#! /bin/sh

# You first run findoidjoins on the template1 database, and send that
# output into this script to generate a list of SQL statements.

# NOTE: any field that findoidjoins thinks joins to more than one table
# will NOT be checked by the output of this script.  You should be
# suspicious of multiple entries in findoidjoins' output.

# Caution: you may need to use GNU awk.
AWK=${AWK:-awk}

TMP="${TMPDIR:-/tmp}/make_oidjoins_check.$$"
trap "rm -rf $TMP" 0 1 2 3 15

# Create a temporary directory with the proper permissions so no one can
# intercept our temporary files and cause a security breach.
OMASK="`umask`"
umask 077
if ! mkdir $TMP
then	echo "Can't create temporary directory $TMP." 1>&2
	exit 1
fi
umask "$OMASK"
unset OMASK

INPUTFILE="$TMP/a"
DUPSFILE="$TMP/b"
NONDUPSFILE="$TMP/c"

# Read input
cat "$@" >$INPUTFILE

# Look for fields with multiple references.
cat $INPUTFILE | cut -d' ' -f2 | sort | uniq -d >$DUPSFILE
if [ -s $DUPSFILE ] ; then
	echo "Ignoring these fields that link to multiple tables:" 1>&2
	cat $DUPSFILE 1>&2
fi

# Get the non-multiply-referenced fields.
cat $INPUTFILE | while read LINE
do
	set -- $LINE
	grep "^$2\$" $DUPSFILE >/dev/null 2>&1 || echo $LINE
done >$NONDUPSFILE

# Generate the output.
cat $NONDUPSFILE |
$AWK -F'[ \.]' '\
	BEGIN \
	{
		printf "\
--\n\
-- This is created by pgsql/contrib/findoidjoins/make_oidjoin_check\n\
--\n";
	}
	{
		printf "\
SELECT	ctid, %s \n\
FROM	%s.%s fk \n\
WHERE	%s != 0 AND \n\
	NOT EXISTS(SELECT 1 FROM %s.%s pk WHERE pk.oid = fk.%s);\n",
	$4, $2, $3, $4,
	$6, $7, $4;
	}'

exit 0
