#!/bin/bash

# jpegmunge
# by Jon Jensen <jon@swelter.net>
# 2004-09-12

transform=
rename=
while [ "${1:0:1}" = "-" ]
do
	if [ $1 = "-90" ]; then
		transform="$transform -rotate 90"
	elif [ $1 = "-180" ]; then
		transform="$transform -rotate 180"
	elif [ $1 = "-270" ]; then
		transform="$transform -rotate 270"
	elif [ $1 = "-o" ]; then
		transform="$transform -optimize"
	elif [ $1 = "-r" ]; then
		rename="$rename -nf%Y%m%d-%H%M%S"
	elif [ $1 = "-t" ]; then
		rename="$rename -ft"
	else
		echo "Ignoring unknown option $1" >&2
	fi
	shift
done

if [ $# -lt 1 ]; then
	cat <<EOF >&2
Usage: $0 [-r] [-t] [-o] [-90|-180|-270] file1 [file2 ...]

File metadata options (calls jhead):
  -r rename to YYYYMMDD-HHMISS.jpg based on EXIF creation timestamp
  -t set timestamp of file to EXIF creation timestamp

Image transform options (calls jpegtran):
  -o optimize (non-lossy)
 -90 rotate 90 degrees
-180 rotate 180 degrees
-270 rotate 270 degrees

Transforms roll file's timestamp ahead by 1 second so that image
viewers can see the file changed and refresh the display.

Preserves ownership, creation and modification timestamps (with the
exception of the 1 second increment), and all EXIF data. Transforms
are saved to a temporary file first to avoid data loss in case of a
crash or abort.
EOF
	exit 1
fi

tmpfile=.jpegrotate.tmp.$$

for i
do
	if [ -n "$transform" ]; then
		jpegtran -trim -copy all $transform -outfile $tmpfile "$i"
		if [ $? -eq 0 ]; then
			if [ "$EUID" -eq 0 ]; then
				chown --reference="$i" $tmpfile
			else
				chgrp -f --reference="$i" $tmpfile
			fi
			chmod -f --reference="$i" $tmpfile
			#touch -c --reference="$i" -F 1 $tmpfile
			touch -c --reference="$i" $tmpfile
			mv -f $tmpfile "$i"
			echo "Transformed $i"
		else
			rm -f $tmpfile
			echo "Error transforming $i" >&2
		fi
	fi
	[ -n "$rename" ] && jhead $rename "$i"
done