import MySQLdb
import yaml
import warnings


def perfdata(max_conn, in_use):
    return "max_connections=%s|in_use=%s" % (max_conn, in_use)

def run(params):
    conn = None
    try:
        f = params.get("defaults-file", "/etc/check_mk/mysql.cfg")

        thresolds = yaml.load(params.get('thresholds'))
        conn = MySQLdb.connect(read_default_file=f)
        cursor = conn.cursor()
        # we connected, so mysql is working, now some additional tests

        # is innodb working? It's crucial to normal operation
        if params.get('innodb',True):
            cursor.execute("""select engine from information_schema.engines where Engine='Innodb' and support='default'""")
            ret = cursor.fetchone()
            if ret[0] != 'InnoDB':
                return [2, 'CRITICAL: InnoDB is not loaded']

        # get number of connections
        cursor.execute("select count(id) from information_schema.processlist")
        current_connections = cursor.fetchone()[0]
        cursor.execute("show variables like 'max_connections'")
        max_connections = cursor.fetchone()[1]

        percent = float(current_connections) / float(max_connections)
        percent = percent * 100

        if percent > thresolds['critical']:
            return [2, 'CRITICAL: {0}% of connections in use'.format(percent), perfdata(max_connections, current_connections)]
        elif percent > thresolds['warning']:
            return [1, 'WARNING: {0}% of connections in use'.format(percent), perfdata(max_connections, current_connections)]
        else:
            return [0, 'OK: {0}% of connections in use'.format(percent), perfdata(max_connections, current_connections)]
    except Exception, e:
        return [2, 'CRITICAL: {0}'.format(str(e))]
    finally:
        try:
            if conn:
                conn.close()
        except:
            # finally clause, don't bother about errors here
            pass

def __run__(params):
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        return run(params)