/*
   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 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 exchangedb/pg_preflight.c
 * @brief Implementation of the preflight function for Postgres
 * @author Christian Grothoff
 */
#include "platform.h"
#include "taler_error_codes.h"
#include "taler_dbevents.h"
#include "taler_pq_lib.h"
#include "pg_preflight.h"
#include "pg_helper.h"


/**
 * Connect to the database if the connection does not exist yet.
 *
 * @param pg the plugin-specific state
 * @param skip_prepare true if we should skip prepared statement setup
 * @return #GNUNET_OK on success
 */
enum GNUNET_GenericReturnValue
TEH_PG_internal_setup (struct PostgresClosure *pg,
                       bool skip_prepare);


enum GNUNET_GenericReturnValue
TEH_PG_preflight (void *cls)
{
  struct PostgresClosure *pg = cls;
  struct GNUNET_PQ_ExecuteStatement es[] = {
    GNUNET_PQ_make_execute ("ROLLBACK"),
    GNUNET_PQ_EXECUTE_STATEMENT_END
  };

  if (! pg->init)
  {
    if (GNUNET_OK !=
        TEH_PG_internal_setup (pg,
                               false))
      return GNUNET_SYSERR;
  }
  if (NULL == pg->transaction_name)
    return GNUNET_OK; /* all good */
  if (GNUNET_OK ==
      GNUNET_PQ_exec_statements (pg->conn,
                                 es))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "BUG: Preflight check rolled back transaction `%s'!\n",
                pg->transaction_name);
  }
  else
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "BUG: Preflight check failed to rollback transaction `%s'!\n",
                pg->transaction_name);
  }
  pg->transaction_name = NULL;
  return GNUNET_NO;
}