path: root/src/backend/taler-merchant-webhook.c

/*
  This file is part of TALER
  Copyright (C) 2023 Taler Systems SA

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

  You should have received a copy of the GNU Affero General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file taler-merchant-webhook.c
 * @brief Process that runs webhooks triggered by the merchant backend
 * @author Christian Grothoff
 */
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <jansson.h>
#include <pthread.h>
#include <curl.h>
#include "taler_merchantdb_lib.h"
#include "taler_merchantdb_plugin.h"
#include "taler_json_lib.h"


/**
 * The exchange's configuration.
 */
static const struct GNUNET_CONFIGURATION_Handle *cfg;

/**
 * Our database plugin.
 */
static struct TALER_MERCHANTDB_Plugin *db_plugin;

/**
 * Next task to run, if any.
 */
static struct GNUNET_SCHEDULER_Task *task;

/**
 * Handle to the context for interacting with the bank / wire gateway.
 */
static struct GNUNET_CURL_Context *ctx;

/**
 * Scheduler context for running the @e ctx.
 */
static struct GNUNET_CURL_RescheduleContext *rc;

/**
 * Value to return from main(). 0 on success, non-zero on errors.
 */
static int global_ret;

/**
 * #GNUNET_YES if we are in test mode and should exit when idle.
 */
static int test_mode;


/**
 * We're being aborted with CTRL-C (or SIGTERM). Shut down.
 *
 * @param cls closure
 */
static void
shutdown_task (void *cls)
{
  (void) cls;
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "Running shutdown\n");
  if (NULL != task)
  {
    GNUNET_SCHEDULER_cancel (task);
    task = NULL;
  }
  db_plugin->rollback (db_plugin->cls); /* just in case */
  TALER_MERCHANTDB_plugin_unload (db_plugin);
  db_plugin = NULL;
  cfg = NULL;
  if (NULL != ctx)
  {
    GNUNET_CURL_fini (ctx);
    ctx = NULL;
  }
  if (NULL != rc)
  {
    GNUNET_CURL_gnunet_rc_destroy (rc);
    rc = NULL;
  }
}


/**
 * Select webhook to process.
 *
 * @param cls NULL
 */
static void
select_work (void *cls);


void
handle_webhook_response (void *cls)
{
  cls->webhook_serial;
  // update DB status on the webhook! (delete or update webhook)

  task = GNUNET_SCHEDULER_add_now (&select_work,
                                   NULL);
}


void
cb ()
{
  CURL *eh;

  eh = curl_easy_new ();

  GNUNET_assert (CURLE_OK ==
                 curl_easy_setopt (eh,
                                   CURLOPT_CUSTOMREQUEST,
                                   method));
  GNUNET_assert (CURLE_OK ==
                 curl_easy_setopt (eh,
                                   CURLOPT_URL,
                                   url));
  // run the job
  job = GNUNET_CURL_job_add2 (ctx,
                              eh,
                              ofh->post_ctx.headers,
                              &handle_webhook_response,
                              NULL /* pass struct with webhook ID for update!*/);
}


/**
 * Select webhook to process.
 *
 * @param cls NULL
 */
static void
select_work (void *cls)
{
  enum GNUNET_DB_QueryStatus qs;

  (void) cls;
  task = NULL;
  if (GNUNET_SYSERR ==
      db_plugin->preflight (db_plugin->cls))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to obtain database connection!\n");
    global_ret = EXIT_FAILURE;
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  qs = db_plugin->lookup_pending_webhooks (db_plugin->cls,
                                           &cb,
                                           NULL);
  switch (qs)
  {
  // FIXME: handle qs
  case 1:
  // wait for completion, then select more work.
  case 0:
    db_plugin->lookup_future_webhook (...);
  case -1 / -2:
    // shutdown.
  }
}


/**
 * First task.
 *
 * @param cls closure, NULL
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param c configuration
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  (void) cls;
  (void) args;
  (void) cfgfile;

  cfg = c;
  GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
                                 NULL);
  ctx = GNUNET_CURL_init (&GNUNET_CURL_gnunet_scheduler_reschedule,
                          &rc);
  rc = GNUNET_CURL_gnunet_rc_create (ctx);
  if (NULL == ctx)
  {
    GNUNET_break (0);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  if (NULL ==
      (db_plugin = TALER_MERCHANTDB_plugin_load (cfg)))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to initialize DB subsystem\n");
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  if (GNUNET_SYSERR ==
      db_plugin->preflight (db_plugin->cls))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to obtain database connection!\n");
    global_ret = EXIT_FAILURE;
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  GNUNET_assert (NULL == task);
  task = GNUNET_SCHEDULER_add_now (&select_work,
                                   NULL);
}


/**
 * The main function of the taler-exchange-transfer.
 *
 * @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)
{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_flag ('t',
                               "test",
                               "run in test mode and exit when idle",
                               &test_mode),
    GNUNET_GETOPT_option_version (VERSION "-" VCS_VERSION),
    GNUNET_GETOPT_OPTION_END
  };
  enum GNUNET_GenericReturnValue ret;

  if (GNUNET_OK !=
      GNUNET_STRINGS_get_utf8_args (argc, argv,
                                    &argc, &argv))
    return EXIT_INVALIDARGUMENT;
  TALER_OS_init ();
  ret = GNUNET_PROGRAM_run (
    argc, argv,
    "taler-merchant-webhook",
    gettext_noop (
      "background process that executes webhooks"),
    options,
    &run, NULL);
  GNUNET_free_nz ((void *) argv);
  if (GNUNET_SYSERR == ret)
    return EXIT_INVALIDARGUMENT;
  if (GNUNET_NO == ret)
    return EXIT_SUCCESS;
  return global_ret;
}


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