2, y2);
                            HBRUSH defBrush = (HBRUSH) SelectObject(hdc, currentBrush);
                            Rectangle(hdc, x, y, x2, y2);
                        }
                        break;

                    case ellipse:
                        {
                            HPEN defPen = (HPEN) SelectObject(hdc, currentPen);
                            Ellipse(hdc, x, y, x2, y2);
                            HBRUSH defBrush = (HBRUSH) SelectObject(hdc, currentBrush);
                            Ellipse(hdc, x, y, x2, y2);
                        }
                        break;

                    case triangle:
                        {
                            POINT pts[3];
                            pts[0].x = x + (x2-x)/2;
                            pts[0].y = y;
                            pts[1].x = x2;
                            pts[1].y = y2;
                            pts[2].x = x;
                            pts[2].y = y2;

                            HPEN defPen = (HPEN) SelectObject(hdc, currentPen);
                            Polygon(hdc, pts , 3);
                            HBRUSH defBrush = (HBRUSH) SelectObject(hdc, currentBrush);
                            Polygon(hdc, pts , 3);
                        }
                        break;
                }

                EndPaint(hwnd, &ps);
            }
            break;

        case WM_RBUTTONDOWN:
            {
                x = LOWORD(lParam);
                y = HIWORD(lParam);

                hdc = GetDC(hwnd);

                if(GetPixel(hdc, x, y) != menuColor && x > menu.left)
                {
                    currentPen = CreatePen(BS_SOLID, 3, GetPixel(hdc, x, y));
                }

                ReleaseDC(hwnd, hdc);
            }
            break;

        case WM_LBUTTONDOWN:
            {
                x = LOWORD(lParam);
                y = HIWORD(lParam);

                hdc = GetDC(hwnd);

                if(GetPixel(hdc, x, y) != menuColor && x > menu.left)
                {
                    currentBrush = CreateSolidBrush(GetPixel(hdc, x, y));
                }

                ReleaseDC(hwnd, hdc);

                if(x > wRect.right - 190 && y > wRect.top + 400 && x < wRect.right - 140 && y < wRect.top + 450)
                {
                    object = rectangle;
                }
                else if(x > wRect.right - 90 && y > wRect.top + 400 && x < wRect.right - 40 && y < wRect.top + 450)
                {
                    object = ellipse;
                }
                else if(x > wRect.right - 190 && y > wRect.top + 470 && x < wRect.right - 140 && y < wRect.top + 520)
                {
                    object = triangle;
                }
            }
            break;

        case WM_LBUTTONUP:
            {
                x2 = LOWORD(lParam);
                y2 = HIWORD(lParam);

                if(x2 < menu.left && x < menu.left)
                {
                    InvalidateRect(hwnd, 0, false);
                }
            }
            break;

        case WM_SIZE:
            {
                InvalidateRect(hwnd, &menu, true);
                UpdateWindow(hwnd);
            }
            break;

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

    return 0;
}

void IconRect(HDC hdc, int left, int top, int right, int bottom)
{
    HBRUSH brush = CreateSolidBrush(RGB(255, 255, 255));
    HBRUSH brush2 = CreateSolidBrush(RGB(0, 0, 0));
    HBRUSH def = (HBRUSH) SelectObject(hdc, brush);

    Rectangle(hdc, left, top, right, bottom);
    SelectObject(hdc, brush2);
    Rectangle(hdc, left + (right-left)*0.15, top + (bottom - top)*0.15, right - (right-left)*0.15, bottom - (bottom - top)*0.15);

    SelectObject(hdc, def);
    DeleteObject(brush);
    DeleteObject(brush2);
}

void IconEllipse(HDC hdc, int left, int top, int right, int bottom)
{
    HBRUSH brush = CreateSolidBrush(RGB(255, 255, 255));
    HBRUSH brush2 = CreateSolidBrush(RGB(0, 0, 0));
    HBRUSH def = (HBRUSH) SelectObject(hdc, brush);

    Rectangle(hdc, left, top, right, bottom);
    SelectObject(hdc, brush2);
    Ellipse(hdc, left + (right-left)*0.15, top + (bottom - top)*0.15, right - (right-left)*0.15, bottom - (bottom - top)*0.15);

    SelectObject(hdc, def);
    DeleteObject(brush);
    DeleteObject(brush2);
}

void IconTriangle(HDC hdc, int left, int top, int right, int bottom)
{
    POINT pts[3];
    pts[0].x = left + (right-left)/2;
    pts[0].y = top + (bottom - top)*0.15;
    pts[1].x = left + (right-left)*22/25;
    pts[1].y = top + (bottom - top)*0.85;
    pts[2].x = left + (right-left)*3/25;
    pts[2].y = top + (bottom - top)*0.85;

    HBRUSH brush = CreateSolidBrush(RGB(255, 255, 255));
    HBRUSH brush2 = CreateSolidBrush(RGB(0, 0, 0));
    HBRUSH def = (HBRUSH) SelectObject(hdc, brush);

    Rectangle(hdc, left, top, right, bottom);
    SelectObject(hdc, brush2);
    Polygon(hdc, pts , 3);

    SelectObject(hdc, def);
    DeleteObject(brush);
    DeleteObject(brush2);
}