/*
     This file is part of GNUnet.
     Copyright (C) 2012, 2013 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 gnunet-namecache.c
 * @brief command line tool to inspect the name cache
 * @author Christian Grothoff
 *
 * TODO:
 * - test
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_dnsparser_lib.h"
#include "gnunet_identity_service.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_namecache_service.h"


/**
 * Handle to the namecache.
 */
static struct GNUNET_NAMECACHE_Handle *ns;

/**
 * Queue entry for the 'query' operation.
 */
static struct GNUNET_NAMECACHE_QueueEntry *qe;

/**
 * Name (label) of the records to list.
 */
static char *name;

/**
 * Public key of the zone to look in.
 */
static struct GNUNET_CRYPTO_EcdsaPublicKey pubkey;

/**
 * Public key of the zone to look in, in ASCII.
 */
static char *pkey;

/**
 * Global return value
 */
static int ret;


/**
 * Task run on shutdown.  Cleans up everything.
 *
 * @param cls unused
 */
static void
do_shutdown (void *cls)
{
  if (NULL != qe)
  {
    GNUNET_NAMECACHE_cancel (qe);
    qe = NULL;
  }
  if (NULL != ns)
  {
    GNUNET_NAMECACHE_disconnect (ns);
    ns = NULL;
  }
}


/**
 * Process a record that was stored in the namecache in a block.
 *
 * @param cls closure, NULL
 * @param rd_len number of entries in @a rd array
 * @param rd array of records with data to store
 */
static void
display_records_from_block (void *cls,
                            unsigned int rd_len,
                            const struct GNUNET_GNSRECORD_Data *rd)
{
  const char *typestring;
  char *s;
  unsigned int i;

  if (0 == rd_len)
  {
    fprintf (stdout, _ ("No records found for `%s'"), name);
    return;
  }
  fprintf (stdout, "%s:\n", name);
  for (i = 0; i < rd_len; i++)
  {
    typestring = GNUNET_GNSRECORD_number_to_typename (rd[i].record_type);
    s = GNUNET_GNSRECORD_value_to_string (rd[i].record_type,
                                          rd[i].data,
                                          rd[i].data_size);
    if (NULL == s)
    {
      fprintf (stdout,
               _ ("\tCorrupt or unsupported record of type %u\n"),
               (unsigned int) rd[i].record_type);
      continue;
    }
    fprintf (stdout, "\t%s: %s\n", typestring, s);
    GNUNET_free (s);
  }
  fprintf (stdout, "%s", "\n");
}


/**
 * Display block obtained from listing (by name).
 *
 * @param cls NULL
 * @param block NULL if not found
 */
static void
handle_block (void *cls, const struct GNUNET_GNSRECORD_Block *block)
{
  qe = NULL;
  if (NULL == block)
  {
    fprintf (stderr, "No matching block found\n");
  }
  else if (GNUNET_OK !=
           GNUNET_GNSRECORD_block_decrypt (block,
                                           &pubkey,
                                           name,
                                           &display_records_from_block,
                                           NULL))
  {
    fprintf (stderr, "Failed to decrypt block!\n");
  }
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Main function that will be run.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param cfg configuration
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct GNUNET_HashCode dhash;

  if (NULL == pkey)
  {
    fprintf (stderr, _ ("You must specify which zone should be accessed\n"));
    return;
  }

  if (GNUNET_OK !=
      GNUNET_CRYPTO_ecdsa_public_key_from_string (pkey, strlen (pkey), &pubkey))
  {
    fprintf (stderr, _ ("Invalid public key for zone `%s'\n"), pkey);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  if (NULL == name)
  {
    fprintf (stderr, _ ("You must specify a name\n"));
    return;
  }

  GNUNET_SCHEDULER_add_shutdown (&do_shutdown, NULL);
  ns = GNUNET_NAMECACHE_connect (cfg);
  GNUNET_GNSRECORD_query_from_public_key (&pubkey, name, &dhash);
  qe = GNUNET_NAMECACHE_lookup_block (ns, &dhash, &handle_block, NULL);
}


/**
 * The main function for gnunet-namecache.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  struct GNUNET_GETOPT_CommandLineOption options[] =
  { GNUNET_GETOPT_option_string ('n',
                                 "name",
                                 "NAME",
                                 gettext_noop (
                                   "name of the record to add/delete/display"),
                                 &name),

    GNUNET_GETOPT_option_string (
      'z',
      "zone",
      "PKEY",
      gettext_noop ("specifies the public key of the zone to look in"),
      &pkey),

    GNUNET_GETOPT_OPTION_END };

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
    return 2;

  GNUNET_log_setup ("gnunet-namecache", "WARNING", NULL);
  if (GNUNET_OK != GNUNET_PROGRAM_run (argc,
                                       argv,
                                       "gnunet-namecache",
                                       _ ("GNUnet zone manipulation tool"),
                                       options,
                                       &run,
                                       NULL))
  {
    GNUNET_free_nz ((void *) argv);
    return 1;
  }
  GNUNET_free_nz ((void *) argv);
  return ret;
}


/* end of gnunet-namecache.c */