/*
  This file is part of TALER
  Copyright (C) 2018 Taler Systems SA

  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, see
  <http://www.gnu.org/licenses/>
*/

/**
 * @file exchange-lib/test_exchange_api_keys_cherry_picking_new.c
 * @brief testcase to test exchange's /keys cherry picking ability
 * @author Marcello Stanisci
 * @author Christian Grothoff
 */

#include "platform.h"
#include "taler_util.h"
#include "taler_signatures.h"
#include "taler_exchange_service.h"
#include "taler_json_lib.h"
#include <gnunet/gnunet_util_lib.h>
#include <microhttpd.h>
#include "taler_bank_service.h"
#include "taler_fakebank_lib.h"
#include "taler_testing_lib.h"


/**
 * Configuration file we use.  One (big) configuration is used
 * for the various components for this test.
 */
#define CONFIG_FILE "test_exchange_api_keys_cherry_picking.conf"

/**
 * Used to increase the number of denomination keys.
 */
#define CONFIG_FILE_EXTENDED \
  "test_exchange_api_keys_cherry_picking_extended.conf"

/**
 * Used to increase the number of denomination keys.
 */
#define CONFIG_FILE_EXTENDED_2 \
  "test_exchange_api_keys_cherry_picking_extended_2.conf"

/**
 * Current time.
 */
struct GNUNET_TIME_Absolute now;

/**
 * Adds to the current time.
 *
 * @param relative number of _seconds_ to add to the current time.
 * @return a new absolute time, modified according to @e relative.
 */
#define NOWPLUSSECS(secs) \
  GNUNET_TIME_absolute_add \
    (now, \
     GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, \
                                    secs))
#define JAN1971 "1971-01-01"
#define JAN2030 "2030-01-01"

/**
 * Exchange base URL; mainly purpose is to make the compiler happy.
 */
static char *exchange_url;

/**
 * Auditor base URL; mainly purpose is to make the compiler happy.
 */
static char *auditor_url;

/**
 * Wrapper around the time parser.
 *
 * @param str human-readable time string.
 * @return the parsed time from @a str.
 */
static struct GNUNET_TIME_Absolute
TTH_parse_time (const char *str)
{
  struct GNUNET_TIME_Absolute ret;

  GNUNET_assert
    (GNUNET_OK == GNUNET_STRINGS_fancy_time_to_absolute (str,
                                                         &ret));
  return ret;
}


/**
 * Main function that will tell the interpreter what commands to
 * run.
 *
 * @param cls closure
 */
static void
run (void *cls,
     struct TALER_TESTING_Interpreter *is)
{
  struct TALER_TESTING_Command keys_serialization[] = {

    TALER_TESTING_cmd_serialize_keys
      ("serialize-keys"),

    TALER_TESTING_cmd_connect_with_state
      ("reconnect-with-state",
       "serialize-keys"),

    TALER_TESTING_cmd_wire
      ("verify-/wire-with-serialized-keys",
       "x-taler-bank",
       NULL,
       MHD_HTTP_OK),

    /**
     * This loads a very big lookahead_sign (3500s).
     */
    TALER_TESTING_cmd_exec_keyup
      ("keyup-serialization",
       CONFIG_FILE_EXTENDED_2),

    #if 0

    FIXME: #5672
    
    The test below fails on different systems.  Infact, different
    systems can generate different "anchors" values for their
    denoms, therefore the fixed value required by the test below
    (45) is condemned to fail.

    However, this seems to happen only when very big values are
    used for the "lookahead_sign" value.  Here we use 3500 seconds,
    and the test breaks.

    A reasonable fix is to allow for some slack in the number of
    the expected keys.

    TALER_TESTING_cmd_check_keys ("check-freshest-keys",
                       /* At this point, /keys has been
                        * downloaded roughly 6 times, so by
                        * forcing 10 here we make sure we get
                        * all the new ones.  */
                                  10, 
                       /* We use a very high number here to make
                        * sure the "big" lookahead value got
                        * respected.  */
                                  45),
    #endif
    TALER_TESTING_cmd_wire ("verify-/wire-with-fresh-keys",
                            "x-taler-bank",
                            NULL,
                            MHD_HTTP_OK),

    TALER_TESTING_cmd_end (),

  };

  now = GNUNET_TIME_absolute_get ();
  struct TALER_TESTING_Command ordinary_cherry_pick[] = {

    /**
     * 1 DK with 80s withdraw duration, lookahead_sign is 60s
     * => expect 1 DK.
     */
    TALER_TESTING_cmd_check_keys ("check-keys-1",
                                  1, /* generation */
                                  1),
    /**
     * The far-future now will cause "keyup" to start a fresh
     * key set.  The new KS will have only one key, because the
     * current lookahead_sign == 60 seconds and the key's withdraw
     * duration is 80 seconds.
     */
    TALER_TESTING_cmd_exec_keyup_with_now
      ("keyup-1",
       CONFIG_FILE,
       TTH_parse_time (JAN2030)),

     /**
     * Should return 1 new key, + the original one.  NOTE: the
     * original DK will never be 'cancelled' as for the current
     * libtalerexchange logic, so it must always be counted.
     */
    TALER_TESTING_cmd_check_keys_with_now
      ("check-keys-2",
       2, /* generation */
       2,
       TTH_parse_time (JAN2030)),

    /**
     * We now load a very high lookahead_sign value of 3500 s,
     * with now == JAN2030.
     */
    TALER_TESTING_cmd_exec_keyup_with_now
      ("keyup-3",
       CONFIG_FILE_EXTENDED_2,
       TTH_parse_time (JAN2030)),

    /**
     * For each DK with a withdraw duration of 80 s
     * (- 1 s of overlap), and for the latest 3500 s
     * lookahead_sign value, we should have ((3500 - _79_) / 79)
     * keys we just downloaded + 2 old DK keys stored in memory
     * (total 46).  The _79_ seconds we subtract are from the one
     * key generated at "keyup-1".
     *
     * This currently fails: look for XXX-ANCHOR at
     * taler-exchange-keyup.c to get some insight about the reason
     * behind.
     */
    TALER_TESTING_cmd_check_keys_with_now
      ("check-keys-3",
       3, 
       46,
       TTH_parse_time (JAN2030)),

    TALER_TESTING_cmd_end ()
  };
  struct TALER_TESTING_Command commands[] = {

    TALER_TESTING_cmd_batch ("ordinary-cherry-pick",
                             ordinary_cherry_pick),
    /*
    TALER_TESTING_cmd_batch ("keys-serialization",
                             keys_serialization),
    */
    TALER_TESTING_cmd_end ()
  };

  TALER_TESTING_run (is,
		     commands);
}


int
main (int argc,
      char * const *argv)
{
  /* These environment variables get in the way... */
  unsetenv ("XDG_DATA_HOME");
  unsetenv ("XDG_CONFIG_HOME");
  GNUNET_log_setup ("test-exchange-api-cherry-picking-new",
                    "DEBUG",
                    NULL);
  TALER_TESTING_cleanup_files (CONFIG_FILE);
  /* @helpers.  Run keyup, create tables, ... Note: it
   * fetches the port number from config in order to see
   * if it's available. */
  switch (TALER_TESTING_prepare_exchange (CONFIG_FILE,
                                          &auditor_url,
					  &exchange_url))
  {
  case GNUNET_SYSERR:
    GNUNET_break (0);
    return 1;
  case GNUNET_NO:
    return 77;
  case GNUNET_OK:
    if (GNUNET_OK !=
        /* Set up event loop and reschedule context, plus
         * start/stop the exchange.  It calls TALER_TESTING_setup
         * which creates the 'is' object.
         */
        TALER_TESTING_setup_with_exchange (&run,
                                           NULL,
                                           CONFIG_FILE))
      return 1;
    break;
  default:
    GNUNET_break (0);
    return 1;
  }
  return 0;
}

/* end of test_exchange_api_keys_cherry_picking_new.c */