#!/bin/bash

set -a
source .env
set +a

file=$HOME/.dynv6.addr6
[ -e $file ] && old=`cat $file`

if [ -z "$hostname" -o -z "$token" ]; then
  echo "Usage: token=<your-authentication-token> [netmask=64] $0 your-name.dynv6.net [device]"
  exit 1
fi

if [ -z "$netmask" ]; then
  netmask=128
fi

if [ -n "$device" ]; then
  device="dev $device"
fi
address=$(ip -6 addr list scope global $device | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)

if [ -e /usr/bin/curl ]; then
  bin="curl -fsS"
elif [ -e /usr/bin/wget ]; then
  bin="wget -O-"
else
  echo "neither curl nor wget found"
  exit 1
fi

if [ -z "$address" ]; then
  echo "no IPv6 address found"
  exit 1
fi

# address with netmask
current=$address/$netmask

if [ "$old" = "$current" ]; then
  #echo "IPv6 address unchanged"
  exit
fi

# send addresses to dynv6
curl -i --silent -H "Authorization: Bearer $token" -H "Accept: application/json" -H "Content-Type: application/json" -X PATCH \
         -d '{"name":"'$hostname'","data":"'$address'","type":"AAAA"}' \
        $api_url | grep HTTP | grep -v 200

# save current address
echo $current > $file