add lib function for forget order

1 files changed, 270 insertions, 0 deletions

diff --git a/src/lib/merchant_api_patch_order_forget.c b/src/lib/merchant_api_patch_order_forget.c
new file mode 100644
index 00000000..ff24274b
--- /dev/null
+++ b/src/lib/merchant_api_patch_order_forget.c
@@ -0,0 +1,270 @@
+/*
+  This file is part of TALER
+  Copyright (C) 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_patch_order_forget.c
+ * @brief Implementation of the PATCH /orders/$ID/forget request
+ *        of the merchant's HTTP API
+ * @author Jonathan Buchanan
+ */
+#include "platform.h"
+#include <curl/curl.h>
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_merchant_service.h"
+#include <taler/taler_json_lib.h>
+#include <taler/taler_curl_lib.h>
+
+
+/**
+ * Handle for a PATCH /orders/$ORDER_ID/forget operation.
+ */
+struct TALER_MERCHANT_OrderForgetHandle
+{
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_MERCHANT_ForgetCallback cb;
+
+  /**
+   * Closure for @a cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Reference to the execution context.
+   */
+  struct GNUNET_CURL_Context *ctx;
+
+  /**
+   * Minor context that holds body and headers.
+   */
+  struct TALER_CURL_PostContext post_ctx;
+
+};
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP PATCH /orders/$ORDER_ID/forget request.
+ *
+ * @param cls the `struct TALER_MERCHANT_OrderForgetHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param json response body, NULL if not in JSON
+ */
+static void
+handle_forget_finished (void *cls,
+                        long response_code,
+                        const void *response)
+{
+  struct TALER_MERCHANT_OrderForgetHandle *ofh = cls;
+  const json_t *json = response;
+  struct TALER_MERCHANT_HttpResponse hr = {
+    .http_status = (unsigned int) response_code,
+    .reply = json
+  };
+
+  ofh->job = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "PATCH /orders/$ORDER_ID/forget completed with response code %u\n",
+              (unsigned int) response_code);
+  switch (response_code)
+  {
+  case 0:
+    hr.ec = TALER_EC_INVALID_RESPONSE;
+    break;
+  case MHD_HTTP_OK:
+    break;
+  case MHD_HTTP_BAD_REQUEST:
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    break;
+  case MHD_HTTP_CONFLICT:
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    /* Server had an internal issue; we should retry,
+       but this API leaves this to the application */
+    break;
+  default:
+    TALER_MERCHANT_parse_error_details_ (json,
+                                         response_code,
+                                         &hr);
+    /* unexpected response code */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d\n",
+                (unsigned int) response_code,
+                (int) hr.ec);
+    GNUNET_break_op (0);
+    break;
+  }
+  ofh->cb (ofh->cb_cls,
+           &hr);
+  TALER_MERCHANT_order_forget_cancel (ofh);
+}
+
+
+/**
+ * Run a payment forget operation, which forgets certain fields in an order's
+ * contract terms without changing the hash of the contract terms.
+ *
+ * @param ctx execution context.
+ * @param merchant_url base URL of the merchant.
+ * @param order_id order to forget.
+ * @param fields_length length of @e fields.
+ * @param fields the fields in the contract terms to forget.
+ * @param cb the callback to call when a reply for this request is available.
+ * @param cb_cls closure for @a cb.
+ * @return a handle for this request.
+ */
+struct TALER_MERCHANT_OrderForgetHandle *
+TALER_MERCHANT_order_forget (struct GNUNET_CURL_Context *ctx,
+                             const char *merchant_url,
+                             const char *order_id,
+                             unsigned int fields_length,
+                             const char *fields[],
+                             TALER_MERCHANT_ForgetCallback cb,
+                             void *cb_cls)
+{
+  struct TALER_MERCHANT_OrderForgetHandle *ofh;
+  json_t *req_fields;
+  json_t *req_obj;
+
+  req_fields = json_array ();
+  if (NULL == req_fields)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  for (unsigned int i = 0; i<fields_length; i++)
+  {
+    if (0 !=
+        json_array_append_new (req_fields,
+                               json_string (fields[i])))
+    {
+      GNUNET_break (0);
+      json_decref (req_fields);
+      return NULL;
+    }
+  }
+  req_obj = json_pack ("{s:o}",
+                       "fields",
+                       req_fields);
+  if (NULL == req_obj)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  ofh = GNUNET_new (struct TALER_MERCHANT_OrderForgetHandle);
+  ofh->ctx = ctx;
+  ofh->cb = cb;
+  ofh->cb_cls = cb_cls;
+  {
+    char *path;
+
+    GNUNET_asprintf (&path,
+                     "private/orders/%s/forget",
+                     order_id);
+    ofh->url = TALER_url_join (merchant_url,
+                               path,
+                               NULL);
+    GNUNET_free (path);
+  }
+  if (NULL == ofh->url)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Could not construct request URL.\n");
+    json_decref (req_obj);
+    GNUNET_free (ofh);
+    return NULL;
+  }
+  {
+    CURL *eh;
+
+    eh = curl_easy_init ();
+    if (GNUNET_OK !=
+        TALER_curl_easy_post (&ofh->post_ctx,
+                              eh,
+                              req_obj))
+    {
+      GNUNET_break (0);
+      json_decref (req_obj);
+      GNUNET_free (ofh);
+      return NULL;
+    }
+
+    json_decref (req_obj);
+    GNUNET_assert (CURLE_OK == curl_easy_setopt (eh,
+                                                 CURLOPT_URL,
+                                                 ofh->url));
+    GNUNET_assert (CURLE_OK ==
+                   curl_easy_setopt (eh,
+                                     CURLOPT_CUSTOMREQUEST,
+                                     MHD_HTTP_METHOD_PATCH));
+    ofh->job = GNUNET_CURL_job_add2 (ctx,
+                                     eh,
+                                     ofh->post_ctx.headers,
+                                     &handle_forget_finished,
+                                     ofh);
+  }
+  return ofh;
+}
+
+
+/**
+ * Cancel a PATCH /orders/$ID/forget request.  Note that if you cancel a request
+ * like this, you have no assurance that the request has not yet been
+ * forwarded to the merchant.
+ *
+ * @param ofh the forget request handle
+ */
+void
+TALER_MERCHANT_order_forget_cancel (struct
+                                    TALER_MERCHANT_OrderForgetHandle *ofh)
+{
+  if (NULL != ofh->job)
+  {
+    GNUNET_CURL_job_cancel (ofh->job);
+    ofh->job = NULL;
+  }
+  TALER_curl_easy_post_finished (&ofh->post_ctx);
+  GNUNET_free (ofh->url);
+  GNUNET_free (ofh);
+}
+
+
+/* end of merchant_api_patch_order_forget.c */