/* This file is part of guile-sql.
   Copyright (C) 2002, 2004, 2005 Sergey Poznyakoff

   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/>. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <string.h>
#include <guile-sql.h>
#include <mysql/mysql.h>

static SCM
s_mysql_mark(struct sql_connect *conn)
{
	return SCM_BOOL_F;
}

static scm_sizet
s_mysql_free(struct sql_connect *conn)
{
	MYSQL *mysql = (MYSQL*) conn->data;
	if (!mysql)
		return 0;
	mysql_close(mysql);
	return sizeof(MYSQL);
}

static SCM
s_mysql_connect (const char *hostname, int port,
		 const char *dbname, const char *user, const char *pass,
		 const char *why)
{
	MYSQL *mysql;
	SCM smob;
	struct sql_connect *conn;
	const char *socket_path = NULL;
	
	mysql = mysql_init(NULL);
	if (!mysql) 
		scm_throw(gsql_error,
			  scm_list_2(scm_makfrom0str("mysql_init() failed"),
				     scm_makfrom0str("")));

	if (hostname[0] == '/') {
		socket_path = hostname;
		hostname = "localhost";
	}
	if (!mysql_real_connect(mysql, hostname,
				user, pass, dbname,
				port, socket_path, 0)) {
		SCM args = scm_list_2(scm_makfrom0str("Cannot connect to the database"),
				      scm_makfrom0str(mysql_error(mysql)));
		mysql_close(mysql);
		scm_throw(gsql_error, args);
	}
	
	smob = sql_connect_create("mysql");
	conn = (struct sql_connect *)SCM_CDR(smob);
	conn->data = mysql;
	return smob;
}

static SCM
s_mysql_query(struct sql_connect *conn, const char *query)
{
	MYSQL *mysql = conn->data;
	MYSQL_RES *result;
	SCM cell;
	
	if (mysql_query(mysql, query))
		scm_throw(gsql_error, scm_list_2(scm_makfrom0str("Error executing MySQL query"),
						 scm_makfrom0str(mysql_error(mysql))));

	result = mysql_store_result(mysql);

	if (result) {
		int nfields = mysql_num_fields(result);
		int nrows = mysql_num_rows(result);
		int i, j;
		SCM row_head = SCM_EOL, row_tail;

		for (i = 0; i < nrows; i++) {
			SCM new_row;
			SCM head = SCM_EOL, tail;
			MYSQL_ROW row = mysql_fetch_row(result);

			if (!row)
				break;
			for (j = 0; j < nfields; j++) {
				SCM new_elt = scm_cons(scm_makfrom0str(row[j]),
						       SCM_EOL);
				if (head == SCM_EOL)
					head = new_elt;
				else
					SCM_SETCDR(tail, new_elt);
				tail = new_elt;
			}

			new_row = scm_cons(head, SCM_EOL);
			if (row_head == SCM_EOL) 
				row_head = new_row;
			else 
				SCM_SETCDR(row_tail, new_row);
			row_tail = new_row;
		}
		cell = row_head;
		mysql_free_result(result);
	} else { /* should it have returned something? */ 
		if (mysql_field_count(mysql) == 0) {
			cell = scm_makenum(mysql_affected_rows(mysql));
		} else { /* mysql_store_result() should have returned data */
			scm_throw(gsql_error,
				  scm_list_2(scm_makfrom0str("Query should have returned data"),
					     scm_makfrom0str(mysql_error(mysql))));
		}
	}
	return cell;
}

static void
s_mysql_close(struct sql_connect *conn)
{
	if (conn->data)
		mysql_close(conn->data);
	conn->data = NULL;
}

struct sql_iface mysql_iface = {
	"mysql",
	s_mysql_mark,
	s_mysql_free,
	s_mysql_connect,
	s_mysql_close,
	s_mysql_query,
};