#!/bin/bash
#-----------------------------------------------------------------------------------------------------------------------
#
# MyIP
# Copyright (C) 2025 Arnaud G. GIBERT
# mailto:arnaud@rx3.net
# 
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
#-----------------------------------------------------------------------------------------------------------------------

WEB_SERVER_NAME="www.rx3"
  WEB_SERVER_IP="10.0.0.65"

RESOLVER_NAME="resolver1.opendns.com"
  RESOLVER_IP="208.67.222.222"

declare -g RESOLV_STATUS="OK"





#-----------------------------------------------------------------------------------------------------------------------
# ip_filter
#-----------------------------------------------------------------------------------------------------------------------

ip_filter()
{
    grep -E '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'
}





#-----------------------------------------------------------------------------------------------------------------------
# resolv
#-----------------------------------------------------------------------------------------------------------------------

resolv()
{
    local host_name="$1"
    local   host_ip="$2"

    
          resolv_ip="$( dig +short "${host_name}" | ip_filter)"

    if [[ "${resolv_ip}" == "" ]]
    then
        RESOLV_STATUS="KO"
          resolv_ip="${host_ip=}"
    else
        RESOLV_STATUS="OK"
    fi
}





#-----------------------------------------------------------------------------------------------------------------------
# main
#-----------------------------------------------------------------------------------------------------------------------

if [[ "$1" == "-h" ]]
then
    echo "myip [-i] | [-a] | [-h]"
    echo "default: external IP"
    echo "     -i: internal IP"
    echo "     -a: internal + external IP"
else
    if [[ "$1" == "-a" ]]
    then
            int_flag="TRUE"
            ext_flag="TRUE"
        verbose_flag="TRUE"
    else
        verbose_flag="FALSE"
        
        if [[ "$1" == "-i" ]]
        then
            int_flag="TRUE"
            ext_flag="FALSE"
        else
            int_flag="FALSE"
            ext_flag="TRUE"
        fi
    fi
fi



if [[ ${verbose_flag} == "TRUE" ]]
then
    int_label="Internal IP: "
    ext_label="External IP: "
else
    int_label=""
    ext_label=""
fi


if [[ ${int_flag} == "TRUE" ]]
then
    resolv "${WEB_SERVER_NAME}" "${WEB_SERVER_IP}"
    web_server_ip="${resolv_ip}"
    
           int_ip="$( curl --resolve ${WEB_SERVER_NAME}:80:${web_server_ip} -s http://www.rx3/cgi-bin/myip.cgi | ip_filter)"

    if [[ ( "${int_label}" != "") && ( "${RESOLV_STATUS}" != "OK") ]]
    then
        echo "Warning: resolver failed for [${WEB_SERVER_NAME}], using default address: [${WEB_SERVER_IP}]"
    fi
    
    echo "${int_label}${int_ip}"
fi

if [[ ${ext_flag} == "TRUE" ]]
then
    resolv "${RESOLVER_NAME}" "${RESOLVER_IP}"
      resolver_ip="${resolv_ip}"
    
           ext_ip="$( dig +short myip.opendns.com @${resolver_ip} | ip_filter)"

    if [[ ( "${ext_label}" != "") && ( "${RESOLV_STATUS}" != "OK") ]]
    then
        echo "Warning: resolver failed for [${RESOLVER_NAME}], using default address: [${RESOLVER_IP}]"
    fi
   
    echo "${ext_label}${ext_ip}"
fi