implement GET /products

2 files changed, 281 insertions, 0 deletions

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 3199dd32..b92733ff 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -24,6 +24,7 @@ libtalermerchant_la_SOURCES = \
   merchant_api_get_config.c \
   merchant_api_get_instance.c \
   merchant_api_get_instances.c \
+  merchant_api_get_products.c \
   merchant_api_patch_instance.c \
   merchant_api_post_instances.c \
   merchant_api_check_payment.c \
diff --git a/src/lib/merchant_api_get_products.c b/src/lib/merchant_api_get_products.c
new file mode 100644
index 00000000..3c7eae54
--- /dev/null
+++ b/src/lib/merchant_api_get_products.c
@@ -0,0 +1,280 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018, 2020 Taler Systems SA
+
+  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_get_products.c
+ * @brief Implementation of the GET /products request of the merchant's HTTP API
+ * @author Christian Grothoff
+ */
+#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>
+
+
+/**
+ * Handle for a GET /products operation.
+ */
+struct TALER_MERCHANT_ProductsGetHandle
+{
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_MERCHANT_ProductsGetCallback cb;
+
+  /**
+   * Closure for @a cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Reference to the execution context.
+   */
+  struct GNUNET_CURL_Context *ctx;
+
+};
+
+
+/**
+ * Parse product information from @a ia.
+ *
+ * @param ia JSON array (or NULL!) with product data
+ * @param pgh operation handle
+ * @return #GNUNET_OK on success
+ */
+static int
+parse_products (const json_t *ia,
+                struct TALER_MERCHANT_ProductsGetHandle *pgh)
+{
+  unsigned int ies_len = json_array_size (ia);
+  struct TALER_MERCHANT_InventoryEntry ies[ies_len];
+  size_t index;
+  json_t *value;
+  int ret;
+
+  ret = GNUNET_OK;
+  json_array_foreach (ia, index, value) {
+    struct TALER_MERCHANT_InventoryEntry *ie = &ies[index];
+    struct GNUNET_JSON_Specification spec[] = {
+      GNUNET_JSON_spec_string ("product_id",
+                               &ie->product_id),
+      GNUNET_JSON_spec_end ()
+    };
+
+    if (GNUNET_OK !=
+        GNUNET_JSON_parse (value,
+                           spec,
+                           NULL, NULL))
+    {
+      GNUNET_break_op (0);
+      ret = GNUNET_SYSERR;
+      continue;
+    }
+    if (GNUNET_SYSERR == ret)
+      break;
+  }
+  if (GNUNET_OK == ret)
+  {
+    struct TALER_MERCHANT_HttpResponse hr = {
+      .http_status = MHD_HTTP_OK
+    };
+
+    pgh->cb (pgh->cb_cls,
+             &hr,
+             ies_len,
+             ies);
+    pgh->cb = NULL; /* just to be sure */
+  }
+  return ret;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /products request.
+ *
+ * @param cls the `struct TALER_MERCHANT_ProductsGetHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param json response body, NULL if not in JSON
+ */
+static void
+handle_get_products_finished (void *cls,
+                              long response_code,
+                              const void *response)
+{
+  struct TALER_MERCHANT_ProductsGetHandle *pgh = cls;
+  const json_t *json = response;
+  struct TALER_MERCHANT_HttpResponse hr = {
+    .http_status = (unsigned int) response_code,
+    .reply = json
+  };
+
+  pgh->job = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Got /products response with status code %u\n",
+              (unsigned int) response_code);
+  switch (response_code)
+  {
+  case MHD_HTTP_OK:
+    {
+      json_t *products;
+      struct GNUNET_JSON_Specification spec[] = {
+        GNUNET_JSON_spec_json ("products",
+                               &products),
+        GNUNET_JSON_spec_end ()
+      };
+
+      if (GNUNET_OK !=
+          GNUNET_JSON_parse (json,
+                             spec,
+                             NULL, NULL))
+      {
+        hr.http_status = 0;
+        hr.ec = TALER_EC_INVALID_RESPONSE;
+      }
+      else
+      {
+        if ( (! json_is_array (products)) ||
+             (GNUNET_OK ==
+              parse_products (products,
+                              pgh)) )
+        {
+          GNUNET_JSON_parse_free (spec);
+          TALER_MERCHANT_products_get_cancel (pgh);
+          return;
+        }
+        else
+        {
+          hr.http_status = 0;
+          hr.ec = TALER_EC_INVALID_RESPONSE;
+        }
+      }
+      GNUNET_JSON_parse_free (spec);
+      break;
+    }
+  default:
+    /* unexpected response code */
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d\n",
+                (unsigned int) response_code,
+                (int) hr.ec);
+    break;
+  }
+  pgh->cb (pgh->cb_cls,
+           &hr,
+           0,
+           NULL);
+  TALER_MERCHANT_products_get_cancel (pgh);
+}
+
+
+/**
+ * Make a GET /products request.
+ *
+ * @param ctx the context
+ * @param backend_url HTTP base URL for the backend
+ * @param instance_id instance to query about its products,
+ *                    NULL to query the default instance
+ * @param cb function to call with the backend's inventory information
+ * @param cb_cls closure for @a cb
+ * @return the request handle; NULL upon error
+ */
+struct TALER_MERCHANT_ProductsGetHandle *
+TALER_MERCHANT_products_get (
+  struct GNUNET_CURL_Context *ctx,
+  const char *backend_url,
+  const char *instance_id,
+  TALER_MERCHANT_ProductsGetCallback cb,
+  void *cb_cls)
+{
+  struct TALER_MERCHANT_ProductsGetHandle *pgh;
+  CURL *eh;
+
+  pgh = GNUNET_new (struct TALER_MERCHANT_ProductsGetHandle);
+  pgh->ctx = ctx;
+  pgh->cb = cb;
+  pgh->cb_cls = cb_cls;
+  {
+    char *path;
+
+    if (NULL == instance_id)
+      GNUNET_asprintf (&path,
+                       "products");
+    else
+      GNUNET_asprintf (&path,
+                       "instances/%s/products",
+                       instance_id);
+    pgh->url = TALER_url_join (backend_url,
+                               path,
+                               NULL);
+    GNUNET_free (path);
+  }
+  if (NULL == pgh->url)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Could not construct request URL.\n");
+    GNUNET_free (pgh);
+    return NULL;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Requesting URL '%s'\n",
+              pgh->url);
+  eh = curl_easy_init ();
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_URL,
+                                   pgh->url));
+  pgh->job = GNUNET_CURL_job_add (ctx,
+                                  eh,
+                                  GNUNET_YES,
+                                  &handle_get_products_finished,
+                                  pgh);
+  return pgh;
+}
+
+
+/**
+ * Cancel /products request.  Must not be called by clients after
+ * the callback was invoked.
+ *
+ * @param pgh request to cancel.
+ */
+void
+TALER_MERCHANT_products_get_cancel (
+  struct TALER_MERCHANT_ProductsGetHandle *pgh)
+{
+  if (NULL != pgh->job)
+    GNUNET_CURL_job_cancel (pgh->job);
+  GNUNET_free (pgh->url);
+  GNUNET_free (pgh);
+}