/* completion.c - complete a command, a disk, a partition or a file */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004,2005  Free Software Foundation, Inc.
 *
 *  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.
 *
 *  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, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <grub/normal.h>
#include <grub/misc.h>
#include <grub/err.h>
#include <grub/mm.h>
#include <grub/partition.h>
#include <grub/disk.h>
#include <grub/file.h>

/* The disk that is used for grub_partition_iterate.  */
static grub_device_t disk_dev;

/* The current word.  */
static char *current_word;

/* The matched string.  */
static char *match;

/* The count of candidates.  */
static int num_found;

/* The string to be appended.  */
static const char *suffix;



static void
print_simple_completion (const char *str)
{
  grub_printf (" %s", str);
}

static void
print_partition_completion (const char *str)
{
  grub_print_partinfo (disk_dev, (char *) str);
  grub_errno = GRUB_ERR_NONE;
}

/* Add a string to the list of possible completions. COMPLETION is the
   string that should be added. EXTRA will be appended if COMPLETION
   matches uniquely. The string WHAT contains a description of the
   kind of data that is added. Use PRINT to show the completions
   if there are multiple matches.  */
static int
add_completion (const char *completion, const char *extra, const char *what,
		void (*print) (const char *))
{
  if (grub_strncmp (current_word, completion, grub_strlen (current_word)) == 0)
    {
      num_found++;

      switch (num_found)
	{
	case 1:
	  match = grub_strdup (completion);
	  if (! match)
	    return 1;
	  suffix = extra;
	  break;

	case 2:
	  grub_printf ("\nPossible %s are:\n", what);
	  print (match);
	  
	  /* Fall through.  */

	default:
	  {
	    char *s = match;
	    const char *t = completion;
	    
	    print (completion);
			    
	    /* Detect the matched portion.  */
	    while (*s && *t && *s == *t)
	      {
		s++;
		t++;
	      }

	    *s = '\0';
	  }
	  break;
	}
    }
      
  return 0;
}

static int
iterate_partition (const grub_partition_t p)
{
  return add_completion (grub_partition_get_name (p), ")", "partitions", 
			 print_partition_completion);
}

static int
iterate_dir (const char *filename, int dir)
{
  if (! dir)
    {
      if (add_completion (filename, " ", "files", print_simple_completion))
	return 1;
    }
  else
    {
      char fname[grub_strlen (filename) + 2];

      grub_sprintf (fname, "%s/", filename);
      if (add_completion (fname, "", "files", print_simple_completion))
	return 1;
    }
  
  return 0;
}

static int
iterate_dev (const char *devname)
{
  grub_device_t dev;
  
  /* Complete the partition part.  */
  dev = grub_device_open (devname);
  
  if (dev)
    {
      if (dev->disk && dev->disk->has_partitions)
	{
	  if (add_completion (devname, ",", "devices",
			      print_simple_completion))
	    return 1;
	}
      else
	{
	  if (add_completion (devname, ")", "devices",
			      print_simple_completion))
	    return 1;
	}
    }
  
  grub_errno = GRUB_ERR_NONE;
  return 0;
}

static int
iterate_command (grub_command_t cmd)
{
  if (grub_command_find (cmd->name))
    {
      if (cmd->flags & GRUB_COMMAND_FLAG_CMDLINE)
	{
	  if (add_completion (cmd->name, " ", "commands",
			      print_simple_completion))
	    return 1;
	}
    }
  
  return 0;
}

/* Complete a device.  */
static int
complete_device (void)
{
  /* Check if this is a device or a partition.  */
  char *p = grub_strchr (++current_word, ',');
  
  if (! p)
    {
      /* Complete the disk part.  */
      if (grub_disk_dev_iterate (iterate_dev))
	return 1;
    }
  else
    {
      /* Complete the partition part.  */
      *p = '\0';
      disk_dev = grub_device_open (current_word);
      *p = ',';
      grub_errno = GRUB_ERR_NONE;
      
      if (disk_dev)
	{
	  if (disk_dev->disk && disk_dev->disk->has_partitions)
	    {
	      current_word = p + 1;
	      
	      if (grub_partition_iterate (disk_dev->disk, iterate_partition))
		{
		  grub_device_close (disk_dev);
		  return 1;
		}
	    }
	  
	  grub_device_close (disk_dev);
	}
      else
	return 1;
    }

  return 0;
}

/* Complete a file.  */
static int
complete_file (void)
{
  char *device;
  char *dir;
  char *last_dir;
  grub_fs_t fs;
  grub_device_t dev;
  int ret = 0;
  
  device = grub_file_get_device_name (current_word);
  if (grub_errno != GRUB_ERR_NONE)
    return 1;
  
  dev = grub_device_open (device);
  if (! dev)
    {
      ret = 1;
      goto fail;
    }
  
  fs = grub_fs_probe (dev);
  if (! fs)
    {
      ret = 1;
      goto fail;
    }

  dir = grub_strchr (current_word, '/');
  last_dir = grub_strrchr (current_word, '/');
  if (dir)
    {
      char *dirfile;
      
      current_word = last_dir + 1;
      
      dir = grub_strdup (dir);
      if (! dir)
	{
	  ret = 1;
	  goto fail;
	}
      
      /* Cut away the filename part.  */
      dirfile = grub_strrchr (dir, '/');
      dirfile[1] = '\0';
      
      /* Iterate the directory.  */
      (fs->dir) (dev, dir, iterate_dir);
      
      grub_free (dir);
      
      if (grub_errno)
	{
	  ret = 1;
	  goto fail;
	}
    }
  else
    {
      current_word += grub_strlen (current_word);
      match = grub_strdup ("/");
      if (! match)
	{
	  ret = 1;
	  goto fail;
	}
      
      suffix = "";
      num_found = 1;
    }

 fail:
  if (dev)
    grub_device_close (dev);
  grub_free (device);
  return ret;
}

/* Try to complete the string in BUF. Return the characters that
   should be added to the string.  This command outputs the possible
   completions, in that case set RESTORE to 1 so the caller can
   restore the prompt.  */
char *
grub_normal_do_completion (char *buf, int *restore)
{
  char *first_word;

  /* Initialize variables.  */
  disk_dev = 0;
  match = 0;
  num_found = 0;
  suffix = "";

  *restore = 1;
  
  /* Find the first word.  */
  for (first_word = buf; *first_word == ' '; first_word++)
    ;

  /* Find the delimeter of the current word.  */
  for (current_word = first_word + grub_strlen (first_word);
       current_word > first_word;
       current_word--)
    if (*current_word == ' ' || *current_word == '=')
      break;
  
  if (current_word == first_word)
    {
      /* Complete a command.  */
      if (grub_iterate_commands (iterate_command))
	goto fail;
    }
  else
    {
      current_word++;
      
      if (*current_word == '(' && ! grub_strchr (current_word, ')'))
	{
	  /* Complete a device.  */
	  if (complete_device ())
	    goto fail;
	}
      else
	{
	  /* Complete a file.  */
	  if (complete_file ())
	    goto fail;
	}
    }

  /* If more than one match is found those matches will be printed and
     the prompt should be restored.  */
  if (num_found > 1)
    *restore = 1;
  else
    *restore = 0;

  /* Return the part that matches.  */
  if (match)
    {
      char *ret;
      int current_len;
      int match_len;

      current_len = grub_strlen (current_word);
      match_len = grub_strlen (match);
      ret = grub_malloc (match_len - current_len + grub_strlen (suffix) + 1);
      grub_strcpy (ret, match + current_len);
      if (num_found == 1)
	grub_strcat (ret, suffix);
      
      grub_free (match);

      return ret;
    }

 fail:
  grub_free (match);
  grub_errno = GRUB_ERR_NONE;

  return 0;
}