/**

 * 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);

}