/**

  * GMyth Library

  *

  * @file gmyth/gmyth_query.c

  * 

  * @brief <p> GMythQuery class provides a wrapper for accessing

  * the libmysqlclient funtions.

  *

  * Copyright (C) 2006 INdT - Instituto Nokia de Tecnologia.

  * @author Leonardo Sobral Cunha <leonardo.cunha@indt.org.br>

  *

  * 

  * This program 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 of the License, or

  * (at your option) any later version.

  *

  * This program 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 Lesser General Public License

  * along with this program; if not, write to the Free Software

  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  */

 #ifdef HAVE_CONFIG_H

 #include "config.h"

 #endif

 #include <stdlib.h>

 #include <stdio.h>

 #include "gmyth_query.h"

 #include "gmyth_debug.h"

 static void     gmyth_query_class_init(GMythQueryClass * klass);

 static void     gmyth_query_init(GMythQuery * object);

 static void     gmyth_query_dispose(GObject * object);

 static void     gmyth_query_finalize(GObject * object);

 static void     gmyth_query_print_error(MYSQL * conn, char *message);

 G_DEFINE_TYPE(GMythQuery, gmyth_query, G_TYPE_OBJECT)

     static void     gmyth_query_class_init(GMythQueryClass * klass)

 {

     GObjectClass   *gobject_class;

     gobject_class = (GObjectClass *) klass;

     gobject_class->dispose = gmyth_query_dispose;

     gobject_class->finalize = gmyth_query_finalize;

 }

 static void

 gmyth_query_init(GMythQuery * gmyth_query)

 {

     gmyth_query->backend_info = NULL;

     /*

      * initialize connection handler 

      */

     gmyth_query->conn = mysql_init(NULL);

     if (!(gmyth_query->conn))

         g_warning("[%s] MSQL structure not initialized", __FUNCTION__);

 }

 static void

 gmyth_query_dispose(GObject * object)

 {

     GMythQuery     *gmyth_query = GMYTH_QUERY(object);

     if (gmyth_query->backend_info) {

         g_object_unref(gmyth_query->backend_info);

         gmyth_query->backend_info = NULL;

     }

     G_OBJECT_CLASS(gmyth_query_parent_class)->dispose(object);

 }

 static void

 gmyth_query_finalize(GObject * object)

 {

     gmyth_query_disconnect(GMYTH_QUERY(object));

     G_OBJECT_CLASS(gmyth_query_parent_class)->finalize(object);

 }

 /** Creates a new instance of GMythQuery.

  *

  * @return a new instance of GMythQuery.

  */

 GMythQuery     *

 gmyth_query_new()

 {

     GMythQuery     *sql_query =

         GMYTH_QUERY(g_object_new(GMYTH_QUERY_TYPE, NULL));

     return sql_query;

 }

 gboolean

 gmyth_query_connect_with_timeout(GMythQuery * gmyth_query,

                                  GMythBackendInfo * backend_info,

                                  guint timeout)

 {

     g_return_val_if_fail(gmyth_query != NULL, FALSE);

     if (gmyth_query->conn == NULL)

         gmyth_query->conn = mysql_init(NULL);

     if (timeout != 0) {

       /*

        * sets connection timeout

        */

         mysql_options(gmyth_query->conn, MYSQL_OPT_CONNECT_TIMEOUT,

                       (gchar *) & timeout);

     }

     return gmyth_query_connect(gmyth_query, backend_info);

 }

 /** Connects to the Mysql database in the backend. The backend address

  * is loaded from the GMythBackendInfo instance.

  *

  * @param gmyth_query the GMythEPG instance to be connected.

  * @return true if connection was success, false if failed.

  */

 gboolean

 gmyth_query_connect(GMythQuery * gmyth_query,

                     GMythBackendInfo * backend_info)

 {

     g_return_val_if_fail(gmyth_query != NULL, FALSE);

     g_return_val_if_fail(backend_info != NULL, FALSE);

     g_return_val_if_fail(backend_info->hostname != NULL, FALSE);

     g_return_val_if_fail(backend_info->username != NULL, FALSE);

     g_return_val_if_fail(backend_info->password != NULL, FALSE);

     g_return_val_if_fail(backend_info->db_name != NULL, FALSE);

     if (gmyth_query->backend_info != NULL) {

         g_object_unref(gmyth_query->backend_info);

     }

     gmyth_query->backend_info = g_object_ref(backend_info);

     if (gmyth_query->conn == NULL) {

         gmyth_query->conn = mysql_init(NULL);

     }

     /*

      * connect to server

      */

     if (mysql_real_connect(gmyth_query->conn,

                            gmyth_query->backend_info->hostname,

                            gmyth_query->backend_info->username,

                            gmyth_query->backend_info->password,

                            gmyth_query->backend_info->db_name, 

                            gmyth_query->backend_info->db_port, 

                            NULL,

                            0) == NULL) {

         gmyth_query_print_error(gmyth_query->conn,

                                 "mysql_real_connect() failed");

         return FALSE;

     }

     gmyth_debug

         ("[%s] Connection to Mysql server succeeded! (host = %s, user = %s, "

          "password = %s, db name = %s)", __FUNCTION__,

          gmyth_query->backend_info->hostname,

          gmyth_query->backend_info->username,

          gmyth_query->backend_info->password,

          gmyth_query->backend_info->db_name);

     return TRUE;

 }

 gboolean

 gmyth_query_is_alive (GMythQuery *gmyth_query) 

 {

     g_return_val_if_fail (gmyth_query != NULL, FALSE);

     if (gmyth_query->conn == NULL)

         return FALSE;

     return (mysql_ping (gmyth_query->conn) == 0);

 }

 /** Disconnects from the Mysql database in the backend.

  * 

  * @param gmyth_query the GMythQuery instance to be disconnected

  * @return true if disconnection was success, false if failed.

  */

 gboolean

 gmyth_query_disconnect(GMythQuery * gmyth_query)

 {

     g_return_val_if_fail(gmyth_query != NULL, FALSE);

     if (gmyth_query->conn == NULL)

         return TRUE;

     /*

      * TODO: Check how to return error 

      */

     gmyth_debug("[%s] Closing gmyth_query->conn", __FUNCTION__);

     mysql_close(gmyth_query->conn);

     gmyth_query->conn = NULL;

     return TRUE;

 }

 static void

 gmyth_query_print_error(MYSQL * conn, char *message)

 {

     gmyth_debug("%s", message);

     if (conn != NULL) {

 #if MYSQL_VERSION_ID >= 40101

         gmyth_debug("Error %u (%s): %s\n",

                     mysql_errno(conn), mysql_sqlstate(conn),

                     mysql_error(conn));

 #else

         gmyth_debug("Error %u: %s\n", mysql_errno(conn),

                     mysql_error(conn));

 #endif

     }

 }

 /** Sends the given query to the backend returning the query result as

  * MYSQL_RES pointer.

  * 

  * FIXME: this function is returning NULL whether any error happens

  * or no rows are returned (e.g. UPDATE or REPLACE).

  * 

  * @param gmyth_query the GMythQuery instance.

  * @param stmt_str the query text.

  * @return the MYSQL_RES result pointer or NULL if any error happens.

  */

 MYSQL_RES*

 gmyth_query_process_statement(GMythQuery * gmyth_query, char *stmt_str)

 {

     g_return_val_if_fail(gmyth_query != NULL, NULL);

     gmyth_debug("[%s] Running mysql query %s", __FUNCTION__, stmt_str);

     //the statement failed

     if (gmyth_query->conn == NULL ||

       mysql_query(gmyth_query->conn, stmt_str) != 0) {

         gmyth_query_print_error(gmyth_query->conn,

                                 "Could not execute statement");

         return NULL;

     }

     //the statement succeeded; determine whether it returned data

     return mysql_store_result(gmyth_query->conn);

 }

 MYSQL_RES*

 gmyth_query_process_statement_with_increment(GMythQuery * gmyth_query,

                                              char *stmt_str, gulong * id)

 {

     g_return_val_if_fail(gmyth_query != NULL, NULL);

     gmyth_debug("[%s] Running mysql query %s", __FUNCTION__, stmt_str);

     /*

      * the statement failed

      */

     if (gmyth_query->conn == NULL ||

       mysql_query(gmyth_query->conn, stmt_str) != 0) {

         gmyth_query_print_error(gmyth_query->conn,

                                 "Could not execute statement");

         return NULL;

     }

     *id = (my_ulonglong) mysql_insert_id(gmyth_query->conn);

     /*

      * the statement succeeded; determine whether it returned data 

      */

     return mysql_store_result(gmyth_query->conn);

 }