#!/usr/bin/env bash
#
# Convert xopp to pdf
#
# @author Daniel Langbein <daniel@systemli.org>
# @license MIT License
#

SCRIPT_TITLE='Convert *.xopp to *.pdf'
depends=(xournalpp)
optdepends=(libnotify)

# Uncomment for debugging:
# exec 1> "${HOME}"/xopp-to-pdf.log 2>&1
# set -x

#######

function command_exists(){
  command -v "${1}" > /dev/null
}

function notify() {
  # $1: Message summary
  # $2: Message body
  # $3-$n: notify-send options

  if command_exists notify-send; then
    notify-send "$@";
  else
    # Write message to stderr
    printf '%s: %s\n' "${1}" "${2}" 1>&2;
  fi
}

function check_depends() {
  for dep in "${depends[@]}"; do
    if ! command_exists "${dep}"; then
      notify "${SCRIPT_TITLE}" "The dependency ${dep} is missing!" --icon=dialog-information;
      exit 1;
    fi
  done

  for dep in "${optdepends[@]}"; do
    if ! command_exists "${dep}"; then
      # Inform about missing opt. dependency on /dev/stderr
      printf 'Info: The optional dependency %s is missing.' "${dep}" 1>&2;
    fi
  done
}

function convert() {
  # $1: filepath

  local filename
  filename="$(basename -- "${1}")"

  if [[ "${filename}" != *".xopp" ]] ; then
    notify "${SCRIPT_TITLE}" "Not a *.xopp file! Skipping conversion of ${filename}" --icon=dialog-information;
    return 1;
  fi

  local target
  target="${1}".pdf;

  if [ -f "${target}" ]; then
    notify "${SCRIPT_TITLE}" "Skipping conversion as the target $(basename -- "${target}") does already exist!" --icon=dialog-information;
    return 1;
  else
    xournalpp --create-pdf="${target}" "${1}" || notify "${SCRIPT_TITLE}" "Conversion of ${filename} failed!" --icon=dialog-information;
  fi
}

check_depends

#
# Convert files selected by nautilus/GNOME files
#

# read newline-delimited absolute paths of selected files (on local filesystem)
echo "${NAUTILUS_SCRIPT_SELECTED_FILE_PATHS}" | while read file; do
  # If $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS contains a tailing newline,
  # $file may be the empty string
  if [ "${file}" = '' ]; then
    continue;
  fi
  convert "${file}"
done

#
# Convert files selected by Nemo
#

# read newline-delimited absolute paths of selected files (on local filesystem)
echo "${NEMO_SCRIPT_SELECTED_FILE_PATHS}" | while read file; do
  # If $NEMO_SCRIPT_SELECTED_FILE_PATHS contains a tailing newline,
  # $file may be the empty string
  if [ "${file}" = '' ]; then
    continue;
  fi
  convert "${file}"
done

notify "${SCRIPT_TITLE}" 'Done!' --icon=dialog-information;