#!/bin/bash
# brezular v0.1

function show_choices {
 echo -e "\n*** Script configures wifi network, select from options below ***\n"
 echo -e "a) Change SSID"
 echo -e "b) Change WPA passphrase"
 echo -e "c) Restart wifi network"
 echo -e "q) Quit script\n"
}

function get_credentials {
  ssid="$(grep "^ssid" /usr/local/etc/hostapd.conf | cut -d "=" -f2)"
  passphrase="$(grep "^wpa_passphrase" /usr/local/etc/hostapd.conf | cut -d "=" -f2)"
}

function my_hostapd {
 [ "$1" == 'restart' ] && /usr/bin/pkill hostapd
 sleep 3
 /usr/local/bin/hostapd -B /usr/local/etc/hostapd.conf 1>/dev/null
}

function check_hostapd_pid {
 ps -ef | grep hostapd | grep -v grep 1>/dev/null           
 [ "$?" == 0 ] && my_hostapd restart || my_hostapd
}

function check_length {
 read word                                               
 len=${#word}                              
 until [[ "$len" -ge "$2" && "$len" -le "$3" ]]; do    
    echo -en "\nEnter $4 (min $2, max $3 chars): "     
    read word                                                                            
    len=${#word}                                                                 
 done                           
 if [ "$1" == 'newssid' ]; then
    newssid="$word"
 elif [ "$1" == 'newpassphrase' ]; then 
    newpassphrase="$word"
 fi
}

uid="$UID"
[ "$uid" != 0 ] && echo -e "\nRun '$0' as root, exiting" && exit 1

while true; do
 show_choices
 read val
 case $val in
    a)
       get_credentials
       echo -en "\nEnter new SSID (min 1, max 32 chars): "
       check_length newssid 1 32 "new SSID"
       sed -i "s/ssid=$ssid/ssid=$newssid/g" /usr/local/etc/hostapd.conf
       check_hostapd_pid 
       /usr/bin/filetool.sh -b 1>/dev/null
       echo -e "\n*** SSID changed successfully ***"
       ;;
    b)
       get_credentials
       echo -en "\nEnter new WPA passphrase (min 8, max 64 chars): "
       check_length newpassphrase 8 64 "new WPA passphrase"
       sed -i "s/wpa_passphrase=$passphrase/wpa_passphrase=$newpassphrase/g" /usr/local/etc/hostapd.conf
       check_hostapd_pid       
       /usr/bin/filetool.sh -b 1>/dev/null
       echo -e "\n*** WPA passphrase changed successfully ***"
       ;;
    c)
       my_hostapd restart
       echo -e "\n*** Wifi network restarted successfully ***" 
       ;;
    q)                        
       exit 0            
       ;;      
    *)
       echo -e "\n*** Please, enter valid option ***"
       ;;
 esac
done