/*
 * This file is distributed as part of the MariaDB Corporation MaxScale.  It 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.
 *
 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Copyright MariaDB Corporation Ab 2013-2015
 */

#include <monitor_common.h>
#include <maxscale_pcre2.h>

monitor_event_t mon_name_to_event(char* tok);

/**
 * Set a pending status bit in the monitor server
 *
 * @param server        The server to update
 * @param bit           The bit to clear for the server
 */
void monitor_set_pending_status(MONITOR_SERVERS *ptr, int bit)
{
    ptr->pending_status |= bit;
}

/**
 * Clear a pending status bit in the monitor server
 *
 * @param server        The server to update
 * @param bit           The bit to clear for the server
 */
void monitor_clear_pending_status(MONITOR_SERVERS *ptr, int bit)
{
    ptr->pending_status &= ~bit;
}

monitor_event_t mon_get_event_type(MONITOR_SERVERS* node)
{
    unsigned int prev = node->mon_prev_status;

    if ((prev & (SERVER_MASTER | SERVER_RUNNING)) == (SERVER_MASTER | SERVER_RUNNING) &&
        SERVER_IS_DOWN(node->server))
    {
        return MASTER_DOWN_EVENT;
    }
    if ((prev & (SERVER_RUNNING)) == 0 &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_MASTER(node->server))
    {
        return MASTER_UP_EVENT;
    }
    if ((prev & (SERVER_SLAVE | SERVER_RUNNING)) == (SERVER_SLAVE | SERVER_RUNNING) &&
        SERVER_IS_DOWN(node->server))
    {
        return SLAVE_DOWN_EVENT;
    }
    if ((prev & (SERVER_RUNNING)) == 0 &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_SLAVE(node->server))
    {
        return SLAVE_UP_EVENT;
    }

    /** Galera specific events */
    if ((prev & (SERVER_JOINED | SERVER_RUNNING)) == (SERVER_JOINED | SERVER_RUNNING) &&
        SERVER_IS_DOWN(node->server))
    {
        return SYNCED_DOWN_EVENT;
    }
    if ((prev & (SERVER_RUNNING)) == 0 &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_JOINED(node->server))
    {
        return SYNCED_UP_EVENT;
    }

    /** NDB events*/
    if ((prev & (SERVER_NDB | SERVER_RUNNING)) == (SERVER_NDB | SERVER_RUNNING) &&
        SERVER_IS_DOWN(node->server))
    {
        return NDB_DOWN_EVENT;
    }
    if ((prev & (SERVER_RUNNING)) == 0 &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_NDB(node->server))
    {
        return NDB_UP_EVENT;
    }

    if ((prev & (SERVER_RUNNING)) == SERVER_RUNNING &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_MASTER(node->server))
    {
        return NEW_MASTER_EVENT;
    }
    if ((prev & (SERVER_RUNNING)) == SERVER_RUNNING &&
        SERVER_IS_RUNNING(node->server) && SERVER_IS_SLAVE(node->server))
    {
        return NEW_SLAVE_EVENT;
    }

    /** Status loss events */
    if ((prev & (SERVER_RUNNING | SERVER_MASTER)) == (SERVER_RUNNING | SERVER_MASTER) &&
        SERVER_IS_RUNNING(node->server) && !SERVER_IS_MASTER(node->server))
    {
        return LOST_MASTER_EVENT;
    }
    if ((prev & (SERVER_RUNNING | SERVER_SLAVE)) == (SERVER_RUNNING | SERVER_SLAVE) &&
        SERVER_IS_RUNNING(node->server) && !SERVER_IS_SLAVE(node->server))
    {
        return LOST_SLAVE_EVENT;
    }
    if ((prev & (SERVER_RUNNING | SERVER_JOINED)) == (SERVER_RUNNING | SERVER_JOINED) &&
        SERVER_IS_RUNNING(node->server) && !SERVER_IS_JOINED(node->server))
    {
        return LOST_SYNCED_EVENT;
    }
    if ((prev & (SERVER_RUNNING | SERVER_NDB)) == (SERVER_RUNNING | SERVER_NDB) &&
        SERVER_IS_RUNNING(node->server) && !SERVER_IS_NDB(node->server))
    {
        return LOST_NDB_EVENT;
    }


    /** Generic server failure */
    if ((prev & SERVER_RUNNING) == 0 &&
        SERVER_IS_RUNNING(node->server))
    {
        return SERVER_UP_EVENT;
    }
    if ((prev & SERVER_RUNNING) == SERVER_RUNNING &&
        SERVER_IS_DOWN(node->server))
    {
        return SERVER_DOWN_EVENT;
    }

    /** Something else, most likely a state that does not matter.
     * For example SERVER_DOWN -> SERVER_MASTER|SERVER_DOWN still results in a
     * server state equal to not running.*/
    return UNDEFINED_MONITOR_EVENT;
}

char* mon_get_event_name(MONITOR_SERVERS* node)
{
    switch (mon_get_event_type(node))
    {
        case UNDEFINED_MONITOR_EVENT:
            return "undefined";

        case MASTER_DOWN_EVENT:
            return "master_down";

        case MASTER_UP_EVENT:
            return "master_up";

        case SLAVE_DOWN_EVENT:
            return "slave_down";

        case SLAVE_UP_EVENT:
            return "slave_up";

        case SERVER_DOWN_EVENT:
            return "server_down";

        case SERVER_UP_EVENT:
            return "server_up";

        case SYNCED_DOWN_EVENT:
            return "synced_down";

        case SYNCED_UP_EVENT:
            return "synced_up";

        case DONOR_DOWN_EVENT:
            return "donor_down";

        case DONOR_UP_EVENT:
            return "donor_up";

        case NDB_DOWN_EVENT:
            return "ndb_down";

        case NDB_UP_EVENT:
            return "ndb_up";

        case LOST_MASTER_EVENT:
            return "lost_master";

        case LOST_SLAVE_EVENT:
            return "lost_slave";

        case LOST_SYNCED_EVENT:
            return "lost_synced";

        case LOST_DONOR_EVENT:
            return "lost_donor";

        case LOST_NDB_EVENT:
            return "lost_ndb";

        case NEW_MASTER_EVENT:
            return "new_master";

        case NEW_SLAVE_EVENT:
            return "new_slave";

        case NEW_SYNCED_EVENT:
            return "new_synced";

        case NEW_DONOR_EVENT:
            return "new_donor";

        case NEW_NDB_EVENT:
            return "new_ndb";

        default:
            return "MONITOR_EVENT_FAILURE";

    }


}

/**
 * Create a list of running servers
 * @param start Monitored servers
 * @param dest Destination where the string is formed
 * @param len Length of @c dest
 */
void mon_append_node_names(MONITOR_SERVERS* start, char* dest, int len)
{
    MONITOR_SERVERS* ptr = start;
    bool first = true;
    int slen = strlen(dest);
    char arr[MAX_SERVER_NAME_LEN + 32]; // Some extra space for port
    while (ptr && slen < len)
    {
        if (SERVER_IS_RUNNING(ptr->server))
        {
            if (!first)
            {
                strncat(dest, ",", len);
            }
            first = false;
            snprintf(arr, sizeof(arr), "%s:%d", ptr->server->name, ptr->server->port);
            strncat(dest, arr, len);
            slen = strlen(dest);
        }
        ptr = ptr->next;
    }
}

/**
 * Check if current monitored server status has changed
 *
 * @param mon_srv       The monitored server
 * @return              true if status has changed or false
 */
bool mon_status_changed(
                        MONITOR_SERVERS* mon_srv)
{
    bool succp;

    /** This is the first time the server was set with a status*/
    if (mon_srv->mon_prev_status == -1)
    {
        return false;
    }

    if (mon_srv->mon_prev_status != mon_srv->server->status)
    {
        succp = true;
    }
    else
    {
        succp = false;
    }
    return succp;
}

/**
 * Check if current monitored server has a loggable failure status
 *
 * @param mon_srv	The monitored server
 * @return		true if failed status can be logged or false
 */
bool mon_print_fail_status(
                           MONITOR_SERVERS* mon_srv)
{
    bool succp;
    int errcount = mon_srv->mon_err_count;

    if (SERVER_IS_DOWN(mon_srv->server) && errcount == 0)
    {
        succp = true;
    }
    else
    {
        succp = false;
    }
    return succp;
}

/**
 * Launch a script
 * @param mon Owning monitor
 * @param ptr The server which has changed state
 * @param script Script to execute
 */
void monitor_launch_script(MONITOR* mon, MONITOR_SERVERS* ptr, char* script)
{
    char nodelist[PATH_MAX + MON_ARG_MAX + 1] = {'\0'};
    char event[strlen(mon_get_event_name(ptr))];
    char initiator[strlen(ptr->server->name) + 24]; // Extra space for port

    snprintf(initiator, sizeof(initiator), "%s:%d", ptr->server->name, ptr->server->port);
    snprintf(event, sizeof(event), "%s", mon_get_event_name(ptr));
    mon_append_node_names(mon->databases, nodelist, PATH_MAX + MON_ARG_MAX);

    EXTERNCMD* cmd = externcmd_allocate(script);

    if (cmd == NULL)
    {
        skygw_log_write(LE, "Failed to initialize script: %s", script);
        return;
    }

    externcmd_substitute_arg(cmd, "[$]INITIATOR", initiator);
    externcmd_substitute_arg(cmd, "[$]EVENT", event);
    externcmd_substitute_arg(cmd, "[$]NODELIST", nodelist);

    if (externcmd_execute(cmd))
    {
        skygw_log_write(LOGFILE_ERROR,
                        "Error: Failed to execute script "
                        "'%s' on server state change event %s.",
                        script, mon_get_event_name(ptr));
    }
    externcmd_free(cmd);
}

/**
 * Parse a string of event names to an array with enabled events.
 * @param events Pointer to an array of boolean values
 * @param count Size of the array
 * @param string String to parse
 * @return 0 on success. 1 when an error has occurred or an unexpected event was
 * found.
 */
int mon_parse_event_string(bool* events, size_t count, char* string)
{
    char *tok, *saved;
    monitor_event_t event;

    tok = strtok_r(string, ",| ", &saved);

    if (tok == NULL)
    {
        return -1;
    }

    while (tok)
    {
        event = mon_name_to_event(tok);
        if (event == UNDEFINED_MONITOR_EVENT)
        {
            skygw_log_write(LE, "Error: Invalid event name %s", tok);
            return -1;
        }
        events[event] = true;
        tok = strtok_r(NULL, ",| ", &saved);
    }

    return 0;
}

monitor_event_t mon_name_to_event(char* tok)
{
    if (!strcasecmp("master_down", tok))
    {
        return MASTER_DOWN_EVENT;
    }
    else if (!strcasecmp("master_up", tok))
    {
        return MASTER_UP_EVENT;
    }
    else if (!strcasecmp("slave_down", tok))
    {
        return SLAVE_DOWN_EVENT;
    }
    else if (!strcasecmp("slave_up", tok))
    {
        return SLAVE_UP_EVENT;
    }
    else if (!strcasecmp("server_down", tok))
    {
        return SERVER_DOWN_EVENT;
    }
    else if (!strcasecmp("server_up", tok))
    {
        return SERVER_UP_EVENT;
    }
    else if (!strcasecmp("synced_down", tok))
    {
        return SYNCED_DOWN_EVENT;
    }
    else if (!strcasecmp("synced_up", tok))
    {
        return SYNCED_UP_EVENT;
    }
    else if (!strcasecmp("donor_down", tok))
    {
        return DONOR_DOWN_EVENT;
    }
    else if (!strcasecmp("donor_up", tok))
    {
        return DONOR_UP_EVENT;
    }
    else if (!strcasecmp("ndb_down", tok))
    {
        return NDB_DOWN_EVENT;
    }
    else if (!strcasecmp("ndb_up", tok))
    {
        return NDB_UP_EVENT;
    }
    else if (!strcasecmp("lost_master", tok))
    {
        return LOST_MASTER_EVENT;
    }
    else if (!strcasecmp("lost_slave", tok))
    {
        return LOST_SLAVE_EVENT;
    }
    else if (!strcasecmp("lost_synced", tok))
    {
        return LOST_SYNCED_EVENT;
    }
    else if (!strcasecmp("lost_donor", tok))
    {
        return LOST_DONOR_EVENT;
    }
    else if (!strcasecmp("lost_ndb", tok))
    {
        return LOST_NDB_EVENT;
    }
    else if (!strcasecmp("new_master", tok))
    {
        return NEW_MASTER_EVENT;
    }
    else if (!strcasecmp("new_slave", tok))
    {
        return NEW_SLAVE_EVENT;
    }
    else if (!strcasecmp("new_synced", tok))
    {
        return NEW_SYNCED_EVENT;
    }
    else if (!strcasecmp("new_donor", tok))
    {
        return NEW_DONOR_EVENT;
    }
    else if (!strcasecmp("new_ndb", tok))
    {
        return NEW_NDB_EVENT;
    }

    return UNDEFINED_MONITOR_EVENT;
}

/**
 * Connect to a database. This will always leave a valid database handle in the
 * database->con pointer. This allows the user to call MySQL C API functions to
 * find out the reason of the failure.
 * @param mon Monitor
 * @param database Monitored database
 * @return MONITOR_CONN_OK if the connection is OK else the reason for the failure
 */
connect_result_t mon_connect_to_db(MONITOR* mon, MONITOR_SERVERS *database)
{
    connect_result_t rval = MONITOR_CONN_OK;

    /** Return if the connection is OK */
    if (database->con && mysql_ping(database->con) == 0)
    {
        return rval;
    }

    int connect_timeout = mon->connect_timeout;
    int read_timeout = mon->read_timeout;
    int write_timeout = mon->write_timeout;
    char *uname = database->server->monuser ? database->server->monuser : mon->user;
    char *passwd = database->server->monpw ? database->server->monpw : mon->password;
    char *dpwd = decryptPassword(passwd);

    if (database->con)
    {
        mysql_close(database->con);
    }
    database->con = mysql_init(NULL);

    mysql_options(database->con, MYSQL_OPT_CONNECT_TIMEOUT, (void *) &connect_timeout);
    mysql_options(database->con, MYSQL_OPT_READ_TIMEOUT, (void *) &read_timeout);
    mysql_options(database->con, MYSQL_OPT_WRITE_TIMEOUT, (void *) &write_timeout);

    time_t start = time(NULL);
    bool result = (mysql_real_connect(database->con,
                                      database->server->name,
                                      uname,
                                      dpwd,
                                      NULL,
                                      database->server->port,
                                      NULL,
                                      0) != NULL);
    time_t end = time(NULL);

    if (!result)
    {
        if ((int) difftime(end, start) >= connect_timeout)
        {
            rval = MONITOR_CONN_TIMEOUT;
        }
        else
        {
            rval = MONITOR_CONN_REFUSED;
        }
    }

    free(dpwd);
    return rval;
}

/**
 * Log an error about the failure to connect to a backend server
 * and why it happened.
 * @param database Backend database
 * @param rval Return value of mon_connect_to_db
 */
void mon_log_connect_error(MONITOR_SERVERS* database, connect_result_t rval)
{
    if (rval == MONITOR_CONN_TIMEOUT)
    {
        skygw_log_write_flush(LOGFILE_ERROR,
                              "Error : Monitor timed out when connecting to "
                              "server %s:%d : \"%s\"",
                              database->server->name,
                              database->server->port,
                              mysql_error(database->con));
    }
    else
    {
        skygw_log_write_flush(LOGFILE_ERROR,
                              "Error : Monitor was unable to connect to "
                              "server %s:%d : \"%s\"",
                              database->server->name,
                              database->server->port,
                              mysql_error(database->con));
    }
}