webhook sketch

1 files changed, 276 insertions, 0 deletions

diff --git a/src/backend/taler-merchant-webhook.c b/src/backend/taler-merchant-webhook.c
new file mode 100644
index 00000000..f9aea28b
--- /dev/null
+++ b/src/backend/taler-merchant-webhook.c
@@ -0,0 +1,276 @@
+/*
+  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 */