// -*- mode: c++ -*-
//
// This file is part of libyacurs.
// Copyright (C) 2013  Rafael Ostertag
//
// This program is free software: you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see
// <http://www.gnu.org/licenses/>.
//
//
// $Id$

#ifndef EVENT_H
#define EVENT_H 1

// Can't use #ifdef HAVE_STDINT_H since that would require pulling in
// config.h or libyacurscfg.h which might cause undesired side
// effects.
#include <stdint.h>

#include <cstring>
#include <stdexcept>

#include "area.h"

namespace YACURS {
// forward declaration because windowbase.h includes event.h
class WindowBase;

/**
 * @defgroup Event Event related code
 *
 * Events, Event Queue, and Event Connectors.
 *
 * Events (@c EventType) can be connected to by means of Event
 * Connectors (@c EventConnectorBase). A list of Event Connectors is
 * maintained by the Event Queue (@c EventQueue). Events can be
 * submitted to the Event Queue, which in turn calls all Event
 * Connectors for a given Event.
 */

/**
 * @ingroup Event
 *
 * Event Types that can be connected to.
 *
 * One event handler can be connected to each event type
 * per object using an Event Connector.
 *
 * @see EventConnectorBase
 * @see EventQueue
 */
class EventType {
   private:
    enum { MAX_NAME_LENGTH = 64 };

    char _name[MAX_NAME_LENGTH];
    uint32_t _hashval;

   public:
    EventType(std::string name);

    EventType(const EventType &et);

    virtual ~EventType();

    EventType &operator=(const EventType &rhs);

    bool operator==(const EventType &rhs) const;

    bool operator!=(const EventType &rhs) const;

    bool operator<(const EventType &rhs) const;

    bool operator>(const EventType &rhs) const;

    operator std::string() const;

    operator uint32_t() const;
};

/**
 * Terminates the EventQueue main loop
 */
const EventType EVT_QUIT("EVT_QUIT");
/**
 * Key pressed
 */
const EventType EVT_KEY("EVT_KEY");
/**
 * A refresh is usually issued after a resize. The refresh
 * must not be immediate, i.e. no wrefresh(), but
 * wnoutrefresh().
 */
const EventType EVT_REFRESH("EVT_REFRESH");
/**
 * Force a redraw. This is used to completely redraw the screen
 * upon Ctrl-L. Can be implement as a call to wclear().
 *
 * @internal
 *
 * EVT_REDRAW has been introduced, since EVT_FORCEREFRESH had no
 * effect if screen content was `damaged', e.g., a background
 * process overwriting screen content. Instead of using wtouch()
 * for EVT_FORCEREFRESH, we created a new event to be used with
 * Ctrl-L.
 */
const EventType EVT_REDRAW("EVT_REDRAW");
/**
 * Force curses window to refresh. The handler can be implemented
 * as simple call to touchwin().
 */
const EventType EVT_FORCEREFRESH("EVT_FORCEREFRESH");
/**
 * A doupdate is usually issued after a refresh. Only one
 * EVT_DOUPDATE handler should exist, since curses takes care
 * of refreshing all windows.
 */
const EventType EVT_DOUPDATE("EVT_DOUPDATE");
/**
 * Re-setup terminal. Mainly used when resizing screen or
 * complete screen refresh. @sa EventQueue
 */
const EventType EVT_TERMRESETUP("EVT_TERMRESETUP");
/**
 * Notification of window size change.
 *
 * Only Curses is supposed to handle this Event. Widgets and
 * Windows should not use it in order to resize.
 */
const EventType EVT_SIGWINCH("EVT_SIGWINCH");
/**
 * Notification of alarm signal
 */
const EventType EVT_SIGALRM("EVT_SIGALRM");
const EventType EVT_SIGUSR1("EVT_SIGUSR1");
const EventType EVT_SIGUSR2("EVT_SIGUSR2");
const EventType EVT_SIGINT("EVT_SIGINT");
const EventType EVT_SIGTERM("EVT_SIGTERM");
const EventType EVT_SIGQUIT("EVT_SIGQUIT");
const EventType EVT_SIGCONT("EVT_SIGCONT");
const EventType EVT_SIGTSTP("EVT_SIGTSTP");
/**
 * Advises Focus Manager to give focus to the next Widget in
 * the Current Focus Group.
 */
const EventType EVT_FOCUS_NEXT("EVT_FOCUS_NEXT");
/**
 * Advises Focus Manager to give focus to the next Widget in
 * the Current Focus Group.
 */
const EventType EVT_FOCUS_PREVIOUS("EVT_FOCUS_PREVIOUS");
/**
 * Windows emit events of this type when shown by calling
 * show().
 */
const EventType EVT_WINDOW_SHOW("EVT_WINDOW_SHOW");
/**
 * Windows emit events of this type when closed by calling
 * close().
 */
const EventType EVT_WINDOW_CLOSE("EVT_WINDOW_CLOSE");
/**
 * Will be emitted when Button is pressed.
 */
const EventType EVT_BUTTON_PRESS("EVT_BUTTON_PRESS");
/**
 * Will be emitted when ENTER is pressed in ListBox.
 */
const EventType EVT_LISTBOX_ENTER("EVT_LISTBOX_ENTER");
/**
 * Will be emitted when the selection changes in a CheckBox.
 */
const EventType EVT_CHECKBOX_SELECTION("EVT_CHECKBOX_SELECTION");

/**
 * @ingroup Event
 *
 * An Event is generated (key stroke, signal) and submitted into
 * the EventQueue. The event queue passes the Event to
 * EventConnectors (i.e. calls the function or method connected to
 * the event).
 */
class Event {
   private:
    /**
     * The type of the Event
     */
    EventType event_type;

    /**
     * Indicate whether or not the Event should not be
     * processed further.
     */
    bool _stop;

   public:
    /**
     * @param et the event type
     */
    Event(const EventType et);

    Event(const Event &e);

    virtual ~Event();

    Event &operator=(const Event &_rhs);

    /**
     * Tests Event objects for equality.
     *
     * @param e reference to rhs
     *
     * @return \c true if the event type of the events are
     * equal. \c false otherwise.
     */
    virtual bool operator==(const Event &e) const;

    /**
     * Tests whether the given event type is equal to type of this
     * object.
     *
     * @param et rhs EventType
     *
     * @return \c true if the event types are equal, \c false
     * otherwise.
     */
    bool operator==(const EventType et) const;

    /**
     * Get the event type of the object.
     *
     * @return event type of the object.
     */
    const EventType type() const;

    /**
     * Set stop flag.
     *
     * When stop flag is set (@c true) the event will no be
     * processed further.
     *
     * @param _s when set to @c true, the event will not be
     * processed further.
     */
    void stop(bool _s);

    /**
     * Get stop flag.
     *
     * @return @c true, the event will not be processed further,
     * @c false otherwise.
     */
    bool stop() const;

    /**
     * Create a copy of the object. The caller is responsible for
     * freeing the memory of the object returned.
     *
     * @return pointer to copy of this object. The memory has to
     * be freed by the caller.
     */
    virtual Event *clone() const;

    operator const EventType() const;

    static std::string evt2str(const EventType et);
};

/**
 * @ingroup Event
 *
 * Extends Event and adds a payload to the event in order to pass
 * information to the EventConnectors.
 *
 * The data may be modified by EventConnectors.
 */
template <class T>
class EventEx : public Event {
   private:
    /// The data transported by the event.
    T _payload;

   public:
    /**
     * @param et the event type
     *
     * @param _payload reference to the data. The data will be copied to
     * an internal variable.
     */
    EventEx<T>(const EventType et, const T &_payload)
        : Event(et), _payload(_payload) {}

    EventEx<T>(const EventEx<T> &e) : Event(e), _payload(e._payload) {}

    EventEx<T> &operator=(const EventEx<T> &_rhs) {
        if (this == &_rhs) return *this;

        Event::operator=(_rhs);

        _payload = _rhs._payload;

        return *this;
    }

    /**
     * Create an exact copy of this object.
     *
     * Create an exact copy of this object. The memory occupied
     * has to be freed by the caller.
     */
    EventEx<T> *clone() const { return new EventEx<T>(*this); }

    /**
     * @return a reference to the data of the event.
     */
    virtual T &data() { return _payload; }
};
}  // namespace YACURS

#endif  // EVENT_H