/*
  This file is part of TALER
  Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)

  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-mint-reservemod.c
 * @brief Modify reserves.  Allows manipulation of reserve balances.
 * @author Florian Dold
 * @author Benedikt Mueller
 */
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <libpq-fe.h>
#include "taler_util.h"
#include "taler_signatures.h"
#include "taler_mintdb_plugin.h"
#include "taler_pq_lib.h"


/**
 * Director of the mint, containing the keys.
 */
static char *mint_directory;

/**
 * Public key of the reserve to manipulate.
 */
static struct GNUNET_CRYPTO_EddsaPublicKey *reserve_pub;

/**
 * Handle to the mint's configuration
 */
static struct GNUNET_CONFIGURATION_Handle *cfg;

/**
 * Database connection handle.
 */
static PGconn *db_conn;


/**
 * Create a new or add to existing reserve.  Fails if currencies do
 * not match.
 *
 * @param denom denomination to add
 * @return #GNUNET_OK on success,
 *         #GNUNET_SYSERR on error
 */
// FIXME: this should use the DB abstraction layer. (#3717)
// FIXME: this should be done by adding an inbound transaction
//        to the table with the transactions for this reserve,
//        not by modifying some 'total' value for the reserve!
//        (we should in fact probably never modify, always just append!) (#3633)
static int
reservemod_add (struct TALER_Amount denom)
{
  PGresult *result;
  const void *param_values[] = {
    reserve_pub
  };
  int param_lengths[] = {
    sizeof(struct GNUNET_CRYPTO_EddsaPublicKey)
  };
  int param_formats[] = {
    1
  };
  struct TALER_Amount old_denom;
  struct TALER_Amount new_denom;
  struct TALER_AmountNBO new_denom_nbo;

  result = PQexecParams (db_conn,
                         "SELECT balance_value, balance_fraction, balance_currency"
                         " FROM reserves"
                         " WHERE reserve_pub=$1"
                         " LIMIT 1;",
                         1,
                         NULL,
                         (const char * const *) param_values,
                         param_lengths,
                         param_formats,
                         1);
  if (PGRES_TUPLES_OK != PQresultStatus (result))
  {
    fprintf (stderr,
             "Select failed: %s\n",
             PQresultErrorMessage (result));
    return GNUNET_SYSERR;
  }
  if (0 == PQntuples (result))
  {
    struct GNUNET_TIME_AbsoluteNBO exnbo;
    uint32_t value = htonl (denom.value);
    uint32_t fraction = htonl (denom.fraction);
    const void *param_values[] = {
      reserve_pub,
      &value,
      &fraction,
      denom.currency,
      &exnbo
    };
    int param_lengths[] = {
      sizeof (struct GNUNET_CRYPTO_EddsaPublicKey),
      sizeof (uint32_t),
      sizeof (uint32_t),
      strlen (denom.currency),
      sizeof (struct GNUNET_TIME_AbsoluteNBO)
    };
    int param_formats[] = {
      1, 1, 1, 1, 1
    };

    exnbo = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_YEARS));
    result = PQexecParams (db_conn,
                           "INSERT INTO reserves (reserve_pub, balance_value, balance_fraction, balance_currency, expiration_date)"
                           " VALUES ($1,$2,$3,$4,$5);",
                           5,
                           NULL,
                           (const char **) param_values,
                           param_lengths,
                           param_formats,
                           1);

    if (PGRES_COMMAND_OK != PQresultStatus (result))
    {
      fprintf (stderr,
               "Insert failed: %s\n",
               PQresultErrorMessage (result));
      return GNUNET_SYSERR;
    }
  }
  else
  {
    const void *param_values[] = {
      &new_denom_nbo.value,
      &new_denom_nbo.fraction,
      reserve_pub
    };
    int param_lengths[] = {
      sizeof (new_denom_nbo.value),
      sizeof (new_denom_nbo.fraction),
      sizeof (struct GNUNET_CRYPTO_EddsaPublicKey)
    };
    int param_formats[] = {
      1, 1, 1
    };

    GNUNET_assert (GNUNET_OK ==
                   TALER_PQ_extract_amount (result, 0,
                                            "balance_value",
                                            "balance_fraction",
                                            "balance_currency",
                                            &old_denom));
    TALER_amount_add (&new_denom,
                      &old_denom,
                      &denom);
    TALER_amount_hton (&new_denom_nbo,
                       &new_denom);
    result = PQexecParams (db_conn,
                           "UPDATE reserves"
                           " SET balance_value = $1, balance_fraction = $2, status_sig = NULL, status_sign_pub = NULL"
                           " WHERE reserve_pub = $3;",
                           3,
                           NULL,
                           (const char **) param_values,
                           param_lengths,
                           param_formats,
                           1);

    if (PGRES_COMMAND_OK != PQresultStatus (result))
    {
      fprintf (stderr,
               "Update failed: %s\n",
               PQresultErrorMessage (result));
      return GNUNET_SYSERR;
    }
    /* Yes, for historic reasons libpq returns a 'const char *'... */
    if (0 != strcmp ("1",
                     PQcmdTuples (result)))
    {
      fprintf (stderr,
               "Update failed (updated `%s' tupes instead of '1')\n",
               PQcmdTuples (result));
      return GNUNET_SYSERR;
    }
  }
  return GNUNET_OK;
}


/**
 * The main function of the reservemod tool
 *
 * @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 char *reserve_pub_str;
  static char *add_str;
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_OPTION_HELP ("gnunet-mint-reservemod OPTIONS"),
    {'d', "mint-dir", "DIR",
     "mint directory with keys to update", 1,
     &GNUNET_GETOPT_set_filename, &mint_directory},
    {'R', "reserve", "KEY",
     "reserve (public key) to modify", 1,
     &GNUNET_GETOPT_set_string, &reserve_pub_str},
    {'a', "add", "DENOM",
     "value to add", 1,
     &GNUNET_GETOPT_set_string, &add_str},
    GNUNET_GETOPT_OPTION_END
  };
  char *connection_cfg_str;

  GNUNET_assert (GNUNET_OK ==
                 GNUNET_log_setup ("taler-mint-reservemod",
                                   "WARNING",
                                   NULL));

  if (GNUNET_GETOPT_run ("taler-mint-reservemod",
                         options,
                         argc, argv) < 0)
    return 1;
  if (NULL == mint_directory)
  {
    fprintf (stderr,
             "Mint directory not given\n");
    return 1;
  }

  reserve_pub = GNUNET_new (struct GNUNET_CRYPTO_EddsaPublicKey);
  if ((NULL == reserve_pub_str) ||
      (GNUNET_OK !=
       GNUNET_STRINGS_string_to_data (reserve_pub_str,
                                      strlen (reserve_pub_str),
                                      reserve_pub,
                                      sizeof (struct GNUNET_CRYPTO_EddsaPublicKey))))
  {
    fprintf (stderr,
             "Parsing reserve key invalid\n");
    return 1;
  }
  cfg = TALER_config_load (mint_directory);
  if (NULL == cfg)
  {
    fprintf (stderr,
             "Failed to load mint configuration\n");
    return 1;
  }
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg,
                                             "mint",
                                             "db",
                                             &connection_cfg_str))
  {
    fprintf (stderr,
             "Database configuration string not found\n");
    return 1;
  }
  db_conn = PQconnectdb (connection_cfg_str);
  if (CONNECTION_OK != PQstatus (db_conn))
  {
    fprintf (stderr,
             "Database connection failed: %s\n",
             PQerrorMessage (db_conn));
    return 1;
  }
  if (NULL != add_str)
  {
    struct TALER_Amount add_value;

    if (GNUNET_OK !=
        TALER_string_to_amount (add_str,
                                &add_value))
    {
      fprintf (stderr,
               "Failed to parse currency amount `%s'\n",
               add_str);
      return 1;
    }
    if (GNUNET_OK !=
        reservemod_add (add_value))
    {
      fprintf (stderr,
               "Failed to update reserve.\n");
      return 1;
    }
  }
  return 0;
}

/* end taler-mint-reservemod.c */