/*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
*                                                                              *
*                              Gem-graph client                                *
*                                                                              *
*                        Finite State Machine / Journal                        *
*                                                                              *
*         Copyright © 2024 Libre en Communs <contact@a-lec.org>                *
*         Copyright © 2024 Adrien Bourmault <neox@a-lec.org>                   *
*         Copyright © 2024 Jean Sirmai <jean@a-lec.org>                        *
*                                                                              *
*                        This file is part of Gem-graph.                       *
*                                                                              *
*   This program is free software: you can redistribute it and/or modify it    *
*         under the terms of the GNU Affero 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 Affero General Public License for more details.          *
*                                                                              *
*   You should have received a copy of the GNU Affero General Public License   *
*     along with this program.  If not, see <http://www.gnu.org/licenses/>.    *
*                                                                              *
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  */

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include "../../include/fsm.h"

/******************************************************************************/
/*        A journal (a pile) stores chronologically the fsm events            */
/*             during a session run   (rules exec, mainly)                    */
/******************************************************************************/



int fsm_journal_push (journal **jj, int vv)
{
    journal *element = malloc (sizeof(journal));
    if (!element) exit (EXIT_FAILURE);     // Si l'allocation a échoué.
    element->value = vv;
    element->prev = *jj;
    *jj = element;       // Le pointeur pointe sur le dernier élément.
    return vv;
}

int fsm_journal_pop (journal **jj)
{
    int vv;
    journal *tmp;
    if (!*jj) return -1;     // Retourne -1 si le journal est vide.
    tmp = (*jj)->prev;
    vv = (*jj)->value;
    free (*jj);
    *jj = tmp;       // Le pointeur pointe sur le dernier élément.
    return vv;      // retourne la value retirée du journal.
}

void fsm_journal_clear (journal **jj)
{
    journal *tmp;
    while (*jj)
    {
        tmp = (*jj)->prev;
        free (*jj);
        *jj = tmp;
    }
}

int fsm_journal_length (journal *jj)
{
    int n=0;
    while (jj)
    {
        n++;
        jj = jj->prev;
    }
    return n;
}

void fsm_journal_view (journal *jj)
{
    printf ("view journal  (n = %d)\n", fsm_journal_length (jj));
    while (jj)
    {
        printf (">  %d\n", jj->value);
        jj = jj->prev;
    }
    puts ("------");
}

void fsm_journal_seek (journal *jj, int vv)
{

}