/* Invite */
/* 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/>. */

#include "prompt.h"

#include "xmalloc.h"

#include <string.h>
#include <stdlib.h>

char *local_prompt_prefix; /* partie de l'invite avant le dernier saut de ligne */
char *local_prompt;        /* derniere ligne logique de l'invite */
int prompt_visible_length; /* nombre de caracteres visibles dans local_prompt */

/* Tous les caracteres situes entre '\001' et '\002' sont consideres comme
 * invisibles. */
static int expand(const char *s, size_t n, char *buf)
{
  int visible_length;
  char *p;
  int visible;
  char c;

  visible_length = 0;
  p = buf;
  visible = 1;
  while (n--) {
    c = *s++;
    if (visible) {
      if (c == '\001') {
        visible = 0;
        continue;
      }
    }
    else
      if (c == '\002') {
        visible = 1;
        continue;
      }
    *p++ = c;
    if (visible)
      visible_length++;
  }
  *p = '\0';
  return visible_length;
}

static void expand_prompt(const char *prompt)
{
  char *p;
  int len;

  if ((p = strrchr(prompt, '\n'))) {
    p++;
    len = p - prompt;
    local_prompt_prefix = xmalloc(len + 1);
    expand(prompt, len, local_prompt_prefix);
    prompt = p;
  }
  else
    local_prompt_prefix = NULL;
  len = strlen(prompt);
  local_prompt = xmalloc(len + 1);
  prompt_visible_length = expand(prompt, len, local_prompt);
}

void set_prompt(const char *prompt)
{
  if (prompt)
    expand_prompt(prompt);
  else {
    local_prompt_prefix = NULL;
    local_prompt = NULL;
    prompt_visible_length = 0;
  }
}

void free_prompt()
{
  if (local_prompt_prefix)
    free(local_prompt_prefix);
  if (local_prompt)
    free(local_prompt);
}