#! /bin/sh
# Update 3rd field (minimum art. #) of a 4-field active file.



# =()<. ${NEWSCONFIG-@<NEWSCONFIG>@}>()=
. ${NEWSCONFIG-/usr/local/libexec/cnews/config}



PATH=$NEWSCTL/bin:$NEWSBIN/maint:$NEWSBIN:$NEWSPATH ; export PATH
umask $NEWSUMASK

maxlen=200			# max length for shell cmd; 200 is pretty safe
replace=yes
what=normal			# update min, make sure max has a 0 on front
lserr=/dev/null
interpose=
for dummy
do
	case "$1" in
	-b)	what=both	;;	# update both max and min
	-p)	what=plain	;;	# don't do ANYTHING to max
	-s)	maxlen=0	;;	# ls is funny, do slow way
	'-#')	replace=no ; lserr=$NEWSCTL/active.errs	;;	# debugging
	-I)	interpose="$2" ; shift ;;	# interpose pgm for testing
	--)	shift ; break	;;
	-*)	echo "$0: unknown option \`$1'" >&2 ; exit 2	;;
	*)	break		;;
	esac
	shift
done

cd $NEWSCTL

# lock news system momentarily and grab a copy of the active file
lock LOCK $$ || exit 1
status=1
trap 'unlock LOCK ; trap 0 ; exit $status' 0 1 2 15
sort active >active.upact || exit	# sort brings related dirs together
trap 0 1 2 15
unlock LOCK

# check out the active file
checkactive -n -q active.upact >active.eek
if test -s active.eek
then
	echo "$0: problems in active file -- aborting" >&2
	cat active.eek >&2
	rm -f active.eek active.upact
	exit 1
fi

# Bernd Felsche of MetaPro Systems came up with this general approach,
# which minimizes the number of processes spawned, although this code is
# rather different from his.  Thanks, Bernd!

# first, find minima, efficiently
# translate names to dirs, turn dirs into "ls -f" commands, run them, pick
# the desired data out of the output, turn dirs back into names, sort again,
# and merge in old-max values
tr '.' '/' <active.upact |
	awk 'BEGIN {
		maxlen = '"$maxlen"'
		dirs = ""
		ndirs = 0
		print "cd '"$NEWSARTS"'"
	}
	length($1) + length(dirs) > maxlen && ndirs > 0 {
		if (ndirs == 1)
			print "echo " substr(dirs, 2) ":"
		print "ls -f" dirs
		dirs = ""
		ndirs = 0
	}
	# the /. on the end eliminates problems with names including ":"
	{ dirs = dirs " " $1 "/." ; ndirs++ }
	END {
		if (ndirs == 1)
			print "echo " substr(dirs, 2) ":"
		print "ls -f" dirs
		print "echo /.:"		# simplifies later logic
	}' | sh 2>$lserr |
	awk -F' ' 'BEGIN {
		OFMT = "%.12g"
		big = 99999999999
		lowest = big
		small = 0
		highest = small
		dir = ""
	}
	$0 ~ /^[0-9]+$/ {
		# some old awks do not think $0 is numeric, so use $1
		if ($1 < lowest)
			lowest = $1
		if ($1 > highest)
			highest = $1
		next
	}
	$0 ~ /\/\.:$/ {
		if (dir != "") {
			if (highest != small)
				print dir, highest, lowest
			else
				print dir, "-", "-"
		}
		dir = substr($0, 1, length($0)-3)	# trim off /.:
		lowest = big
		highest = small
	}' | tr '/' '.' | sort |
	join -o 1.1 2.2 1.2 1.3 - active.upact >active.hilow
# active.hilow now is newsgroup, old max, high file, low file

# testing hook
if test " $interpose" != " "
then
	$interpose
fi

# lock news system again
lock LOCK $$ || exit 1
status=1
trap 'unlock LOCK ; trap 0 ; exit $status' 0 1 2 15

# decide on any extra processing needed
extra=
case "$what" in
both)	extra='$7 != "-" && $7 > $3 {
		# update max from high file
		s = "000000000000000" $7
		len = length($3)
		if (length($7) > len)
			len = length($7) + 1
		s = substr(s, length(s)-len+1)
		if (s !~ /^0/)
			s = "0" s
		$3 = s
	}'
	;;
normal)	extra='$3 !~ /^0/ { $3 = "0" $3 }'	;;
esac

# build new active file, cautiously
# The result of the join is line number (for the sort -n that restores the
# old order of the active file), newsgroup, active max, active min, active
# flags, old max, high file, low file.
awk '{ print $1, $2, $3, $4, NR }' active | sort |
	join -a1 -e - -o 1.5 1.1 1.2 1.3 1.4 2.2 2.3 2.4 - active.hilow |
	sort -n |
	awk 'BEGIN { OFMT = "%.12g" }
	$1 == "-" { next }		# no longer in active file
	'"$extra"'
	{
		# find a new value for min
		if ($8 != "-" && $8 != "")	# there was a low file
			s = $8			# use it
		else if ($6+0 != $3+0)		# oldmax != newmax, race cond!
			s = $4			# use old value to be safe
		else				# no files and no race
			s = $3 + 1		# use max+1

		if (length(s) < 5) {
			s = "00000" s
			s = substr(s, length(s)-5+1)
		}
		print $2, ($3 ""), s, $5	# the "" forces string version
	}' >active.tmp

# check that everything looks okay
checkactive -q active.tmp >active.eek
if test -s active.eek
then
	echo "$0: errors in active.tmp -- aborting" >&2
	cat active.eek >&2
	exit			# with status=1
fi
if test `wc -l <active.tmp` -lt `wc -l <active`
then
	echo "$0: active.tmp is bad (short) -- aborting" >&2
	exit			# with status=1
fi
rm -f active.eek active.hilow active.upact	# clean up temporaries

# if we weren't asked to install it, don't
case "$replace" in
no)	status=0 ; exit	;;
esac

# replace active, carefully
rm -f active.old
mv active active.old && mv active.tmp active
if test -f active.tmp
then
	echo "$0: replacing active didn't work" >&2
	exit			# with status=1
fi

status=0			# trap 0 does the actual exit