#!/usr/bin/env zsh

###
: '
Scans a single page using sane’s `scanimage` and converts it to PDF using
ImageMagick.
'
###

# find your device URI by doing `lpstat -s`!
# (mine is an HP network printer connected through HPLIP)
_device="hpaio:/net/DeskJet_3630_series?hostname=drucker.vandenhorz.de"
# change this to your preferred PDF viewer
_viewer="zathura"

###

trap _ctrlc INT

function _cleanup() {
  # clean up _tmpdir, if created earlier
  if [ ! -z $_tmpdir ] ; then rm -rf $_tmpdir; fi
}
function _ctrlc() {
  echo "cancelled by SIGINT/^C"
  _cleanup
  exit 1
}

_cmd=""
_file=""
_landscape=false
_silent=false
_tmpdir=""

usage () {
  echo 'Scans a single page using sane’s `scanimage` and converts it to PDF using ImageMagick and opens it in Evince.

options:
  -h, --help
    prints this message
  -l, --landscape
    rotates the page 90° left for landscape scans
  -o, --outfile FILE
    silently writes the scan to FILE instead of using a temporary file
    implies -s
  -r, --rotate
    same as -l
  -s, --silent
    silently write output file, don’t open it
  --viewer CMD
    uses CMD as PDF viewer instead of Evince'
}

###~begin option parsing
zparseopts -A _OPTS -D -E -- h l o: r s -help -outfile: -landscape -rotate -silent -viewer
if [ ! -z "$@" ] ; then
  usage
  exit 1
fi

for opt in "${(@k)_OPTS}"; do
  case $opt in
    -h|--help)
      usage
      exit 0
      ;;
    -l|-r|--landscape|--rotate)
      _landscape=true
      ;;
    -o|--outfile)
      _file="$_OPTS[$opt]"
      _silent=true
      ;;
    -s|--silent)
      _silent=true
      ;;
    --viewer)
      _viewer="$_OPTS[$opt]"
      ;;
  esac
done
###~end option parsing

# check file ending if outfile is specified (and add it), else use tmpfile
# skip when silent (e.g. invoked by `scanmultipage`)
if [ ! -z $_file ] ; then
  if [[ ! "$_file" =~ ".*\.pdf" ]] ; then ( $_silent ) || _file="${_file}.pdf"; fi
else
  _tmpdir=`mktemp -d`
  _file="${_tmpdir}/$(date +%Y-%m-%d).pdf"
fi

scanimage -d "$_device" -p --resolution 300 --mode Color -x 210 -y 297 --format=png | magick $( ( $_landscape ) && print  "\-rotate \-90 ")- $_file && \
( $_silent ) || $_viewer $_file >/dev/null 2>/dev/null

_cleanup