#!/usr/bin/env bash
# ---------------------------------------------------
# Repair broken PDF file using gs
#
# Depends on :
#   * ghostscript
#   * mupdf-tools
#
# Parameter :
#   $1 - URI of original PDF
#
# Revision history :
#   08/11/2014, V1.0 - Creation by N. Bernaerts
#   20/11/2014, V1.1 - Add file selection dialog box
#   24/01/2015, V1.2 - Check tools availability
#   24/11/2017, V2.0 - Add MuTool repair method (thank to Willie Wildgrube idea)
#   01/05/2020, V2.1 - Add method selection with --method
#                      Adaptation for Ubuntu 20.04 LTS 
#   07/05/2020, V2.2 - Multiple files management 
# ---------------------------------------------------

# variable
ERROR=""
METHOD="ghostscript"

# if no argument, display help
if [ $# -eq 0 ] 
then
	echo "Tool to repair a PDF documents"
	echo "Parameters are :"
	echo "  --method <method>   Reparation method (ghostscrit or mutool)"
	echo "  <file1> <file2>     Files to repair"
	exit 1
fi

# iterate thru parameters
while test ${#} -gt 0
do
	case $1 in
		--method) shift; METHOD="$1"; shift; ;;
		*) ARR_FILE=( "${ARR_FILE[@]}" "$1" ); shift; ;;
    esac
done

# --------------------------
# check tools availability
# --------------------------

# check tools availability
command -v gs >/dev/null 2>&1 || { zenity --error --text="Please install gs [ghostscript]"; exit 1; }
command -v mutool >/dev/null 2>&1 || { zenity --error --text="Please install mutool [mupdf-tools]"; exit 1; }

# generate temporary directory
TMP_DIR=$(mktemp -t -d "pdf-repair-XXXXXXXX")
TMP_ORIGINAL="${TMP_DIR}/original.pdf"
TMP_REPAIRED="${TMP_DIR}/repaired.pdf"
pushd "${TMP_DIR}"

# check at least one file is provided
NBR_FILE=${#ARR_FILE[@]}
[ "${ERROR}" = "" -a ${NBR_FILE} -eq 0 ] && ERROR="No file selected"

# check repair method
[ "${ERROR}" = "" -a "${METHOD}" != "ghostscript" -a "${METHOD}" != "mutool" ] && ERROR="Unknown repair tool"

# --------------------
#   PDF repair
# --------------------

# loop thru image files
if [ "${ERROR}" = "" ] 
then
	(
	INDEX=0
	for ORIGINAL_URI in "${ARR_FILE[@]}"
	do
		# increment file index
		INDEX=$((INDEX+1))

		# generate filenames
		ORIGINAL_DIR=$(dirname "${ORIGINAL_URI}")
		ORIGINAL_FILE=$(basename "${ORIGINAL_URI}")
		ORIGINAL_NAME="${ORIGINAL_FILE%.*}"

		# copy input file to temporary folder
		echo "# ${INDEX} / ${NBR_FILE} - Copy of original PDF document ..."
		gio copy "${ORIGINAL_URI}" "${TMP_ORIGINAL}"
	
		# repair PDF
		echo "# ${INDEX} / ${NBR_FILE} - Repair original PDF using ${METHOD} ..."
		[ "${METHOD}" = "ghostscript" ] && gs -q -dNOPAUSE -dBATCH -dSAFER -sDEVICE=pdfwrite -sOutputFile="${TMP_REPAIRED}" "${TMP_ORIGINAL}" \
		                                || mutool clean "${TMP_ORIGINAL}" "${TMP_REPAIRED}"

		# place corrected file side to original 
		echo "# ${INDEX} / ${NBR_FILE} - Copy of repaired PDF ..."
		gio copy "${TMP_REPAIRED}" "${ORIGINAL_DIR}/${ORIGINAL_NAME}-repaired.pdf"
	done
	
	) | zenity --width=500 --height=25 --progress --pulsate --auto-close --title "Repair PDF" --window-icon="/usr/share/icons/pdf-repair.png"
fi

# -------------------
#   End of operation
# -------------------

# display error message
[ "${ERROR}" != "" ] && zenity --error --width=600 --text="${ERROR}"

# remove temporary directory
popd
rm -r "${TMP_DIR}"