merchant

Merchant backend to process payments, run by merchants
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lookup_categories.c (4542B)

      1 /*
      2    This file is part of TALER
      3    Copyright (C) 2024 Taler Systems SA
      4 
      5    TALER is free software; you can redistribute it and/or modify it under the
      6    terms of the GNU General Public License as published by the Free Software
      7    Foundation; either version 3, or (at your option) any later version.
      8 
      9    TALER is distributed in the hope that it will be useful, but WITHOUT ANY
     10    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     11    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
     12 
     13    You should have received a copy of the GNU General Public License along with
     14    TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
     15  */
     16 /**
     17  * @file src/backenddb/lookup_categories.c
     18  * @brief Implementation of the lookup_categories function for Postgres
     19  * @author Christian Grothoff
     20  */
     21 #include "platform.h"
     22 #include <taler/taler_pq_lib.h>
     23 #include "merchant-database/lookup_categories.h"
     24 #include "helper.h"
     25 
     26 
     27 /**
     28  * Context used for TALER_MERCHANTDB_lookup_categories().
     29  */
     30 struct LookupCategoryContext
     31 {
     32   /**
     33    * Function to call with the results.
     34    */
     35   TALER_MERCHANTDB_CategoriesCallback cb;
     36 
     37   /**
     38    * Closure for @a cb.
     39    */
     40   void *cb_cls;
     41 
     42   /**
     43    * Did database result extraction fail?
     44    */
     45   bool extract_failed;
     46 };
     47 
     48 
     49 /**
     50  * Function to be called with the results of a SELECT statement
     51  * that has returned @a num_results results about otp_device.
     52  *
     53  * @param[in,out] cls of type `struct LookupCategoryContext *`
     54  * @param result the postgres result
     55  * @param num_results the number of results in @a result
     56  */
     57 static void
     58 lookup_categories_cb (void *cls,
     59                       PGresult *result,
     60                       unsigned int num_results)
     61 {
     62   struct LookupCategoryContext *tlc = cls;
     63 
     64   for (unsigned int i = 0; i < num_results; i++)
     65   {
     66     uint64_t category_id;
     67     char *category_name;
     68     json_t *category_name_i18n;
     69     uint64_t product_count;
     70     struct GNUNET_PQ_ResultSpec rs[] = {
     71       GNUNET_PQ_result_spec_uint64 ("category_serial",
     72                                     &category_id),
     73       GNUNET_PQ_result_spec_string ("category_name",
     74                                     &category_name),
     75       TALER_PQ_result_spec_json ("category_name_i18n",
     76                                  &category_name_i18n),
     77       GNUNET_PQ_result_spec_uint64 ("product_count",
     78                                     &product_count),
     79       GNUNET_PQ_result_spec_end
     80     };
     81 
     82     if (GNUNET_OK !=
     83         GNUNET_PQ_extract_result (result,
     84                                   rs,
     85                                   i))
     86     {
     87       GNUNET_break (0);
     88       tlc->extract_failed = true;
     89       return;
     90     }
     91     tlc->cb (tlc->cb_cls,
     92              category_id,
     93              category_name,
     94              category_name_i18n,
     95              product_count);
     96     GNUNET_PQ_cleanup_result (rs);
     97   }
     98 }
     99 
    100 
    101 enum GNUNET_DB_QueryStatus
    102 TALER_MERCHANTDB_lookup_categories (
    103   struct TALER_MERCHANTDB_PostgresContext *pg,
    104   const char *instance_id,
    105   TALER_MERCHANTDB_CategoriesCallback cb,
    106   void *cb_cls)
    107 {
    108   struct LookupCategoryContext tlc = {
    109     .cb = cb,
    110     .cb_cls = cb_cls,
    111     /* Can be overwritten by the lookup_categories_cb */
    112     .extract_failed = false,
    113   };
    114   struct GNUNET_PQ_QueryParam params[] = {
    115     GNUNET_PQ_query_param_end
    116   };
    117   enum GNUNET_DB_QueryStatus qs;
    118 
    119   GNUNET_assert (NULL != pg->current_merchant_id);
    120   GNUNET_assert (0 == strcmp (instance_id,
    121                               pg->current_merchant_id));
    122   check_connection (pg);
    123   TMH_PQ_prepare_anon (pg,
    124                        "SELECT"
    125                        " mc.category_serial"
    126                        ",mc.category_name"
    127                        ",mc.category_name_i18n::TEXT"
    128                        ",COALESCE(COUNT(mpc.product_serial),0)"
    129                        "   AS product_count"
    130                        " FROM merchant_categories mc"
    131                        " LEFT JOIN merchant_product_categories mpc"
    132                        "   USING (category_serial)"
    133                        " GROUP BY mc.category_serial"
    134                        " ORDER BY mc.category_serial;");
    135   qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
    136                                              "",
    137                                              params,
    138                                              &lookup_categories_cb,
    139                                              &tlc);
    140   /* If there was an error inside lookup_categories_cb, return a hard error. */
    141   if (tlc.extract_failed)
    142     return GNUNET_DB_STATUS_HARD_ERROR;
    143   return qs;
    144 }