#!/usr/bin/env bash
# Pi-hole: A black hole for Internet advertisements
# (c) 2015, 2016 by Jacob Salmela
# Network-wide ad blocking via your Raspberry Pi
# http://pi-hole.net
# Blacklists domains
#
# Pi-hole 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
# (at your option) any later version.

if [[ $# = 0 ]]; then
    echo "Immediately blacklists one or more domains in the hosts file"
    echo " "
    echo "Usage: blacklist.sh domain1 [domain2 ...]"
    echo "  "
    echo "Options:"
    echo "  -d, --delmode		Remove domains from the blacklist"
    echo "  -nr, --noreload	Update blacklist without refreshing dnsmasq"
    echo "  -f, --force		Force updating of the hosts files, even if there are no changes"
    echo "  -q, --quiet		output is less verbose"
    exit 1
fi

#globals
blacklist=/etc/pihole/blacklist.txt
adList=/etc/pihole/gravity.list
reload=true
addmode=true
force=false
versbose=true
domList=()
domToRemoveList=()

piholeIPv6file=/etc/pihole/.useIPv6

# Otherwise, the IP address can be taken directly from the machine, which will happen when the script is run by the user and not the installation script
IPv4dev=$(ip route get 8.8.8.8 | awk '{for(i=1;i<=NF;i++)if($i~/dev/)print $(i+1)}')
piholeIPCIDR=$(ip -o -f inet addr show dev "$IPv4dev" | awk '{print $4}' | awk 'END {print}')
piholeIP=${piholeIPCIDR%/*}

modifyHost=false


if [[ -f $piholeIPv6file ]];then
    # If the file exists, then the user previously chose to use IPv6 in the automated installer
    piholeIPv6=$(ip -6 route get 2001:4860:4860::8888 | awk -F " " '{ for(i=1;i<=NF;i++) if ($i == "src") print $(i+1) }')
fi


function HandleOther(){
  #check validity of domain
	validDomain=$(echo "$1" | perl -ne'print if /\b((?=[a-z0-9-]{1,63}\.)(xn--)?[a-z0-9]+(-[a-z0-9]+)*\.)+[a-z]{2,63}\b/')
	if [ -z "$validDomain" ]; then
		echo "$1" is not a valid argument or domain name
	else	  
	  domList=("${domList[@]}" $validDomain)
	fi
}

function PopBlacklistFile(){
	#check blacklist file exists, and if not, create it
	if [[ ! -f $blacklist ]];then
  	  touch $blacklist
	fi
	for dom in "${domList[@]}"; do
	  if "$addmode"; then
	  	AddDomain "$dom"
	  else
	    RemoveDomain "$dom"
	  fi
	done
}

function AddDomain(){
#| sed 's/\./\\./g'
	bool=false
	grep -Ex -q "$1" $blacklist || bool=true
	if $bool; then
	  #domain not found in the blacklist file, add it!
	  if $versbose; then
	  echo -n "::: Adding $1 to blacklist file..."
	  fi
		echo "$1" >> $blacklist
		modifyHost=true
		echo " done!"
	else
	if $versbose; then
		echo "::: $1 already exists in blacklist.txt! No need to add"
		fi
	fi
}

function RemoveDomain(){

  bool=false
  grep -Ex -q "$1" $blacklist || bool=true
  if $bool; then
  	#Domain is not in the blacklist file, no need to Remove
  	if $versbose; then
  	echo "::: $1 is NOT blacklisted! No need to remove"
  	fi
  else
    #Domain is in the blacklist file, add to a temporary array
    if $versbose; then
    echo "::: Un-blacklisting $dom..."
    fi
    domToRemoveList=("${domToRemoveList[@]}" $1)
    modifyHost=true
  fi
}

function ModifyHostFile(){
	 if $addmode; then
	    #add domains to the hosts file
	    if [[ -r $blacklist ]];then
	      numberOf=$(cat $blacklist | sed '/^\s*$/d' | wc -l)
        plural=; [[ "$numberOf" != "1" ]] && plural=s
        echo ":::"
        echo -n "::: Modifying HOSTS file to blacklist $numberOf domain${plural}..."	   		    
	    	if [[ -n $piholeIPv6 ]];then	    	  
				$blacklist | awk -v ipv4addr="$piholeIP" -v ipv6addr="$piholeIPv6" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> $adList
	      	else	        
				$blacklist | awk -v ipv4addr="$piholeIP" '{sub(/\r$/,""); print ipv4addr" "$0}' >>$adList
	      	fi		    
	  	fi
	  else
		echo ":::"
	  	for dom in "${domToRemoveList[@]}"
		do
	      #we need to remove the domains from the blacklist file and the host file
			echo "::: $dom"
			echo -n ":::    removing from HOSTS file..."
	      	echo "$dom" | sed 's/\./\\./g' | xargs -I {} perl -i -ne'print unless /[^.]'{}'(?!.)/;' $adList  
	      	echo " done!"
	      	echo -n ":::    removing from blackist.txt..."
	      	echo "$dom" | sed 's/\./\\./g' | xargs -I {} perl -i -ne'print unless /'{}'(?!.)/;' $blacklist
	      	echo " done!"
		done
	fi
}

function Reload() {
	# Reload hosts file
	echo ":::"
	echo -n "::: Refresh lists in dnsmasq..."

	dnsmasqPid=$(pidof dnsmasq)

	if [[ $dnsmasqPid ]]; then
		# service already running - reload config
		sudo kill -HUP "$dnsmasqPid"
	else
		# service not running, start it up
		sudo service dnsmasq start
	fi
	echo " done!"
}

###################################################

for var in "$@"
do
  case "$var" in
    "-nr"| "--noreload"  ) reload=false;;
    "-d" | "--delmode"   ) addmode=false;;
    "-f" | "--force"     ) force=true;;
    "-q" | "--quiet"     ) versbose=false;;  			
    *                    ) HandleOther "$var";;
  esac
done

PopBlacklistFile

if $modifyHost || $force; then
	ModifyHostFile
else
  if $versbose; then
	echo "::: No changes need to be made"
	fi
	exit 1
fi

if $reload; then
	Reload
fi