#!/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.
#
# Compiles a list of ad-serving domains by downloading them from multiple sources
#
# This file is copyright under the latest version of the EUPL.
# Please see LICENSE file for your rights under this license.

# Run this script as root or under sudo

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

helpFunc() {
  echo "Usage: pihole -g
Update domains from blocklists specified in adlists.list

Options:
  -f, --force          Force the download of all specified blocklists
  -h, --help           Show this help dialog"
  exit 0
}

PIHOLE_COMMAND="/usr/local/bin/pihole"

adListFile=/etc/pihole/adlists.list
adListDefault=/etc/pihole/adlists.default # Deprecated
adListRepoDefault=/etc/.pihole/adlists.default
whitelistScript="${PIHOLE_COMMAND} -w"
whitelistFile=/etc/pihole/whitelist.txt
blacklistFile=/etc/pihole/blacklist.txt
readonly wildcardlist="/etc/dnsmasq.d/03-pihole-wildcard.conf"

# Source the setupVars from install script for the IP
setupVars=/etc/pihole/setupVars.conf
if [[ -f "${setupVars}" ]];then
  . /etc/pihole/setupVars.conf
else
  echo -e "  ${COL_LIGHT_RED}Error: /etc/pihole/setupVars.conf missing. Possible installation failure.${COL_NC}
  Please run 'pihole -r', and choose the 'reconfigure' option to reconfigure."
  exit 1
fi

# Remove the /* from the end of the IPv4addr.
IPV4_ADDRESS=${IPV4_ADDRESS%/*}
IPV6_ADDRESS=${IPV6_ADDRESS}

# Variables for various stages of downloading and formatting the list
basename=pihole
piholeDir=/etc/${basename}
adList=${piholeDir}/gravity.list
blackList=${piholeDir}/black.list
localList=${piholeDir}/local.list
justDomainsExtension=domains
matterAndLight=${basename}.0.matterandlight.txt
supernova=${basename}.1.supernova.txt
preEventHorizon=list.preEventHorizon
eventHorizon=${basename}.2.supernova.txt
accretionDisc=${basename}.3.accretionDisc.txt

skipDownload=false

# Warn users still using pihole.conf that it no longer has any effect
if [[ -r ${piholeDir}/pihole.conf ]]; then
echo -e "  ${COL_LIGHT_RED}pihole.conf file no longer supported. Overrides in this file are ignored.${COL_NC}"
fi

###########################
# Collapse - begin formation of pihole
gravity_collapse() {

  #New Logic:
  # Does /etc/pihole/adlists.list exist? If so leave it alone
  #                                      If not, cp /etc/.pihole/adlists.default /etc/pihole/adlists.list
  # Read from adlists.list

  # The following two blocks will sort out any missing adlists in the /etc/pihole directory, and remove legacy adlists.default
  if [[ -f "${adListDefault}" ]] && [[ -f "${adListFile}" ]]; then
    rm "${adListDefault}"
  fi

  if [ ! -f "${adListFile}" ]; then
    cp "${adListRepoDefault}" "${adListFile}"
  fi

  echo -e "  ${INFO} Neutrino emissions detected..."
  echo ""
  local str="Pulling source lists into range"
  echo -ne "  ${INFO} ${str}..."

  sources=()
  while IFS= read -r line || [[ -n "$line" ]]; do
    # Do not read commented out or blank lines
    if [[ ${line} = \#* ]] || [[ ! ${line} ]]; then
      echo "" > /dev/null
    else
      sources+=(${line})
    fi
  done < ${adListFile}

  echo -e "${OVER}  ${TICK} ${str}"
}

# patternCheck - check to see if curl downloaded any new files.
gravity_patternCheck() {
  patternBuffer=$1
  success=$2
  error=$3
  if [[ "${success}" = true ]]; then
    # Check if download was successful but list has not been modified
    if [[ "${error}" == "304" ]]; then
      echo -e "  ${TICK} No changes detected, transport skipped!"
    # Check if the patternbuffer is a non-zero length file
    elif [[ -s "${patternBuffer}" ]]; then
      # Some blocklists are copyright, they need to be downloaded and stored
      # as is. They can be processed for content after they have been saved.
      mv "${patternBuffer}" "${saveLocation}"
      echo -e "  ${TICK} List updated, transport successful!"
    else
      # Empty file -> use previously downloaded list
      echo -e "  ${INFO} Received empty file, ${COL_LIGHT_GREEN}using cached one${COL_NC} (list not updated!)"
    fi
  else
    # Check if cached list exists
    if [[ -r "${saveLocation}" ]]; then
      echo -e "  ${CROSS} List download failed, using cached list (list not updated!)"
    else
      echo -e "  ${CROSS} Download failed and no cached list available (list will not be considered)"
    fi
  fi
}

# transport - curl the specified url with any needed command extentions
gravity_transport() {
  url=$1
  cmd_ext=$2
  agent=$3

  # tmp file, so we don't have to store the (long!) lists in RAM
  patternBuffer=$(mktemp)
  heisenbergCompensator=""
  if [[ -r ${saveLocation} ]]; then
    # If domain has been saved, add file for date check to only download newer
    heisenbergCompensator="-z ${saveLocation}"
  fi

  # Silently curl url
  echo -e "${OVER}  ${TICK} ${str}"
  local str="Status:"
  echo -ne "  ${INFO} ${str} Pending"
  err=$(curl -s -L ${cmd_ext} ${heisenbergCompensator} -w %{http_code} -A "${agent}" ${url} -o ${patternBuffer})

  # Analyze http response
  case "$err" in
    "200"  ) echo -e "${OVER}  ${TICK} ${str} Success (OK)"; success=true;;
    "304"  ) echo -e "${OVER}  ${TICK} ${str} Not modified"; success=true;;
    "403"  ) echo -e "${OVER}  ${CROSS} ${str} Forbidden"; success=false;;
    "404"  ) echo -e "${OVER}  ${CROSS} ${str} Not found"; success=false;;
    "408"  ) echo -e "${OVER}  ${CROSS} ${str} Time-out"; success=false;;
    "451"  ) echo -e "${OVER}  ${CROSS} ${str} Unavailable For Legal Reasons"; success=false;;
    "521"  ) echo -e "${OVER}  ${CROSS} ${str} Web Server Is Down (Cloudflare)"; success=false;;
    "522"  ) echo -e "${OVER}  ${CROSS} ${str} Connection Timed Out (Cloudflare)"; success=false;;
    "500"  ) echo -e "${OVER}  ${CROSS} ${str} Internal Server Error"; success=false;;
    *      ) echo -e "${OVER}  ${CROSS} ${str} Status $err"; success=false;;
  esac

  # Process result
  gravity_patternCheck "${patternBuffer}" "${success}" "${err}"

  # Delete temp file if it hasn't been moved
  if [[ -f "${patternBuffer}" ]]; then
    rm "${patternBuffer}"
  fi
}

# spinup - main gravity function
gravity_spinup() {
  echo ""
  # Loop through domain list. Download each one and remove commented lines (lines beginning with '# 'or '/') and # blank lines
  for ((i = 0; i < "${#sources[@]}"; i++)); do
    url=${sources[$i]}
    # Get just the domain from the URL
    domain=$(cut -d'/' -f3 <<< "${url}")

    # Save the file as list.#.domain
    saveLocation=${piholeDir}/list.${i}.${domain}.${justDomainsExtension}
    activeDomains[$i]=${saveLocation}

    agent="Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36"

    # Use a case statement to download lists that need special cURL commands
    # to complete properly and reset the user agent when required
    case "${domain}" in
      "pgl.yoyo.org")
        cmd_ext="-d mimetype=plaintext -d hostformat=hosts"
      ;;

      # Default is a simple request
      *) cmd_ext=""
    esac

    if [[ "${skipDownload}" == false ]]; then
      local str="Aiming tractor beam at $domain"
      echo -ne "  ${INFO} ${str}..."

      gravity_transport "$url" "$cmd_ext" "$agent" "$str"
      echo ""
    fi
  done
}

# Schwarzchild - aggregate domains to one list and add blacklisted domains
gravity_Schwarzchild() {
  echo ""
  # Find all active domains and compile them into one file and remove CRs
  local str="Aggregating list of domains"
  echo -ne "  ${INFO} ${str}..."
  
  truncate -s 0 ${piholeDir}/${matterAndLight}
  for i in "${activeDomains[@]}"; do
    # Only assimilate list if it is available (download might have failed permanently)
    if [[ -r "${i}" ]]; then
      cat "${i}" | tr -d '\r' >> ${piholeDir}/${matterAndLight}
    fi
  done

  echo -e "${OVER}  ${TICK} ${str}"
}

gravity_Blacklist() {
  # Append blacklist entries to eventHorizon if they exist
  if [[ -f "${blacklistFile}" ]]; then
    numBlacklisted=$(wc -l < "${blacklistFile}")
    plural=; [[ "$numBlacklisted" != "1" ]] && plural=s
    local str="Exact blocked domain${plural}: $numBlacklisted"
    echo -e "  ${INFO} ${str}"
  else
    echo -e "  ${INFO} Nothing to blacklist!"
  fi
}

gravity_Wildcard() {
  # Return number of wildcards in output - don't actually handle wildcards
  if [[ -f "${wildcardlist}" ]]; then
    numWildcards=$(grep -c ^ "${wildcardlist}")
    if [[ -n "${IPV4_ADDRESS}" ]] && [[ -n "${IPV6_ADDRESS}" ]];then
      let numWildcards/=2
    fi
    plural=; [[ "$numWildcards" != "1" ]] && plural=s
    echo -e "  ${INFO} Wildcard blocked domain${plural}: $numWildcards"
  else
    echo -e "  ${INFO} No wildcards used!"
  fi

}

gravity_Whitelist() {
  echo ""
  # Prevent our sources from being pulled into the hole
  plural=; [[ "${sources[@]}" != "1" ]] && plural=s
  local str="Adding adlist source${plural} to the whitelist"
  echo -ne "  ${INFO} ${str}..."

  urls=()
  for url in "${sources[@]}"; do
    tmp=$(awk -F '/' '{print $3}' <<< "${url}")
    urls=("${urls[@]}" ${tmp})
  done

  echo -e "${OVER}  ${TICK} ${str}"

  # Ensure adlist domains are in whitelist.txt
  ${whitelistScript} -nr -q "${urls[@]}" > /dev/null

  # Check whitelist.txt exists.
  if [[ -f "${whitelistFile}" ]]; then
    # Remove anything in whitelist.txt from the Event Horizon
    numWhitelisted=$(wc -l < "${whitelistFile}")
    plural=; [[ "$numWhitelisted" != "1" ]] && plural=s
    local str="Whitelisting $numWhitelisted domain${plural}"
    echo -ne "  ${INFO} ${str}..."

    # Print everything from preEventHorizon into eventHorizon EXCEPT domains in whitelist.txt
    grep -F -x -v -f ${whitelistFile} ${piholeDir}/${preEventHorizon} > ${piholeDir}/${eventHorizon}

    echo -e "${OVER}  ${TICK} ${str}"
  else
    echo -e "  ${INFO} Nothing to whitelist!"
  fi
}

gravity_unique() {
  # Sort and remove duplicates
  local str="Removing duplicate domains"
  echo -ne "  ${INFO} ${str}..."

  sort -u  ${piholeDir}/${supernova} > ${piholeDir}/${preEventHorizon}

  echo -e "${OVER}  ${TICK} ${str}"
  numberOf=$(wc -l < ${piholeDir}/${preEventHorizon})
  echo -e "  ${INFO} ${COL_LIGHT_BLUE}${numberOf}${COL_NC} unique domains trapped in the event horizon."
}

gravity_doHostFormat() {
  # Check vars from setupVars.conf to see if we're using IPv4, IPv6, Or both.
  if [[ -n "${IPV4_ADDRESS}" ]] && [[ -n "${IPV6_ADDRESS}" ]];then
    # Both IPv4 and IPv6
    awk -v ipv4addr="$IPV4_ADDRESS" -v ipv6addr="$IPV6_ADDRESS" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> "${2}" < "${1}"
  elif [[ -n "${IPV4_ADDRESS}" ]] && [[ -z "${IPV6_ADDRESS}" ]];then
    # Only IPv4
    awk -v ipv4addr="$IPV4_ADDRESS" '{sub(/\r$/,""); print ipv4addr" "$0}' >> "${2}" < "${1}"
  elif [[ -z "${IPV4_ADDRESS}" ]] && [[ -n "${IPV6_ADDRESS}" ]];then
    # Only IPv6
    awk -v ipv6addr="$IPV6_ADDRESS" '{sub(/\r$/,""); print ipv6addr" "$0}' >> "${2}" < "${1}"
  elif [[ -z "${IPV4_ADDRESS}" ]] &&[[  -z "${IPV6_ADDRESS}" ]];then
    echo -e "${OVER}  ${CROSS} ${str}"
    echo -e "      ${COL_LIGHT_RED}No IP Values found! Please run 'pihole -r' and choose reconfigure to restore values${COL_NC}"
    exit 1
  fi
}

gravity_hostFormatLocal() {
  # Format domain list as "192.168.x.x domain.com"

  if [[ -f "/etc/hostname" ]]; then
    hostname=$(< /etc/hostname)
  elif [ -x "$(command -v hostname)" ]; then
    hostname=$(hostname -f)
  else
    echo -e "  ${CROSS} Unable to determine fully qualified domain name of host"
  fi

  echo -e "${hostname}\npi.hole" > "${localList}.tmp"
  # Copy the file over as /etc/pihole/local.list so dnsmasq can use it
  rm "${localList}"
  gravity_doHostFormat "${localList}.tmp" "${localList}"
  rm "${localList}.tmp"
}

gravity_hostFormatGravity() {
  # Format domain list as "192.168.x.x domain.com"
  echo "" > "${piholeDir}/${accretionDisc}"
  gravity_doHostFormat "${piholeDir}/${eventHorizon}" "${piholeDir}/${accretionDisc}"
  # Copy the file over as /etc/pihole/gravity.list so dnsmasq can use it
  mv "${piholeDir}/${accretionDisc}" "${adList}"

}

gravity_hostFormatBlack() {
  if [[ -f "${blacklistFile}" ]]; then
    numBlacklisted=$(wc -l < "${blacklistFile}")
    # Format domain list as "192.168.x.x domain.com"
    gravity_doHostFormat "${blacklistFile}" "${blackList}.tmp"
    # Copy the file over as /etc/pihole/black.list so dnsmasq can use it
    mv "${blackList}.tmp" "${blackList}"
  else
    echo -e "  ${INFO} Nothing to blacklist!"
  fi
}

# blackbody - remove any remnant files from script processes
gravity_blackbody() {
  # Loop through list files
  for file in ${piholeDir}/*.${justDomainsExtension}; do
    # If list is in active array then leave it (noop) else rm the list
    if [[ " ${activeDomains[@]} " =~ ${file} ]]; then
      :
    else
      rm -f "${file}"
    fi
  done
}

gravity_advanced() {
  # Remove comments and print only the domain name
  # Most of the lists downloaded are already in hosts file format but the spacing/formating is not contigious
  # This helps with that and makes it easier to read
  # It also helps with debugging so each stage of the script can be researched more in depth
  local str="Formatting list of domains to remove comments"
  echo -ne "  ${INFO} ${str}..."

  #awk '($1 !~ /^#/) { if (NF>1) {print $2} else {print $1}}' ${piholeDir}/${matterAndLight} | sed -nr -e 's/\.{2,}/./g' -e '/\./p' >  ${piholeDir}/${supernova}
  #Above line does not correctly grab domains where comment is on the same line (e.g 'addomain.com #comment')
  #Awk -F splits on given IFS, we grab the right hand side (chops trailing #coments and /'s to grab the domain only.
  #Last awk command takes non-commented lines and if they have 2 fields, take the left field (the domain) and leave
  #+ the right (IP address), otherwise grab the single field.
  cat ${piholeDir}/${matterAndLight} | \
    awk -F '#' '{print $1}' | \
    awk -F '/' '{print $1}' | \
    awk '($1 !~ /^#/) { if (NF>1) {print $2} else {print $1}}' | \
    sed -nr -e 's/\.{2,}/./g' -e '/\./p' >  ${piholeDir}/${supernova}

  echo -e "${OVER}  ${TICK} ${str}"

  numberOf=$(wc -l < ${piholeDir}/${supernova})
  echo -e "  ${INFO} ${COL_LIGHT_BLUE}${numberOf}${COL_NC} domains being pulled in by gravity"

  gravity_unique
}

gravity_reload() {
  # Reload hosts file
  echo ""
  local str="Refreshing lists in dnsmasq"
  echo -e "  ${INFO} ${str}..."

  # Ensure /etc/dnsmasq.d/01-pihole.conf is pointing at the correct list!
  # First escape forward slashes in the path:
  adList=${adList//\//\\\/}
  # Now replace the line in dnsmasq file
  #  sed -i "s/^addn-hosts.*/addn-hosts=$adList/" /etc/dnsmasq.d/01-pihole.conf

  "${PIHOLE_COMMAND}" restartdns
}

for var in "$@"; do
  case "${var}" in
    "-f" | "--force"     ) forceGrav=true;;
    "-h" | "--help"      ) helpFunc;;
    "-sd" | "--skip-download"    ) skipDownload=true;;
    "-b" | "--blacklist-only"    ) blackListOnly=true;;
  esac
done

if [[ "${forceGrav}" == true ]]; then
  str="Deleting exising list cache"
  echo -ne "${INFO} ${str}..."

  if rm /etc/pihole/list.* 2> /dev/null; then
    echo -e "${OVER}  ${TICK} ${str}"
  else
    echo -e "${OVER}  ${CROSS} ${str}"
  fi
fi

if [[ ! "${blackListOnly}" == true ]]; then
  gravity_collapse
  gravity_spinup
  if [[ "${skipDownload}" == false ]]; then
    gravity_Schwarzchild
    gravity_advanced
  else
    echo -e "  ${INFO} Using cached Event Horizon list..."
    numberOf=$(wc -l < ${piholeDir}/${preEventHorizon})
    echo -e "  ${INFO} ${COL_LIGHT_BLUE}$numberOf${COL_NC} unique domains trapped in the event horizon."
  fi
  gravity_Whitelist
fi
gravity_Blacklist
gravity_Wildcard

str="Formatting domains into a HOSTS file"
echo -ne "  ${INFO} ${str}..."
if [[ ! "${blackListOnly}" == true ]]; then
  gravity_hostFormatLocal
  gravity_hostFormatGravity
fi
gravity_hostFormatBlack
echo -e "${OVER}  ${TICK} ${str}"

gravity_blackbody

if [[ ! "${blackListOnly}" == true ]]; then
  # Clear no longer needed files...
  str="Cleaning up un-needed files"
  echo -ne "  ${INFO} ${str}..."

  rm ${piholeDir}/pihole.*.txt 2> /dev/null
  
  echo -e "${OVER}  ${TICK} ${str}"
fi

gravity_reload
"${PIHOLE_COMMAND}" status