#!/usr/bin/env bash
set -euo pipefail

usage() {
    cat <<EOF
Usage: pos network ip

Display network interfaces, default route, and public IP.
EOF
    exit 0
}

case "${1:-}" in
    -h|--help) usage ;;
esac

SEP() { printf '\u2550%.0s' $(seq 1 47); echo; }

SEP
echo "Network Interfaces"
SEP

ip -o -4 addr show | while read -r _ ifname _ ipaddr _; do
    printf "%-20s %s\n" "$ifname" "${ipaddr%%/*}"
done

echo

SEP
echo "Default Route"
SEP

gateway=$(ip route | awk '/default/ {print $3; exit}')
iface=$(ip route | awk '/default/ {print $5; exit}')

printf "%-20s %s\n" "Interface" "${iface:-N/A}"
printf "%-20s %s\n" "Gateway" "${gateway:-N/A}"

echo

SEP
echo "Public IP"
SEP

curl -4 -s --max-time 5 https://ifconfig.me 2>/dev/null || echo "Unavailable"
echo