implement PATCH handlers

1 files changed, 254 insertions, 0 deletions

diff --git a/src/backend/taler-merchant-httpd_private-patch-products-ID.c b/src/backend/taler-merchant-httpd_private-patch-products-ID.c
new file mode 100644
index 00000000..8177207c
--- /dev/null
+++ b/src/backend/taler-merchant-httpd_private-patch-products-ID.c
@@ -0,0 +1,254 @@
+/*
+  This file is part of TALER
+  (C) 2020 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 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 backend/taler-merchant-httpd_private-patch-products.c
+ * @brief implementing PATCH /products/$ID request handling
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "taler-merchant-httpd_private-patch-products-ID.h"
+#include <taler/taler_json_lib.h>
+
+
+/**
+ * How often do we retry the simple INSERT database transaction?
+ */
+#define MAX_RETRIES 3
+
+
+/**
+ * Determine the cause of the PATCH failure in more detail and report.
+ *
+ * @param connection connection to report on
+ * @param instance_id instance we are processing
+ * @param product_id ID of the product to patch
+ * @param pd product details we failed to set
+ */
+static MHD_RESULT
+determine_cause (struct MHD_Connection *connection,
+                 const char *instance_id,
+                 const char *product_id,
+                 const struct TALER_MERCHANTDB_ProductDetails *pd)
+{
+  struct TALER_MERCHANTDB_ProductDetails pdx;
+  enum GNUNET_DB_QueryStatus qs;
+
+  qs = TMH_db->lookup_product (TMH_db->cls,
+                               instance_id,
+                               product_id,
+                               &pdx);
+  switch (qs)
+  {
+  case GNUNET_DB_STATUS_HARD_ERROR:
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_PRODUCTS_PATCH_DB_COMMIT_HARD_ERROR,
+                                       "Failed to get existing product");
+  case GNUNET_DB_STATUS_SOFT_ERROR:
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_INTERNAL_INVARIANT_FAILURE,
+                                       "Serialization error for single-statment request");
+  case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_NOT_FOUND,
+                                       TALER_EC_PRODUCTS_PATCH_UNKNOWN_PRODUCT,
+                                       "The specified product is unknown");
+  case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+    break; /* do below */
+  }
+
+  {
+    enum TALER_ErrorCode ec;
+    const char *hint;
+
+    ec = TALER_EC_INTERNAL_INVARIANT_FAILURE;
+    hint = "transaction failed for causes unknown";
+    if (pdx.total_lost > pd->total_lost)
+    {
+      ec = TALER_EC_PRODUCTS_PATCH_TOTAL_LOST_REDUCED;
+      hint = "total lost cannot be lowered";
+    }
+    if (pdx.total_sold > pd->total_sold)
+    {
+      ec = TALER_EC_PRODUCTS_PATCH_TOTAL_SOLD_REDUCED;
+      hint = "total sold cannot be lowered";
+    }
+    if (pdx.total_stocked > pd->total_stocked)
+    {
+      ec = TALER_EC_PRODUCTS_PATCH_TOTAL_STOCKED_REDUCED;
+      hint = "total stocked cannot be lowered";
+    }
+    GNUNET_free (pdx.description);
+    json_decref (pdx.description_i18n);
+    GNUNET_free (pdx.unit);
+    json_decref (pdx.taxes);
+    json_decref (pdx.image);
+    json_decref (pdx.location);
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_CONFLICT,
+                                       ec,
+                                       hint);
+  }
+}
+
+
+/**
+ * PATCH configuration of an existing instance, given its configuration.
+ *
+ * @param rh context of the handler
+ * @param connection the MHD connection to handle
+ * @param[in,out] hc context with further information about the request
+ * @return MHD result code
+ */
+MHD_RESULT
+TMH_private_patch_products_ID (const struct TMH_RequestHandler *rh,
+                               struct MHD_Connection *connection,
+                               struct TMH_HandlerContext *hc)
+{
+  struct TMH_MerchantInstance *mi = hc->instance;
+  const char *product_id = hc->infix;
+  struct TALER_MERCHANTDB_ProductDetails pd;
+  int64_t total_stocked;
+  enum GNUNET_DB_QueryStatus qs;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_string ("description",
+                             (const char **) &pd.description),
+    GNUNET_JSON_spec_json ("description_i18n",
+                           &pd.description_i18n),
+    GNUNET_JSON_spec_string ("unit",
+                             (const char **) &pd.unit),
+    TALER_JSON_spec_amount ("price",
+                            &pd.price),
+    GNUNET_JSON_spec_json ("image",
+                           &pd.image),
+    GNUNET_JSON_spec_json ("taxes",
+                           &pd.taxes),
+    GNUNET_JSON_spec_json ("location",
+                           &pd.taxes),
+    GNUNET_JSON_spec_int64 ("total_stocked",
+                            &total_stocked),
+    GNUNET_JSON_spec_absolute_time ("next_restock",
+                                    &pd.next_restock),
+    GNUNET_JSON_spec_end ()
+  };
+
+  GNUNET_assert (NULL != mi);
+  GNUNET_assert (NULL != product_id);
+  {
+    enum GNUNET_GenericReturnValue res;
+
+    res = TALER_MHD_parse_json_data (connection,
+                                     hc->request_body,
+                                     spec);
+    /* json is malformed */
+    if (GNUNET_NO == res)
+    {
+      GNUNET_break_op (0);
+      return MHD_YES;
+    }
+    /* other internal errors might have occurred */
+    if (GNUNET_SYSERR == res)
+      return TALER_MHD_reply_with_error (connection,
+                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                         TALER_EC_INTERNAL_INVARIANT_FAILURE,
+                                         "Impossible to parse the order");
+  }
+  if (-1 == total_stocked)
+    pd.total_stocked = UINT64_MAX;
+  else
+    pd.total_stocked = (uint64_t) total_stocked;
+  if (NULL != json_object_get (hc->request_body,
+                               "next_restock"))
+  {
+    enum GNUNET_GenericReturnValue res;
+    struct GNUNET_JSON_Specification spec[] = {
+      GNUNET_JSON_spec_absolute_time ("next_restock",
+                                      &pd.next_restock),
+      GNUNET_JSON_spec_end ()
+    };
+
+    res = TALER_MHD_parse_json_data (connection,
+                                     hc->request_body,
+                                     spec);
+    /* json is malformed */
+    if (GNUNET_NO == res)
+    {
+      GNUNET_break_op (0);
+      GNUNET_JSON_parse_free (spec);
+      return MHD_YES;
+    }
+    /* other internal errors might have occurred */
+    if (GNUNET_SYSERR == res)
+    {
+      GNUNET_JSON_parse_free (spec);
+      return TALER_MHD_reply_with_error (connection,
+                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                         TALER_EC_INTERNAL_INVARIANT_FAILURE,
+                                         "Impossible to parse the restock time");
+    }
+  }
+  else
+  {
+    pd.next_restock.abs_value_us = 0;
+  }
+
+  qs = TMH_db->update_product (TMH_db->cls,
+                               mi->settings.id,
+                               product_id,
+                               &pd);
+  {
+    MHD_RESULT ret;
+    switch (qs)
+    {
+    case GNUNET_DB_STATUS_HARD_ERROR:
+      ret = TALER_MHD_reply_with_error (connection,
+                                        MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                        TALER_EC_PRODUCTS_PATCH_DB_COMMIT_HARD_ERROR,
+                                        "Failed to commit change");
+      break;
+    case GNUNET_DB_STATUS_SOFT_ERROR:
+      GNUNET_break (0);
+      ret = TALER_MHD_reply_with_error (connection,
+                                        MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                        TALER_EC_INTERNAL_INVARIANT_FAILURE,
+                                        "Serialization error for single-statment request");
+      break;
+    case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+      ret = determine_cause (connection,
+                             mi->settings.id,
+                             product_id,
+                             &pd);
+      break;
+    case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+      ret = TALER_MHD_reply_static (connection,
+                                    MHD_HTTP_NO_CONTENT,
+                                    NULL,
+                                    NULL,
+                                    0);
+      break;
+    }
+    GNUNET_JSON_parse_free (spec);
+    return ret;
+  }
+}
+
+
+/* end of taler-merchant-httpd_private-patch-products-ID.c */