#!/bin/bash
# read SONiC immutable variables
[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment

function help()
{
    echo -e "Usage: $0 -n [0 to $(($NUM_ASIC-1))] [OPTION]... " 1>&2; exit 1;
}

DEV=""
PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}

# Parse the device specific asic conf file, if it exists
ASIC_CONF=/usr/share/sonic/device/$PLATFORM/asic.conf
[ -f $ASIC_CONF ] && . $ASIC_CONF

if [[ ($NUM_ASIC -gt 1) ]]; then
    while getopts ":n:h:" opt; do
        case "${opt}" in
            h) help
               ;;
            n) DEV=${OPTARG}
               [ $DEV -lt $NUM_ASIC -a  $DEV -ge 0 ] || help
               ;;
        esac
    done

    if [ -z "${DEV}" ]; then
        help
    fi

    # Skip the arguments -n <inst> while passing to docker command
    shift 2
fi

# Determine whether stdout is on a terminal
if [ -t 1 ] ; then
  # Prepare a function to send HUP signal to vtysh in the container
  # we mark the new instance of vtysh with the current tty as a tag
  TTY=$(tty)
  function cleanup
  {
    docker exec -i bgp$DEV pkill -HUP -f "vtysh $TTY"
  }
  trap cleanup HUP
  docker exec -ti bgp$DEV vtysh "$TTY" "$@"
else
  docker exec -i bgp$DEV vtysh "$@"
fi