#!/bin/sh -e
# Automatically make snapshot tarballs of CVS modules.
# Adam Sampson <ats@offog.org>

# This needs to set CVSROOT, MODULES, OUTDIR and MAXSNAPSHOTS, and define a
# postcmd function.
. ~/.mksnapshotsrc

temp=/tmp/mksnapshots.$$
date=`date '+%Y%m%d'`

mkdir -p $temp
cd $temp

for module in $MODULES ; do
	moddir=$OUTDIR/$module
	mkdir -p $moddir

	# Check out current tree
	cvs -Q -d $CVSROOT checkout $module
	(cd $module && cvs2cl -g "-Q" -f mksnapshots-ChangeLog)
	mv -f $module/mksnapshots-ChangeLog ChangeLog
	find $module -name CVS | xargs rm -rf

	name=$module-CVS-$date.tar.bz2
	
	# Extract last snapshot
	last=`ls $moddir | grep -v '(CVS-latest|ChangeLog)' | sort | tail -n1`
	mkdir last
	if [ "$last" != "" ] ; then
		bunzip2 <$moddir/$last | tar -C last -xf -
	fi

	# Compare the two and make a new snapshot if different
	if diff -Nuqr $module last/$module >/dev/null ; then
		:
	else
		tar -cf - $module | bzip2 -9 >$moddir/$name
		cp ChangeLog $moddir/ChangeLog
		ln -sf $name $moddir/$module-CVS-latest.tar.bz2
		echo "New snapshot: $name"
	fi

	# Remove old snapshots past $MAXSNAPSHOTS
	find $moddir -type f -name '*.tar.bz2' | sort | head --lines=-$MAXSNAPSHOTS | xargs rm -f

	rm -rf $module last ChangeLog
done

rmdir $temp
cd /

postcmd