#!/bin/sh
# cpdate -- makes sure you have a backup copy of the file you are going
# 	to edit
#
# This is a classical ASS: Arse Saving Script
#
# Par Leijonhufvud, 1999-11-25
# 
# Updated to check for the existance of LONGDATE and LONGNOTE files
# 	PKL, 2000-07-13
#
# 
# We have two options: if just one argument is given,
# then we assume that is a filename and add a date 
# (and possibly time). If we get two arguments,
# then we take the first one as the filename, and the
# second one as the suffix (in case of conflict we add the
# date+time after that suffix, analogous to the first case).
# 
# Before doing anything we test to make sure that the source file 
# exists. If not, we get an error message and exits.
# 
# In the extremely unlikley case that the LONGDATE (or LONGNOTE)
# file already exists we get an an error message. Trying again will
# (as suggested) almost certainly help unless you have a rather special
# collection of files in that directory.
#
# TODO Allow for a specified destination directory, rather than the
# same one as the source file lives in. 
# 

DATE_BINARY='/bin/date'
CP='/bin/cp -p'


# complain if we get no arguments
if [ $# -eq 0 ]; then
	echo "Syntax : cpdate file [suffix]"
	echo "(You must give at least one argument)"
	exit 1
fi

if [ $# -gt 2 ]; then
	echo "Syntax : cpdate file [suffix]"
	echo "(No more the two arguments)"
	exit 1
fi

if [ ! -r $1 ] ; then
	echo "Syntax : cpdate file [suffix]"
	echo "(The source file must exist; I can't find \"$1\")"
	exit 1
fi

# use todays date if we just get a filename
if [ $# -eq 1 ] ; then

	SOURCE=$1

	# set the two versions of the date-string
	DATE="`$DATE_BINARY +'%Y%m%d'`"
	LONGDATE="`$DATE_BINARY +'%Y%m%dT%T'`"

	# make sure we aren't overwriting something
	if [ ! -r  $SOURCE.$DATE ] ; then	# use DATE
		$CP $SOURCE $SOURCE.$DATE
	elif [ -r $SOURCE.$DATE ] ; then	# use LONGDATE

		# the DATE file exists, test if the LONDATE file exists...
		if [ ! -r $SOURCE.$LONGDATE ] ;  then   
			$CP $SOURCE $SOURCE.$LONGDATE
		else				   
			# generate an error message and exit
			echo "$SOURCE.$LONGDATE exists!"
			echo "(Trying again will almost certainly help)"
			exit 1
		fi
	else
		exit 1
	fi
	exit 0
fi

# if we get more than one argument, use the second one as a suffix
if [ $# -eq 2 ] ; then

	SOURCE=$1
	NOTE=$2
	LONGNOTE=$2_`$DATE_BINARY +'%Y%m%dT%T'`

	# once more, make sure we aren't clobbering something (see the
	# DATE sequence above for details on how this works)
	if [ ! -r  $SOURCE.$NOTE ] ; then
		$CP $SOURCE $SOURCE.$NOTE
	elif [ -r $SOURCE.$NOTE ] ; then
		if [ ! -r $SOURCE.$LONGNOTE ] ; then
			$CP  $SOURCE $SOURCE.$LONGNOTE
		else
			echo "$SOURCE.$LONGNOTE exists!"
			echo "(Trying again will almost certainly help)"
			exit 1
		fi
	else
		exit 1
	fi
	exit 0
fi