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

# This test case aims to verify that client-side backup compression work
# properly, and it also aims to verify that pg_verifybackup can verify a base
# backup that didn't start out in plain format.

use strict;
use warnings;
use File::Path qw(rmtree);
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;

my $primary = PostgreSQL::Test::Cluster->new('primary');
$primary->init(allows_streaming => 1);
$primary->start;

my $backup_path  = $primary->backup_dir . '/client-backup';
my $extract_path = $primary->backup_dir . '/extracted-backup';

my @test_configuration = (
	{
		'compression_method' => 'none',
		'backup_flags'       => [],
		'backup_archive'     => 'base.tar',
		'enabled'            => 1
	},
	{
		'compression_method' => 'gzip',
		'backup_flags'       => [ '--compress', 'client-gzip:5' ],
		'backup_archive'     => 'base.tar.gz',
		'decompress_program' => $ENV{'GZIP_PROGRAM'},
		'decompress_flags'   => ['-d'],
		'enabled'            => check_pg_config("#define HAVE_LIBZ 1")
	},
	{
		'compression_method' => 'lz4',
		'backup_flags'       => [ '--compress', 'client-lz4:5' ],
		'backup_archive'     => 'base.tar.lz4',
		'decompress_program' => $ENV{'LZ4'},
		'decompress_flags'   => ['-d'],
		'output_file'        => 'base.tar',
		'enabled'            => check_pg_config("#define USE_LZ4 1")
	},
	{
		'compression_method' => 'zstd',
		'backup_flags'       => [ '--compress', 'client-zstd:5' ],
		'backup_archive'     => 'base.tar.zst',
		'decompress_program' => $ENV{'ZSTD'},
		'decompress_flags'   => ['-d'],
		'enabled'            => check_pg_config("#define USE_ZSTD 1")
	},
	{
		'compression_method' => 'parallel zstd',
		'backup_flags'       => [ '--compress', 'client-zstd:workers=3' ],
		'backup_archive'     => 'base.tar.zst',
		'decompress_program' => $ENV{'ZSTD'},
		'decompress_flags'   => ['-d'],
		'enabled'            => check_pg_config("#define USE_ZSTD 1"),
		'possibly_unsupported' =>
		  qr/could not set compression worker count to 3: Unsupported parameter/
	});

for my $tc (@test_configuration)
{
	my $method = $tc->{'compression_method'};

  SKIP:
	{
		skip "$method compression not supported by this build", 3
		  if !$tc->{'enabled'};
		skip "no decompressor available for $method", 3
		  if exists $tc->{'decompress_program'}
		  && (!defined $tc->{'decompress_program'}
			|| $tc->{'decompress_program'} eq '');

		# Take a client-side backup.
		my @backup = (
			'pg_basebackup', '-D', $backup_path,
			'-Xfetch', '--no-sync', '-cfast', '-Ft');
		push @backup, @{ $tc->{'backup_flags'} };
		my $backup_stdout = '';
		my $backup_stderr = '';
		my $backup_result = $primary->run_log(\@backup, '>', \$backup_stdout,
			'2>', \$backup_stderr);
		if ($backup_stdout ne '')
		{
			print "# standard output was:\n$backup_stdout";
		}
		if ($backup_stderr ne '')
		{
			print "# standard error was:\n$backup_stderr";
		}
		if (  !$backup_result
			&& $tc->{'possibly_unsupported'}
			&& $backup_stderr =~ /$tc->{'possibly_unsupported'}/)
		{
			skip "compression with $method not supported by this build", 3;
		}
		else
		{
			ok($backup_result, "client side backup, compression $method");
		}

		# Verify that the we got the files we expected.
		my $backup_files = join(',',
			sort grep { $_ ne '.' && $_ ne '..' } slurp_dir($backup_path));
		my $expected_backup_files =
		  join(',', sort ('backup_manifest', $tc->{'backup_archive'}));
		is($backup_files, $expected_backup_files,
			"found expected backup files, compression $method");

		# Decompress.
		if (exists $tc->{'decompress_program'})
		{
			my @decompress = ($tc->{'decompress_program'});
			push @decompress, @{ $tc->{'decompress_flags'} }
			  if $tc->{'decompress_flags'};
			push @decompress, $backup_path . '/' . $tc->{'backup_archive'};
			push @decompress, $backup_path . '/' . $tc->{'output_file'}
			  if $tc->{'output_file'};
			system_or_bail(@decompress);
		}

	  SKIP:
		{
			my $tar = $ENV{TAR};
			# don't check for a working tar here, to accommodate various odd
			# cases such as AIX. If tar doesn't work the init_from_backup below
			# will fail.
			skip "no tar program available", 1
			  if (!defined $tar || $tar eq '');

			# Untar.
			mkdir($extract_path);
			system_or_bail($tar, 'xf', $backup_path . '/base.tar',
				'-C', $extract_path);

			# Verify.
			$primary->command_ok(
				[
					'pg_verifybackup', '-n',
					'-m', "$backup_path/backup_manifest",
					'-e', $extract_path
				],
				"verify backup, compression $method");
		}

		# Cleanup.
		rmtree($extract_path);
		rmtree($backup_path);
	}
}

done_testing();