#!/bin/sh
set -ex
base=$HOME/things/Adns/Cvs-Convert
cd $base
tmp=$base/tmp

rm -rf converted

if ! test -d $tmp/git-cvsi; then
	rm -rf tmp
	mkdir tmp
	git cvsimport -d `pwd`/cvs-repo -C tmp/git-cvsi.new -k -p --norc adns
	mv tmp/git-cvsi.new tmp/git-cvsi
fi
cd tmp

rsync -aH --delete git-cvsi/. adjust
cd adjust

abandonbranch () {
	local oldbranchname=$1
	local newtagname=$2
	git tag $newtagname $oldbranchname
	git branch -D $oldbranchname
}
ensurenotag () {
	local tagname=$1
	# these two together unconditionally delete the tag if it exists
	git tag -f $tagname master
	git tag -d $tagname
}
abandondatedbranch () {
	local date=$1
	local olddesc=$2
	local newdesc=$3
	if [ "x$newdesc" = x ]; then newdesc=$olddesc; fi
	abandonbranch branch-$date-$olddesc abandon.$date.$newdesc
	ensurenotag branchpoint-$date-$olddesc master
}
graftmergein () {
	local desc=$1
	local mergecommit=$2
	local branchname=branch-$desc
	mkdir -p .git/info
	local branchtip=`git rev-parse $branchname~0`
	local oldparents=`git log -n1 --pretty=format:%P $mergecommit`
	cat <<END >>.git/info/grafts
$2 $oldparents $branchtip
END
	git branch -D $branchname
	ensurenotag mergepoint-$desc
	ensurenotag branchpoint-$desc
}

abandonbranch branch-rrtypenoenum abandon.1998-10-04.rrtypenoenum
abandondatedbranch 1999-04-10 mthread multithread
abandondatedbranch 1999-04-11 ipv6

abandondatedbranch 2000-05-07 ipv6
abandonbranch branch-0-7-inftodebug abandon.2000-03-26.infotodebug-0.7

graftmergein logcallbackfn 741a795cdaa539b48f83afbc0ac8e471543b9bf6
graftmergein 1999-05-09-gplvslgpl e7cf3a99e5829bf53a9f36e08769787a78261045
graftmergein 1999-04-11-pollfds f889c99835eec14dacda4b18da0636911dcd8cbc

xargs git tag -d <<END
tochiark-1998-11-08
fromchiark-1998-11-09
tochiark-1998-11-09-b
fromchiark-1998-11-14
tochiark-1998-11-15
tochiark-1998-11-17
fromchiark-1998-11-28
END

(set -e
 cd $base/script
 if [ x"`git diff`" != x ]; then
	git checkout master~0
	git commit -a -m autocommit
	git tag -f actual
	git reset master
	git checkout master
 else
	git tag -f actual
 fi)

git checkout master
git fetch $base/script actual
git merge -m 'CVS to git conversion

Record the scripts etc. we used (and their history) for posterity,
by binding them into the history.' FETCH_HEAD

git branch -d origin
git tag cvs-to-git-conversion

cat >$tmp/msg-filter <<'FEND'
perl -ne '
		$out .= $_;
	END {
		if ($out =~ /\*\*\* empty log message/) {
			($out = `git diff $ENV{GIT_COMMIT}^ $ENV{GIT_COMMIT} -- changelog`)
			   =~ s/\A.*\n\@\@ /\@\@ /s;
		}
		if ($out !~ /\n.*\n/) {
			$out = `fmt <<'\''EOF'\''
$out
EOF
`;
		}
		if ($out =~ m/^\@\@/s &&
		    ($out =~ m/^\+(?!u?adns).*\w.*$/m ||
		     $out =~ m/^\-(?!u?adns).*\w.*$/m)) {
			print $&, "\n\n" or die $!;
		}
		print $out or die $!;
	}
'
FEND
chmod +x $tmp/msg-filter

git filter-branch --msg-filter $tmp/msg-filter \
	`git show-ref | awk '{print $2}'`

git show-ref | awk '{print $2}' | grep '^refs/original/' \
	| xargs -n1 git update-ref -d

rm -rf $tmp/converted
mkdir $tmp/converted
cd $tmp/converted
git init
git fetch -u $tmp/adjust 'refs/*:refs/*'
git checkout master