#!/bin/bash
set -euo pipefail

HBBR="hbbr"

PID="$(docker inspect -f '{{.State.Pid}}' "$HBBR")"

if [ -z "$PID" ] || [ "$PID" = "0" ]; then
    echo "hbbr container is not running" >&2
    exit 1
fi

get_connections() {
    nsenter -t "$PID" -n ss -H -tn state established '( sport = :21117 )'
}

case "${1:-}" in
    connections)
        get_connections | wc -l
        ;;

    sessions)
        count="$(get_connections | wc -l)"
        echo $((count / 2))
        ;;

    relay_ips)
        get_connections |
            awk '{print $4}' |
            sed -E 's/^\[::ffff:([^]]+)\]:[0-9]+$/\1/' |
            sort -u
        ;;

    *)
        echo "Usage: $0 {connections|sessions|relay_ips}" >&2
        exit 2
        ;;
esac