#!/bin/bash
# this script rotates JPEG files
# you can use the --rotate/-r argument to specify the angle, or you
# can use symlinks that have various bits of text in them to set the
# default.  This script is designed to interact with nautilus nicely.

# default angle
angle=90

# set defaults by $0 so symlinks just do the right thing
case $0 in
  *270*) angle=270 ;;
  *CCW*) angle=270 ;;
  *180*) angle=180 ;;
  *USD*) angle=180 ;;
  *90*)  angle=90  ;;
  *CW*)  angle=90  ;;  # must be listed after CCW for obvious reasons
esac

message ()
{
    if [ -n "$NAUTILUS_SCRIPT_SELECTED_FILE_PATHS" ] ; then
	# we must be running as a nautilus script, report errors...
	nautilus-error-dialog --message="$@" --title="Rotation script failure"
    else
	echo "$*" >&2
    fi
}

usage ()
{
    message $1 $(echo -e '\n') "usage: $0 [-a <angle:90|180|270>] <list of jpeg files>"
}

[ -x /usr/bin/jpegtran ] || {
    message "$0: /usr/bin/jpegtran program not available"
    exit 1
}

filelist=
ignorelist=

while [ $# -gt 0 ] ; do
  case $1 in
    --a*|-a*|--r*|-r*) shift;
      case $1 in
        90)
          angle=90
	  ;;
        180)
          angle=180
	  ;;
        270)
          angle=270
	  ;;
        *)
          usage "unrecognized angle"
	  exit 1
	  ;;
      esac
      ;;
    --h*|-h*) shift;
      usage
      exit 0
      ;;
    *)
      if file "$1" | grep JPEG > /dev/null 2>&1 ; then
        filelist="$filelist $1"
      else
        ignorelist="$ignorelist $1"
      fi
      ;;
  esac
  shift
done

if [ -n "$ignorelist" ] ; then
    message "ignoring unrecognized non-JPEG file(s) $ignorelist..."
fi

for file in $filelist ; do
    dirname=$(dirname $file)

    # Create temp file in the same directory so that it's guaranteed to be
    # on the same filesystem. This makes the final move work
    TMP=$(mktemp $dirname/.$(basename $file).XXXXXX) || {
	message "$0: failed to create temporary file"
    }
    
    jpegtran -rotate $angle -copy all $file > $TMP || {
	message "$0: jpegtran failed on file $file"
	exit 2
    }

    # Keep the old timestamp
    touch -r $file $TMP || message "$0: failed to save timestamp for $file"

    # Nautilus depends on timestamps for its thumbnails, so manually remove
    # any old thumbnails
    
    thumbnail=$dirname/.thumbnails/$(basename $file)
    rm -f $thumbnail.png
    rm -f $thumbnail.png.x

    # Use mv, since it atomically replaces destination. This way we never get
    # Bad data in the file.
    mv $TMP $file || {
	message "$0: rename failed on file $file, $file rotated version available as $TMP"
	exit 3
    }

    thumbnail=$dirname/.thumbnails/$(basename $TMP)
    rm -f $thumbnail.*.png
    rm -f $thumbnail.*.png.x
    
done

# only on successful exit...
rm -f $TMP
exit 0