#!/usr/bin/env python3
# =============================================================================
# Minimal client-side reproduction: run the stored function and procedure via
# the server-side prepared protocol (COM_STMT_EXECUTE), which triggers the
# per-sub-statement audit-event multiplication. 
#
# Example:
#   pip install mysql-connector-python
#   DB_PASSWORD=secret python3 run_repro.py --host 127.0.0.1 --user root
#
# Prerequisites (create the schema used by this script):
#
#   CREATE DATABASE audit_test;
#   USE audit_test;
#   CREATE TABLE t (id INT PRIMARY KEY);
#
#   DELIMITER //
#   CREATE PROCEDURE test_proc(IN p_id INT)
#   BEGIN
#     INSERT INTO t(id) VALUES (p_id);
#     SELECT COUNT(*) INTO @c FROM t WHERE id = p_id;
#     UPDATE t SET id = p_id;
#     DELETE FROM t;
#   END//
#   CREATE FUNCTION test_fn(p INT) RETURNS INT DETERMINISTIC
#   BEGIN
#     DECLARE r1 INT; DECLARE r2 INT; DECLARE r3 INT;
#     SELECT 1 INTO r1;
#     SELECT 2 INTO r2;
#     SELECT 3 INTO r3;
#     RETURN r1 + r2 + r3 + p;
#   END//
#   DELIMITER ;
# =============================================================================

import argparse
import os

import mysql.connector


def parse_args():
    p = argparse.ArgumentParser(description="Run test_fn and test_proc via prepared protocol.")
    p.add_argument("--host", default=os.getenv("DB_HOST", "127.0.0.1"))
    p.add_argument("--port", type=int, default=int(os.getenv("DB_PORT", "3306")))
    p.add_argument("--user", default=os.getenv("DB_USER", "root"))
    p.add_argument("--password", default=os.getenv("DB_PASSWORD", ""))
    p.add_argument("--database", default=os.getenv("DB_NAME", "audit_test"))
    return p.parse_args()


def drain(cur):
    """Consume any result set(s) so the next execute won't hit 'Unread result found'."""
    while True:
        try:
            cur.fetchall()
        except mysql.connector.Error:
            pass
        try:
            if not cur.nextset():
                break
        except mysql.connector.Error:
            break


args = parse_args()

cnx = mysql.connector.connect(
    host=args.host,
    port=args.port,
    user=args.user,
    password=args.password,
    database=args.database,
)

cur = cnx.cursor(prepared=True)     # server-side prepared -> COM_STMT_EXECUTE

cur.execute("SELECT test_fn(?)", (1,))
drain(cur)

cur.execute("CALL test_proc(?)", (1,))
drain(cur)

cur.close()
cnx.commit()
cnx.close()