post_install() {
  echo -e "\e[1;33m==>\e[0m Read setup instructions at \e[1;36mhttps://wiki.archlinux.org/index.php/Pi-hole\e[0m"
  echo -e "\e[1;33m==>\e[0m Generating initial block list, please wait...\e[0m"
  chown -R http:http /srv/http/pihole
  /opt/pihole/mimic_setupVars.conf.sh

  _dnsmasq_address_setup

  # best solution to managing script-created files I can think of
  # is to install them to /usr/share/pihole/configs/ using sed magic
  # and copy them into /etc/dnsmasq.d/ on the first install only
  # from then on users can edit these and not have them overwritten
  # by an update
  install -Dm644 /usr/share/pihole/configs/01-pihole.example.conf /etc/dnsmasq.d/01-pihole.conf
  install -Dm644 /usr/share/pihole/configs/02-pihole.example.conf /etc/dnsmasq.d/02-pihole.conf

  # update lists on first run
  pihole -g > /dev/null
}

post_upgrade() {
  # clean old/unused/deprecated files
  [ -e /etc/pihole/hosts ] && rm /etc/pihole/hosts
  [ -e /etc/pihole/.useIPv6 ] && rm /etc/pihole/.useIPv6

  # if neither file is present, bash throws an non-0 exit
  return 0
}

post_remove() {
  [ -e /run/log/pihole/pihole.log ] && rm /run/log/pihole/pihole.log

  # delete all temp files except those modified the user
  # TODO - make this more intelligent to save *.pacsave.# where # is a number
  find /etc/pihole -type f ! -name '*.pacsave' ! -name 'pihole-FTL.conf' ! -name 'pihole-FTL.db' -delete
}

_dnsmasq_address_setup() {   # official code here
  . /etc/pihole/setupVars.conf
  dnsmasq_pihole_conf=/usr/share/pihole/configs/02-pihole.example.conf

  if [[ -f /etc/hostname ]]; then
    hostname=$(</etc/hostname)
  elif [ -x "$(command -v hostname)" ]; then
    hostname=$(hostname -f)
  fi

  #Replace IPv4 and IPv6 tokens in 01-pihole.conf for pi.hole resolution.
  if [[ "${IPV4_ADDRESS}" != "" ]]; then
    tmp=${IPV4_ADDRESS%/*}
    sed -i "s/@IPv4@/$tmp/" ${dnsmasq_pihole_conf}
  else
    sed -i '/^address=\/pi.hole\/@IPv4@/d' ${dnsmasq_pihole_conf}
    sed -i '/^address=\/@HOSTNAME@\/@IPv4@/d' ${dnsmasq_pihole_conf}
  fi

  if [[ "${IPV6_ADDRESS}" != "" ]]; then
    sed -i "s/@IPv6@/$IPV6_ADDRESS/" ${dnsmasq_pihole_conf}
  else
    sed -i '/^address=\/pi.hole\/@IPv6@/d' ${dnsmasq_pihole_conf}
    sed -i '/^address=\/@HOSTNAME@\/@IPv6@/d' ${dnsmasq_pihole_conf}
  fi

  if [[ "${hostname}" != "" ]]; then
    sed -i "s/@HOSTNAME@/$hostname/" ${dnsmasq_pihole_conf}
  else
    sed -i '/^address=\/@HOSTNAME@*/d' ${dnsmasq_pihole_conf}
  fi
}