#!/bin/bash

NETWORK_INI="/var/local/emhttp/network.ini"
SYSTEM="/sys/class/net"
EXTRA="/boot/config/network-extra.cfg"

link() {
  grep -Pom1 "^$1=\"\K[^\"]+" $NETWORK_INI.eth
}

zero() {
  data=;
  for i in ${!bind[@]}; do
    [[ ${bind[$i]} == $1 ]] && data=$1
  done
  echo $data
}

show() {
  case $# in
    1) ip addr show to $1 2>/dev/null|grep -Pom1 '^\d+: \K[^:]+';;
    2) ip addr show $1 $2 2>/dev/null|grep -Pom1 'inet6? \K[^\/]+';;
    3) ip $1 addr show $2 $3 2>/dev/null|grep -Pom1 'inet6? \K[^\/]+';;
  esac
}

remove() {
  [[ $# -eq 0 ]] && return
  for i in ${!bind[@]}; do
    [[ ${bind[$i]} == $1 ]] && unset 'bind[i]'
  done
}

extra() {
  source <(/usr/bin/fromdos <$EXTRA)
  for net in $include_interfaces; do
    if [[ -z ${net//[^.:]} ]]; then
      # net is an interface name, validate
      [[ -n $(show dev $net) && -z $(zero $net) ]] && bind+=($net)
    else
      # net is an IP address, convert to name
      net=$(show $net)
      [[ -n $net && -z $(zero $net) ]] && bind+=($net)
    fi
  done
  for net in $exclude_interfaces; do
    if [[ -z ${net//[^.:]} ]]; then
      # net is an interface name, remove
      remove $net
    else
      # net is an IP address, convert to name and remove
      remove $(show $net)
    fi
  done
}

bind=();
if [[ -f $NETWORK_INI ]]; then
  # get interface and vlan configurations
  for eth in $(grep -Po '^\[\K[^\]]+' $NETWORK_INI); do
    # main interface
    if [[ -e $SYSTEM/$eth ]]; then
      sed -n "/^\[$eth\]/,/^\[eth/p" $NETWORK_INI >$NETWORK_INI.eth
      net=$eth
      [[ $(link BONDING) == yes ]] && net=${eth/eth/bond}
      [[ $(link BRIDGING) == yes ]] && net=${eth/eth/br}
      net4=$(link IPADDR:0)
      net6=$(link IPADDR6:0)
      [[ -n $net4 || -n $net6 ]] && bind+=($net)
      if [[ $(link TYPE) == trunk ]]; then
        # vlan interface
        for vlan in $(grep -Po '^VLANID:\K\d+' $NETWORK_INI.eth); do
          net4=$(link IPADDR:$vlan)
          net6=$(link IPADDR6:$vlan)
          [[ -n $net4 || -n $net6 ]] && bind+=($net.$vlan)
        done
      fi
    fi
  done
  # add active WG tunnels
  for wg in $(wg show interfaces); do
    net4=$(show -4 dev $wg)
    net6=$(show -6 dev $wg)
    [[ -n $net4 || -n $net6 ]] && bind+=($wg)
  done
  # add user defined interfaces
  [[ -f $EXTRA ]] && extra
  # remove temporary file
  rm -f $NETWORK_INI.eth
fi
bind=${bind[@]}
echo ${bind// /, }