/*
  This file is part of TALER
  (C) 2022 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 taler-merchant-httpd_post-using-templates.c
 * @brief implementing POST /using-templates request handling
 * @author Priscilla HUANG
 */
#include "platform.h"
#include "taler-merchant-httpd_post-using-templates.h"
#include "taler-merchant-httpd_private-post-orders.h"
#include "taler-merchant-httpd_helper.h"
#include <taler/taler_json_lib.h>


MHD_RESULT
TMH_post_using_templates_ID (const struct TMH_RequestHandler *rh,
                             struct MHD_Connection *connection,
                             struct TMH_HandlerContext *hc)
{
  struct TMH_MerchantInstance *mi = hc->instance;
  MHD_RESULT mret;
  const char *template_id = hc->infix;
  const char *summary = NULL;
  const char *fulfillment_url = NULL;
  const char *fulfillment_message = NULL;
  struct TALER_Amount amount;
  bool no_amount;
  json_t *fake_body;
  bool no_summary;
  struct TALER_MERCHANTDB_TemplateDetails etp;

  struct GNUNET_JSON_Specification spec[] = {
    GNUNET_JSON_spec_mark_optional (
      GNUNET_JSON_spec_string ("summary",
                               &summary),
      NULL),
    GNUNET_JSON_spec_mark_optional (
      TALER_JSON_spec_amount ("amount",
                              TMH_currency,
                              &amount),
      &no_amount),
    GNUNET_JSON_spec_end ()
  };

  {
    enum GNUNET_GenericReturnValue res;

    res = TALER_MHD_parse_json_data (connection,
                                     hc->request_body,
                                     spec);
    if (GNUNET_OK != res)
    {
      GNUNET_break_op (0);
      return (GNUNET_NO == res)
             ? MHD_YES
             : MHD_NO;
    }
  }

  {
    enum GNUNET_DB_QueryStatus qs;

    qs = TMH_db->lookup_template (TMH_db->cls,
                                  mi->settings.id,
                                  template_id,
                                  &etp);
    switch (qs)
    {
    case GNUNET_DB_STATUS_HARD_ERROR:
      /* Clean up and fail hard */
      GNUNET_break (0);
      GNUNET_JSON_parse_free (spec);
      return TALER_MHD_reply_with_error (connection,
                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
                                         TALER_EC_GENERIC_DB_FETCH_FAILED,
                                         NULL);
    case GNUNET_DB_STATUS_SOFT_ERROR:
      /* this should be impossible (single select) */
      GNUNET_break (0);
      GNUNET_JSON_parse_free (spec);
      return TALER_MHD_reply_with_error (connection,
                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
                                         TALER_EC_GENERIC_DB_FETCH_FAILED,
                                         NULL);
    case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
      /* template not found! */
      GNUNET_JSON_parse_free (spec);
      return TALER_MHD_reply_with_error (connection,
                                         MHD_HTTP_NOT_FOUND,
                                         TALER_EC_MERCHANT_GENERIC_TEMPLATE_UNKNOWN,
                                         template_id);
    case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
      /* all good */
      break;
    } /* End of the switch */
  }

  const char *tsummary;
  uint32_t min_age;
  struct GNUNET_TIME_Relative pay_duration;
  struct TALER_Amount tamount;
  bool no_tamount;

  struct GNUNET_JSON_Specification tspec[] = {
    GNUNET_JSON_spec_mark_optional (
      GNUNET_JSON_spec_string ("summary",
                               &tsummary),
      NULL),
    GNUNET_JSON_spec_mark_optional (
      TALER_JSON_spec_amount ("amount",
                              TMH_currency,
                              &tamount),
      &no_tamount),
    GNUNET_JSON_spec_uint32 ("minimum_age",
                             &min_age),
    GNUNET_JSON_spec_relative_time ("pay_duration",
                                    &pay_duration),
    GNUNET_JSON_spec_end ()
  };

  {
    enum GNUNET_GenericReturnValue res;
    const char *err_name;
    unsigned int err_line;

    res = GNUNET_JSON_parse (etp.template_contract,
                             tspec,
                             &err_name,
                             &err_line);
    if (GNUNET_OK != res)
    {
      GNUNET_break (0);
      json_dumpf (etp.template_contract,
                  stderr,
                  JSON_INDENT (2));
      GNUNET_JSON_parse_free (spec);
      return TALER_MHD_reply_with_error (connection,
                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
                                         TALER_EC_GENERIC_DB_FETCH_FAILED,
                                         err_name);
    }
  }

  // if amount given in template AND request
  if ((! no_amount) && (! no_tamount))
  {
    GNUNET_JSON_parse_free (spec);
    return TALER_MHD_reply_with_error (connection,
                                       MHD_HTTP_CONFLICT,
                                       TALER_EC_MERCHANT_POST_USING_TEMPLATES_AMOUNT_CONFLICT_TEMPLATES_CONTRACT_AMOUNT,
                                       NULL);
  }

  // if there is no amount in template and request
  if (no_amount && no_tamount)
  {
    GNUNET_JSON_parse_free (spec);
    return TALER_MHD_reply_with_error (connection,
                                       MHD_HTTP_CONFLICT,
                                       TALER_EC_MERCHANT_POST_USING_TEMPLATES_NO_AMOUNT,
                                       NULL);
  }

  if ( (NULL!=summary) && (NULL != tsummary))
  {

    GNUNET_JSON_parse_free (spec);
    return TALER_MHD_reply_with_error (connection,
                                       MHD_HTTP_CONFLICT,
                                       TALER_EC_MERCHANT_POST_USING_TEMPLATES_SUMMARY_CONFLICT_TEMPLATES_CONTRACT_SUBJECT,
                                       NULL);
  }

  // if there is no summary in template and request
  if ( (NULL == summary) && (NULL == tsummary) )
  {
    GNUNET_JSON_parse_free (spec);
    return TALER_MHD_reply_with_error (connection,
                                       MHD_HTTP_CONFLICT,
                                       TALER_EC_MERCHANT_POST_USING_TEMPLATES_NO_SUMMARY,
                                       NULL);
  }
  no_summary = (NULL == summary);
  fake_body = GNUNET_JSON_PACK (
    GNUNET_JSON_pack_object_steal ("order",
                                   GNUNET_JSON_PACK (
                                     TALER_JSON_pack_amount ("amount",
                                                             no_amount ?
                                                             &tamount :
                                                             &amount),
                                     GNUNET_JSON_pack_string ("summary",
                                                              no_summary ?
                                                              tsummary :
                                                              summary),
                                     GNUNET_JSON_pack_allow_null (
                                       GNUNET_JSON_pack_string (
                                         "fulfillment_url",
                                         fulfillment_url)),
                                     GNUNET_JSON_pack_allow_null (
                                       GNUNET_JSON_pack_string (
                                         "fulfillment_message",
                                         fulfillment_message))
                                     ))
    );
  TALER_MERCHANTDB_template_details_free (&etp);
  {
    struct TMH_HandlerContext fake_hc = {
      .request_body = fake_body,
      .instance = hc->instance
    };

    mret = TMH_private_post_orders (NULL, /* not even used */
                                    connection,
                                    &fake_hc);
  }
  json_decref (fake_body);
  return mret;
}