#!/bin/bash
#
#	Ross J. Michaels (1995)
#	rjm2@lehigh.edu
#
#	and
#
#	Judith Elaine
#	blondie@cybertia.org.tenn.com
#
#	(Only the major functional lines were entered by Bill 
#	Stearns (wstearns@pobox.com).  The full text can be found
#	in the November 1995 Linux Gazette at:
#	http://www.ssc.com/lg/linux/gazette.nov.html
#
# Since this was typed in, improvements have been made by Bill
# Stearns.

#Version 0.5

#FIXME: check for unset HOME, fix with /root, /home/nnnn, /tmp

CONFIG_DIR="$HOME/config"
DIR_DIST="$HOME/config/dist"
DIR_LINKS="$HOME/config/links"
DIR_BACKUPS="$HOME/config/backup"
EDITED_FILES="$HOME/config/edited_files"
for OneDir in $CONFIG_DIR $DIR_DIST $DIR_BACKUPS $DIR_LINKS ; do
	if [ ! -d $OneDir ]; then
		mkdir $OneDir
		chmod 711 $OneDir
	fi
done
if [ ! -f $EDITED_FILES ]; then
	touch $EDITED_FILES
	chmod 600 $EDITED_FILES
fi

if [ -z "$RealEditor" ]; then
	for TryEditor in `type -path mcedit || :` `type -path pico || :` `type -path vi || :` `type -path jove || :` `type -path nedit || :` `type -path emacs || :` ; do
		if [ -z "$RealEditor" ]; then
			case "$TryEditor" in
			*pico)
				RealEditor="$TryEditor -w"
				;;
			*mcedit)
				RealEditor="$TryEditor -c"
				;;
			*)
				RealEditor="$TryEditor"
				;;
			esac
			echo Editor default of $RealEditor taken.  If you prefer another editor, please add
			echo export RealEditor=myeditorname
			echo to ~/.bash_profile
		fi
	done
	unset TryEditor || :
	if [ -z "$RealEditor" ]; then
		echo No editor was specified by the RealEditor= variable and this
		echo script was unable to find mcedit, pico, vi, jove, nedit or
		echo emacs on your system. Please put
		echo export RealEditor=the_name_of_an_editor
		echo in ~/.bash_profile or your environment and re-start. Exiting.
		exit 4
	fi #no suitable editor found
fi


if [ -z "$1" ]; then echo "hack: filename is missing" ;				exit 2	; fi
if [ -d "$1" ]; then echo "hack: filename is a directory" ;			exit 3	; fi

BaseName="`basename $1`"
FilePath="`( cd $(dirname $1) ; pwd )`"
echo "Working with \"$FilePath\"/\"$BaseName\""
if [ -z "$FilePath" ] || [ -z "$BaseName" ]; then
	echo Missing filepath or filename, exiting.
	exit 1
fi

if [ ! -f "$1" ]; then
	#FIXME - handle wildcards, perhaps?
	echo "hack: No file by that name.  Shall I create one for you? (y/N)"
	read CreateOne
	case "$CreateOne" in
	y*|Y*)
		touch "$1"
		;;
	*)
		echo "Exiting."
		exit 3
		;;
	esac
fi

#Debugging sanity check
if [ ! "$1" -ef "$FilePath/$BaseName" ]; then
	echo "Fatal: $1 and "$FilePath/$BaseName are not identical files, exiting.
	exit 1
fi
#Don't use $1 from here on.

if [ -f "$DIR_DIST/$BaseName.dist" ]; then
	echo "hack: $DIR_DIST/$BaseName.dist already exists"
else
	cp -p "$FilePath/$BaseName" "$DIR_DIST/$BaseName.dist"
	echo "hack: creating file $DIR_DIST/$BaseName.dist"
fi


#FIXME - relative paths?
if [ -L "$DIR_LINKS/$BaseName" ]; then
	if [ ! -e "$DIR_LINKS/$BaseName" ]; then
		echo "$DIR_LINKS/$BaseName is not pointing at any file, shall I replace it? (y/N)"
		read ReplaceIt
		case "$ReplaceIt" in
		y*|Y*)
			rm -rf $DIR_LINKS/$BaseName
			ln -s "$FilePath/$BaseName" "$DIR_LINKS/$BaseName"
			echo "hack: linking $FilePath/$BaseName"
			;;
		*)
			echo Not replacing.
		esac
	fi
else
	ln -s "$FilePath/$BaseName" "$DIR_LINKS/$BaseName"
	echo "hack: linking $FilePath/$BaseName"
fi
echo "$FilePath/$BaseName" >> $EDITED_FILES


if [ `ls -al "$FilePath/$BaseName" | awk '{print $2}'` -gt 1 ]; then
	echo "$FilePath/$BaseName is hardlinked, copying to break link."
	if type -path mktemp >/dev/null 2>/dev/null ; then
		notempfile () {
		#Handle the case where the temp file can't be created for some reason.
			echo Couldn\'t create $1 temp file, exiting.
			exit 1
		}
		TEMPFILE=`mktemp -q /tmp/hack.XXXXXX` || notempfile hack
	else
		echo No mktemp on this system, using insecure method for temp file.
		TEMPFILE=/tmp/hack.$$.$RANDOM
		rm -f $TEMPFILE
	fi
	cp -p "$FilePath/$BaseName" $TEMPFILE
	rm -f "$FilePath/$BaseName"
	mv $TEMPFILE "$FilePath/$BaseName"
else
	echo "$FilePath/$BaseName" has only a single link, good.
fi

cp --backup=numbered "$FilePath/$BaseName" "$DIR_BACKUPS/$BaseName.`date +%y%m%d`"
echo "hack: creating dated backup $BaseName.`date +%y%m%d`"

rm -f $EDITED_FILES.tmp
cp $EDITED_FILES $EDITED_FILES.tmp
cat $EDITED_FILES.tmp | sort | uniq > $EDITED_FILES
rm -f $EDITED_FILES.tmp

if [ "$TERM" = "xterm" -o "$TERM" = "xterm-color" ]; then 
	echo -ne "\033]0;hack ${BaseName}\007"
fi

#Many thanks to Johannes Ullrich for the rcs tutorial.
if [ -f "$FilePath/$BaseName,v" ] || [ -f "$FilePath/RCS/$BaseName,v" ]; then
#FIXME - testme
	if [ -w "$FilePath/$BaseName" ]; then
		echo "Warning: RCS-enabled $FilePath/$BaseName is writeable.  Continue? (y/N)"
		read Continue
		case "$Continue" in
		y*|Y*)
			:
			;;
		*)
			echo Exiting
			exit 5
			;;
		esac
	fi
	echo Checking out and locking "$FilePath/$BaseName" file in rcs.
	co -l "$FilePath/$BaseName"
fi

#FIXME - case for *hack* ;-)
$RealEditor "$FilePath/$BaseName"

if [ -f "$FilePath/$BaseName,v" ] || [ -f "$FilePath/RCS/$BaseName,v" ]; then
	echo Checking in and unlocking "$FilePath/$BaseName" file in rcs.
	ci -u "$FilePath/$BaseName"
fi

if [ "$TERM" = "xterm" -o "$TERM" = "xterm-color" ]; then 
	if [ -n "$XTITLE" ]; then 
		echo -ne "\033]0;${XTITLE}\007" ; 
	else
		echo -ne "\033]0;${USER}@${SHOSTNAME} ${PWD}\007" | sed -e "s@${HOME}@\~@"
	fi
fi

exit





#FIXME $1
#Test is too crude, this sees itself.  ;-(
#if ps ax | grep "[h]ack $1" >/dev/null 2>/dev/null ; then
#	echo "It appears someone is already editing $1:"
#	ps ax | grep "[h]ack $1"
#	echo "Continue? (y/N)"
#	read GoAnyways
#	case "$GoAnyways" in
#	y*|Y*)
#		:
#		;;
#	*)
#		echo Exiting.
#		exit 1
#		;;	
#	esac
##else
##	echo "It does not appear anyone is editing $1, good."
#fi