/* Copie de l'historique pour l'edition. */
/* Copyright (C) 2008  Emmanuel Varoquaux

   This file is part of XOS.

   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/>. */
/* A la difference de GNU readline, cette implementation ne permet pas de
 * modifier l'historique pendant l'edition. A la place, les lignes de
 * l'historique sont copiees pendant l'edition, et seules les copies sont
 * modifiables. */

#include "localhist.h"

#include "line.h"
#include "xmalloc.h"

#include <readline/history.h>
#include <stdlib.h>

/* derniere ligne de l'historique, i.e., la ligne en cours d'edition */
static struct linebuf_struct local_history_end_linebuf;

static struct linebuf_struct *fetch_history(HIST_ENTRY *hist_entry)
{
  if (!hist_entry->data) {
    hist_entry->data = xmalloc(sizeof (struct linebuf_struct));
    linebuf_init(hist_entry->data, hist_entry->line);
  }
  return hist_entry->data;
}

static void cleanup_hist_entry(HIST_ENTRY *hist_entry)
{
  if (hist_entry->data) {
    linebuf_destroy(hist_entry->data);
    free(hist_entry->data);
    hist_entry->data = NULL;
  }
}

void local_history_init()
{
  using_history();
  linebuf_init(&local_history_end_linebuf, "");
}

struct linebuf_struct *local_history_current()
{
  HIST_ENTRY *hist_entry;

  return (hist_entry = current_history()) ? current_history()->data : &local_history_end_linebuf;
}

struct linebuf_struct *local_history_previous()
{
  HIST_ENTRY *hist_entry;

  if (!(hist_entry = previous_history()))
    return NULL;
  return fetch_history(hist_entry);
}

struct linebuf_struct *local_history_next()
{
  HIST_ENTRY *hist_entry;

  if (!current_history())
    return NULL;
  return (hist_entry = next_history()) ? fetch_history(hist_entry) : &local_history_end_linebuf;
}

struct linebuf_struct *local_history_begin()
{
  if (where_history() == 0)
    return NULL;
  history_set_pos(0);
  return fetch_history(current_history());
}

struct linebuf_struct *local_history_end()
{
  if (!current_history())
    return NULL;
  using_history();
  return &local_history_end_linebuf;
}

void local_history_destroy()
{
  HIST_ENTRY *hist_entry;

  using_history();
  linebuf_destroy(&local_history_end_linebuf);
  while ((hist_entry = previous_history()))
    cleanup_hist_entry(hist_entry);
}