#!/usr/bin/env bash
# Pi-hole: A black hole for Internet advertisements
# (c) 2017 Pi-hole, LLC (https://pi-hole.net)
# Network-wide ad blocking via your own hardware.
#
# Whitelist and blacklist domains
#
# This file is copyright under the latest version of the EUPL.
# Please see LICENSE file for your rights under this license.

# Globals
basename=pihole
piholeDir=/etc/"${basename}"
whitelist="${piholeDir}"/whitelist.txt
blacklist="${piholeDir}"/blacklist.txt
readonly regexlist="/etc/pihole/regex.list"
reload=false
addmode=true
verbose=true
wildcard=false

domList=()

listMain=""
listAlt=""

colfile="/opt/pihole/COL_TABLE"
source ${colfile}


helpFunc() {
  if [[ "${listMain}" == "${whitelist}" ]]; then
    param="w"
    type="white"
  elif [[ "${listMain}" == "${regexlist}" ]]; then
    param="wild"
    type="regex black"
  else
    param="b"
    type="black"
  fi

    echo "Usage: pihole -${param} [options] <domain> <domain2 ...>
Example: 'pihole -${param} site.com', or 'pihole -${param} site1.com site2.com'
${type^}list one or more domains

Options:
  -d, --delmode       Remove domain(s) from the ${type}list
  -nr, --noreload     Update ${type}list without refreshing dnsmasq
  -q, --quiet         Make output less verbose
  -h, --help          Show this help dialog
  -l, --list          Display all your ${type}listed domains
  --nuke              Removes all entries in a list"

  exit 0
}

EscapeRegexp() {
  # This way we may safely insert an arbitrary
  # string in our regular expressions
  # This sed is intentionally executed in three steps to ease maintainability
  # The first sed removes any amount of leading dots
  echo $* | sed 's/^\.*//' | sed "s/[]\.|$(){}?+*^]/\\\\&/g" | sed "s/\\//\\\\\//g"
}

HandleOther() {
  # Convert to lowercase
  domain="${1,,}"

  # Check validity of domain (don't check for regex entries)
  if [[ "${#domain}" -le 253 ]]; then
    if [[ "${listMain}" == "${regexlist}" && "${wildcard}" == false ]]; then
      validDomain="${domain}"
    else
      validDomain=$(grep -P "^((-|_)*[a-z\\d]((-|_)*[a-z\\d])*(-|_)*)(\\.(-|_)*([a-z\\d]((-|_)*[a-z\\d])*))*$" <<< "${domain}") # Valid chars check
      validDomain=$(grep -P "^[^\\.]{1,63}(\\.[^\\.]{1,63})*$" <<< "${validDomain}") # Length of each label
    fi
  fi

  if [[ -n "${validDomain}" ]]; then
    domList=("${domList[@]}" ${validDomain})
  else
    echo -e "  ${CROSS} ${domain} is not a valid argument or domain name!"
  fi
}

PoplistFile() {
  # Check whitelist file exists, and if not, create it
  if [[ ! -f "${whitelist}" ]]; then
    touch "${whitelist}"
  fi

  # Check blacklist file exists, and if not, create it
  if [[ ! -f "${blacklist}" ]]; then
    touch "${blacklist}"
  fi

  for dom in "${domList[@]}"; do
      # Logic: If addmode then add to desired list and remove from the other; if delmode then remove from desired list but do not add to the other
    if ${addmode}; then
      AddDomain "${dom}" "${listMain}"
      RemoveDomain "${dom}" "${listAlt}"
    else
      RemoveDomain "${dom}" "${listMain}"
    fi
  done
}

AddDomain() {
  list="$2"
  domain=$(EscapeRegexp "$1")

  [[ "${list}" == "${whitelist}" ]] && listname="whitelist"
  [[ "${list}" == "${blacklist}" ]] && listname="blacklist"

  if [[ "${list}" == "${whitelist}" || "${list}" == "${blacklist}" ]]; then
    [[ "${list}" == "${whitelist}" && -z "${type}" ]] && type="--whitelist-only"
    [[ "${list}" == "${blacklist}" && -z "${type}" ]] && type="--blacklist-only"
    bool=true
    # Is the domain in the list we want to add it to?
    grep -Ex -q "${domain}" "${list}" > /dev/null 2>&1 || bool=false

    if [[ "${bool}" == false ]]; then
      # Domain not found in the whitelist file, add it!
      if [[ "${verbose}" == true ]]; then
      echo -e "  ${INFO} Adding ${1} to ${listname}..."
      fi
      reload=true
      # Add it to the list we want to add it to
      echo "$1" >> "${list}"
    else
      if [[ "${verbose}" == true ]]; then
        echo -e "  ${INFO} ${1} already exists in ${listname}, no need to add!"
      fi
    fi
  elif [[ "${list}" == "${regexlist}" ]]; then
    [[ -z "${type}" ]] && type="--wildcard-only"
    bool=true
    domain="${1}"

    [[ "${wildcard}" == true ]] && domain="((^)|(\\.))$(echo domain | sed "s/\./\\\./g")$"

    # Is the domain in the list?
    # Search only for exactly matching lines
    grep -Fx "${domain}" "${regexlist}" > /dev/null 2>&1 || bool=false

    if [[ "${bool}" == false ]]; then
      if [[ "${verbose}" == true ]]; then
      echo -e "  ${INFO} Adding ${domain} to regex list..."
      fi
      reload="restart"
      echo "$domain" >> "${regexlist}"
    else
      if [[ "${verbose}" == true ]]; then
        echo -e "  ${INFO} ${domain} already exists in regex list, no need to add!"
      fi
    fi
  fi
}

RemoveDomain() {
  list="$2"
  domain=$(EscapeRegexp "$1")

  [[ "${list}" == "${whitelist}" ]] && listname="whitelist"
  [[ "${list}" == "${blacklist}" ]] && listname="blacklist"

  if [[ "${list}" == "${whitelist}" || "${list}" == "${blacklist}" ]]; then
    bool=true
    [[ "${list}" == "${whitelist}" && -z "${type}" ]] && type="--whitelist-only"
    [[ "${list}" == "${blacklist}" && -z "${type}" ]] && type="--blacklist-only"
    # Is it in the list? Logic follows that if its whitelisted it should not be blacklisted and vice versa
    grep -Ex -q "${domain}" "${list}" > /dev/null 2>&1 || bool=false
    if [[ "${bool}" == true ]]; then
      # Remove it from the other one
      echo -e "  ${INFO} Removing $1 from ${listname}..."
      # /I flag: search case-insensitive
      sed -i "/${domain}/Id" "${list}"
      reload=true
    else
      if [[ "${verbose}" == true ]]; then
        echo -e "  ${INFO} ${1} does not exist in ${listname}, no need to remove!"
      fi
    fi
  elif [[ "${list}" == "${regexlist}" ]]; then
    [[ -z "${type}" ]] && type="--wildcard-only"
    domain="${1}"

    [[ "${wildcard}" == true ]] && domain="((^)|(\\.))$(echo domain | sed "s/\./\\\./g")$"

    bool=true
    # Is it in the list?
    grep -Fx "${domain}" "${regexlist}" > /dev/null 2>&1 || bool=false
    if [[ "${bool}" == true ]]; then
      # Remove it from the other one
      echo -e "  ${INFO} Removing $domain from regex list..."
      local lineNumber
      lineNumber=$(grep -Fnx "$domain" "${list}" | cut -f1 -d:)
      sed -i "${lineNumber}d" "${list}"
      reload=true
    else
      if [[ "${verbose}" == true ]]; then
        echo -e "  ${INFO} ${domain} does not exist in regex list, no need to remove!"
      fi
    fi
  fi
}

# Update Gravity
Reload() {
  echo ""
  pihole -g --skip-download "${type:-}"
}

Displaylist() {
  if [[ -f ${listMain} ]]; then
    if [[ "${listMain}" == "${whitelist}" ]]; then
      string="gravity resistant domains"
    else
      string="domains caught in the sinkhole"
    fi
    verbose=false
    echo -e "Displaying $string:\n"
    count=1
    while IFS= read -r RD; do
      echo "  ${count}: ${RD}"
      count=$((count+1))
    done < "${listMain}"
  else
    echo -e "  ${COL_LIGHT_RED}${listMain} does not exist!${COL_NC}"
  fi
  exit 0;
}

NukeList() {
  if [[ -f "${listMain}" ]]; then
    # Back up original list
    cp "${listMain}" "${listMain}.bck~"
    # Empty out file
    echo "" > "${listMain}"
  fi
}

for var in "$@"; do
  case "${var}" in
    "-w" | "whitelist"   ) listMain="${whitelist}"; listAlt="${blacklist}";;
    "-b" | "blacklist"   ) listMain="${blacklist}"; listAlt="${whitelist}";;
    "-wild" | "wildcard" ) listMain="${regexlist}"; wildcard=true;;
    "-regex" | "regex"   ) listMain="${regexlist}";;
    "-nr"| "--noreload"  ) reload=false;;
    "-d" | "--delmode"   ) addmode=false;;
    "-q" | "--quiet"     ) verbose=false;;
    "-h" | "--help"      ) helpFunc;;
    "-l" | "--list"      ) Displaylist;;
    "--nuke"             ) NukeList;;
    *                    ) HandleOther "${var}";;
  esac
done

shift

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

PoplistFile

if [[ "${reload}" != false ]]; then
  # Ensure that "restart" is used for Wildcard updates
  Reload "${reload}"
fi