/* grub-mount.c - FUSE driver for filesystems that GRUB understands */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2008,2009,2010 Free Software Foundation, Inc.
 *
 *  GRUB 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.
 *
 *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */
#define FUSE_USE_VERSION 26
#include <config.h>
#include <grub/types.h>
#include <grub/emu/misc.h>
#include <grub/util/misc.h>
#include <grub/misc.h>
#include <grub/device.h>
#include <grub/disk.h>
#include <grub/file.h>
#include <grub/fs.h>
#include <grub/env.h>
#include <grub/term.h>
#include <grub/mm.h>
#include <grub/lib/hexdump.h>
#include <grub/crypto.h>
#include <grub/command.h>
#include <grub/i18n.h>
#include <fuse/fuse.h>

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

#include "progname.h"
#include "argp.h"

static char *root = NULL;
static char **images = NULL;
static char *debug_str = NULL;
static char **fuse_args = NULL;
static int fuse_argc = 0;
static int num_disks = 0;

static grub_err_t
execute_command (char *name, int n, char **args)
{
  grub_command_t cmd;

  cmd = grub_command_find (name);
  if (! cmd)
    grub_util_error (_("can\'t find command %s"), name);

  return (cmd->func) (cmd, n, args);
}

static int
fuse_getattr (const char *path, struct stat *st)
{
  char *filename, *pathname, *path2;
  const char *pathname_t;
  grub_fs_t fs;
  grub_device_t dev;
  struct grub_dirhook_info file_info;
  int file_exists = 0;
  
  /* A hook for iterating directories. */
  auto int find_file (const char *cur_filename,
		      const struct grub_dirhook_info *info);
  int find_file (const char *cur_filename,
		 const struct grub_dirhook_info *info)
  {
    if ((info->case_insensitive ? grub_strcasecmp (cur_filename, filename)
	 : grub_strcmp (cur_filename, filename)) == 0)
      {
	file_info = *info;
	file_exists = 1;
	return 1;
      }
    return 0;
  }

  if (path[0] == '/' && path[1] == 0)
    {
      st->st_dev = 0;
      st->st_ino = 0;
      st->st_mode = 0555 | S_IFDIR;
      st->st_uid = 0;
      st->st_gid = 0;
      st->st_rdev = 0;
      st->st_size = 0;
      st->st_blksize = 512;
      st->st_blocks = (st->st_blksize + 511) >> 9;
      st->st_atime = st->st_mtime = st->st_ctime = 0;
      return 0;
    }

  file_exists = 0;
  dev = grub_device_open (0);
  if (! dev)
    return -1;

  fs = grub_fs_probe (dev);
  if (! fs)
    {
      grub_device_close (dev);
      return -1;
    }

  pathname_t = grub_strchr (path, ')');
  if (! pathname_t)
    pathname_t = path;
  else
    pathname_t++;
  pathname = xstrdup (pathname_t);
  
  /* Remove trailing '/'. */
  while (*pathname && pathname[grub_strlen (pathname) - 1] == '/')
    pathname[grub_strlen (pathname) - 1] = 0;

  /* Split into path and filename. */
  filename = grub_strrchr (pathname, '/');
  if (! filename)
    {
      path2 = grub_strdup ("/");
      filename = pathname;
    }
  else
    {
      filename++;
      path2 = grub_strdup (pathname);
      path2[filename - pathname] = 0;
    }

  /* It's the whole device. */
  (fs->dir) (dev, path2, find_file);

  grub_device_close (dev);
  grub_free (path2);
  if (!file_exists)
    return -1;
  st->st_dev = 0;
  st->st_ino = 0;
  st->st_mode = file_info.dir ? (0555 | S_IFDIR) : (0444 | S_IFREG);
  st->st_uid = 0;
  st->st_gid = 0;
  st->st_rdev = 0;
  if (!file_info.dir)
    {
      grub_file_t file;
      file = grub_file_open (path);
      if (! file)
	{
	  grub_print_error ();
	  return -1;
	}
      st->st_size = file->size;
      grub_file_close (file);
    }
  else
    st->st_size = 0;
  st->st_blksize = 512;
  st->st_blocks = (st->st_size + 511) >> 9;
  st->st_atime = st->st_mtime = st->st_ctime = file_info.mtimeset
    ? file_info.mtime : 0;
  return 0;
}

static int
fuse_opendir (const char *path, struct fuse_file_info *fi) 
{
  return 0;
}

/* FIXME */
static grub_file_t files[65536];
static int first_fd = 1;

static int 
fuse_open (const char *path, struct fuse_file_info *fi __attribute__ ((unused)))
{
  grub_file_t file;
  file = grub_file_open (path);
  if (! file)
    {
      grub_print_error ();
      return -1;
    }
  files[first_fd++] = file;
  fi->fh = first_fd;
  files[first_fd++] = file;
  return 0;
} 

static int 
fuse_read (const char *path, char *buf, size_t sz, off_t off,
	   struct fuse_file_info *fi)
{
  grub_file_t file = files[fi->fh];

  if (off > file->size)
    return -1;

  file->offset = off;
  
  return grub_file_read (file, buf, sz);
} 

static int 
fuse_release (const char *path, struct fuse_file_info *fi)
{
  grub_file_close (files[fi->fh]);
  files[fi->fh] = NULL;
  return 0;
}

static int 
fuse_readdir (const char *path, void *buf,
	      fuse_fill_dir_t fill, off_t off, struct fuse_file_info *fi)
{
  char *pathname;
  grub_fs_t fs;
  grub_device_t dev;

  auto int call_fill (const char *filename,
		      const struct grub_dirhook_info *info);
  int call_fill (const char *filename, const struct grub_dirhook_info *info)
  {
    fill (buf, filename, NULL, 0);
    return 0;
  }

  dev = grub_device_open (0);
  if (! dev)
    {
      return 1;
    }

  fs = grub_fs_probe (dev);
  if (! fs)
    {
      grub_device_close (dev);
      return 1;
    }

  pathname = xstrdup (path);
  
  /* Remove trailing '/'. */
  while (pathname [0] && pathname[1]
	 && pathname[grub_strlen (pathname) - 1] == '/')
    pathname[grub_strlen (pathname) - 1] = 0;

  (fs->dir) (dev, pathname, call_fill);
  grub_device_close (dev);
  free (pathname);
  return 0;
}

struct fuse_operations grub_opers = {
  .getattr = fuse_getattr,
  .open = fuse_open,
  .release = fuse_release,
  .opendir = fuse_opendir,
  .readdir = fuse_readdir,
  .read = fuse_read
};

static void
fuse_init (void)
{
  int i;

  for (i = 0; i < num_disks; i++)
    {
      char *argv[2];
      char *host_file;
      char *loop_name;
      loop_name = grub_xasprintf ("loop%d", i);
      if (!loop_name)
	grub_util_error (grub_errmsg);

      host_file = grub_xasprintf ("(host)%s", images[i]);
      if (!host_file)
	grub_util_error (grub_errmsg);

      argv[0] = loop_name;
      argv[1] = host_file;

      if (execute_command ("loopback", 2, argv))
        grub_util_error (_("loopback command fails"));

      grub_free (loop_name);
      grub_free (host_file);
    }

  grub_lvm_fini ();
  grub_mdraid09_fini ();
  grub_mdraid1x_fini ();
  grub_raid_fini ();
  grub_raid_init ();
  grub_mdraid09_init ();
  grub_mdraid1x_init ();
  grub_lvm_init ();

  fuse_main (fuse_argc, fuse_args, &grub_opers, NULL);

  for (i = 0; i < num_disks; i++)
    {
      char *argv[2];
      char *loop_name;

      loop_name = grub_xasprintf ("loop%d", i);
      if (!loop_name)
	grub_util_error (grub_errmsg);

      argv[0] = "-d";      
      argv[1] = loop_name;

      execute_command ("loopback", 2, argv);

      grub_free (loop_name);
    }
}

static struct argp_option options[] = {  
  {"root",      'r', N_("DEVICE_NAME"), 0, N_("Set root device."),                 2},
  {"debug",     'd', "S",           0, N_("Set debug environment variable."),  2},
  {"verbose",   'v', NULL, OPTION_ARG_OPTIONAL, N_("Print verbose messages."), 2},
  {0, 0, 0, 0, 0, 0}
};

/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "%s (%s) %s\n", program_name, PACKAGE_NAME, PACKAGE_VERSION);
}
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

error_t 
argp_parser (int key, char *arg, struct argp_state *state)
{
  char *p;

  switch (key)
    {
    case 'r':
      root = arg;
      return 0;

    case 'd':
      debug_str = arg;
      return 0;

    case 'v':
      verbosity++;
      return 0;

    case ARGP_KEY_ARG:
      if (arg[0] != '-')
	break;

    default:
      if (!arg)
	return 0;

      fuse_args = xrealloc (fuse_args, (fuse_argc + 1) * sizeof (fuse_args[0]));
      fuse_args[fuse_argc] = xstrdup (arg);
      fuse_argc++;
      return 0;
    }

  if (arg[0] != '/')
    {
      fprintf (stderr, "%s", _("Must use absolute path.\n"));
      argp_usage (state);
    }
  images = xrealloc (images, (num_disks + 1) * sizeof (images[0]));
  images[num_disks] = xstrdup (arg);
  num_disks++;

  return 0;
}

struct argp argp = {
  options, argp_parser, N_("IMAGE1 [IMAGE2 ...] MOUNTPOINT"),
  N_("Debug tool for filesystem driver."), 
  NULL, NULL, NULL
};

int
main (int argc, char *argv[])
{
  char *default_root, *alloc_root;

  set_program_name (argv[0]);

  grub_util_init_nls ();

  fuse_args = xrealloc (fuse_args, (fuse_argc + 1) * sizeof (fuse_args[0]));
  fuse_args[fuse_argc] = xstrdup (argv[0]);
  fuse_argc++;

  argp_parse (&argp, argc, argv, 0, 0, 0);
  
  if (num_disks < 2)
    grub_util_error ("need an image and mountpoint");
  fuse_args = xrealloc (fuse_args, (fuse_argc + 2) * sizeof (fuse_args[0]));
  fuse_args[fuse_argc] = images[num_disks - 1];
  fuse_argc++;
  num_disks--;
  fuse_args[fuse_argc] = NULL;

  /* Initialize all modules. */
  grub_init_all ();

  if (debug_str)
    grub_env_set ("debug", debug_str);

  default_root = (num_disks == 1) ? "loop0" : "md0";
  alloc_root = 0;
  if (root)
    {
      if ((*root >= '0') && (*root <= '9'))
        {
          alloc_root = xmalloc (strlen (default_root) + strlen (root) + 2);

          sprintf (alloc_root, "%s,%s", default_root, root);
          root = alloc_root;
        }
    }
  else
    root = default_root;

  grub_env_set ("root", root);

  if (alloc_root)
    free (alloc_root);

  /* Do it.  */
  fuse_init ();

  /* Free resources.  */
  grub_fini_all ();

  return 0;
}