#!/usr/bin/python

# Copyright (c) 2016 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""This script uses T-REX stateless API to drive t-rex instance.

Requirements:
- T-REX: https://github.com/cisco-system-traffic-generator/trex-core
 - compiled and running T-REX process (eg. ./t-rex-64 -i -c 4)
 - trex_stl_lib.api library
- Script must be executed on a node with T-REX instance

Functionality:
1. Stop any running traffic

"""

import sys

sys.path.insert(0, "/opt/trex-core-2.03/scripts/automation/"+\
                   "trex_control_plane/stl/")
from trex_stl_lib.api import *


def stop_all_traffic_streams():
    """Stop traffic if any is running.

    :return: nothing
    """

    # create client
    client = STLClient()

    try:
        # turn this off if too many logs
        #client.set_verbose("high")

        # connect to server
        client.connect()

        client.acquire(force=True)
        client.stop(ports=[0, 1])

        # read the stats after the test
        stats = client.get_stats()

        print "#####statistics (approx.)#####"
        print json.dumps(stats, indent=4,
                         separators=(',', ': '), sort_keys=True)

        lost_a = stats[0]["opackets"] - stats[1]["ipackets"]
        lost_b = stats[1]["opackets"] - stats[0]["ipackets"]

        total_sent = stats[0]["opackets"] + stats[1]["opackets"]
        total_rcvd = stats[0]["ipackets"] + stats[1]["ipackets"]

        print "\npackets lost from 0 --> 1:   {0} pkts".format(lost_a)
        print "packets lost from 1 --> 0:   {0} pkts".format(lost_b)

    except STLError as ex_error:
        print_error(str(ex_error))
        sys.exit(1)

    finally:
        client.disconnect()



def print_error(msg):
    """Print error message on stderr.

    :param msg: Error message to print.
    :type msg: string
    :return: nothing
    """

    sys.stderr.write(msg+'\n')


def main():
    """Main function."""

    stop_all_traffic_streams()

if __name__ == "__main__":
    main()