package CGI::Easy::Session;
use 5.010001;
use warnings;
use strict;
use utf8;
use Carp;

our $VERSION = 'v2.0.0';

use Data::UUID;
use CGI::Easy::Util qw( quote_list unquote_hash );

use constant SESSION_EXPIRE => 365*24*60*60; # 1 year

my $UG;


sub new {
    my ($class, $r, $h) = @_;
    my $self = {
        id      => undef,
        perm    => undef,
        temp    => undef,
        _r      => $r,
        _h      => $h,
    };
    bless $self, $class;
    $self->_init;
    return $self;
}

sub _init {
    my ($self) = @_;
    my $r = $self->{_r};
    my $c = $r->{cookie};
    if ($c->{sid}) {
        $self->{id} = $c->{sid};
    }
    else {
        my $referer = $r->{ENV}{HTTP_REFERER} || q{};
        if ($referer !~ m{\A\w+://\Q$r->{host}\E[:/]}xms) {
            $UG ||= Data::UUID->new();
            $self->{id} = $UG->create_b64();
        }
    }
    if ($self->{id}) {
        $self->{_h}->add_cookie({
            name    => 'sid',
            value   => $self->{id},
            expires => time + SESSION_EXPIRE,
        });
    }
    $self->{perm} = unquote_hash($c->{perm}) || {};
    $self->{temp} = unquote_hash($c->{temp}) || {};
    return;
}

sub save {
    my ($self) = @_;
    my $h = $self->{_h};
    my @other_cookies = grep {$_->{name} ne 'perm' && $_->{name} ne 'temp'}
        @{ $h->{'Set-Cookie'} };
    $h->{'Set-Cookie'} = [
        @other_cookies,
        {
            name    => 'perm',
            value   => quote_list(%{ $self->{perm} }),
            expires => time + SESSION_EXPIRE,
        },
        {
            name    => 'temp',
            value   => quote_list(%{ $self->{temp} }),
        },
    ];
    return;
}


1; # Magic true value required at end of module
__END__

=encoding utf8

=head1 NAME

CGI::Easy::Session - Support unique session ID and session data in cookies


=head1 VERSION

This document describes CGI::Easy::Session version v2.0.0


=head1 SYNOPSIS

    use CGI::Easy::Request;
    use CGI::Easy::Headers;
    use CGI::Easy::Session;

    my $r = CGI::Easy::Request->new();
    my $h = CGI::Easy::Headers->new();
    my $sess = CGI::Easy::Session->new($r, $h);

    if (defined $sess->{id}) {
        printf "Session ID: %s\n", $sess->{id};
    } else {
        print "User has no cookie support\n";
    }
    printf "Permanent var 'a': %s\n", $sess->{perm}{a};
    printf "Temporary var 'a': %s\n", $sess->{temp}{a};

    $sess->{perm}{b} = 'data';
    $sess->{temp}{answer} = 42;
    $sess->save();                  # BEFORE $h->compose()


=head1 DESCRIPTION

Manage session for CGI applications.

Detect is user has cookie support.
Generate unique session ID for each user.
Store persistent and temporary (until browser closes) data in cookies.

This module will set cookies C< sid >, C< perm > and C< temp >, so you
shouldn't use cookies with these names if you using this module.


=head1 INTERFACE

=over

=item new( $r, $h )

Take $r (CGI::Easy::Request object) and $h (CGI::Easy::Headers object)
and create new CGI::Easy::Session object with these public fields:

    id      STRING (unique session ID or undef if no cookie support)
    perm    HASHREF (simple hash with scalar-only values)
    temp    HASHREF (simple hash with scalar-only values)

You can both read existing session data in {perm} and {temp} and
add/update new data there, but keep in mind overall cookie size is limited
(usual limit is few kilobytes and it differ between browsers).
After changing {perm} or {temp} don't forget to call save().

Complex data structures in {perm} and {temp} doesn't supported (you can
manually pack/unpack them using any data serialization tool).

Will set cookie "sid" (with session ID) in 'Set-Cookie' header, which will
expire in 1 YEAR after last visit.

Return created CGI::Easy::Session object.


=item save()

Set/update 'Set-Cookie' header with current {perm} and {temp} values.
Should be called before sending reply to user (with C<< $h->compose() >>)
if {perm} or {temp} was modified.

Cookie "perm" (with hash {perm} data) will expire in 1 YEAR after last visit.
Cookie "temp" (with hash {temp} data) will expire when browser will be closed.

Return nothing.


=back


=head1 SUPPORT

=head2 Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker
at L<https://github.com/powerman/perl-CGI-Easy/issues>.
You will be notified automatically of any progress on your issue.

=head2 Source Code

This is open source software. The code repository is available for
public review and contribution under the terms of the license.
Feel free to fork the repository and submit pull requests.

L<https://github.com/powerman/perl-CGI-Easy>

    git clone https://github.com/powerman/perl-CGI-Easy.git

=head2 Resources

=over

=item * MetaCPAN Search

L<https://metacpan.org/search?q=CGI-Easy>

=item * CPAN Ratings

L<http://cpanratings.perl.org/dist/CGI-Easy>

=item * AnnoCPAN: Annotated CPAN documentation

L<http://annocpan.org/dist/CGI-Easy>

=item * CPAN Testers Matrix

L<http://matrix.cpantesters.org/?dist=CGI-Easy>

=item * CPANTS: A CPAN Testing Service (Kwalitee)

L<http://cpants.cpanauthors.org/dist/CGI-Easy>

=back


=head1 AUTHOR

Alex Efros E<lt>powerman@cpan.orgE<gt>


=head1 COPYRIGHT AND LICENSE

This software is Copyright (c) 2009-2010 by Alex Efros E<lt>powerman@cpan.orgE<gt>.

This is free software, licensed under:

  The MIT (X11) License


=cut