#!perl -w
# Copyright (C) all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
# Tests for binding Unix domain sockets
use v5.12;
use PublicInbox::TestCommon;
use Errno qw(EADDRINUSE);
use Cwd qw(abs_path);
use Carp qw(croak);
use autodie qw(close);
require_mods qw(-httpd);
use IO::Socket::UNIX;
use POSIX qw(mkfifo);
require PublicInbox::Sigfd;
my ($tmpdir, $for_destroy) = tmpdir();
my $unix = "$tmpdir/unix.sock";
my $psgi = './t/httpd-corner.psgi';
my $out = "$tmpdir/out.log";
my $err = "$tmpdir/err.log";
my $td;

my $register_exit_fifo = sub {
	my ($s, $f) = @_;
	my $sock = new_sock($s);
	ok($sock->write("GET /exit-fifo$f HTTP/1.0\r\n\r\n"),
		'request exit-fifo');
	ok($sock->read(my $buf, 4096), 'read exit-fifo response');
	like($buf, qr!\r\n\r\nfifo \Q$f\E registered\z!, 'set exit fifo');
};

my $spawn_httpd = sub {
	my (@args) = @_;
	my $cmd = [ '-httpd', @args, "--stdout=$out", "--stderr=$err", $psgi ];
	$td = start_script($cmd);
};

{
	require PublicInbox::Daemon;
	my $l = "$tmpdir/named.sock";
	my $s = IO::Socket::UNIX->new(Listen => 5, Local => $l,
					Type => SOCK_STREAM);
	is(PublicInbox::Daemon::sockname($s), $l, 'sockname works for UNIX');
}

ok(!-S $unix, 'UNIX socket does not exist, yet');
my $f1 = "$tmpdir/f1";
mkfifo($f1, 0600);
{
	local $ENV{TEST_OPEN_FIFO} = $f1;
	$spawn_httpd->("-l$unix", '-W0');
	open my $fh, '<', $f1 or xbail "open($f1): $!";
	is(my $hi = <$fh>, "hi\n", 'got FIFO greeting');
}
ok(-S $unix, 'UNIX socket was bound by -httpd');

sub new_sock ($) {
	IO::Socket::UNIX->new(Peer => $_[0], Type => SOCK_STREAM)
		// xbail "E: $! connecting to $_[0]";
}

sub check_sock ($) {
	my ($unix) = @_;
	my $sock = new_sock($unix);
	ok($sock->write("GET /host-port HTTP/1.0\r\n\r\n"),
		'wrote req to server');
	ok($sock->read(my $buf, 4096), 'read response');
	like($buf, qr!\r\n\r\n127\.0\.0\.1 0\z!,
		'set REMOTE_ADDR and REMOTE_PORT for Unix socket');
}

check_sock($unix);

{ # do not clobber existing socket
	my %err = ( 'linux' => EADDRINUSE, 'freebsd' => EADDRINUSE );
	open my $out, '>>', "$tmpdir/1" or die "redirect failed: $!";
	open my $err, '>>', "$tmpdir/2" or die "redirect failed: $!";
	my $cmd = ['-httpd', '-l', $unix, '-W0', $psgi];
	my $ftd = start_script($cmd, undef, { 1 => $out, 2 => $err });
	$ftd->join;
	isnt($?, 0, 'httpd failure set $?');
	SKIP: {
		my $ec = $err{$^O} or
			skip("not sure if $^O fails with EADDRINUSE", 1);
		is($? >> 8, $ec, 'httpd failed with EADDRINUSE');
	};
	open my $fh, "$tmpdir/2" or die "failed to open $tmpdir/2: $!";
	local $/;
	my $e = <$fh>;
	like($e, qr/no listeners bound/i, 'got error message');
	is(-s "$tmpdir/1", 0, 'stdout was empty');
}

{
	is($td->kill, 1, 'terminate existing process');
	$td->join;
	is($?, 0, 'existing httpd exited successfully');
	ok(-S $unix, 'unix socket still exists');
}

# portable Perl can delay or miss signal dispatches due to races,
# so disable some tests on systems lacking signalfd(2) or EVFILT_SIGNAL
my $has_sigfd = PublicInbox::Sigfd->new({}) ? 1 : $ENV{TEST_UNRELIABLE};
PublicInbox::DS::Reset() if $has_sigfd;

sub delay_until {
	my ($cond, $msg) = @_;
	my $end = time + 30;
	do {
		return if $cond->();
		tick(0.012);
	} until (time > $end);
	Carp::confess($msg // 'condition failed');
}

SKIP: {
	require_mods('Net::Server::Daemonize', 52);
	$has_sigfd or skip('signalfd / EVFILT_SIGNAL not available', 52);
	my $pid_file = "$tmpdir/pid";
	my $read_pid = sub {
		my $f = shift;
		open my $fh, '<', $f or die "open $f failed: $!";
		my $pid = do { local $/; <$fh> };
		chomp($pid) or die("pid file not ready $!");
		$pid;
	};

	for my $w (qw(-W0 -W1)) {
		my ($p0, $p1) = quit_waiter_pipe;
		# wait for daemonization
		$spawn_httpd->("-l$unix", '-D', '-P', $pid_file, $w);
		close $p1;
		$td->join;
		is($?, 0, "daemonized $w process");
		check_sock($unix);
		ok(-s $pid_file, "$w pid file written");
		my $pid = $read_pid->($pid_file);
		no_pollerfd($pid) if $w eq '-W1';
		is(kill('TERM', $pid), 1, "signaled daemonized $w process");
		delete $td->{-extra}; # drop tail(1) process
		wait_for_eof($p0, "httpd $w quit pipe");
		ok(!-e $pid_file, "$w pid file unlinked at exit");
	}

	my $httpd = abs_path('blib/script/public-inbox-httpd');
	$psgi = abs_path($psgi);
	my $opt = { run_mode => 0 };
	my @args = ("-l$unix", '-D', '-P', $pid_file, -1, $out, -2, $err);

	if ('USR2 upgrades with workers') {
		my ($p0, $p1) = quit_waiter_pipe;
		$td = start_script([$httpd, @args, $psgi], undef, $opt);
		close $p1;
		$td->join;
		is($?, 0, "daemonized process again");
		check_sock($unix);
		ok(-s $pid_file, 'pid file written');
		my $pid = $read_pid->($pid_file);

		# stop worker to ensure check_sock below hits $new_pid
		kill('TTOU', $pid) or die "TTOU failed: $!";

		kill('USR2', $pid) or die "USR2 failed: $!";
		delay_until(sub {
			$pid != (eval { $read_pid->($pid_file) } // $pid)
		});
		my $new_pid = $read_pid->($pid_file);
		isnt($new_pid, $pid, 'new child started');
		ok($new_pid > 0, '$new_pid valid');
		delay_until(sub { -s "$pid_file.oldbin" });
		my $old_pid = $read_pid->("$pid_file.oldbin");
		is($old_pid, $pid, '.oldbin pid file written');
		ok($old_pid > 0, '$old_pid valid');

		check_sock($unix); # ensures $new_pid is ready to receive signals

		# first, back out of the upgrade
		kill('QUIT', $new_pid) or die "kill new PID failed: $!";
		delay_until(sub {
			$pid == (eval { $read_pid->($pid_file) } // 0)
		});

		delay_until(sub { !kill(0, $new_pid) }, 'new PID really died');

		is($read_pid->($pid_file), $pid, 'old PID file restored');
		ok(!-f "$pid_file.oldbin", '.oldbin PID file gone');

		# retry USR2 upgrade
		kill('USR2', $pid) or die "USR2 failed: $!";
		delay_until(sub {
			$pid != (eval { $read_pid->($pid_file) } // $pid)
		});
		$new_pid = $read_pid->($pid_file);
		isnt($new_pid, $pid, 'new child started again');
		$old_pid = $read_pid->("$pid_file.oldbin");
		is($old_pid, $pid, '.oldbin pid file written');

		# drop the old parent
		kill('QUIT', $old_pid) or die "QUIT failed: $!";
		delay_until(sub { !kill(0, $old_pid) }, 'old PID really died');

		ok(!-f "$pid_file.oldbin", '.oldbin PID file gone');

		# drop the new child
		check_sock($unix);
		kill('QUIT', $new_pid) or die "QUIT failed: $!";

		wait_for_eof($p0, 'new process');
		ok(!-f $pid_file, 'PID file is gone');
	}

	if ('try USR2 without workers (-W0)') {
		my ($p0, $p1) = quit_waiter_pipe;
		$td = start_script([$httpd, @args, '-W0', $psgi], undef, $opt);
		close $p1;
		$td->join;
		is($?, 0, 'daemonized w/o workers');
		$register_exit_fifo->($unix, $f1);
		my $pid = $read_pid->($pid_file);

		# replace running process
		kill('USR2', $pid) or xbail "USR2 failed: $!";
		open my $fh, '<', $f1 or xbail "open($f1): $!";
		is(my $bye = <$fh>, "bye from $pid\n", 'got FIFO bye');

		check_sock($unix);
		$pid = $read_pid->($pid_file);
		kill('QUIT', $pid) or xbail "USR2 failed: $!";

		wait_for_eof($p0, '-W0 USR2 test pipe');
		ok(!-f $pid_file, 'PID file is gone');
	}
}

done_testing();