#!/bin/bash
### BEGIN INIT INFO
# Provides: ynh-vpnclient
# Required-Start:    $network $remote_fs $syslog
# Required-Stop:     $network $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start VPN client.
# Description:       Start VPN client.
### END INIT INFO

has_nativeip6() {
  ip -6 r | grep -q default\ via
}

is_ip6addr_set() {
  yunohost app list -f hotspot --json | grep -q '"installed": true'\
  || ip a s dev tun0 | grep -q <TPL:IP6_ADDR>/128
}

is_ip6interco_set() {
  ip -6 r | grep -q <TPL:IP6_INTERCO>/
}

is_openvpn_running() {
  service openvpn status &> /dev/null
}

is_running() {
  ((has_nativeip6 && is_ip6interco_set) || ! has_nativeip6) && is_openvpn_running
}

gw6=$(ip -6 r | grep default\ via | awk '{ print $3 }')

case "$1" in
  start)
    if is_running; then
      echo "Already correctly set"
    else
      if ! is_openvpn_running; then
        echo "Run openvpn"

        proto=udp
        [ ! -z "${gw6}" ] && proto=udp6
        sed "s|<TPL:PROTO>|${proto}|" /etc/openvpn/client.conf.tpl > /etc/openvpn/client.conf
        sed 's|^<TPL:UDP_COMMENT>||' -i /etc/openvpn/client.conf

        service openvpn start

        false || while [ $? -ne 0 ]; do
          sleep 1
          ip l sh dev tun0 &> /dev/null
        done

        sleep 2
      fi

      if has_nativeip6 && ! is_ip6interco_set; then
        echo "Set IPv6 interco route"
        ip r a <TPL:IP6_INTERCO>/128 via ${gw6} dev <TPL:WIRED_DEVICE>
      fi

      if ! is_ip6addr_set; then
        echo "Set IPv6 address"
        ip a a <TPL:IP6_ADDR>/128 dev tun0
      fi
    fi
  ;;
  stop)
    if is_ip6addr_set; then
      echo "Unset IPv6 address"
      ip a d <TPL:IP6_ADDR>/128 dev tun0
    fi

    if is_ip6interco_set; then
      echo "Unset IPv6 interco route"
      ip r d <TPL:IP6_INTERCO>/128 via ${gw6} dev <TPL:WIRED_DEVICE>
    fi
  
    if is_openvpn_running; then
      echo "Stop openvpn"
      service openvpn stop
    fi
  ;;
  restart)
    $0 stop
    $0 start
  ;;
  status)
    exitcode=0

    if is_ip6addr_set; then
      echo "IPv6 address is correctly set"
    else
      echo "IPv6 address is NOT set"
      exitcode=1
    fi

    if has_nativeip6; then
      if is_ip6interco_set; then
        echo "IPv6 interco route is correctly set"
      else
        echo "IPv6 interco route is NOT set"
        exitcode=1
      fi
    else
      echo "No native IPv6 detected"
    fi

    if is_openvpn_running; then
      echo "Openvpn is running"
    else
      echo "Openvpn is NOT running"
      exitcode=1
    fi

    exit ${exitcode}
  ;;
  *)
    echo "Usage: $0 {start|stop|restart|status}"
    exit 1
  ;;
esac

exit 0