/*
     This file is part of GNUnet.
     (C) 2012 Christian Grothoff (and other contributing authors)

     GNUnet 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, 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/
/**
 * @file gnunet-gns.c
 * @brief command line tool to access distributed GNS
 * @author Christian Grothoff
 *
 */
#include "platform.h"
#include <gnunet_util_lib.h>
#include <gnunet_dnsparser_lib.h>
#include <gnunet_namestore_service.h>
#include <gnunet_gns_service.h>

/**
 * Handle to GNS service.
 */
static struct GNUNET_GNS_Handle *gns;

/**
 * GNS name to shorten. (-s option)
 */
static char *shorten_name;

/**
 * GNS name to lookup. (-u option)
 */
static char *lookup_name;

/**
 * record type to look up (-t option)
 */
static char *lookup_type;

/**
 * name to look up authority for (-a option)
 */
static char *auth_name;

/**
 * raw output
 */
static int raw;

/**
 * Requested record type.
 */
static enum GNUNET_GNS_RecordType rtype;

/**
 * Handle to lookup request 
 */
static struct GNUNET_GNS_LookupRequest *lookup_request;

/**
 * Handle to shorten request 
 */
static struct GNUNET_GNS_ShortenRequest *shorten_request;

/**
 * Handle to get authority request
 */
static struct GNUNET_GNS_GetAuthRequest *getauth_request;


/**
 * Task run on shutdown.  Cleans up everything.
 *
 * @param cls unused
 * @param tc scheduler context
 */
static void
do_shutdown (void *cls,
	     const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  if (NULL != lookup_request)
  {
    GNUNET_GNS_cancel_lookup_request (lookup_request);
    lookup_request = NULL;
  }
  if (NULL != shorten_request)
  {
    GNUNET_GNS_cancel_shorten_request (shorten_request);
    shorten_request = NULL;
  }
  if (NULL != getauth_request)
  {
    GNUNET_GNS_cancel_get_auth_request (getauth_request);
    getauth_request = NULL;
  }
  if (NULL != gns)
  {
    GNUNET_GNS_disconnect (gns);
    gns = NULL;
  }
}


/**
 * Function called with the result of a shorten operation.
 * Prints the result.
 *
 * @param cls a 'const char *' with the original (long) name
 * @param nshort the shortened name
 */
static void
process_shorten_result (void* cls, const char *nshort)
{
  const char *original_name = cls;

  shorten_request = NULL;
  if (raw)
    printf("%s", nshort);
  else
    printf("%s shortened to %s\n", original_name, nshort);
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Function called with the result of a GADS lookup.
 *
 * @param cls the 'const char *' name that was resolved
 * @param rd_count number of records returned
 * @param rd array of 'rd_count' records with the results
 */
static void
process_lookup_result (void* cls, uint32_t rd_count,
		       const struct GNUNET_NAMESTORE_RecordData *rd)
{
  const char* name = cls;
  uint32_t i;
  const char* typename;
  char* string_val;

  lookup_request = NULL; 
  if (!raw) 
  {
    if (0 == rd_count)
      printf("No results.\n");
    else
      printf("%s:\n", name);
  }
  for (i=0; i<rd_count; i++)
  {
    typename = GNUNET_NAMESTORE_number_to_typename (rd[i].record_type);
    string_val = GNUNET_NAMESTORE_value_to_string (rd[i].record_type,
						   rd[i].data,
						   rd[i].data_size);
    if (raw)
      printf ("%s\n", string_val);
    else
      printf ("Got `%s' record: %s\n", typename, string_val);
    GNUNET_free_non_null (string_val);
  }
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Function called with the result of an authority lookup.
 *
 * @param cls the 'const char *' with the name for which the
 *            authority was resolved
 * @param auth name of the authority
 */
static void
process_auth_result (void* cls, 
		     const char *auth)
{
  getauth_request = NULL;
  printf ("%s\n", auth);
  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)
{
  char* keyfile;
  struct GNUNET_CRYPTO_RsaPrivateKey *key = NULL;
  struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;
  struct GNUNET_CRYPTO_ShortHashCode *zone = NULL;
  struct GNUNET_CRYPTO_ShortHashCode user_zone;
  struct GNUNET_CRYPTO_ShortHashAsciiEncoded zonename;
  struct GNUNET_CRYPTO_RsaPrivateKey *shorten_key = NULL;
  struct GNUNET_CRYPTO_RsaPrivateKey *private_key = NULL;
  struct GNUNET_CRYPTO_ShortHashCode *private_zone = NULL;
  struct GNUNET_CRYPTO_ShortHashCode *shorten_zone = NULL;

  gns = GNUNET_GNS_connect (cfg);
  if (NULL == gns)
  {
    fprintf (stderr,
	     _("Failed to connect to GNS\n"));
    return;
  }
  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "gns",
                                                           "ZONEKEY", &keyfile))
  {
    if (! raw)
      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                  "No private key for root zone found, using default!\n");
  }
  else
  {
    key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
    GNUNET_CRYPTO_rsa_key_get_public (key, &pkey);
    GNUNET_CRYPTO_short_hash (&pkey,
			      sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
			      &user_zone);
    zone = &user_zone;
    GNUNET_CRYPTO_short_hash_to_enc (zone, &zonename);
    if (!raw)
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		  "Using zone: %s!\n", &zonename);
    GNUNET_CRYPTO_rsa_key_free (key);  
    GNUNET_free(keyfile);
  }
  
  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "gns",
							    "SHORTEN_ZONEKEY", &keyfile))
  {
    if (! raw)
      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                  "No shorten key found!\n");
  }
  else
  {
    shorten_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
    GNUNET_CRYPTO_rsa_key_get_public (shorten_key, &pkey);
    shorten_zone = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_ShortHashCode));
    GNUNET_CRYPTO_short_hash(&pkey,
			     sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
			     shorten_zone);
    GNUNET_CRYPTO_short_hash_to_enc (shorten_zone, &zonename);
    if (! raw)
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		  "Using shorten zone: %s!\n", &zonename);
    GNUNET_free (keyfile);
  }
    
  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "gns",
							    "PRIVATE_ZONEKEY", &keyfile))
  {
    if (! raw)
      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                  "No private zone key file name specified in configuration!\n");
  }
  else
  {
    private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
    GNUNET_CRYPTO_rsa_key_get_public (private_key, &pkey);
    private_zone = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_ShortHashCode));
    GNUNET_CRYPTO_short_hash(&pkey,
			     sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
			     private_zone);
    GNUNET_CRYPTO_short_hash_to_enc (private_zone, &zonename);
    if (! raw)
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		  "Using private zone: %s!\n", &zonename);
    GNUNET_CRYPTO_rsa_key_free (private_key);
  }
  
  if (NULL != lookup_type)
    rtype = GNUNET_NAMESTORE_typename_to_number (lookup_type);
  else
    rtype = GNUNET_GNS_RECORD_A;

  if ( (NULL != shorten_name) && 
       (NULL != shorten_zone) && 
       (NULL != private_zone) )
  {
    shorten_request = GNUNET_GNS_shorten_zone (gns, shorten_name,
					       private_zone,
					       shorten_zone,
					       zone,
					       &process_shorten_result,
					       shorten_name);
  }
  if (NULL != lookup_name)
  {
    lookup_request = GNUNET_GNS_lookup_zone (gns, lookup_name,
					     zone,
					     rtype,
					     GNUNET_NO, /* Use DHT */
					     shorten_key,
					     &process_lookup_result, 
					     lookup_name);
  }
  if (NULL != auth_name)
  {
    getauth_request = GNUNET_GNS_get_authority (gns, auth_name,
						&process_auth_result, auth_name);
  }

  if (NULL != shorten_key)
    GNUNET_CRYPTO_rsa_key_free (shorten_key);
  if (NULL != shorten_zone)
    GNUNET_free (shorten_zone);
  if (NULL != private_zone)
    GNUNET_free (private_zone);
  
  if ( (NULL == auth_name) &&
       (NULL == shorten_name) &&
       (NULL == lookup_name))
  {
    fprintf (stderr,
	     _("Please specify lookup, shorten or authority operation!\n"));
    GNUNET_SCHEDULER_add_now (&do_shutdown, NULL);
    return;
  }
  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
				&do_shutdown, NULL);
}


/**
 * The main function for gnunet-gns.
 *
 * @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)
{
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    {'s', "shorten", "NAME",
     gettext_noop ("try to shorten a given name"), 1,
     &GNUNET_GETOPT_set_string, &shorten_name},
    {'u', "lookup", "NAME",
      gettext_noop ("Lookup a record for the given name"), 1,
      &GNUNET_GETOPT_set_string, &lookup_name},
    {'a', "authority", "NAME",
      gettext_noop ("Get the authority of a particular name"), 1,
      &GNUNET_GETOPT_set_string, &auth_name},
    {'t', "type", "TYPE",
      gettext_noop ("Specify the type of the record to lookup"), 1,
      &GNUNET_GETOPT_set_string, &lookup_type},
    {'r', "raw", NULL,
      gettext_noop ("No unneeded output"), 0,
      &GNUNET_GETOPT_set_one, &raw},
    GNUNET_GETOPT_OPTION_END
  };
  int ret;

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

  GNUNET_log_setup ("gnunet-gns", "WARNING", NULL);
  ret =
      (GNUNET_OK ==
       GNUNET_PROGRAM_run (argc, argv, "gnunet-gns",
                           _("GNUnet GNS access tool"), 
			   options,
                           &run, NULL)) ? 0 : 1;
  GNUNET_free ((void*) argv);
  return ret;
}

/* end of gnunet-gns.c */