#!/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.

#rootcheck
if [[ $EUID -eq 0 ]];then
	echo "::: You are root."
else
	echo "::: sudo will be used."
	# Check if it is actually installed
	# If it isn't, exit because the install cannot complete
	if [ -x "$(command -v sudo)" ];then
		export SUDO="sudo"
	else
		echo "::: Please install sudo or run this script as root."
		exit 1
	fi
fi

function helpFunc()
{
	echo "::: Immediately whitelists one or more domains in the hosts file"
	echo ":::"
	echo "::: Usage: pihole -w domain1 [domain2 ...]"
	echo ":::"
	echo "::: Options:"
	echo ":::  -d, --delmode			Remove domains from the whitelist"
	echo ":::  -nr, --noreload			Update Whitelist 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"
	echo ":::  -h, --help				Show this help dialog"
	echo ":::  -l, --list				Display your whitelisted domains"
	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

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 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
}

function 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
}

function 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
}

function 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
}

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

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

function 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