#! /bin/sh
# checkgroups - check active file for missing or extra newsgroups or groups
#	with incorrect moderation status, and update the newsgroups file.
#	stdin must a checkgroups news article, sends mail to $NEWSMASTER.

# =()<. ${NEWSCONFIG-@<NEWSCONFIG>@}>()=
. ${NEWSCONFIG-/var/lib/news/bin/config}
export NEWSCTL NEWSBIN NEWSARTS
PATH=$NEWSCTL/bin:$NEWSBIN:$NEWSPATH ; export PATH
desc=/tmp/cg$$d
hiers=/tmp/cg$$h
canact=/tmp/cg$$a
newact=/tmp/cg$$n
diffs=/tmp/cg$$df
actgrps=/tmp/cg$$ag
newgrps=/tmp/cg$$ng
samegrps=/tmp/cg$$sg
addgrps=/tmp/cg$$ad
remgrps=/tmp/cg$$rm
sameact=/tmp/cg$$sa
samenew=/tmp/cg$$sn
modchng=/tmp/cg$$mc

umask $NEWSUMASK
trap 'rm -f /tmp/cg$$*; exit' 0 1 2 15

# behead stdin (checkgroups article) & ignore lines that don't fit the syntax
# (should just be able to reject tabless lines, but Bitnet buggers that).
# ignore signatures and initial !mod lines.
ngalpha='-_+a-zA-Z0-9'
sed -n -e '1,/^$/d' -e '1{/^!mod$/d;}' -e '/^-- $/,$d' \
	-e "/^[$ngalpha][	 ][	 ]*/p" \
	-e "/^[$ngalpha][$ngalpha.]*[$ngalpha][	 ][	 ]*/p" \
	>$desc

# generate list of hierarchies affected
sed 's/\..*//' $desc | sort -u >$hiers

# backup newsgroups before updating it
cp $NEWSCTL/newsgroups $NEWSCTL/newsgroups.bac || { exit 1; }
# toss out old newsgroups rubbish
hierlist="`cat $hiers`"		# message is assumed authoritative for these
hierpat="` echo $hierlist | tr ' ' , `"	# one more time, with commas
(gngp -av "$hierpat" $NEWSCTL/newsgroups.bac
 # add new newsgroups rubbish
 cat $desc) >$NEWSCTL/newsgroups

# canonicalise active file & select interesting hierarchies
awk '{
	modstat = $4
	if (modstat != "y" && modstat != "m")
		modstat = "y"
	print $1, modstat
}' $NEWSCTL/active | gngp -a "$hierpat" | sort >$canact

# canonicalise body into an active-file-like thing
awk '
/Moderated/	{ print $1, "m" } # TODO: " (Moderated)$"? as per B 2.11.19
!/Moderated/	{ print $1, "y" }
' $desc | sort >$newact

# what's different?  first, what groups have vanished or appeared?
sed 's/ .*//' $canact >$actgrps
sed 's/ .*//' $newact >$newgrps
comm -12 $actgrps $newgrps >$samegrps
comm -23 $actgrps $newgrps >$remgrps
comm -13 $actgrps $newgrps >$addgrps
if test -s $remgrps; then
	echo
	echo 'obsolete groups:'
	cat $remgrps
fi >$diffs
if test -s $addgrps; then
	echo
	echo 'new groups:'
	cat $addgrps
fi >>$diffs

# next, what surviving groups have changed moderation status?
join $samegrps $canact >$sameact
join $samegrps $newact >$samenew
comm -13 $sameact $samenew >$modchng
if test -s $modchng; then
	echo
	echo 'groups needing moderation status changed to that shown:'
	cat $modchng
fi >>$diffs

if test -s $diffs; then
	(echo "Subject: possible active file problems"; echo;
	 echo "If you believe this checkgroups control message, the following"
	 echo "differences may reflect groups that should be added, deleted,"
	 echo "or have their moderation status(es) changed:"
	 cat $diffs) | mail "$NEWSMASTER"
fi
exit 0		## end of new one