/* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

   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; version 2 of the License.

   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, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

DROP PROCEDURE IF EXISTS ps_setup_reload_saved;

DELIMITER $$

CREATE DEFINER='root'@'localhost' PROCEDURE ps_setup_reload_saved ()
    COMMENT '
             Description
             -----------

             Reloads a saved Performance Schema configuration,
             so that you can alter the setup for debugging purposes, 
             but restore it to a previous state.
             
             Use the companion procedure - ps_setup_save(), to 
             save a configuration.

             Requires the SUPER privilege for "SET sql_log_bin = 0;".

             Parameters
             -----------

             None.

             Example
             -----------

             mysql> CALL sys.ps_setup_save();
             Query OK, 0 rows affected (0.08 sec)

             mysql> UPDATE performance_schema.setup_instruments SET enabled = \'YES\', timed = \'YES\';
             Query OK, 547 rows affected (0.40 sec)
             Rows matched: 784  Changed: 547  Warnings: 0

             /* Run some tests that need more detailed instrumentation here */

             mysql> CALL sys.ps_setup_reload_saved();
             Query OK, 0 rows affected (0.32 sec)
            '
    SQL SECURITY INVOKER
    NOT DETERMINISTIC
    MODIFIES SQL DATA
BEGIN
    DECLARE v_done bool DEFAULT FALSE;
    DECLARE v_lock_result INT;
    DECLARE v_lock_used_by BIGINT;
    DECLARE v_signal_message TEXT;
    DECLARE EXIT HANDLER FOR SQLEXCEPTION
    BEGIN
        SIGNAL SQLSTATE VALUE '90001'
           SET MESSAGE_TEXT = 'An error occurred, was sys.ps_setup_save() run before this procedure?';
    END;

    SET @log_bin := @@sql_log_bin;
    SET sql_log_bin = 0;

    SELECT IS_USED_LOCK('sys.ps_setup_save') INTO v_lock_used_by;

    IF (v_lock_used_by != CONNECTION_ID()) THEN
        SET v_signal_message = CONCAT('The sys.ps_setup_save lock is currently owned by ', v_lock_used_by);
        SIGNAL SQLSTATE VALUE '90002'
           SET MESSAGE_TEXT = v_signal_message;
    END IF;

    DELETE FROM performance_schema.setup_actors;
    INSERT INTO performance_schema.setup_actors SELECT * FROM tmp_setup_actors;

    BEGIN
        /* Workaround for http://bugs.mysql.com/bug.php?id=70025 */
        DECLARE v_name varchar(64);
        DECLARE v_enabled enum('YES', 'NO');
        DECLARE c_consumers CURSOR FOR SELECT NAME, ENABLED FROM tmp_setup_consumers;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET v_done = TRUE;

        SET v_done = FALSE;
        OPEN c_consumers;
        c_consumers_loop: LOOP
            FETCH c_consumers INTO v_name, v_enabled;
            IF v_done THEN
               LEAVE c_consumers_loop;
            END IF;

            UPDATE performance_schema.setup_consumers
               SET ENABLED = v_enabled
             WHERE NAME = v_name;
         END LOOP;
         CLOSE c_consumers;
    END;

    UPDATE performance_schema.setup_instruments
     INNER JOIN tmp_setup_instruments USING (NAME)
       SET performance_schema.setup_instruments.ENABLED = tmp_setup_instruments.ENABLED,
           performance_schema.setup_instruments.TIMED   = tmp_setup_instruments.TIMED;
    BEGIN
        /* Workaround for http://bugs.mysql.com/bug.php?id=70025 */
        DECLARE v_thread_id bigint unsigned;
        DECLARE v_instrumented enum('YES', 'NO');
        DECLARE c_threads CURSOR FOR SELECT THREAD_ID, INSTRUMENTED FROM tmp_threads;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET v_done = TRUE;

        SET v_done = FALSE;
        OPEN c_threads;
        c_threads_loop: LOOP
            FETCH c_threads INTO v_thread_id, v_instrumented;
            IF v_done THEN
               LEAVE c_threads_loop;
            END IF;

            UPDATE performance_schema.threads
               SET INSTRUMENTED = v_instrumented
             WHERE THREAD_ID = v_thread_id;
        END LOOP;
        CLOSE c_threads;
    END;

    UPDATE performance_schema.threads
       SET INSTRUMENTED = IF(PROCESSLIST_USER IS NOT NULL,
                             sys.ps_is_account_enabled(PROCESSLIST_HOST, PROCESSLIST_USER),
                             'YES')
     WHERE THREAD_ID NOT IN (SELECT THREAD_ID FROM tmp_threads);

    DROP TEMPORARY TABLE tmp_setup_actors;
    DROP TEMPORARY TABLE tmp_setup_consumers;
    DROP TEMPORARY TABLE tmp_setup_instruments;
    DROP TEMPORARY TABLE tmp_threads;

    SELECT RELEASE_LOCK('sys.ps_setup_save') INTO v_lock_result;

    SET sql_log_bin = @log_bin; 
END$$

DELIMITER ;