/** 
 * @file history.h
 * @copyright (C) 2001-2006 Marcus Bjurman\n
 * @copyright (C) 2007-2012 Piotr Eljasiak\n
 * @copyright (C) 2013-2023 Uwe Scholz\n
 *
 * @copyright 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 2 of the License, or
 * (at your option) any later version.
 *
 * @copyright 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.
 *
 * @copyright You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#pragma once

class History
{
    gint max;
    gboolean is_locked {FALSE};

    GList *pos {NULL};

  public:

    GList *ents {NULL};

    explicit History(gint maxHistory) { max = maxHistory;}
    ~History();

    History &operator = (GList *list);

    guint size()                                         {  return g_list_length (ents);  }
    gboolean empty()                                     {  return ents==NULL;            }

    const gchar *front()          {  return empty() ? NULL : (const gchar *) ents->data;  }

    void add(const gchar *text);
    void reverse()                               {  pos = ents = g_list_reverse (ents);  }

    gboolean can_back()                                     {  return pos && pos->next;  }
    gboolean can_forward()                                  {  return pos && pos->prev;  }

    const gchar *first();
    const gchar *back();
    const gchar *forward();
    const gchar *last();

    void lock()                                             {  is_locked = TRUE;         }
    void unlock()                                           {  is_locked = FALSE;        }

    gboolean locked() const                                 {  return is_locked;         }
};

inline History &History::operator = (GList *list)
{
    if (ents)
    {
        g_list_foreach (ents, (GFunc) g_free, NULL);
        g_list_free (ents);
    }

    pos = ents = list;      //  FIXME: no check for max and dups...

    return *this;
}