#!/bin/sh
#
# tiff-batch-convert.sh, Copyright © 2017 Matteo Cypriani
#
# This program is free software. It comes without any warranty, to the extent
# permitted by applicable law. You can redistribute it and/or modify it under
# the terms of the Do What The Fuck You Want To Public License, Version 2, as
# published by Sam Hocevar. See http://sam.zoy.org/wtfpl/COPYING for more
# details.
#
# This script batch-converts TIFF images to another format of your choice.
#
# Dependencies:
# - convert from ImageMagick
# - tiffinfo from libtiff

set -e
#set -x

######################
# USER CONFIGURATION #
######################

# Format to convert the TIFF images to (lowercase)
FORMAT="jpg"

# Maximum size of the pictures for the "low" quality setting.
LOW_SCALE="800x800"

# Maximum size of the pictures for the "medium" quality setting.
MEDIUM_SCALE="2000x2000"

#############################
# END OF USER CONFIGURATION #
#############################

# Do we have at least a quality setting, an input album and a destination
# folder?
if [ $# -lt 3 ] ; then
	echo "Usage:" >&2
	echo "	$0 <QUALITY> <DESTINATION> <ALBUM1> [ALBUM2 [...]]" >&2
	echo '<QUALITY> can be "high" (no rescaling), "medium" or "low".' >&2
	echo '<DESTINATION> is the base directory in which the converted albums will be stored.' >&2
	echo 'Each <ALBUM> is a directory containing TIFF files.' >&2
	exit 1
fi

QUALITY="$1"
shift
ALBUM_DEST="$1"
shift

# Should the pictures be resized, depending on the quality setting?
if [ "$QUALITY" = "low" ] ; then
	SCALE_OPT="-scale $LOW_SCALE"
elif [ "$QUALITY" = "medium" ] ; then
	SCALE_OPT="-scale $MEDIUM_SCALE"
elif [ "$QUALITY" = "high" ] ; then
	# No rescaling
	SCALE_OPT=""
else
	echo "Error! Quality setting unknown \"$QUALITY\"." >&2
	exit 1
fi

# Convert the pictures
while [ $# -gt 0 ] ; do
	ALBUM="$1"
	shift
	ALBUM_NAME=$(basename "$ALBUM")
	mkdir -p "$ALBUM_DEST/$ALBUM_NAME"

	for FILE in "$ALBUM"/*.tiff ; do
		DEST_NAME=$(basename "$FILE" | sed "s/tiff$/$FORMAT/")
		DEST_FILE="$ALBUM_DEST/$ALBUM_NAME/$DEST_NAME"
		echo "\"$FILE\" -> \"$DEST_FILE\""

		# Should we rotate the image?
		ORIENTATION=$(tiffinfo "$FILE" | sed -n 's/^[\t ]*Orientation: //p')
		if [ "$ORIENTATION" = "row 0 top, col 0 lhs" ] ; then
			ROTATE_OPT="" # No rotation
		elif [ "$ORIENTATION" = "row 0 bottom, col 0 rhs" ] ; then
			ROTATE_OPT="-rotate 180"
		else
			# Print a warning to tell the user the script should be
			# improved :-)
			echo "Warning! Image orientation unknown: \"$ORIENTATION\"." >&2
		fi

		# shellcheck disable=SC2086
		convert $SCALE_OPT $ROTATE_OPT "$FILE" "$DEST_FILE"
	done
done

echo
echo "Converted everything successfuly!"