/*
  This file is part of TALER
  Copyright (C) 2016-2020 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU Affero 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 Affero Public License for more details.

  You should have received a copy of the GNU Affero Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file auditor/report-lib.h
 * @brief helper library to facilitate generation of audit reports
 * @author Christian Grothoff
 */
#ifndef REPORT_LIB_H
#define REPORT_LIB_H

#include <gnunet/gnunet_util_lib.h>
#include "taler_auditordb_plugin.h"
#include "taler_exchangedb_lib.h"
#include "taler_json_lib.h"
#include "taler_bank_service.h"
#include "taler_signatures.h"


/**
 * Command-line option "-r": TALER_ARL_restart audit from scratch
 */
extern int TALER_ARL_restart;

/**
 * Handle to access the exchange's database.
 */
extern struct TALER_EXCHANGEDB_Plugin *TALER_ARL_edb;

/**
 * Which TALER_ARL_currency are we doing the audit for?
 */
extern char *TALER_ARL_currency;

/**
 * How many fractional digits does the TALER_ARL_currency use?
 */
extern struct TALER_Amount TALER_ARL_currency_round_unit;

/**
 * Our configuration.
 */
extern const struct GNUNET_CONFIGURATION_Handle *TALER_ARL_cfg;

/**
 * Our session with the #TALER_ARL_edb.
 */
extern struct TALER_EXCHANGEDB_Session *TALER_ARL_esession;

/**
 * Handle to access the auditor's database.
 */
extern struct TALER_AUDITORDB_Plugin *TALER_ARL_adb;

/**
 * Our session with the #TALER_ARL_adb.
 */
extern struct TALER_AUDITORDB_Session *TALER_ARL_asession;

/**
 * Master public key of the exchange to audit.
 */
extern struct TALER_MasterPublicKeyP TALER_ARL_master_pub;

/**
 * At what time did the auditor process start?
 */
extern struct GNUNET_TIME_Absolute start_time;


/**
 * Convert absolute time to human-readable JSON string.
 *
 * @param at time to convert
 * @return human-readable string representing the time
 */
json_t *
TALER_ARL_json_from_time_abs_nbo (struct GNUNET_TIME_AbsoluteNBO at);


/**
 * Convert absolute time to human-readable JSON string.
 *
 * @param at time to convert
 * @return human-readable string representing the time
 */
json_t *
TALER_ARL_json_from_time_abs (struct GNUNET_TIME_Absolute at);


/**
 * Add @a object to the TALER_ARL_report @a array.  Fail hard if this fails.
 *
 * @param array TALER_ARL_report array to append @a object to
 * @param object object to append, should be check that it is not NULL
 */
void
TALER_ARL_report (json_t *array,
                  json_t *object);


/**
 * Obtain information about a @a denom_pub.
 *
 * @param dh hash of the denomination public key to look up
 * @param[out] issue set to detailed information about @a denom_pub, NULL if not found, must
 *                 NOT be freed by caller
 * @return TALER_ARL_transaction status code
 */
enum GNUNET_DB_QueryStatus
TALER_ARL_get_denomination_info_by_hash (
  const struct GNUNET_HashCode *dh,
  const struct TALER_DenominationKeyValidityPS **issue);


/**
 * Obtain information about a @a denom_pub.
 *
 * @param denom_pub key to look up
 * @param[out] issue set to detailed information about @a denom_pub, NULL if not found, must
 *                 NOT be freed by caller
 * @param[out] dh set to the hash of @a denom_pub, may be NULL
 * @return TALER_ARL_transaction status code
 */
enum GNUNET_DB_QueryStatus
TALER_ARL_get_denomination_info (
  const struct TALER_DenominationPublicKey *denom_pub,
  const struct TALER_DenominationKeyValidityPS **issue,
  struct GNUNET_HashCode *dh);


/**
 * Type of an analysis function.  Each analysis function runs in
 * its own transaction scope and must thus be internally consistent.
 *
 * @param cls closure
 * @return transaction status code
 */
typedef enum GNUNET_DB_QueryStatus
(*TALER_ARL_Analysis)(void *cls);


/**
 * Initialize DB sessions and run the analysis.
 *
 * @param ana analysis to run
 * @param ana_cls closure for @a ana
 * @return #GNUNET_OK on success
 */
int
TALER_ARL_setup_sessions_and_run (TALER_ARL_Analysis ana,
                                  void *ana_cls);


/**
 * Setup global variables based on configuration.
 *
 * @param c configuration to use
 * @return #GNUNET_OK on success
 */
int
TALER_ARL_init (const struct GNUNET_CONFIGURATION_Handle *c);


/**
 * Generate the report and close connectios to the database.
 *
 * @param report the report to output, may be NULL for no report
 */
void
TALER_ARL_done (json_t *report);

#endif