#!/bin/bash
#B. Vandeportaele 2018
OUTPUT_DIR="./pdf/"
OUTPUT_FILENAME=cours_comm

#check that soffice is not already run
SOFFICE_RUNNING=$(pstree | grep soffice)
if [ ! -z "$SOFFICE_RUNNING" ];
then
  echo soffice have to be closed before lauching this script!
  echo save your data and try pkill soffice
exit -1
fi
#create output directory
mkdir -p ${OUTPUT_DIR}

#generate list and convert files to pdf if required
FILE_LIST=""
while read line  #for each line of list
do
  echo processing ${line}
  if [ ! -z "${line}" ]; #avoid processing empty lines
  then
    OFFICE_FILE=${line}
    PDF_FILE="${OFFICE_FILE/".odp"/".pdf"}"
    PDF_FILE_WITH_FOLDER="${OUTPUT_DIR}${PDF_FILE}"
    # test if the office file is newer than the pdf, it works also if the pdf file is not existing
    if [ ${OFFICE_FILE} -nt ${PDF_FILE_WITH_FOLDER} ]
    then
       echo "this file has changed, converting it to pdf: ${OFFICE_FILE} -> ${PDF_FILE_WITH_FOLDER}"
       rm ${PDF_FILE_WITH_FOLDER}
       #convert each individual file to pdf
       echo "soffice --convert-to pdf --outdir ${OUTPUT_DIR}  ${OFFICE_FILE}"
       soffice --convert-to pdf --outdir ${OUTPUT_DIR}  ${OFFICE_FILE}
    else
      echo "this file has not changed, keeping the previous pdf: ${OFFICE_FILE} -> ${PDF_FILE_WITH_FOLDER}"
    fi
    #add to the list of file in variable and subsitute odp with pdf
    FILE_LIST="${FILE_LIST} ${OUTPUT_DIR}${line/".odp"/".pdf"}"
  fi
done < listoffilestoconcatenate.txt
#I'm obliged to use while .... in that order so the scope of ${FILE_LIST} is not only local inside the loop
echo list of files: ${FILE_LIST}

#concatenate the files to a single one
gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=${OUTPUT_DIR}${OUTPUT_FILENAME}.pdf -dBATCH ${FILE_LIST}

#count the number of pages in the concatened file
# https://stackoverflow.com/questions/1672580/get-number-of-pages-in-a-pdf-using-a-cmd-batch-file
NUMBEROFPAGES=$(pdfinfo "${OUTPUT_DIR}${OUTPUT_FILENAME}.pdf" | grep Pages | sed 's/[^0-9]*//')
echo $NUMBEROFPAGES pages found
#set the right number of pages to generate in numbers.tex from the generic numbers.in.tex file
sed "s/NUMBEROFPAGESTOGENERATE/$NUMBEROFPAGES/g" <numbers.in.tex >${OUTPUT_DIR}numbers.tex
cat ${OUTPUT_DIR}numbers.tex
#compute the pdf for pages numbers
 pdflatex -output-directory ${OUTPUT_DIR} ${OUTPUT_DIR}numbers.tex

#merge the pdf containing the content and the pdf containing the page numbers
# http://cazencott.info/index.php/post/2015/04/30/Numbering-PDF-Pages
# sudo apt install pdftk
if false
then
  #split files to individual pages
  pdftk ${OUTPUT_DIR}numbers.pdf burst output ${OUTPUT_DIR}number_%03d.pdf
  pdftk ${OUTPUT_DIR}${OUTPUT_FILENAME}.pdf burst output ${OUTPUT_DIR}page_%03d.pdf
  for i in $(seq -f %03g 1 $NUMBEROFPAGES) ; do pdftk ${OUTPUT_DIR}page_$i.pdf stamp ${OUTPUT_DIR}number_$i.pdf ${OUTPUT_DIR}output new_$i.pdf ; done
  pdftk ${OUTPUT_DIR}new_???.pdf output ${OUTPUT_DIR}${OUTPUT_FILENAME}_numbered.pdf
else
  #direct method dealing with the 2 files without merging individual pages
  pdftk ${OUTPUT_DIR}${OUTPUT_FILENAME}.pdf multistamp ${OUTPUT_DIR}numbers.pdf output ${OUTPUT_DIR}${OUTPUT_FILENAME}_numbered.pdf
fi

#generate the 6 slides per page for printing
pdfnup --nup 2x3 --no-landscape -o  ${OUTPUT_DIR}${OUTPUT_FILENAME}_numbered_six.pdf  ${OUTPUT_DIR}${OUTPUT_FILENAME}_numbered.pdf 

#add annexes if required....