// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
#ifndef OPENCV_HIGHGUI_BACKEND_HPP
#define OPENCV_HIGHGUI_BACKEND_HPP

#include <memory>
#include <map>

namespace cv { namespace highgui_backend {

class CV_EXPORTS UIWindowBase
{
public:
    typedef std::shared_ptr<UIWindowBase> Ptr;
    typedef std::weak_ptr<UIWindowBase> WeakPtr;

    virtual ~UIWindowBase();

    virtual const std::string& getID() const = 0;  // internal name, used for logging

    virtual bool isActive() const = 0;

    virtual void destroy() = 0;
};  // UIWindowBase

class UITrackbar;

class CV_EXPORTS UIWindow : public UIWindowBase
{
public:
    virtual ~UIWindow();

    virtual void imshow(InputArray image) = 0;

    virtual double getProperty(int prop) const = 0;
    virtual bool setProperty(int prop, double value) = 0;

    virtual void resize(int width, int height) = 0;
    virtual void move(int x, int y) = 0;

    virtual Rect getImageRect() const = 0;

    virtual void setTitle(const std::string& title) = 0;

    virtual void setMouseCallback(MouseCallback onMouse, void* userdata /*= 0*/) = 0;

    //TODO: handle both keys and mouse events (both with mouse coordinates)
    //virtual void setInputCallback(InputCallback onInputEvent, void* userdata /*= 0*/) = 0;

    virtual std::shared_ptr<UITrackbar> createTrackbar(
        const std::string& name,
        int count,
        TrackbarCallback onChange /*= 0*/,
        void* userdata /*= 0*/
    ) = 0;

    virtual std::shared_ptr<UITrackbar> findTrackbar(const std::string& name) = 0;

#if 0  // QT only
    virtual void displayOverlay(const std::string& text, int delayms = 0) = 0;
    virtual void displayStatusBar(const std::string& text, int delayms /*= 0*/) = 0;
    virtual int createButton(
        const std::string& bar_name, ButtonCallback on_change,
        void* userdata = 0, int type /*= QT_PUSH_BUTTON*/,
        bool initial_button_state /*= false*/
    ) = 0;
    // addText, QtFont stuff
#endif

#if 0  // OpenGL
    virtual void imshow(const ogl::Texture2D& tex) = 0;
    virtual void setOpenGlDrawCallback(OpenGlDrawCallback onOpenGlDraw, void* userdata = 0) = 0;
    virtual void setOpenGlContext() = 0;
    virtual void updateWindow() = 0;
#endif

};  // UIWindow


class CV_EXPORTS UITrackbar : public UIWindowBase
{
public:
    virtual ~UITrackbar();

    virtual int getPos() const = 0;
    virtual void setPos(int pos) = 0;

    virtual cv::Range getRange() const = 0;
    virtual void setRange(const cv::Range& range) = 0;
};  // UITrackbar


class CV_EXPORTS UIBackend
{
public:
    virtual ~UIBackend();

    virtual void destroyAllWindows() = 0;

    // namedWindow
    virtual std::shared_ptr<UIWindow> createWindow(
        const std::string& winname,
        int flags
    ) = 0;

    virtual int waitKeyEx(int delay /*= 0*/) = 0;
    virtual int pollKey() = 0;
};

std::shared_ptr<UIBackend>& getCurrentUIBackend();
void setUIBackend(const std::shared_ptr<UIBackend>& api);
bool setUIBackend(const std::string& backendName);

#ifndef BUILD_PLUGIN

#ifdef HAVE_WIN32UI
std::shared_ptr<UIBackend> createUIBackendWin32UI();
#endif

#ifdef HAVE_GTK
std::shared_ptr<UIBackend> createUIBackendGTK();
#endif

#if 0  // TODO: defined HAVE_QT
std::shared_ptr<UIBackend> createUIBackendQT();
#endif

#endif  // BUILD_PLUGIN

}  // namespace highgui_backend

}  // namespace cv

#endif // OPENCV_HIGHGUI_BACKEND_HPP