#!/bin/sh
#
# $Id$
#
# Rename a picture taken with the Digital Camera File specification to
# use a more Unix-friendly name.
#
# Usage:
#
USAGE='Usage: camrename [-d] [-v] jpeg-files'
#
# Each given file is renamed.  If the existing name begins or ends in
# four digits (preference given to ending), those four digits will be
# preserved in the new name as "seq"; otherwise "seqn" will be set to
# ensure a unique filename, starting at 0001 or one more than the
# largest existing sequence number.  The remainder of the name will be
# created as follows:
#
#	Pyyyy.mm.dd-hh.mm.ss-seqn.jpg
#	 ^^^^ ^^ ^^ ^^ ^^ ^^ ^^^^
#	  |   |  |  |  |  |   |
#	  |   |  |  |  |  |   +--- Image sequence number
#	  |   |  |  |  |  |
#	  |   |  |  |  |  +------- Seconds of image creation date/time
#	  |   |  |  |  |
#	  |   |  |  |  +---------- Minutes of image creation date/time
#	  |   |  |  |
#	  |   |  |  +------------- Hours of image creation date/time
#	  |   |  |
#	  |   |  +---------------- Day of month image created
#	  |   |
#	  |   +------------------- Month image created
#	  |
#	  +----------------------- Year image created
#
#
# As a side effect, to compensate for MS-DOS stupidity, the execute
# permissions are turned off on all renamed files.
#
# Options:
#
# -d		Debug: report what would be done, but don't do it.
# -v		Verbose: report each rename as it is done.
#

debug=false
verbose=false

#
# Argument processing
#
while [ $# -gt 0 ]
do
    case "$1" in
	-d)
	    debug=true
	    verbose=true
	    ;;
	-v)
	    verbose=true
	    ;;
	--)
	    shift
	    break
	    ;;
	-*)	
	    echo "$USAGE" 1>&2
	    exit 2
	    ;;
	*)
	    break
	    ;;
    esac
    shift
done

case "$#" in
    0)
	echo "$USAGE" 1>&2
	exit 2
	;;
esac

#
# Process all file arguments
#
TMP=/tmp/cre$$

trap "rm -f $TMP.*; exit 1" 1 2 15
trap "rm -f $TMP.*; exit 0" 13

for file
do
    dir=`dirname $file`
    case "$file" in
	*.jpg)
	    base=`basename "$file" .jpg`
	    origExtension=jpg
	    extension=jpg
	    ;;
	*.jpeg)
	    base=`basename "$file" .jpeg`
	    origExtension=jpeg
	    extension=jpg
	    ;;
	*.JPG)
	    base=`basename "$file" .JPG`
	    origExtension=JPG
	    extension=jpg
	    ;;
	*.JPEG)
	    base=`basename "$file" .JPEG`
	    origExtension=JPEG
	    extension=jpg
	    ;;
	*.tif)
	    base=`basename "$file" .tif`
	    origExtension=tif
	    extension=tiff
	    ;;
	*.TIF)
	    base=`basename "$file" .TIF`
	    origExtension=TIF
	    extension=tiff
	    ;;
	*.tiff)
	    base=`basename "$file" .tiff`
	    origExtension=tiff
	    extension=tiff
	    ;;
	*.TIFF)
	    base=`basename "$file" .TIFF`
	    origExtension=TIFF
	    extension=tiff
	    ;;
	*)
	    echo "Can't handle file '$file', skipping" 1>&2
	    continue
	    ;;
    esac
    #
    # Extract file information with metacam.
    #
    if ! metacam "$file" > $TMP.a 2>&1
    then
	echo "Can't extract meta-information from '$file', skipping" 1>&2
	continue
    fi
    datePart=`egrep 'Image Capture Date:' $TMP.a \
      | head -1 \
      | cut -d: -f2- \
      | sed 's/ //;s/ /-/;s/:/./g'`
    #
    # Figure out new name, with *lots* of safety checks.
    #
    case "$base" in
	*[0-9][0-9][0-9][0-9])
	    seq=`expr "$base" : '.*\([0-9][0-9][0-9][0-9]\)$'`
	    ;;
	[0-9][0-9][0-9][0-9]*)
	    seq=`expr "$base" : '\([0-9][0-9][0-9][0-9]\).*$'`
	    ;;
	*)
	    topFile=`ls $dir/P$datePart-*.$extension 2>/dev/null | tail -1`
	    case "$topFile" in
		"$dir/P$datePart-*.$extension")
		    seq=0001
		    ;;
		*)
		    seq=`expr "$topFile" \
		      : ".*/P$datePart-\([0-9][0-9][0-9][0-9]\).$extension"'$'`
		    if [ "X$seq" = X ]
		    then
			seq=0001
		    fi
		    ;;
	    esac
	    while [ -e "$dir/P$datePart-$seq.$extension" ]
	    do
		seq=`echo $seq | awk '{printf "%4.4d\n", $1 + 1}'`
		if  [ $seq -gt 9999 ]
		then
		    echo "Can't find unique sequence number to rename $file " \
		      "to $dir/P$datePart-*.$extension; not renamed" 1>&2
		    continue
		fi
	    done
	    ;;
    esac
    target="$dir/P$datePart-$seq.$extension"
    if [ "$target" = "$dir/$base.$origExtension" ]
    then
	# Already in proper format
	echo "$base is already in proper format; skipped" 1>&2
	continue
    elif [ -e "$target" ]
    then
	echo "$target already exists; $file not renamed" 1>&2
	continue
    fi
    #
    # Finally, we're ready to do the rename.
    #
    $verbose  &&  echo mv "$file" "$target"
    if ! $debug
    then
	mv "$file" "$target"
	chmod a-x "$target"
    fi
done

rm -f $TMP.*