#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#

# Returns the next free SIP extension number

# License
# =======
#
# Copyright (C) 2015 Bob Mottram <bob@robotics.uk.to>
#
# 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 3 of the License, or
# (at your option) 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, see <http://www.gnu.org/licenses/>.

CONFIG_FILE=/etc/sipwitch.conf

extensions=()

# get the used extensions
IFS=''
for line in $(cat $CONFIG_FILE | grep "extension"); do
    extnum=$(echo "$line" | awk -F '>' '{print $2}' | awk -F '<' '{print $1}')
    extensions+=($extnum)
done

# find the max extension number
maxnum=201
for i in ${extensions[@]}; do
    if [ $i -gt $maxnum ]; then
        maxnum=$i
        break
    fi
done

if [ $maxnum -gt 299 ]; then
	exit 1
fi

echo $(($maxnum + 1))
exit 0