#!/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.

helpFunc() {
	cat << EOM
::: Immediately blacklists one or more domains in the hosts file
:::
:::
::: Usage: pihole -b domain1 [domain2 ...]
::: Options:
:::  -d, --delmode			Remove domains from the blacklist
:::  -nr, --noreload			Update blacklist without refreshing dnsmasq
:::  -f, --force			Force updating of the hosts files, even if there are no changes
:::  -q, --quiet			output is less verbose
:::  -h, --help				Show this help dialog
:::  -l, --list				Display your blacklisted domains
EOM
	exit 1
}

if [[ $# = 0 ]]; then
	helpFunc
fi

#globals
basename=pihole
piholeDir=/etc/${basename}
adList=${piholeDir}/gravity.list
blacklist=${piholeDir}/blacklist.txt
reload=true
addmode=true
force=false
verbose=true

domList=()
domToRemoveList=()

piholeIPfile=/etc/pihole/piholeIP
piholeIPv6file=/etc/pihole/.useIPv6

if [[ -f ${piholeIPfile} ]]; then
	# If the file exists, it means it was exported from the installation script and we should use that value instead of detecting it in this script
	piholeIP=$(cat ${piholeIPfile})
	#rm $piholeIPfile
else
	# Otherwise, the IP address can be taken directly from the machine, which will happen when the script is run by the user and not the installation script
	IPv4dev=$(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%/*}
fi

modifyHost=false

# After setting defaults, check if there's local overrides
if [[ -r ${piholeDir}/pihole.conf ]]; then
	echo "::: Local calibration requested..."
	. ${piholeDir}/pihole.conf
fi


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

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
}

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
}

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 ${verbose}; then
			echo -n "::: Adding $1 to blacklist file..."
		fi
		echo "${1}" >> ${blacklist}
		modifyHost=true
		echo " done!"
	else
	if ${verbose}; then
		echo "::: ${1} already exists in ${blacklist}! No need to add"
		fi
	fi
}

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

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
				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
}

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

	dnsmasqPid=$(pidof dnsmasq)

	if [[ ${dnsmasqPid} ]]; then
		# service already running - reload config
		if [ -x "$(command -v systemctl)" ]; then
			systemctl restart dnsmasq
		else
			service dnsmasq restart
		fi
	else
		# service not running, start it up
		if [ -x "$(command -v systemctl)" ]; then
			systemctl start dnsmasq
		else
			service dnsmasq start
		fi
	fi
	echo " done!"
}

DisplayBlist() {
	verbose=false
	echo -e " Displaying Gravity Affected Domains \n"
	count=1
	while IFS= read -r AD; do
		echo "${count}: ${AD}"
		count=$((count+1))
	done < "${blacklist}"
}

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

for var in "$@"; do
	case "$var" in
		"-nr"| "--noreload"  ) reload=false;;
		"-d" | "--delmode"   ) addmode=false;;
		"-f" | "--force"     ) force=true;;
		"-q" | "--quiet"     ) verbose=false;;
		"-h" | "--help"      ) helpFunc;;
		"-l" | "--list"      ) DisplayBlist;;
		*                    ) HandleOther "$var";;
	esac
done

PopBlacklistFile

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

if ${reload}; then
	Reload
fi