package Catalyst::Plugin::Session::Store::MongoDB;
use strict;
use warnings;

our $VERSION = '0.02';

use Moose;
use namespace::autoclean;

use MongoDB::Connection;
use Data::Dumper;

BEGIN { extends 'Catalyst::Plugin::Session::Store' }

has hostname => (
	isa => 'Str',
	is => 'ro',
	lazy_build => 1,
);

has port => (
	isa => 'Int',
	is => 'ro',
	lazy_build => 1,
);

has dbname => (
	isa => 'Str',
	is => 'ro',
	lazy_build => 1,
);

has collectionname => (
	isa => 'Str',
	is => 'ro',
	lazy_build => 1,
);

has '_collection' => (
	isa => 'MongoDB::Collection',
	is => 'ro',
	lazy_build => 1,
);

has '_connection' => (
	isa => 'MongoDB::Connection',
	is => 'ro',
	lazy_build => 1,
);

has '_db' => (
	isa => 'MongoDB::Database',
	is => 'ro',
	lazy_build => 1,
);

sub _cfg_or_default {
	my ($self, $name, $default) = @_;

	my $cfg = $self->_session_plugin_config;

	return $cfg->{$name} || $default;
}

sub _build_hostname {
	my ($self) = @_;
	return $self->_cfg_or_default('hostname', 'localhost');
}

sub _build_port {
	my ($self) = @_;
	return $self->_cfg_or_default('port', 27017);
}

sub _build_dbname {
	my ($self) = @_;
	return $self->_cfg_or_default('dbname', 'catalyst');
}

sub _build_collectionname {
	my ($self) = @_;
	return $self->_cfg_or_default('collectionname', 'session');
}

sub _build__collection {
    my ($self) = @_;

    return $self->_db->get_collection($self->collectionname);
}

sub _build__connection {
    my ($self) = @_;

    return MongoDB::Connection->new(
        host => $self->hostname,
        port => $self->port,
    );
}

sub _build__db {
    my ($self) = @_;

    return $self->_connection->get_database($self->dbname);
}

sub _serialize {
	my ($self, $data) = @_;

	my $d = Data::Dumper->new([ $data ]);

	return $d->Indent(0)->Purity(1)->Terse(1)->Quotekeys(0)->Dump;
}

sub get_session_data {
	my ($self, $key) = @_;

	my ($prefix, $id) = split(/:/, $key);

	my $found = $self->_collection->find_one({ _id => $id },
		{ $prefix => 1, 'expires' => 1 });

	return undef unless $found;

	if ($found->{expires} && time() > $found->{expires}) {
		$self->delete_session_data($id);
		return undef;
	}

	return eval($found->{$prefix});
}

sub store_session_data {
	my ($self, $key, $data) = @_;

	my ($prefix, $id) = split(/:/, $key);

	# we need to not serialize the expires date, since it comes in as an
	# integer and we need to preserve that in order to be able to use
	# mongodb's '$lt' function in delete_expired_sessions()
	my $serialized;
	if ($prefix =~ /^expires$/) {
		$serialized = $data;
	} else {
		$serialized = $self->_serialize($data);
	}

	$self->_collection->update({ _id => $id },
		{ '$set' => { $prefix => $serialized } }, { upsert => 1 });
}

sub delete_session_data {
	my ($self, $key) = @_;

	my ($prefix, $id) = split(/:/, $key);

	my $found = $self->_collection->find_one({ _id => $id });
	return unless $found;

	if (exists($found->{$prefix})) {
		if ((scalar(keys(%$found))) > 2) {
			$self->_collection->update({ _id => $id },
				{ '$unset' => { $prefix => 1 }} );
			return;
		} else {
			$self->_collection->remove({ _id => $id });
		}
	}
}

sub delete_expired_sessions {
	my ($self) = @_;

	$self->_collection->remove({ 'expires' => { '$lt' => time() } });
}

__PACKAGE__->meta->make_immutable;

1;

__END__

=head1 NAME

Catalyst::Plugin::Session::Store::MongoDB - MongoDB session store for Catalyst

=head1 SYNOPSIS

In your MyApp.pm:

	use Catalyst qw/
		Session
		Session::Store::MongoDB
		Session::State::Cookie # or similar
	/;

and in your MyApp.conf

	<Plugin::Session>
		hostname foo		# defaults to localhost
		port 0815		# defaults to 27017
		dbname test		# defaults to catalyst
		collectionname s2	# defaults to session
	</Plugin::Session>

Then you can use it as usual:

    $c->session->{foo} = 'bar'; # will be saved

=head1 DESCRIPTION

C<Catalyst::Plugin::Session::Store::MongoDB> is a session storage plugin using
MongoDB (L<http://www.mongodb.org>) as it's backend.

=head1 USAGE

=over 4

=item B<Expired Sessions>

This store automatically deletes sessions when they expire. Additionally it
implements the optional delete_expired_sessions() method.

=back

=head1 AUTHOR

    Stefan Völkel
    bd@bc-bd.org
    http://bc-bd.org

=head1 COPYRIGHT

Copyright 2010 Stefan Völkel <bd@bc-bd.org>

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License v2 as published
by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.

=cut