#!/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.

source /etc/pihole/Functions/pihole.var
source /etc/pihole/Functions/pihole.funcs

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
reload=true
addmode=true
force=false
versbose=true
domList=()
domToRemoveList=()
IPv6=false

# 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
piholeIP=${IPv4addr%/*}
modifyHost=false

if [[ -f piholeIPv6file ]];then
    # If the file exists, then the user previously chose to use IPv6 in the automated installer
    IPv6=true
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 [[ IPv6 ]];then
				cat $blacklist | awk -v ipv4addr="$piholeIP" -v ipv6addr="$piholeIPv6" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> $adList
			else
				cat $blacklist | awk -v ipv4addr="$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