/*
  This file is part of TALER
  Copyright (C) 2015 GNUnet e.V.

  TALER 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.

  TALER 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
  TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file taler-exchange-sepa.c
 * @brief Create signed response for /wire/sepa requests.
 * @author Christian Grothoff
 */
#include <platform.h>
#include <jansson.h>
#include <gnunet/gnunet_json_lib.h>
#include "taler_crypto_lib.h"
#include "taler_signatures.h"


/**
 * Filename of the master private key.
 */
static char *masterkeyfile;

/**
 * Account holder name.
 */
static char *sepa_name;

/**
 * Account holder address.
 */
static char *sepa_address;

/**
 * IBAN number.
 */
static char *iban;

/**
 * BIC number.
 */
static char *bic;

/**
 * Where to write the result.
 */
static char *output_filename;


/**
 * The main function of the taler-exchange-sepa tool.  This tool is used
 * to sign the SEPA bank account details using the master key.
 *
 * @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[] = {
    {'a', "address", "ADDRESS",
     "account holder address", 1,
     &GNUNET_GETOPT_set_string, &sepa_address},
    {'b', "bic", "BICCODE",
     "bank BIC code", 1,
     &GNUNET_GETOPT_set_string, &bic},
    {'i', "iban", "IBAN",
     "IBAN number of the account", 1,
     &GNUNET_GETOPT_set_string, &iban},
    {'m', "master-key", "FILE",
     "master key file (private key)", 1,
     &GNUNET_GETOPT_set_filename, &masterkeyfile},
    {'n', "name", "NAME",
     "name of the account holder", 1,
     &GNUNET_GETOPT_set_string, &sepa_name},
    {'o', "output", "FILE",
     "where to write the result", 1,
     &GNUNET_GETOPT_set_filename, &output_filename},
    TALER_GETOPT_OPTION_HELP ("Setup /wire/sepa response"),
    GNUNET_GETOPT_OPTION_VERSION (VERSION "-" VCS_VERSION),
    GNUNET_GETOPT_OPTION_END
  };
  struct GNUNET_CRYPTO_EddsaPrivateKey *eddsa_priv;
  struct TALER_MasterWireSepaDetailsPS wsd;
  struct TALER_MasterSignatureP sig;
  struct GNUNET_HashContext *hc;
  json_t *reply;
  char *json_str;
  struct GNUNET_HashCode salt;

  GNUNET_assert (GNUNET_OK ==
                 GNUNET_log_setup ("taler-exchange-sepa",
                                   "WARNING",
                                   NULL));

  if (GNUNET_GETOPT_run ("taler-exchange-sepa",
                         options,
                         argc, argv) < 0)
    return 1;
  if (NULL == masterkeyfile)
  {
    fprintf (stderr,
             "Master key file not given\n");
    return 1;
  }
  eddsa_priv = GNUNET_CRYPTO_eddsa_key_create_from_file (masterkeyfile);
  if (NULL == eddsa_priv)
  {
    fprintf (stderr,
             "Failed to initialize master key from file `%s'\n",
             masterkeyfile);
    return 1;
  }
  if ( (NULL == sepa_address) ||
       (NULL == iban) ||
       (NULL == sepa_name) ||
       (NULL == bic) )
  {
    fprintf (stderr,
             "Required arguments missing\n");
    return 1;
  }

  /* Compute message to sign */
  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
                              &salt,
                              sizeof (salt));
  hc = GNUNET_CRYPTO_hash_context_start ();
  GNUNET_CRYPTO_hash_context_read (hc,
				   sepa_name,
				   strlen (sepa_name) + 1);
  GNUNET_CRYPTO_hash_context_read (hc,
				   iban,
				   strlen (iban) + 1);
  GNUNET_CRYPTO_hash_context_read (hc,
				   bic,
				   strlen (bic) + 1);
  wsd.purpose.size = htonl (sizeof (wsd));
  wsd.purpose.purpose = htonl (TALER_SIGNATURE_MASTER_SEPA_DETAILS);
  GNUNET_CRYPTO_hash_context_finish (hc,
				     &wsd.h_sepa_details);
  GNUNET_CRYPTO_eddsa_sign (eddsa_priv,
			    &wsd.purpose,
			    &sig.eddsa_signature);
  GNUNET_free (eddsa_priv);

  /* build JSON message */
  reply = json_pack ("{s:s, s:s, s:s, s:s, s:s, s:o, s:o}",
                     "type", "sepa",
                     "address", sepa_address,
		     "receiver_name", sepa_name,
		     "iban", iban,
		     "bic", bic,
                     "salt", GNUNET_JSON_from_data (&salt,
                                                    sizeof (salt)),
		     "sig", GNUNET_JSON_from_data (&sig,
                                                   sizeof (sig)));
  GNUNET_assert (NULL != reply);

  /* dump result to stdout */
  json_str = json_dumps (reply, JSON_INDENT(2));
  GNUNET_assert (NULL != json_str);

  if (NULL != output_filename)
  {
    fclose (stdout);
    stdout = fopen (output_filename,
		    "w+");
  }
  fprintf (stdout,
	   "%s",
	   json_str);
  fflush (stdout);
  free (json_str);
  return 0;
}

/* end of taler-exchange-sepa.c */