#!/bin/sh

set -eu

usage() {
    echo "Usage:"
    echo "scope launch [<peer> ...]"
    echo "scope stop"
    echo
    echo "scope <peer>    is of the form <ip_address_or_fqdn>[:<port>]"
    exit 1
}

SCRIPT_VERSION="(unreleased version)"
if [ "$SCRIPT_VERSION" = "(unreleased version)" ] ; then
    IMAGE_VERSION=latest
else
    IMAGE_VERSION=$SCRIPT_VERSION
fi
IMAGE_VERSION=${VERSION:-$IMAGE_VERSION}
SCOPE_IMAGE=weaveworks/scope:$IMAGE_VERSION
SCOPE_CONTAINER_NAME=weavescope
IP_REGEXP="[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}"
IP_ADDR_CMD="find /sys/class/net -type l | xargs -n1 basename | grep -vE 'docker|veth|lo' | \
    xargs -n1 ip addr show | grep inet | awk '{ print \$2 }' | grep -oE '$IP_REGEXP'"
WEAVESCOPE_DOCKER_ARGS=${WEAVESCOPE_DOCKER_ARGS:-}

[ $# -gt 0 ] || usage
COMMAND=$1
shift 1

# Check that a container named $1 with image $2 is not running
check_not_running() {
    case $(docker inspect --format='{{.State.Running}} {{.Config.Image}}' $1 2>/dev/null) in
        "true $2")
            echo "$1 is already running." >&2
            exit 1
            ;;
        "true $2:"*)
            echo "$1 is already running." >&2
            exit 1
            ;;
        "false $2")
            docker rm $1 >/dev/null
            ;;
        "false $2:"*)
            docker rm $1 >/dev/null
            ;;
        true*)
            echo "Found another running container named '$1'. Aborting." >&2
            exit 1
            ;;
        false*)
            echo "Found another container named '$1'. Aborting." >&2
            exit 1
            ;;
    esac
}

case "$COMMAND" in

    launch)
        check_not_running $SCOPE_CONTAINER_NAME $SCOPE_IMAGE
        docker rm -f $SCOPE_CONTAINER_NAME >/dev/null 2>&1 || true

        CONTAINER=$(docker run --privileged -d --name=$SCOPE_CONTAINER_NAME --net=host --pid=host \
            -v /var/run/docker.sock:/var/run/docker.sock \
            $WEAVESCOPE_DOCKER_ARGS $SCOPE_IMAGE --probe.docker true "$@")
        echo $CONTAINER

        if ! echo "$@" | grep -E "\-\-no\-app|\-\-service\-token" 1>/dev/null; then
            IP_ADDRS=$(docker run --rm --net=host --entrypoint /bin/sh $SCOPE_IMAGE -c "$IP_ADDR_CMD")
            echo "Weave Scope is reachable at the following URL(s):" >&2
            for ip in $IP_ADDRS; do
                echo "  * http://$ip:4040/" >&2
            done
        fi
        ;;

    stop)
        [ $# -eq 0 ] || usage
        if ! docker stop $SCOPE_CONTAINER_NAME >/dev/null 2>&1 ; then
            echo "Weave Scope is not running." >&2
        fi
        ;;

    *)
        echo "Unknown scope command '$COMMAND'" >&2
        usage
        ;;

esac