#!/usr/bin/perl
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

use strict;
use warnings;

use Test::More;

use File::Spec;

use Dpkg::IPC;
use Dpkg::File qw(file_slurp);
use Dpkg::Path qw(find_command);

my $srcdir = $ENV{srcdir} || '.';
my $tmpdir = 't.tmp/update_alternatives';
my $admindir = File::Spec->rel2abs("$tmpdir/admindir"),
my $altdir = File::Spec->rel2abs("$tmpdir/alternatives");
my $bindir = File::Spec->rel2abs("$tmpdir/bin");
my @ua = ("$ENV{builddir}/update-alternatives", '--log', '/dev/null',
          '--quiet', '--admindir', "$admindir", '--altdir', "$altdir");

my %paths = (
    true => find_command('true'),
    false => find_command('false'),
    yes => find_command('yes'),
    cat => find_command('cat'),
    date => find_command('date'),
    sleep => find_command('sleep'),
);

if (! -x "$ENV{builddir}/update-alternatives") {
    plan skip_all => 'update-alternatives not available';
    exit(0);
}

my $main_link = "$bindir/generic-test";
my $main_name = 'generic-test';
my @choices = (
    {
	path => $paths{true},
	priority => 20,
	slaves => [
	    {
		link => "$bindir/slave2",
		name => 'slave2',
		path => $paths{cat},
	    },
	    {
		link => "$bindir/slave3",
		name => 'slave3',
		path => $paths{cat},
	    },
	    {
		link => "$bindir/slave1",
		name => 'slave1',
		path => $paths{yes},
	    },
	    {
		link => "$bindir/slave4",
		name => 'slave4',
		path => $paths{cat},
	    },
	],
    },
    {
        path => $paths{false},
        priority => 10,
        slaves => [
	    {
		link => "$bindir/slave1",
		name => 'slave1',
		path => $paths{date},
	    },
        ],
    },
    {
        path => $paths{sleep},
        priority => 5,
        slaves => [],
    },
);
my $nb_slaves = 4;
plan tests => (4 * ($nb_slaves + 1) + 2) * 26 # number of check_choices
               + 110;                         # rest

sub cleanup {
    system("rm -rf $tmpdir && mkdir -p $admindir && mkdir -p $altdir");
    system("mkdir -p $bindir/more");
}

sub call_ua {
    my ($params, %opts) = @_;
    spawn(exec => [ @ua, @$params ], nocheck => 1,
	  wait_child => 1, env => { LC_ALL => 'C' }, %opts);
    my $test_id = '';
    $test_id = "$opts{test_id}: " if defined $opts{test_id};
    if ($opts{expect_failure}) {
	ok($? != 0, "${test_id}update-alternatives @$params should fail.") or
	    diag("Did not fail as expected: @ua @$params");
    } else {
	ok($? == 0, "${test_id}update-alternatives @$params should work.") or
	    diag("Did not succeed as expected: @ua @$params");
    }
}

sub install_choice {
    my ($id, %opts) = @_;
    my $alt = $choices[$id];
    my @params;
    push @params, @{$opts{params}} if exists $opts{params};
    push @params, '--install', "$main_link", "$main_name",
		  $alt->{path}, $alt->{priority};
    foreach my $slave (@{ $alt->{slaves} }) {
	push @params, '--slave', $slave->{link}, $slave->{name}, $slave->{path};
    }
    call_ua(\@params, %opts);
}

sub remove_choice {
    my ($id, %opts) = @_;
    my $alt = $choices[$id];
    my @params;
    push @params, @{$opts{params}} if exists $opts{params};
    push @params, '--remove', $main_name, $alt->{path};
    call_ua(\@params, %opts);
}

sub remove_all_choices {
    my (%opts) = @_;
    my @params;
    push @params, @{$opts{params}} if exists $opts{params};
    push @params, '--remove-all', $main_name;
    call_ua(\@params, %opts);
}

sub set_choice {
    my ($id, %opts) = @_;
    my $alt = $choices[$id];
    my @params;
    push @params, @{$opts{params}} if exists $opts{params};
    push @params, '--set', $main_name, $alt->{path};
    call_ua(\@params, %opts);
}

sub config_choice {
    my ($id, %opts) = @_;
    my ($input, $output) = ('', '');
    if ($id >= 0) {
	my $alt = $choices[$id];
	$input = $alt->{path};
    } else {
	$input = '0';
    }
    $input .= "\n";
    $opts{from_string} = \$input;
    $opts{to_string} = \$output;
    my @params;
    push @params, @{$opts{params}} if exists $opts{params};
    push @params, '--config', $main_name;
    call_ua(\@params, %opts);
}

sub get_slaves_status {
    my ($id) = @_;
    my %slaves;
    # None of the slaves are installed
    foreach my $alt (@choices) {
	for my $i (0 .. @{$alt->{slaves}} - 1) {
	    $slaves{$alt->{slaves}[$i]{name}} = $alt->{slaves}[$i];
	    $slaves{$alt->{slaves}[$i]{name}}{installed} = 0;
	}
    }
    # except those of the current alternative (minus optional slaves)
    if (defined($id)) {
	my $alt = $choices[$id];
	for my $i (0 .. @{$alt->{slaves}} - 1) {
	    $slaves{$alt->{slaves}[$i]{name}} = $alt->{slaves}[$i];
	    if (-e $alt->{slaves}[$i]{path}) {
		$slaves{$alt->{slaves}[$i]{name}}{installed} = 1;
	    }
	}
    }
    my @slaves = sort { $a->{name} cmp $b->{name} } values %slaves;

    return @slaves;
}

sub check_link {
    my ($link, $value, $msg) = @_;
    ok(-l $link, "$msg: $link disappeared.");
    is(readlink($link), $value, "$link doesn't point to $value.");
}
sub check_no_link {
    my ($link, $msg) = @_;
    lstat($link);
    ok(!-e _, "$msg: $link still exists.");
    ok(1, 'fake test'); # Same number of tests as check_link
}

sub check_slaves {
    my ($id, $msg) = @_;
    foreach my $slave (get_slaves_status($id)) {
	if ($slave->{installed}) {
	    check_link("$altdir/$slave->{name}", $slave->{path}, $msg);
	    check_link($slave->{link}, "$altdir/$slave->{name}", $msg);
	} else {
	    check_no_link("$altdir/$slave->{name}", $msg);
	    check_no_link($slave->{link}, $msg);
	}
    }
}
# (4 * (nb_slaves+1) + 2) tests in each check_choice() call
sub check_choice {
    my ($id, $mode, $msg) = @_;
    my $output;
    if (defined $id) {
	# Check status
	call_ua([ '--query', "$main_name" ], to_string => \$output, test_id => $msg);
	$output =~ /^Status: (.*)$/im;
	is($1, $mode, "$msg: status is not $mode.");
	# Check links
	my $alt = $choices[$id];
	check_link("$altdir/$main_name", $alt->{path}, $msg);
	check_link($main_link, "$altdir/$main_name", $msg);
	check_slaves($id, $msg);
    } else {
	call_ua([ '--query', "$main_name" ], error_to_string => \$output,
	        expect_failure => 1, test_id => $msg);
	ok($output =~ /no alternatives/, "$msg: bad error message for --query.");
	# Check that all links have disappeared
	check_no_link("$altdir/$main_name", $msg);
	check_no_link($main_link, $msg);
	check_slaves(undef, $msg);
    }
}

### START OF TESTS
cleanup();
# removal when not installed should not fail
remove_choice(0);
# successive install in auto mode
install_choice(1);
check_choice(1, 'auto', 'initial install 1');
install_choice(2); # 2 is lower prio, stays at 1
check_choice(1, 'auto', 'initial install 2');
install_choice(0); # 0 is higher priority
check_choice(0, 'auto', 'initial install 3');

# verify that the administrative file is sorted properly
{
    my $content = file_slurp("$admindir/generic-test");
    my $expected =
"auto
$bindir/generic-test
slave1
$bindir/slave1
slave2
$bindir/slave2
slave3
$bindir/slave3
slave4
$bindir/slave4

";

    my %slaves;

    # Store slaves in a hash to easily retrieve present and missing ones.
    foreach my $alt (@choices) {
        foreach my $slave (@{$alt->{slaves}}) {
            $slaves{$slave->{name}}{$alt->{path}} = $slave;
        }
    }

    foreach my $alt (sort { $a->{path} cmp $b->{path} } @choices) {
        $expected .= $alt->{path} . "\n";
        $expected .= $alt->{priority} . "\n";
        foreach my $slave_name (sort keys %slaves) {
            $expected .= $slaves{$slave_name}{$alt->{path}}{path} || '';
            $expected .= "\n";
        }
    }
    $expected .= "\n";

    is($content, $expected, 'administrative file is as expected');
}

# manual change with --set-selections
my $input = "doesntexist auto $paths{date}\ngeneric-test manual $paths{false}\n";
my $output = '';
call_ua(['--set-selections'], from_string => \$input,
        to_string => \$output, test_id => 'manual update with --set-selections');
check_choice(1, 'manual', 'manual update with --set-selections');
$input = "generic-test auto $paths{true}\n";
call_ua(['--set-selections'], from_string => \$input,
        to_string => \$output, test_id => 'auto update with --set-selections');
check_choice(0, 'auto', 'auto update with --set-selections');
# manual change with set
set_choice(2, test_id => 'manual update with --set');
check_choice(2, 'manual', 'manual update with --set'); # test #388313
remove_choice(2, test_id => 'remove manual, back to auto');
check_choice(0, 'auto', 'remove manual, back to auto');
remove_choice(0, test_id => 'remove best');
check_choice(1, 'auto', 'remove best');
remove_choice(1, test_id => 'no alternative left');
check_choice(undef, '', 'no alternative left');
# single choice in manual mode, to be removed
install_choice(1);
set_choice(1);
check_choice(1, 'manual', 'single manual choice');
remove_choice(1);
check_choice(undef, '', 'removal single manual');
# test --remove-all
install_choice(0);
install_choice(1);
install_choice(2);
remove_all_choices(test_id => 'remove all');
check_choice(undef, '', 'no alternative left');
# check auto-recovery of user mistakes (#100135)
install_choice(1);
ok(unlink("$bindir/generic-test"), 'failed removal');
ok(unlink("$bindir/slave1"), 'failed removal');
install_choice(1);
check_choice(1, 'auto', 'recreate links in auto mode');
set_choice(1);
ok(unlink("$bindir/generic-test"), 'failed removal');
ok(unlink("$bindir/slave1"), 'failed removal');
install_choice(1);
check_choice(1, 'manual', 'recreate links in manual mode');
# check recovery of /etc/alternatives/*
install_choice(0);
ok(unlink("$altdir/generic-test"), 'failed removal');
install_choice(1);
check_choice(0, 'auto', '<altdir>/generic-test lost, back to auto');
# test --config
config_choice(0);
check_choice(0, 'manual', 'config to best but manual');
config_choice(1);
check_choice(1, 'manual', 'config to manual');
config_choice(-1);
check_choice(0, 'auto', 'config auto');

# test rename of links
install_choice(0);
my $old_slave = $choices[0]{slaves}[0]{link};
my $old_link = $main_link;
$choices[0]{slaves}[0]{link} = "$bindir/more/generic-slave";
$main_link = "$bindir/more/mytest";
install_choice(0);
check_choice(0, 'auto', 'test rename of links');
check_no_link($old_link, 'test rename of links');
check_no_link($old_slave, 'test rename of links');
# rename with installing other alternatives
$old_link = $main_link;
$main_link = "$bindir/generic-test";
install_choice(1);
check_choice(0, 'auto', 'rename link');
check_no_link($old_link, 'rename link');
# rename with lost file
unlink($old_slave);
$old_slave = $choices[0]{slaves}[0]{link};
$choices[0]{slaves}[0]{link} = "$bindir/generic-slave-bis";
install_choice(0);
check_choice(0, 'auto', 'rename lost file');
check_no_link($old_slave, 'rename lost file');
# update of alternative with many slaves not currently installed
# and the link of the renamed slave exists while it should not
set_choice(1);
symlink("$paths{cat}", "$bindir/generic-slave-bis");
$choices[0]{slaves}[0]{link} = "$bindir/slave2";
install_choice(0, test_id => 'update with non-installed slaves');
check_no_link("$bindir/generic-slave-bis",
              'drop renamed symlink that should not be installed');

# test install with empty admin file (#457863)
cleanup();
system("touch $admindir/generic-test");
install_choice(0);
# test install with garbage admin file
cleanup();
system("echo garbage > $admindir/generic-test");
install_choice(0, error_to_file => '/dev/null', expect_failure => 1);

# test invalid usages
cleanup();
install_choice(0);
# try to install a slave alternative as new master
call_ua(['--install', "$bindir/testmaster", 'slave1', "$paths{date}", '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# try to install a master alternative as slave
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/testslave", 'generic-test', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# try to reuse master link in slave
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/testmaster", 'testslave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# try to reuse links in master alternative
call_ua(['--install', "$bindir/slave1", 'testmaster', "$paths{date}", '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# try to reuse links in slave alternative
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/generic-test", 'testslave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# try to reuse slave link in another slave alternative of another choice of
# the same main alternative
call_ua(['--install', $main_link, $main_name, "$paths{date}", '10',
         '--slave', "$bindir/slave1", 'testslave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# lack of absolute filenames in links or file path, non-existing path,
call_ua(['--install', '../testmaster', 'testmaster', "$paths{date}", '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
call_ua(['--install', "$bindir/testmaster", 'testmaster', './update-alternatives.pl', '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# non-existing alternative path
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$bindir/doesntexist", '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# invalid alternative name in master
call_ua(['--install', "$bindir/testmaster", 'test/master', "$paths{date}", '10'],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# invalid alternative name in slave
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/testslave", 'test slave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
# install in non-existing dir should fail
call_ua(['--install', "$bindir/doesntexist/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/testslave", 'testslave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');
call_ua(['--install', "$bindir/testmaster", 'testmaster', "$paths{date}", '10',
         '--slave', "$bindir/doesntexist/testslave", 'testslave', "$paths{true}" ],
        expect_failure => 1, to_file => '/dev/null', error_to_file => '/dev/null');

# non-existing alternative path in slave is not a failure
my $old_path = $choices[0]{slaves}[0]{path};
$old_slave = $choices[0]{slaves}[0]{link};
$choices[0]{slaves}[0]{path} = "$bindir/doesntexist";
$choices[0]{slaves}[0]{link} = "$bindir/baddir/slave2";
# test rename of slave link that existed but that doesn't anymore
# and link is moved into non-existing dir at the same time
install_choice(0);
check_choice(0, 'auto', 'optional renamed slave2 in non-existing dir');
# same but on fresh install
cleanup();
install_choice(0);
check_choice(0, 'auto', 'optional slave2 in non-existing dir');
$choices[0]{slaves}[0]{link} = $old_slave;
# test fresh install with a non-existing slave file
cleanup();
install_choice(0);
check_choice(0, 'auto', 'optional slave2');
$choices[0]{slaves}[0]{path} = $old_path;

# test management of pre-existing files
cleanup();
system("touch $main_link $bindir/slave1");
install_choice(0);
ok(!-l $main_link, 'install preserves files that should be links');
ok(!-l "$bindir/slave1", 'install preserves files that should be slave links');
remove_choice(0);
ok(-f $main_link, 'removal keeps real file installed as master link');
ok(-f "$bindir/slave1", 'removal keeps real files installed as slave links');
install_choice(0, params => ['--force']);
check_choice(0, 'auto', 'install --force replaces files with links');

# test management of pre-existing files #2
cleanup();
system("touch $main_link $bindir/slave2");
install_choice(0);
install_choice(1);
ok(!-l $main_link, 'inactive install preserves files that should be links');
ok(!-l "$bindir/slave2", 'inactive install preserves files that should be slave links');
ok(-f $main_link, 'inactive install keeps real file installed as master link');
ok(-f "$bindir/slave2", 'inactive install keeps real files installed as slave links');
set_choice(1);
ok(!-l $main_link, 'manual switching preserves files that should be links');
ok(!-l "$bindir/slave2", 'manual switching preserves files that should be slave links');
ok(-f $main_link, 'manual switching keeps real file installed as master link');
ok(-f "$bindir/slave2", 'manual switching keeps real files installed as slave links');
remove_choice(1);
ok(!-l $main_link, 'auto switching preserves files that should be links');
ok(!-l "$bindir/slave2", 'auto switching preserves files that should be slave links');
ok(-f $main_link, 'auto switching keeps real file installed as master link');
ok(-f "$bindir/slave2", 'auto switching keeps real files installed as slave links');
remove_all_choices(params => ['--force']);
ok(!-e "$bindir/slave2", 'forced removeall drops real files installed as slave links');

# test management of pre-existing files #3
cleanup();
system("touch $main_link $bindir/slave2");
install_choice(0);
install_choice(1);
remove_choice(0);
ok(!-l $main_link, 'removal + switching preserves files that should be links');
ok(!-l "$bindir/slave2", 'removal + switching preserves files that should be slave links');
ok(-f $main_link, 'removal + switching keeps real file installed as master link');
ok(-f "$bindir/slave2", 'removal + switching keeps real files installed as slave links');
install_choice(0);
ok(!-l $main_link, 'install + switching preserves files that should be links');
ok(!-l "$bindir/slave2", 'install + switching preserves files that should be slave links');
ok(-f $main_link, 'install + switching keeps real file installed as master link');
ok(-f "$bindir/slave2", 'install + switching keeps real files installed as slave links');
set_choice(1, params => ['--force']);
ok(!-e "$bindir/slave2", 'forced switching w/o slave drops real files installed as slave links');
check_choice(1, 'manual', 'set --force replaces files with links');

# check disappearence of obsolete slaves (#916799)
cleanup();
call_ua([
    '--install', "$bindir/test-obsolete", 'test-obsolete', "$paths{date}", '10',
    '--slave', "$bindir/test-slave-a", 'test-slave-a', "$bindir/impl-slave-a",
    '--slave', "$bindir/test-slave-b", 'test-slave-b', "$bindir/impl-slave-b",
    '--slave', "$bindir/test-slave-c", 'test-slave-c', "$bindir/impl-slave-c",
], to_file => '/dev/null', error_to_file => '/dev/null');

my $content;
my $expected;

$content = file_slurp("$admindir/test-obsolete");
$expected =
"auto
$bindir/test-obsolete
test-slave-a
$bindir/test-slave-a
test-slave-b
$bindir/test-slave-b
test-slave-c
$bindir/test-slave-c

$paths{date}
10
$bindir/impl-slave-a
$bindir/impl-slave-b
$bindir/impl-slave-c

";
is($content, $expected, 'administrative file for non-obsolete slaves is as expected');

call_ua([
    '--install', "$bindir/test-obsolete", 'test-obsolete', "$paths{date}", '20',
    '--slave', "$bindir/test-slave-c", 'test-slave-c', "$bindir/impl-slave-c",
], to_file => '/dev/null', error_to_file => '/dev/null');

$content = file_slurp("$admindir/test-obsolete");
$expected =
"auto
$bindir/test-obsolete
test-slave-c
$bindir/test-slave-c

$paths{date}
20
$bindir/impl-slave-c

";
is($content, $expected, 'administrative file for obsolete slaves is as expected');