# Copyright (c) 2021-2022, PostgreSQL Global Development Group

use strict;
use warnings;

use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
use Time::HiRes qw(usleep);

my $tempdir = PostgreSQL::Test::Utils::tempdir;

my $node = PostgreSQL::Test::Cluster->new('main');
$node->init;
$node->start;

# Test query canceling by sending SIGINT to a running psql
#
# There is, as of this writing, no documented way to get the PID of
# the process from IPC::Run.  As a workaround, we have psql print its
# own PID (which is the parent of the shell launched by psql) to a
# file.
SKIP:
{
	skip "cancel test requires a Unix shell", 2 if $windows_os;

	local %ENV = $node->_get_env();

	my ($stdin, $stdout, $stderr);

	# Test whether shell supports $PPID.  It's part of POSIX, but some
	# pre-/non-POSIX shells don't support it (e.g., NetBSD).
	$stdin = "\\! echo \$PPID";
	IPC::Run::run([ 'psql', '-X', '-v', 'ON_ERROR_STOP=1' ],
		'<', \$stdin, '>', \$stdout, '2>', \$stderr);
	$stdout =~ /^\d+$/ or skip "shell apparently does not support \$PPID", 2;

	# Now start the real test
	my $h = IPC::Run::start([ 'psql', '-X', '-v', 'ON_ERROR_STOP=1' ],
		\$stdin, \$stdout, \$stderr);

	# Get the PID
	$stdout = '';
	$stderr = '';
	$stdin  = "\\! echo \$PPID >$tempdir/psql.pid\n";
	pump $h while length $stdin;
	my $count;
	my $psql_pid;
	until (
		-s "$tempdir/psql.pid"
		  and ($psql_pid =
			PostgreSQL::Test::Utils::slurp_file("$tempdir/psql.pid")) =~
		  /^\d+\n/s)
	{
		($count++ < 100 * $PostgreSQL::Test::Utils::timeout_default)
		  or die "pid file did not appear";
		usleep(10_000);
	}

	# Send sleep command and wait until the server has registered it
	$stdin = "select pg_sleep($PostgreSQL::Test::Utils::timeout_default);\n";
	pump $h while length $stdin;
	$node->poll_query_until('postgres',
		q{SELECT (SELECT count(*) FROM pg_stat_activity WHERE query ~ '^select pg_sleep') > 0;}
	) or die "timed out";

	# Send cancel request
	kill 'INT', $psql_pid;

	my $result = finish $h;

	ok(!$result, 'query failed as expected');
	like(
		$stderr,
		qr/canceling statement due to user request/,
		'query was canceled');
}

done_testing();