/**
 * @file bug601.cpp regression case for bug 601 ("COM_CHANGE_USER fails with correct user/pwd if executed
 * during authentication")
 * - configure Maxscale.cnf to use only one thread
 * - in 100 parallel threads start to open/close session
 * - do change_user 2000 times
 * - check all change_user are ok
 * - check Mascale is alive
 */

/*
 *  Vilho Raatikka 2014-10-30 14:30:57 UTC
 *  If COM_CHANGE_USER is executed while backend protocol's state is not yet MYSQL_AUTH_RECV it will fail in
 * the backend.
 *
 *  If MaxScale uses multiple worked threads this occurs rarely and it would be possible to easily suspend
 * execution of COM_CHANGE_USER.
 *
 *  If MaxScale uses one worker thread then there's currently no way to suspend execution. It would require
 * thread to put current task on hold, complete authentication task and return to COM_CHANGE_USER execution.
 *
 *  In theory it is possible to add an event to client's DCB and let it become notified in the same way than
 * events that occur in sockets. It would have to be added first (not last) and ensure that no other command
 * is executed before it.
 *
 *  Since this is the only case known where this would be necessary, it could be enough to add a "pending auth
 * change" pointer in client's protocol object which would be checked before thread returns to epoll_wait
 * after completing the authentication.
 *  Comment 1 Massimiliano 2014-11-07 17:01:29 UTC
 *  Current code in develop branch let COM_CHANGE_USER work fine.
 *
 *  I noticed sometime a failed authentication issue using only.
 *  This because backend protocol's state is not yet MYSQL_AUTH_RECV and necessary data for succesfull backend
 * change user (such as scramble data from handshake) may be not available.
 *
 *
 *  I put a query before change_user and the issue doesn't appear: that's another proof.
 *  Comment 2 Vilho Raatikka 2014-11-13 15:54:15 UTC
 *  In gw_change_user->gw_send_change_user_to_backend authentication message was sent to backend server before
 * backend had its scramble data. That caused authentication to fail.
 *  Comment 3 Vilho Raatikka 2014-11-13 15:58:34 UTC
 *  if (func.auth ==)gw_change_user->gw_send_change_user_to_backend is called before backend has its scramble,
 * auth packet is set to backend's delauqueue instead of writing it to backend. When backend_write_delayqueue
 * is called COM_CHANGE_USER packets are rewritten with backend's current data.
 */


#include <iostream>
#include "testconnections.h"

using namespace std;

pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER;
int exit_flag = 0;

TestConnections* Test;

void* parall_traffic(void* ptr);


int main(int argc, char* argv[])
{
    int iterations = 1000;
    Test = new TestConnections(argc, argv);
    if (Test->smoke)
    {
        iterations = 100;
    }


    pthread_t parall_traffic1[100];

    Test->set_timeout(60);
    Test->repl->connect();
    Test->repl->execute_query_all_nodes((char*) "set global max_connect_errors=1000;");
    Test->repl->execute_query_all_nodes((char*) "set global max_connections=1000;");

    Test->maxscales->connect_maxscale(0);
    Test->tprintf("Creating one user 'user@%%'");
    execute_query_silent(Test->maxscales->conn_rwsplit[0], (char*) "DROP USER user@'%'");
    Test->try_query(Test->maxscales->conn_rwsplit[0], (char*) "CREATE USER user@'%%' identified by 'pass2'");
    Test->try_query(Test->maxscales->conn_rwsplit[0], (char*) "GRANT SELECT ON test.* TO user@'%%';");
    Test->try_query(Test->maxscales->conn_rwsplit[0], (char*) "FLUSH PRIVILEGES;");

    Test->tprintf("Starting parallel thread which opens/closes session in the loop");

    for (int j = 0; j < 25; j++)
    {
        pthread_create(&parall_traffic1[j], NULL, parall_traffic, NULL);
    }

    Test->tprintf("Doing change_user in the loop");
    for (int i = 0; i < iterations; i++)
    {
        Test->set_timeout(15);
        Test->add_result(mysql_change_user(Test->maxscales->conn_rwsplit[0], "user", "pass2", (char*) "test"),
                         "change_user failed! %s", mysql_error(Test->maxscales->conn_rwsplit[0]));
        Test->add_result(mysql_change_user(Test->maxscales->conn_rwsplit[0], Test->maxscales->user_name,
                                           Test->maxscales->password,
                                           (char*) "test"), "change_user failed! %s",
                         mysql_error(Test->maxscales->conn_rwsplit[0]));
    }

    Test->tprintf("Waiting for all threads to finish");
    exit_flag = 1;
    for (int j = 0; j < 25; j++)
    {
        Test->set_timeout(30);
        pthread_join(parall_traffic1[j], NULL);
    }
    Test->tprintf("All threads are finished");
    Test->repl->flush_hosts();

    Test->tprintf("Change user to '%s' in order to be able to DROP user", Test->maxscales->user_name);
    Test->set_timeout(30);
    mysql_change_user(Test->maxscales->conn_rwsplit[0],
                      Test->maxscales->user_name,
                      Test->maxscales->password,
                      NULL);

    Test->tprintf("Dropping user", Test->maxscales->user_name);
    Test->try_query(Test->maxscales->conn_rwsplit[0], (char*) "DROP USER user@'%%';");
    Test->check_maxscale_alive(0);

    int rval = Test->global_result;
    delete Test;
    return rval;
}

void* parall_traffic(void* ptr)
{
    MYSQL* conn;
    while (exit_flag == 0)
    {
        conn = Test->maxscales->open_rwsplit_connection(0);
        mysql_close(conn);
        if (Test->backend_ssl)
        {
            sleep(1);
        }
    }
    return NULL;
}