implement TALER_MERCHANT_poll_payment()demo-2019-11-02-00

2 files changed, 282 insertions, 5 deletions

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 6a5e9bf8..3d54d682 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -19,16 +19,17 @@ libtalermerchanttesting_la_LDFLAGS = \
   -no-undefined
 
 libtalermerchant_la_SOURCES = \
+  merchant_api_check_payment.c \
+  merchant_api_history.c \
   merchant_api_proposal.c \
   merchant_api_pay.c \
+  merchant_api_poll_payment.c \
+  merchant_api_refund.c \
   merchant_api_tip_authorize.c \
   merchant_api_tip_pickup.c \
+  merchant_api_tip_query.c \
   merchant_api_track_transaction.c \
-  merchant_api_track_transfer.c \
-  merchant_api_history.c \
-  merchant_api_refund.c \
-  merchant_api_check_payment.c \
-  merchant_api_tip_query.c
+  merchant_api_track_transfer.c
 libtalermerchant_la_LIBADD = \
   -ltalerexchange \
   -ltalercurl \
diff --git a/src/lib/merchant_api_poll_payment.c b/src/lib/merchant_api_poll_payment.c
new file mode 100644
index 00000000..84da4431
--- /dev/null
+++ b/src/lib/merchant_api_poll_payment.c
@@ -0,0 +1,276 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2018 GNUnet e.V. and INRIA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Lesser General Public License as published by the Free Software
+  Foundation; either version 2.1, 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 Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License along with
+  TALER; see the file COPYING.LGPL.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file lib/merchant_api_poll_payment.c
+ * @brief Implementation of the /poll-payment GET request
+ * @author Christian Grothoff
+ * @author Marcello Stanisci
+ * @author Florian Dold
+ */
+#include "platform.h"
+#include <curl/curl.h>
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_merchant_service.h"
+#include <taler/taler_json_lib.h>
+#include <taler/taler_signatures.h>
+
+
+/**
+ * @brief A poll payment operation handle
+ */
+struct TALER_MERCHANT_PollPaymentOperation
+{
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_MERCHANT_PollPaymentCallback cb;
+
+  /**
+   * Closure for @a cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Reference to the execution context.
+   */
+  struct GNUNET_CURL_Context *ctx;
+};
+
+
+/**
+ * Function called when we're done processing the GET /poll-payment request.
+ *
+ * @param cls the `struct TALER_MERCHANT_PollPaymentOperation`
+ * @param response_code HTTP response code, 0 on error
+ * @param json response body, should be NULL
+ */
+static void
+handle_poll_payment_finished (void *cls,
+                              long response_code,
+                              const void *response)
+{
+  struct TALER_MERCHANT_PollPaymentOperation *cpo = cls;
+  struct TALER_Amount refund_amount = { 0 };
+  const json_t *json = response;
+  const json_t *refunded;
+
+  struct GNUNET_JSON_Specification spec[] = {
+    TALER_JSON_spec_amount ("refund_amount",
+                            &refund_amount),
+    GNUNET_JSON_spec_end ()
+  };
+
+  cpo->job = NULL;
+
+  if (MHD_HTTP_OK != response_code)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Polling payment failed with HTTP status code %u\n",
+                (unsigned int) response_code);
+    GNUNET_break_op (0);
+    cpo->cb (cpo->cb_cls,
+             response_code,
+             json,
+             GNUNET_SYSERR,
+             GNUNET_SYSERR,
+             NULL,
+             NULL);
+    TALER_MERCHANT_poll_payment_cancel (cpo);
+    return;
+  }
+
+  if (! json_boolean_value (json_object_get (json, "paid")))
+  {
+    const char *taler_pay_uri = json_string_value (json_object_get (json,
+                                                                    "taler_pay_uri"));
+    if (NULL == taler_pay_uri)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "no taler_pay_uri in unpaid poll-payment response\n");
+      GNUNET_break_op (0);
+      cpo->cb (cpo->cb_cls,
+               0,
+               json,
+               GNUNET_SYSERR,
+               GNUNET_SYSERR,
+               NULL,
+               NULL);
+    }
+    else
+    {
+      cpo->cb (cpo->cb_cls,
+               response_code,
+               json,
+               GNUNET_NO,
+               GNUNET_NO,
+               NULL,
+               taler_pay_uri);
+    }
+    TALER_MERCHANT_poll_payment_cancel (cpo);
+    return;
+  }
+
+  if ( (NULL == (refunded = json_object_get (json,
+                                             "refunded"))) ||
+       ( (json_true () == refunded) &&
+         (GNUNET_OK !=
+          GNUNET_JSON_parse (json,
+                             spec,
+                             NULL, NULL)) ) )
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "poll payment failed to parse JSON\n");
+    GNUNET_break_op (0);
+    cpo->cb (cpo->cb_cls,
+             0,
+             json,
+             GNUNET_SYSERR,
+             GNUNET_SYSERR,
+             NULL,
+             NULL);
+    TALER_MERCHANT_poll_payment_cancel (cpo);
+    return;
+  }
+
+  cpo->cb (cpo->cb_cls,
+           MHD_HTTP_OK,
+           json,
+           GNUNET_YES,
+           (json_true () == refunded),
+           (json_true () == refunded) ? &refund_amount : NULL,
+           NULL);
+  TALER_MERCHANT_poll_payment_cancel (cpo);
+}
+
+
+/**
+ * Issue a /poll-payment request to the backend.  Polls the status
+ * of a payment.
+ *
+ * @param ctx execution context
+ * @param backend_url base URL of the merchant backend
+ * @param order_id order id to identify the payment
+ * @param h_contract hash of the contract for @a order_id
+ * @parem session_id sesion id for the payment (or NULL if the payment is not bound to a session)
+ * @param timeout timeout to use in long polling (how long may the server wait to reply
+ *        before generating an unpaid response). Note that this is just provided to
+ *        the server, we as client will block until the response comes back or until
+ *        #TALER_MERCHANT_poll_payment_cancel() is called.
+ * @param poll_payment_cb callback which will work the response gotten from the backend
+ * @param poll_payment_cb_cls closure to pass to @a poll_payment_cb
+ * @return handle for this operation, NULL upon errors
+ */
+struct TALER_MERCHANT_PollPaymentOperation *
+TALER_MERCHANT_poll_payment (struct GNUNET_CURL_Context *ctx,
+                             const char *backend_url,
+                             const char *order_id,
+                             const struct GNUNET_HashCode *h_contract,
+                             const char *session_id,
+                             struct GNUNET_TIME_Relative timeout,
+                             TALER_MERCHANT_PollPaymentCallback
+                             poll_payment_cb,
+                             void *poll_payment_cb_cls)
+{
+  struct TALER_MERCHANT_PollPaymentOperation *cpo;
+  CURL *eh;
+  char *h_contract_s;
+  char *timeout_s;
+  unsigned int ts;
+
+  GNUNET_assert (NULL != backend_url);
+  GNUNET_assert (NULL != order_id);
+  h_contract_s = GNUNET_STRINGS_data_to_string_alloc (h_contract,
+                                                      sizeof (*h_contract));
+  ts = (unsigned int) (timeout.rel_value_us
+                       / GNUNET_TIME_UNIT_SECONDS.rel_value_us);
+  GNUNET_asprintf (&timeout_s,
+                   "%u",
+                   ts);
+  cpo = GNUNET_new (struct TALER_MERCHANT_PollPaymentOperation);
+  cpo->ctx = ctx;
+  cpo->cb = poll_payment_cb;
+  cpo->cb_cls = poll_payment_cb_cls;
+  cpo->url = TALER_url_join (backend_url,
+                             "public/poll-payment",
+                             "order_id", order_id,
+                             "session_id", session_id,
+                             "h_contract", h_contract_s,
+                             (0 != ts) ? "timeout" : NULL,
+                             timeout_s,
+                             NULL);
+  GNUNET_free (h_contract_s);
+  GNUNET_free (timeout_s);
+  eh = curl_easy_init ();
+  if (CURLE_OK != curl_easy_setopt (eh,
+                                    CURLOPT_URL,
+                                    cpo->url))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "polling payment from %s\n",
+              cpo->url);
+
+  if (NULL == (cpo->job = GNUNET_CURL_job_add (ctx,
+                                               eh,
+                                               GNUNET_YES,
+                                               &handle_poll_payment_finished,
+                                               cpo)))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  return cpo;
+}
+
+
+/**
+ * Cancel a GET /poll-payment request.
+ *
+ * @param cph handle to the request to be canceled
+ */
+void
+TALER_MERCHANT_poll_payment_cancel (struct
+                                    TALER_MERCHANT_PollPaymentOperation *cph)
+{
+  if (NULL != cph->job)
+  {
+    GNUNET_CURL_job_cancel (cph->job);
+    cph->job = NULL;
+  }
+  GNUNET_free (cph->url);
+  GNUNET_free (cph);
+}
+
+
+/* end of merchant_api_poll_payment.c */