/*
     This file is part of GNUnet
     Copyright (C) 2012 GNUnet e.V.

     GNUnet 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.

     GNUnet 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/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */
/**
 * @file hello/gnunet-hello.c
 * @brief change HELLO files to never expire
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_protocols.h"
#include "gnunet_hello_lib.h"

/**
 * Closure for #add_to_buf().
 */
struct AddContext
{
  /**
   * Where to add.
   */
  char *buf;

  /**
   * Maximum number of bytes left
   */
  size_t max;

  /**
   * Number of bytes added so far.
   */
  size_t ret;
};

static int address_count;


/**
 * Add the given address with infinit expiration to the buffer.
 *
 * @param cls closure
 * @param address address to add
 * @param expiration old expiration
 * @return #GNUNET_OK keep iterating
 */
static int
add_to_buf (void *cls,
            const struct GNUNET_HELLO_Address *address,
            struct GNUNET_TIME_Absolute expiration)
{
  struct AddContext *ac = cls;
  size_t ret;

  ret = GNUNET_HELLO_add_address (address,
                                  GNUNET_TIME_UNIT_FOREVER_ABS,
                                  ac->buf,
                                  ac->max);
  ac->buf += ret;
  ac->max -= ret;
  ac->ret += ret;
  address_count++;
  return GNUNET_OK;
}


/**
 * Add addresses from the address list to the HELLO.
 *
 * @param cls the HELLO with the addresses to add
 * @param max maximum space available
 * @param buf where to add the addresses
 * @return number of bytes added, 0 to terminate
 */
static ssize_t
add_from_hello (void *cls, size_t max, void *buf)
{
  struct GNUNET_HELLO_Message **orig = cls;
  struct AddContext ac;

  if (NULL == *orig)
    return GNUNET_SYSERR; /* already done */
  ac.buf = buf;
  ac.max = max;
  ac.ret = 0;
  GNUNET_assert (
    NULL ==
    GNUNET_HELLO_iterate_addresses (*orig, GNUNET_NO, &add_to_buf, &ac));
  *orig = NULL;
  return ac.ret;
}


int
main (int argc, char *argv[])
{
  struct GNUNET_DISK_FileHandle *fh;
  struct GNUNET_HELLO_Message *orig;
  struct GNUNET_HELLO_Message *result;
  struct GNUNET_PeerIdentity pid;
  uint64_t fsize;

  address_count = 0;

  GNUNET_log_setup ("gnunet-hello", "INFO", NULL);
  if (argc != 2)
  {
    fprintf (stderr, "%s", _ ("Call with name of HELLO file to modify.\n"));
    return 1;
  }
  if (GNUNET_OK !=
      GNUNET_DISK_file_size (argv[1], &fsize, GNUNET_YES, GNUNET_YES))
  {
    fprintf (stderr,
             _ ("Error accessing file `%s': %s\n"),
             argv[1],
             strerror (errno));
    return 1;
  }
  if (fsize > 65536)
  {
    fprintf (stderr, _ ("File `%s' is too big to be a HELLO\n"), argv[1]);
    return 1;
  }
  if (fsize < sizeof(struct GNUNET_MessageHeader))
  {
    fprintf (stderr, _ ("File `%s' is too small to be a HELLO\n"), argv[1]);
    return 1;
  }
  fh = GNUNET_DISK_file_open (argv[1],
                              GNUNET_DISK_OPEN_READ,
                              GNUNET_DISK_PERM_USER_READ);
  if (NULL == fh)
  {
    fprintf (stderr,
             _ ("Error opening file `%s': %s\n"),
             argv[1],
             strerror (errno));
    return 1;
  }
  {
    char buf[fsize] GNUNET_ALIGN;

    GNUNET_assert (fsize == GNUNET_DISK_file_read (fh, buf, fsize));
    GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fh));
    orig = (struct GNUNET_HELLO_Message *) buf;
    if ((fsize < GNUNET_HELLO_size (orig)) ||
        (GNUNET_OK != GNUNET_HELLO_get_id (orig, &pid)))
    {
      fprintf (stderr,
               _ ("Did not find well-formed HELLO in file `%s'\n"),
               argv[1]);
      return 1;
    }
    {
      char *pids;

      pids = GNUNET_CRYPTO_eddsa_public_key_to_string (&pid.public_key);
      fprintf (stdout, "Processing HELLO for peer `%s'\n", pids);
      GNUNET_free (pids);
    }
    result = GNUNET_HELLO_create (&pid.public_key,
                                  &add_from_hello,
                                  &orig,
                                  GNUNET_HELLO_is_friend_only (orig));
    GNUNET_assert (NULL != result);
    fh =
      GNUNET_DISK_file_open (argv[1],
                             GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE,
                             GNUNET_DISK_PERM_USER_READ
                             | GNUNET_DISK_PERM_USER_WRITE);
    if (NULL == fh)
    {
      fprintf (stderr,
               _ ("Error opening file `%s': %s\n"),
               argv[1],
               strerror (errno));
      GNUNET_free (result);
      return 1;
    }
    fsize = GNUNET_HELLO_size (result);
    if (fsize != GNUNET_DISK_file_write (fh, result, fsize))
    {
      fprintf (stderr,
               _ ("Error writing HELLO to file `%s': %s\n"),
               argv[1],
               strerror (errno));
      (void) GNUNET_DISK_file_close (fh);
      return 1;
    }
    GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fh));
  }
  fprintf (stderr,
           _ ("Modified %u addresses, wrote %u bytes\n"),
           address_count,
           (unsigned int) fsize);
  return 0;
}


/* end of gnunet-hello.c */
