#!/usr/bin/bash

set -e
cd "$(dirname "$0")/.."

echo
echo "-> Generating Compressed PDFs"

if ! command -v gs >/dev/null; then
  echo "Could not find GhostScript."
  echo "Please install it with 'sudo apt install ghostscript'."
  exit 1
fi

pdfs=()

get_compressed_path() {
  echo "$1" | sed -r 's/(.+)\/([^/]+)\.pdf/\1\/compressed\/\2.pdf/'
}

for file in data/*/pdf/*.pdf; do
  compressed="$(get_compressed_path "$file")"
  if [ ! -f "$compressed" ]; then
    pdfs+=("$file")
  fi
done

i=1
n="${#pdfs[@]}"

if [ "$n" == "0" ]; then
  echo "(Nothing to do)"
else
  for file in "${pdfs[@]}"; do
    printf "Compressing PDF $i/$n ($file)... "
    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile="$(get_compressed_path "$file")" "$file"
    printf "Done\n"
    i=$((i + 1))
  done
fi