package Markdent::Role::BalancedEvent;
$Markdent::Role::BalancedEvent::VERSION = '0.25';
use strict;
use warnings;
use namespace::autoclean;

use List::AllUtils qw( all );
use Markdent::Types qw( ArrayRef Str );
use MooseX::Params::Validate qw( pos_validated_list );

use MooseX::Role::Parameterized;

parameter compare => (
    isa => ArrayRef [Str],
);

role {
    my $p = shift;

    my @compare = @{ $p->compare() || [] };

    method balances_event => sub {
        my $self = shift;
        my ($other)
            = pos_validated_list( \@_, { does => 'Markdent::Role::Event' } );

        return 0 unless $self->name() eq $other->name();

        return 0
            unless ( $self->is_start() && $other->is_end() )
            || ( $self->is_end() && $other->is_start() );

        return 1 unless @compare;

        return all { $self->$_() eq $other->$_() } @compare;

        return 0;
    };
};

1;

# ABSTRACT: A parameterized role for events which can check if they match balance another event

__END__

=pod

=head1 NAME

Markdent::Role::BalancedEvent - A parameterized role for events which can check if they match balance another event

=head1 VERSION

version 0.25

=head1 DESCRIPTION

This role provides behavior for start and end events which can be checked for
a balancing event. This includes things like strong, emphasis, and code
start/end events.

=head1 ROLE PARAMETERS

This role accepts the following parameters:

=over 4

=item * compare => [ ... ]

This should be a list of attribute names which will be compared between the
start and end events.

=back

=head1 METHODS

This role provides the following methods:

=head2 $event->balances_event($event2)

Given an event, this returns true if two events balance each other. This is
done by comparing types (StartCode matches EndCode), as well as the attributes
provided in the compare parameter.

=head1 BUGS

See L<Markdent> for bug reporting details.

=head1 AUTHOR

Dave Rolsky <autarch@urth.org>

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by Dave Rolsky.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut