# ResolverBase.pm: build library for sbuild
# Copyright © 2005      Ryan Murray <rmurray@debian.org>
# Copyright © 2005-2008 Roger Leigh <rleigh@debian.org>
# Copyright © 2008      Simon McVittie <smcv@debian.org>
#
# 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
# <http://www.gnu.org/licenses/>.
#
#######################################################################

package Sbuild::AspcudResolver;

use strict;
use warnings;

use Sbuild::Base;
use Sbuild::ResolverBase;

BEGIN {
	use Exporter ();
	our (@ISA, @EXPORT);

	@ISA = qw(Exporter Sbuild::ResolverBase);

	@EXPORT = qw();
}

sub new {
	my $class   = shift;
	my $conf    = shift;
	my $session = shift;
	my $host    = shift;

	my $self = $class->SUPER::new($conf, $session, $host);
	bless($self, $class);

	return $self;
}

sub install_deps {
	my $self = shift;
	my $name = shift;
	my @pkgs = @_;

	my $status         = 0;
	my $session        = $self->get('Session');
	my $dummy_pkg_name = $self->get_sbuild_dummy_pkg_name($name);

	# Call functions to setup an archive to install dummy package.
	$self->log_subsubsection("Setup apt archive");

	if (!$self->setup_apt_archive($dummy_pkg_name, @pkgs)) {
		$self->log_error("Setting up apt archive failed\n");
		return 0;
	}

	if (!$self->update_archive()) {
		$self->log_error("Updating apt archive failed\n");
		return 0;
	}

	$self->log_subsection(
		"Install $name build dependencies (aspcud-based resolver)");
	#install aspcud first:
	my (@aspcud_installed_packages, @aspcud_removed_packages);
	if (
		!$self->run_apt(
			'-y',      \@aspcud_installed_packages, \@aspcud_removed_packages,
			'install', 'apt-cudf',                  'aspcud'
		)
	) {
		$self->log_warning('Could not install aspcud!');
		goto cleanup;
	}
	$self->set_installed(@aspcud_installed_packages);
	$self->set_removed(@aspcud_removed_packages);

	# Install the dummy package
	my (@instd, @rmvd);
	$self->log("Installing build dependencies\n");
	my @apt_args = ("-yf", \@instd, \@rmvd);
	push @apt_args, 'install', $dummy_pkg_name;

	push @apt_args, '--solver', 'aspcud',
	  -o => 'APT::Solver::Strict-Pinning=false',
	  -o => ('APT::Solver::aspcud::Preferences='
		  . $self->get_conf('ASPCUD_CRITERIA'));

	if (!$self->run_apt(@apt_args)) {
		$self->log("Package installation failed\n");
		if (defined($self->get('Session')->get('Session Purged'))
			&& $self->get('Session')->get('Session Purged') == 1) {
			$self->log("Not removing build depends: cloned chroot in use\n");
		} else {
			$self->set_installed(@instd);
			$self->set_removed(@rmvd);
			goto package_cleanup;
		}
		return 0;
	}
	$self->set_installed(@instd);
	$self->set_removed(@rmvd);
	$status = 1;

  package_cleanup:
	if ($status == 0) {
		if (defined($session->get('Session Purged'))
			&& $session->get('Session Purged') == 1) {
			$self->log(
				"Not removing installed packages: cloned chroot in use\n");
		} else {
			$self->uninstall_deps();
		}
	}

  cleanup:
	return $status;
}

sub purge_extra_packages {
	my $self = shift;
	my $name = shift;

	my $dummy_pkg_name = $self->get_sbuild_dummy_pkg_name($name);

	my $session = $self->get('Session');

	# we retrieve the list of installed Essential:yes packages because these
	# must not be removed
	my $pipe = $session->pipe_command({
			COMMAND => [
				'dpkg-query',                 '--showformat',
				'${Essential} ${Package}\\n', '--show'
			],
			USER => $self->get_conf('BUILD_USER') });
	if (!$pipe) {
		$self->log_error("unable to execute dpkg-query\n");
		return 0;
	}
	my @essential;
	while (my $line = <$pipe>) {
		chomp $line;
		if ($line !~ /^yes ([a-zA-Z0-9][a-zA-Z0-9+.-]*)$/) {
			next;
		}
		push @essential, "$1+";
	}
	close $pipe;
	if (scalar @essential == 0) {
		$self->log_error("no essential packages found \n");
		return 0;
	}
# the /dev/null prevents acpcud from even looking at external repositories, so all it can do is remove stuff
# it is also much faster that way
	my (@instd, @rmvd);
	$self->run_apt(
		"-yf",
		\@instd,
		\@rmvd,
		'autoremove',
		@essential,
		$self->get_sbuild_dummy_pkg_name('core') . '+',
		"$dummy_pkg_name+",
		'--solver',
		'aspcud',
		'-o',
		'APT::Solver::aspcud::Preferences=+removed',
		'-o',
		'Dir::State::Lists=/dev/null',
		'--allow-remove-essential'
	);
}

1;
