#! /bin/sh
#
# Copyright (c) 2019,2024 Red Hat.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# Upgrade an older (perl) postgresql PMDA to latest (python) version
#

. $PCP_DIR/etc/pcp.env

if grep -q ^postgresql "$PCP_PMCDCONF_PATH" 2>/dev/null
then
    if grep -q '^postgresql.*perl ' "$PCP_PMCDCONF_PATH" 2>/dev/null
    then
	# convert original perl implementation to python
	sed -i $PCP_PMCDCONF_PATH 2>/dev/null \
	    -e "s,perl $PCP_PMDAS_DIR/postgresql/pmdapostgresql.pl,$PCP_PYTHON_PROG $PCP_PMDAS_DIR/postgresql/pmdapostgresql.python,g"
    fi
    if grep -q ^postgresql "$PCP_PMCDCONF_PATH" 2>/dev/null
    then
	if grep ^postgresql "$PCP_PMCDCONF_PATH" | grep -q "$PCP_PYTHON_PROG" 2>/dev/null
	then
	    :	# already using $PCP_PYTHON_PROG, leave this line untouched
	else
	    # convert hard-coded python binary to PCP_PYTHON_PROG
	    sed -i $PCP_PMCDCONF_PATH 2>/dev/null \
		-e "s,python3 $PCP_PMDAS_DIR/postgresql/,$PCP_PYTHON_PROG $PCP_PMDAS_DIR/postgresql/,g" \
		-e "s,python $PCP_PMDAS_DIR/postgresql/,$PCP_PYTHON_PROG $PCP_PMDAS_DIR/postgresql/,g" \
	    # end
	fi
    fi
fi

perlpath=`which $PCP_PERL_PROG`
original="$PCP_PMDAS_DIR/postgresql/postgresql.conf"
upgraded="$PCP_PMDAS_DIR/postgresql/pmdapostgresql.conf"
if [ -x "$perlpath" -a -f "$original" ]
then
    mv -f "$upgraded" "$upgraded".saved
    #
    # Extract perl parameters in the way the original PMDA did; then
    # convert old format into new and finally move old config aside.
    #
    "$perlpath" > "$upgraded" << EOF
my \$database = undef; # default: 'dbi:Pg:dbname=postgres;host=host;port=port';
my \$username = undef; # default: 'postgres'; -- DB username for DB login
my \$password = undef; # default: ''; -- DBI parameter, often unused for postgres
my \$os_user = undef;  # default: ''; -- O/S user to run the PMDA as

eval \`cat $PCP_PMDAS_DIR/postgresql/postgresql.conf\`;

exit 0 unless defined(\$database) or defined(\$username) or defined(\$password) or defined(\$os_user);

print "[authentication]\n";
if (defined(\$database)) {
    my (\$host, \$port, \$dbname) = (\$database, \$database, \$database);
    \$host =~ s/.*host=(\w+).*/\$1/g;
    if (\$host eq '' or \$host eq \$database) { print "host=local\n"; }
    else { print "host=\$host\n"; }
    \$port =~ s/.*port=(\d+).*/\$1/g;
    if (\$port eq '' or \$port eq \$database) { print "port=5432\n"; }
    else { print "port=\$port\n"; }
    \$dbname =~ s/.*dbname=(\w+).*/\$1/g;
    if (\$dbname eq '' or \$host eq \$database) { print "dbname=postgres\n"; }
    else { print "dbname=\$dbname\n"; }
} else {
    print "dbname=postgres\n";
    print "host=local\n";
    print "port=5432\n";
}

\$username='postgres' unless (defined(\$username) and \$username ne '');
print "user=\$username\n";
\$password='password' unless (defined(\$password) and \$password ne '');
print "password=\$password\n";
\$os_user='postgres' unless (defined(\$os_user) and \$os_user ne '');
print "osuser=\$os_user\n";
EOF
    chmod 600 "$upgraded"
    mv -f "$original" "$original".saved
fi

exit 0