#!/usr/bin/env bash

SOURCE=${BASH_SOURCE[0]}
while [ -L "$SOURCE" ]; do
  DIR=$(cd -P "$(dirname "$SOURCE")" >/dev/null 2>&1 && pwd)
  SOURCE=$(readlink "$SOURCE")
  [[ $SOURCE != /* ]] && SOURCE=$DIR/$SOURCE
done
DIR=$(cd -P "$(dirname "$SOURCE")" >/dev/null 2>&1 && pwd)

if [[ -f "$DIR/../../config/arp-config.sh" ]]; then
  . "$DIR/../../config/arp-config.sh"
else
  echo "$DIR/../../config/arp-config.sh missing!"
  exit 1
fi

if [ "$(id -u)" -ne 0 ]; then
  echo 'This script must be run as root.' >&2
  exit 1
fi

if [ ! -f "/sys/class/net/$ETH_IFACE/operstate" ]; then
  echo "ERROR: $ETH_IFACE does not exist?"
  echo "File does not exist: /sys/class/net/$ETH_IFACE/operstate"
  exit 1
fi

EXITING=0

function ctrl_c() {
  # Reset the interfaces
  if [ $EXITING -eq 0 ]; then # prevent running this multiple times
    EXITING=1
    echo "Cleaning up..."
    ip link set $WLAN_IFACE promisc off
    ip link set dev $ETH_IFACE down
    ip link set dev $ETH_IFACE up
    ip addr del $(/sbin/ip -4 -br addr show $WLAN_IFACE | /bin/grep -Po "\\d+\\.\\d+\\.\\d+\\.\\d+")/32 dev $ETH_IFACE
    exit
  fi
}

# ==============================================================================

while ! ethtool $ETH_IFACE | grep -q "Link detected: yes"; do
  echo "Waiting for wired interface $ETH_IFACE to come up..."
  sleep 10s
done


# Clone our DCHP-allocated IP from wlan0 to eth0 so dhcp-helper will relay for the correct subnet
echo "Initializing..."
trap ctrl_c SIGINT
trap ctrl_c SIGTERM
ip addr add $(/sbin/ip -4 -br addr show $WLAN_IFACE | /bin/grep -Po "\\d+\\.\\d+\\.\\d+\\.\\d+")/32 dev $ETH_IFACE
ip link set $WLAN_IFACE promisc on

while true; do
  WLAN_IFACE_IP=$(ip -4 -br addr show $WLAN_IFACE | grep -Po "\\d+\\.\\d+\\.\\d+\\.\\d+")
  if [ -n "${WLAN_IFACE_IP}" ]; then
    break
  fi
  echo "Waiting for wireless interface $WLAN_IFACE to get an IP..."
  sleep 10s
done

parprouted -d $ETH_IFACE $WLAN_IFACE