#!/bin/sh
# Quick network configurator for the local console.
set -e

# List interfaces (exclude lo)
IFACES=$(ip -o link show | awk -F': ' '$2 != "lo" {print $2}' | cut -d@ -f1)

echo "Interfaces:"
i=1
for iface in $IFACES; do
    ip=$(ip -4 addr show "$iface" 2>/dev/null | awk '/inet /{print $2}' | head -1)
    echo "  $i) $iface  ${ip:-no IP}"
    i=$((i+1))
done
echo ""
printf "Interface name [or Enter to pick first]: "
read IFACE
if [ -z "$IFACE" ]; then
    IFACE=$(echo "$IFACES" | head -1)
fi
echo "Selected: $IFACE"
echo ""
echo "  1) DHCP"
echo "  2) Static"
printf "Mode [1]: "
read MODE
MODE=${MODE:-1}

if [ "$MODE" = "1" ]; then
    echo "Running DHCP on $IFACE..."
    dhclient -v "$IFACE"
else
    printf "IP address (e.g. 192.168.1.100/24): "
    read ADDR
    printf "Gateway (e.g. 192.168.1.1): "
    read GW
    printf "DNS [8.8.8.8]: "
    read DNS
    DNS=${DNS:-8.8.8.8}

    ip addr flush dev "$IFACE"
    ip addr add "$ADDR" dev "$IFACE"
    ip link set "$IFACE" up
    ip route add default via "$GW"
    echo "nameserver $DNS" > /etc/resolv.conf
    echo "Done."
fi

echo ""
ip -4 addr show "$IFACE"