#!/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
# Whitelists 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 whitelists one or more domains in the hosts file
:::
::: Usage: pihole -w domain1 [domain2 ...]
:::
::: Options:
:::  -d, --delmode			Remove domains from the whitelist
:::  -nr, --noreload			Update Whitelist 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 whitelisted domains
EOM
	exit 1
}

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

#globals
basename=pihole
piholeDir=/etc/${basename}
adList=${piholeDir}/gravity.list
whitelist=${piholeDir}/whitelist.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
}

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

AddDomain() {
	#| sed 's/\./\\./g'
	bool=false

	grep -Ex -q "$1" ${whitelist} || bool=true
	if ${bool}; then
	#domain not found in the whitelist file, add it!
		if ${verbose}; then
			echo -n "::: Adding ${1}to ${whitelist}..."
		fi
	echo "${1}" >> ${whitelist}
	modifyHost=true
		if ${verbose}; then
			echo " done!"
		fi
	else
		if ${verbose}; then
			echo "::: ${1} already exists in ${whitelist}, no need to add!"
		fi
	fi
}

RemoveDomain() {

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

ModifyHostFile() {
	if ${addmode}; then
	#remove domains in  from hosts file
		if [[ -r ${whitelist} ]]; then
			# Remove whitelist entries
			numberOf=$(cat ${whitelist} | sed '/^\s*$/d' | wc -l)
			plural=; [[ "${numberOf}" != "1" ]] && plural=s
			echo ":::"
			echo -n "::: Modifying HOSTS file to whitelist $numberOf domain${plural}..."
			awk -F':' '{print $1}' ${whitelist} | while read -r line; do echo "${piholeIP} ${line}"; done > /etc/pihole/whitelist.tmp
			awk -F':' '{print $1}' ${whitelist} | while read -r line; do echo "${piholeIPv6} ${line}"; done >> /etc/pihole/whitelist.tmp
			echo "l" >> /etc/pihole/whitelist.tmp
			grep -F -x -v -f ${piholeDir}/whitelist.tmp ${adList} > ${piholeDir}/gravity.tmp
			rm ${adList}
			mv ${piholeDir}/gravity.tmp ${adList}
			rm ${piholeDir}/whitelist.tmp
			echo " done!"

		fi
	else
		#we need to add the removed domains to the hosts file
		echo ":::"
		echo "::: Modifying HOSTS file to un-whitelist domains..."
		for rdom in "${domToRemoveList[@]}"; do
			if grep -q "${rdom}" /etc/pihole/*.domains; then
				echo ":::    AdLists contain ${rdom}, re-adding block"
				if [[ -n ${piholeIPv6} ]]; then
					echo -n ":::        Restoring block for ${rdom} on IPv4 and IPv6..."
					echo "${rdom}" | awk -v ipv4addr="${piholeIP}" -v ipv6addr="${piholeIPv6}" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> ${adList}
					echo " done!"
				else
					echo -n ":::        Restoring block for ${rdom} on IPv4..."
					echo "${rdom}" | awk -v ipv4addr="${piholeIP}" '{sub(/\r$/,""); print ipv4addr" "$0}' >>${adList}
					echo " done!"
				fi
			fi
			echo -n ":::    Removing $rdom from $whitelist..."
			echo "$rdom" | sed 's/\./\\./g' | xargs -I {} perl -i -ne'print unless /'{}'(?!.)/;' ${whitelist}
			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!"
}

DisplayWlist() {
	verbose=false
	echo -e " Displaying Gravity Resistant Domains \n"
	count=1
	while IFS= read -r RD; do
		echo "${count}: ${RD}"
		count=$((count+1))
	done < "${whitelist}"
}

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

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"      ) DisplayWlist;;
		*                    ) HandleOther "${var}";;
	esac
done

PopWhitelistFile

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

if ${reload}; then
	Reload
fi