#include <Windows.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
static void OnWM_PAINT(const HWND hwnd);
static void OnWM_LBUTTONDOWN(const HWND hwnd, LPARAM lParam, WPARAM wParam);

RECT rSize;
TCHAR className[] = TEXT("Paint v1");

int colors[] = {
    0x000000,
    0xFFFFFF,
    0x7F7F7F,
    0xFF0000,
    0xFF7F00,
    0xFF7F7F,
    0xFF007F,
    0xFF00FF,
    0XFFFF00,
    0x7F0000,
    0x7F7F00,
    0x7F007F,
    0x7FFF00,
    0x7F00FF,
    0x007F00,
    0x00FFFF,
    0x00FF00,
};

enum Type {
    color,
    rectangle,
    elipse,
    triangle
};

class Button {
    POINT leftTop;
    POINT rightBottom;
    Type type;

    int nColor;

public:
    Button() {
        leftTop.x = 0;
        leftTop.y = 0;
        rightBottom.x = 0;
        rightBottom.y = 0;
        type = color;
        nColor = colors[0];
    }

    Button(int nXL, int nYL, int nXR, int nYR, Type type, int nColor) {
        this->leftTop.x = nXL;
        this->leftTop.y = nYL;
        this->rightBottom.x = nXR;
        this->rightBottom.y = nYR;
        this->type = type;
        this->nColor = nColor;
    }

    inline const Type returnType() const { return type; }
    inline const int returnColor() const { return nColor; }
    bool posComare(const int nX, const int nY) const {
        if (nX <= leftTop.x && nX <= rightBottom.x &&
            nY >= leftTop.y && nY <= rightBottom.y)
            return true;

        return false;
    }
    void drawButton(HDC hdc) {
        HBRUSH brush = CreateSolidBrush(this->nColor);
        HBRUSH defaultBrush = (HBRUSH)SelectObject(hdc, brush);
        Rectangle(hdc, leftTop.x, leftTop.y, rightBottom.x, rightBottom.y);
        SelectObject(hdc, defaultBrush);
        DeleteObject(brush);
    }
} buttons[16];

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

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

    if (!RegisterClassEx(&wc)) {
        MessageBox(NULL, TEXT("Błąd przy rejestracji okna!"), TEXT("Błąd!"), MB_OK | MB_ICONERROR);
        return 1;
    }

    HWND hwnd = CreateWindowEx(0, className, TEXT("Paint"), WS_OVERLAPPEDWINDOW, 50, 50, 500, 500, 0, 0, hInstance, 0);

    ShowWindow(hwnd, SW_SHOW);
    UpdateWindow(hwnd);

    MSG msg;

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

    UnregisterClass(className, hInstance);

    return msg.wParam;
}

static void OnWM_LBUTTONDOWN(const HWND hwnd, LPARAM lParam, WPARAM wParam) {
    POINT pos;

    pos.x = LOWORD(lParam);
    pos.y = HIWORD(lParam);

    int actualColor;

    for (int i = 0; i < 16; ++i) {
        if (buttons[i].posComare(pos.x, pos.y) == true)
            actualColor = buttons[i].returnColor();
    }

    if (pos.x < rSize.right - 150) {
        HDC hdc = GetDC(hwnd);
        HBRUSH brush = CreateSolidBrush(actualColor);
        HBRUSH defaultBrush = (HBRUSH)SelectObject(hdc, brush);

        Rectangle(hdc, pos.x, pos.y, pos.x + 20, pos.y + 20);

        SelectObject(hdc, defaultBrush);
        DeleteObject(brush);
        ReleaseDC(hwnd, hdc);
    }



}

static void OnWM_PAINT(const HWND hwnd) {
    PAINTSTRUCT ps;
    HDC hdc;

    HBRUSH brush1 = CreateSolidBrush(RGB(54, 69, 79));
    hdc = BeginPaint(hwnd, &ps);

    HBRUSH defaultBrush = (HBRUSH)SelectObject(hdc, brush1);

    GetClientRect(hwnd, &rSize);
    Rectangle(hdc, rSize.right - 150, rSize.top, rSize.right, rSize.bottom);

    for (int i = 0; i < 16; ++i) {
        if (i % 2 == 1)
            buttons[i] = Button(rSize.right - 95, rSize.top + (i * 20), rSize.right - 125, rSize.top + 30 + (i * 20), color, colors[i]);
        else
            buttons[i] = Button(rSize.right - 30, rSize.top + 20 + (i * 20), rSize.right - 60, rSize.top + 50 + (i * 20), color, colors[i]);
    }

    for (int i = 0; i < 16; ++i)
        buttons[i].drawButton(hdc);

    SelectObject(hdc, defaultBrush);
    EndPaint(hwnd, &ps);

    DeleteObject(brush1);

}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    switch (msg) {
        case WM_PAINT:
            OnWM_PAINT(hwnd); break;

        case WM_LBUTTONDOWN:
            OnWM_LBUTTONDOWN(hwnd, lParam, wParam); break;


        case WM_DESTROY:
            PostQuitMessage(0); break;

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

    return 0;
}