#!/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() {
	echo "::: Immediately blacklists one or more domains in the hosts file"
	echo ":::"
	echo ":::"
	echo "::: Usage: pihole -b domain1 [domain2 ...]"
	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"
	echo ":::  -h, --help				Show this help dialog"
	echo ":::  -l, --list				Display your blacklisted domains"
	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