/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * This program 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 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 General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "db-mysql.h"
#include <mysql/errmsg.h>
#include <mysql/mysqld_error.h>
#include <sys/socket.h>
#include <stdlib.h>

/**
 * SECTION: db-mysql
 * @Short_description: manages a connection to a PostgreSQL database.
 * @Title: DbMysql
 * @See_also: #DbConn
 * 
 * This class manages a connection to a MySQL database internally. This 
 * is accessed through the #DbConn class to internally connect, query and
 * disconnect the database.
 **/
G_DEFINE_TYPE (DbMysql, db_mysql, DB_TYPE_PLUGIN);

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static void db_mysql_close (DbMysql * obj)
{
	if (obj->mysql)
	{
		g_free (obj->host);
		g_free (obj->user);
		g_free (obj->pass);
		obj->host = NULL;
		obj->user = NULL;
		obj->pass = NULL;

		mysql_close (obj->mysql);
		obj->mysql = NULL;
		obj->thread_id = 0;
		obj->socket = -1;
		obj->is_open = FALSE;
	}
}

static gboolean db_mysql_open (DbMysql * obj, const gchar * host,
	const gchar * schema, const gchar * user, const gchar * pass, GError ** err)
{
	if (!obj->mysql)
		obj->mysql = mysql_init (NULL); 

	if (!obj->mysql)
	{
		g_set_error (err
			,DB_CONN_LOG_DOMAIN
			,DB_CONN_ERROR_OPENING
			,_("Can't allocate the needed memory") 
		);
		return FALSE;
	}

	if (!mysql_real_connect (obj->mysql, host, user, pass, schema, 0, NULL, CLIENT_MULTI_STATEMENTS))
	{
		gint error_code;
		
		switch (mysql_errno (obj->mysql))
		{
			case ER_ACCESS_DENIED_ERROR:
				error_code = DB_CONN_ERROR_BAD_LOGIN;
				break;			
			default:
				error_code = DB_CONN_ERROR_OPENING;
		}

		g_set_error (err
			,DB_CONN_ERROR_OPENING
			,error_code
			,"%s", mysql_error (obj->mysql)
		);
		db_mysql_close (obj);
		return FALSE;
	}

	obj->host = g_strdup (host);
	obj->user = g_strdup (user);
	obj->pass = g_strdup (pass);
	obj->socket = obj->mysql->net.fd;
	obj->thread_id = mysql_thread_id (obj->mysql);
	obj->is_open = TRUE;
	
	mysql_set_character_set (obj->mysql, "utf8");
	return TRUE;
}

static void db_mysql_set_ssl (DbMysql * obj, const gchar * ca)
{
	if (!obj->mysql)
		obj->mysql = mysql_init (NULL);

	mysql_ssl_set (obj->mysql, NULL, NULL, ca, NULL, NULL);
}

static void db_mysql_set_value (GValue * value, GType type, const gchar * string, gsize len)
{
	if (!string)
	{
		g_value_init (value, GVN_TYPE_NULL);
		return;
	}
	
	g_value_init (value, type);

	switch (type)
	{
		case G_TYPE_BOOLEAN:
			g_value_set_boolean (value, atoi (string));
			break;
		case G_TYPE_CHAR:
			g_value_set_schar (value, atoi (string));
			break;
		case G_TYPE_INT:
			g_value_set_int (value, atoi (string));
			break;
		case G_TYPE_UINT:
			g_value_set_int (value, (guint) atoi (string));
			break;
		case G_TYPE_LONG:
			g_value_set_long (value, g_ascii_strtoll (string, NULL, 0));
			break;
		case G_TYPE_ULONG:
			g_value_set_ulong (value, g_ascii_strtoull (string, NULL, 0));
			break;
		case G_TYPE_FLOAT:
			g_value_set_float (value, atof (string));
			break;
		case G_TYPE_DOUBLE:
			g_value_set_double (value, g_ascii_strtod (string, NULL));
			break;
		case G_TYPE_STRING:
			g_value_set_string (value, string);
			break;
		default:
		if (type == G_TYPE_DATE)
		{
			GDate * date = NULL;
		
			if (len >= 10)
			{
				GDateDay d = atoi (string + 8);
				GDateMonth m = atoi (string + 5);
				GDateYear y = atoi (string);
			
				if (g_date_valid_dmy (d, m, y))
					date = g_date_new_dmy (d, m, y);
			}
			
			g_value_take_boxed (value, date);
		}
		else if (type == G_TYPE_DATE_TIME)
		{
			GDateTime * date_time = NULL;
		
			if (len >= 19)
				date_time = g_date_time_new_local (
					 atoi (string)
					,atoi (string + 5)
					,atoi (string + 8)
					,atoi (string + 11)
					,atoi (string + 14)
					,atoi (string + 17)
				);
			
			g_value_take_boxed (value, date_time);
		}
		else if (type == G_TYPE_BYTES)
			g_value_take_boxed (value, g_bytes_new (string, len));
		else
			g_warning ("DbMysql: Can't handle this value type: %s",
				g_type_name (type));
	}
}

static DbResultSet * db_mysql_query (DbMysql * obj, const gchar * sql, GError ** err)
{	
	gint i, j;
	guint errno = 0;
	gulong * lengths;
	GValue def = {0};
	MYSQL_ROW myrow;
	MYSQL_RES * res;
	MYSQL_FIELD * field;
	DbRow * row;
	DbColumn * column;
	DbResult * result;
	DbResultSet * set = db_result_set_new ();

	if (!mysql_query (obj->mysql, sql))
	do {
		if ((res = mysql_store_result (obj->mysql)))
		{
			result = g_new (DbResult, 1);
			result->nrows = mysql_num_rows (res);
			result->ncols = mysql_num_fields (res);
			result->column = g_new (DbColumn, result->ncols);
			result->data = g_ptr_array_new_full (result->nrows + 1,
				(GDestroyNotify) db_row_free);
			set->results = g_slist_append (set->results, result);

			field = mysql_fetch_fields (res);
			
			GType gtypes[result->ncols];
	
			for (i = 0; i < result->ncols; i++)
			{
				column = &result->column[i];
				column->info = 0;
				column->name = g_strdup (field[i].org_name);
				column->alias = g_strdup (field[i].name);
				column->table = g_strdup (field[i].org_table);
				column->table_alias = g_strdup (field[i].table);
				
				switch (field[i].type)
				{
					case MYSQL_TYPE_TINY:
					case MYSQL_TYPE_INT24:
					case MYSQL_TYPE_LONG:
					case MYSQL_TYPE_SHORT:
					case MYSQL_TYPE_YEAR:
						gtypes[i] = G_TYPE_INT;
						break;
					case MYSQL_TYPE_LONGLONG:
						gtypes[i] = G_TYPE_LONG;
						break;				
					case MYSQL_TYPE_FLOAT:
						gtypes[i] = G_TYPE_FLOAT;
						break;				
					case MYSQL_TYPE_DOUBLE:
						gtypes[i] = G_TYPE_DOUBLE;
						break;				
					case MYSQL_TYPE_DATE:
						gtypes[i] = G_TYPE_DATE;
						break;
					case MYSQL_TYPE_DATETIME:
					case MYSQL_TYPE_TIMESTAMP:
						gtypes[i] = G_TYPE_DATE_TIME;
						break;
					case MYSQL_TYPE_BLOB:
						gtypes[i] = G_TYPE_BYTES;
						break;
					case MYSQL_TYPE_STRING:
					case MYSQL_TYPE_DECIMAL:
					case MYSQL_TYPE_NEWDECIMAL:
					case MYSQL_TYPE_VAR_STRING:
					case MYSQL_TYPE_TIME:
					case MYSQL_TYPE_SET:
					case MYSQL_TYPE_ENUM:
					case MYSQL_TYPE_NULL:
					default:
						gtypes[i] = G_TYPE_STRING;
				}

				if (field[i].flags & AUTO_INCREMENT_FLAG)
				{
					SqlObject * func = sql_function_new ("LAST_INSERT_ID", NULL);

					g_value_init (&def, SQL_TYPE_FUNCTION);
					g_value_take_object (&def, g_object_ref_sink (func));
				}
				else
					db_mysql_set_value (&def, gtypes[i], field[i].def, field[i].def_length);

				column->spec = gvn_param_spec_new_with_attrs (gtypes[i],
					FALSE, !(field[i].flags & NOT_NULL_FLAG), &def);
				g_value_unset (&def);

				if (field[i].flags & PRI_KEY_FLAG)
					column->info |= DB_COLUMN_PRI_KEY;
			}

			for (i = 0; (myrow = mysql_fetch_row (res)); i++)
			{
				lengths = mysql_fetch_lengths (res);
				row = db_row_new (result->ncols, i);
				g_ptr_array_add (result->data, row);

				for (j = 0; j < result->ncols; j++)
					db_mysql_set_value (&row->value[j], gtypes[j], myrow[j], lengths[j]);
			}

			mysql_free_result (res);
		}
		else if (mysql_field_count (obj->mysql) == 0)
		{
			result = g_new (DbResult, 1);
			result->nrows = mysql_affected_rows (obj->mysql);
			result->ncols = 0;
			result->column = NULL;
			result->data = NULL;
			set->results = g_slist_append (set->results, result);
		}
	}
	while (mysql_more_results (obj->mysql) && !mysql_next_result (obj->mysql));

	if ((errno = mysql_errno (obj->mysql)))
	{
		switch (errno)
		{
			case CR_SERVER_LOST:
			case CR_SERVER_GONE_ERROR:
				errno = DB_CONN_ERROR_LOST;
				break;
			case CR_OUT_OF_MEMORY:
			case CR_COMMANDS_OUT_OF_SYNC:
				errno = DB_CONN_ERROR_QUERY_FATAL;
				break;
			case CR_UNKNOWN_ERROR:
			default:
				errno = DB_CONN_ERROR_UNKNOW;
		}

		g_set_error (err
			,DB_CONN_LOG_DOMAIN
			,errno
			,"%s", mysql_error (obj->mysql)
		);
		db_result_set_free (set);
		set = NULL;
	}

	return set;
}

static void db_mysql_kill_query (DbMysql * obj)
{
	if (obj->mysql)
	{
		gboolean killed = FALSE;
		MYSQL * new_conn = mysql_init (NULL);
	
		if (new_conn
		&& mysql_real_connect (new_conn, obj->host, obj->user, obj->pass, NULL, 0, NULL, 0))
		{
			gchar * sql = g_strdup_printf ("KILL QUERY %lu", obj->thread_id);

			if (!mysql_query (new_conn, sql))
			{
				MYSQL_RES * res = mysql_store_result (new_conn);
				mysql_free_result (res);
				killed = TRUE;
			}

			g_free (sql);
		}
		if (new_conn)
		{
			if (mysql_errno (new_conn))
				g_warning ("DbMysql: %s", mysql_error (new_conn));
		
			mysql_close (new_conn);
		}
		
		if (!killed && obj->socket != -1 && !shutdown (obj->socket, SHUT_RDWR))
			obj->socket = -1;
	}
}

static void db_mysql_value_render (SqlValue * obj, SqlRender * render, SqlBatch * batch)
{
	if (G_VALUE_TYPE (obj->value) == G_TYPE_BYTES)
	{
		gsize to_size;
		gsize from_size;
		GString * buffer = render->buffer;
		GBytes * bin = g_value_get_boxed (obj->value);
		const gchar * from = g_bytes_get_data (bin, &from_size);

		sql_render_add_espace (render);
		sql_render_append (render, "'");
		g_string_set_size (buffer, buffer->len + (from_size * 2 + 1));
		to_size = mysql_real_escape_string (
			DB_MYSQL (render->data)->mysql,
			&(buffer->str[buffer->len]), from, from_size
		);
		buffer->len += to_size;
		sql_render_append (render, "'");
	}
	else
		sql_object_render (SQL_OBJECT (obj), render, batch);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void db_mysql_init (DbMysql * obj)
{
	SqlRender * render = sql_render_new ('`');
	sql_render_register_function (render, SQL_TYPE_VALUE,
		(SqlRenderFunc) db_mysql_value_render);

	DB_PLUGIN (obj)->render = render;
	obj->mysql = NULL;
	obj->host = NULL;
	obj->user = NULL;
	obj->pass = NULL;
	obj->thread_id = 0;
	obj->socket = -1;
	obj->is_open = FALSE;
}

static void db_mysql_class_init (DbMysqlClass * k)
{
	DbPluginClass * klass = DB_PLUGIN_CLASS (k);
	klass->open = (DbPluginOpenFunc) db_mysql_open;
	klass->close = (DbPluginCloseFunc) db_mysql_close;
	klass->set_ssl = (DbPluginSetSSL) db_mysql_set_ssl;
	klass->query = (DbPluginQueryFunc) db_mysql_query;
	klass->kill_query = (DbPluginKillQueryFunc) db_mysql_kill_query;
}