merchant

merchant_api_get_templates.c (6746B)

---

 /*
   This file is part of TALER
   Copyright (C) 2022 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 merchant_api_get_templates.c
  * @brief Implementation of the GET /templates request of the merchant's HTTP API
  * @author Priscilla HUANG
  */
 #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 "merchant_api_curl_defaults.h"
 #include <taler/taler_json_lib.h>
 #include <taler/taler_signatures.h>
 
 
 /**
  * Maximum number of templates we return.
  */
 #define MAX_TEMPLATES 1024
 
 
 /**
  * Handle for a GET /templates operation.
  */
 struct TALER_MERCHANT_TemplatesGetHandle
 {
   /**
    * The url for this request.
    */
   char *url;
 
   /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
 
   /**
    * Function to call with the result.
    */
   TALER_MERCHANT_TemplatesGetCallback cb;
 
   /**
    * Closure for @a cb.
    */
   void *cb_cls;
 
   /**
    * Reference to the execution context.
    */
   struct GNUNET_CURL_Context *ctx;
 
 };
 
 
 /**
  * Parse template information from @a ia.
  *
  * @param ia JSON array (or NULL!) with template data
  * @param[in] tgr partially filled response
  * @param tgh operation handle
  * @return #GNUNET_OK on success
  */
 static enum GNUNET_GenericReturnValue
 parse_templates (const json_t *ia,
                  struct TALER_MERCHANT_TemplatesGetResponse *tgr,
                  struct TALER_MERCHANT_TemplatesGetHandle *tgh)
 {
   unsigned int tmpl_len = (unsigned int) json_array_size (ia);
 
   if ( (json_array_size (ia) != (size_t)  tmpl_len) ||
        (tmpl_len > MAX_TEMPLATES) )
   {
     GNUNET_break (0);
     return GNUNET_SYSERR;
   }
   {
     struct TALER_MERCHANT_TemplateEntry tmpl[GNUNET_NZL (tmpl_len)];
     size_t index;
     json_t *value;
 
     json_array_foreach (ia, index, value) {
       struct TALER_MERCHANT_TemplateEntry *ie = &tmpl[index];
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_string ("template_id",
                                  &ie->template_id),
         GNUNET_JSON_spec_end ()
       };
 
       if (GNUNET_OK !=
           GNUNET_JSON_parse (value,
                              spec,
                              NULL, NULL))
       {
         GNUNET_break_op (0);
         return GNUNET_SYSERR;
       }
     }
     tgr->details.ok.templates_length = tmpl_len;
     tgr->details.ok.templates = tmpl;
     tgh->cb (tgh->cb_cls,
              tgr);
     tgh->cb = NULL; /* just to be sure */
   }
   return GNUNET_OK;
 }
 
 
 /**
  * Function called when we're done processing the
  * HTTP /templates request.
  *
  * @param cls the `struct TALER_MERCHANT_TemplatesGetHandle`
  * @param response_code HTTP response code, 0 on error
  * @param response response body, NULL if not in JSON
  */
 static void
 handle_get_templates_finished (void *cls,
                                long response_code,
                                const void *response)
 {
   struct TALER_MERCHANT_TemplatesGetHandle *tgh = cls;
   const json_t *json = response;
   struct TALER_MERCHANT_TemplatesGetResponse tgr = {
     .hr.http_status = (unsigned int) response_code,
     .hr.reply = json
   };
 
   tgh->job = NULL;
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Got /templates response with status code %u\n",
               (unsigned int) response_code);
   switch (response_code)
   {
   case MHD_HTTP_OK:
     {
       const json_t *templates;
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_array_const ("templates",
                                       &templates),
         GNUNET_JSON_spec_end ()
       };
 
       if (GNUNET_OK !=
           GNUNET_JSON_parse (json,
                              spec,
                              NULL, NULL))
       {
         tgr.hr.http_status = 0;
         tgr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
         break;
       }
       if (GNUNET_OK ==
           parse_templates (templates,
                            &tgr,
                            tgh))
       {
         TALER_MERCHANT_templates_get_cancel (tgh);
         return;
       }
       tgr.hr.http_status = 0;
       tgr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
       break;
     }
   case MHD_HTTP_UNAUTHORIZED:
     tgr.hr.ec = TALER_JSON_get_error_code (json);
     tgr.hr.hint = TALER_JSON_get_error_hint (json);
     /* Nothing really to verify, merchant says we need to authenticate. */
     break;
   default:
     /* unexpected response code */
     tgr.hr.ec = TALER_JSON_get_error_code (json);
     tgr.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) tgr.hr.ec);
     break;
   }
   tgh->cb (tgh->cb_cls,
            &tgr);
   TALER_MERCHANT_templates_get_cancel (tgh);
 }
 
 
 struct TALER_MERCHANT_TemplatesGetHandle *
 TALER_MERCHANT_templates_get (
   struct GNUNET_CURL_Context *ctx,
   const char *backend_url,
   TALER_MERCHANT_TemplatesGetCallback cb,
   void *cb_cls)
 {
   struct TALER_MERCHANT_TemplatesGetHandle *tgh;
   CURL *eh;
 
   tgh = GNUNET_new (struct TALER_MERCHANT_TemplatesGetHandle);
   tgh->ctx = ctx;
   tgh->cb = cb;
   tgh->cb_cls = cb_cls;
   tgh->url = TALER_url_join (backend_url,
                              "private/templates",
                              NULL);
   if (NULL == tgh->url)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Could not construct request URL.\n");
     GNUNET_free (tgh);
     return NULL;
   }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Requesting URL '%s'\n",
               tgh->url);
   eh = TALER_MERCHANT_curl_easy_get_ (tgh->url);
   tgh->job = GNUNET_CURL_job_add (ctx,
                                   eh,
                                   &handle_get_templates_finished,
                                   tgh);
   return tgh;
 }
 
 
 void
 TALER_MERCHANT_templates_get_cancel (
   struct TALER_MERCHANT_TemplatesGetHandle *tgh)
 {
   if (NULL != tgh->job)
     GNUNET_CURL_job_cancel (tgh->job);
   GNUNET_free (tgh->url);
   GNUNET_free (tgh);
 }