package CWB::CQP::More::Parallel;
$CWB::CQP::More::Parallel::VERSION = '0.06';
use 5.006;
use strict;
use warnings;

use base 'CWB::CQP::More';
use Try::Tiny;

=encoding utf-8

=head1 NAME

CWB::CQP::More::Parallel - CWP::CQP::More tweaked for parallel corpora

=head1 SYNOPSIS

   use CWB::CQP::More::Parallel;

   my $cwb = CWB::CQP::More::Parallel->new( { utf8 => 1} );


=head1 DESCRIPTION

CWB::CQP::More prepared for parallel corpora.

=cut

sub new {
    shift; # class
    my $ops = ref $_[0] eq "HASH" ? shift : {};
    $ops->{parallel} = 1;
    __PACKAGE__->SUPER::new($ops, @_);
}

=head2 change_corpus

Change current active parallel corpus. Pass the corpus name as the argument.
Automatically selects the target language corpus.

B<NOTE:> multilanguage corpora not yet supported.

=cut

sub change_corpus($$) {
    my ($self, $cname) = @_;

    my $details = $self->corpora_details($cname);
    die "Can not find details for corpus $cname." unless defined $details;

    # for now, use the first of the aligned corpus
    my ($aligned) = keys %{ $details->{attribute}{a} };

    die "This does not seems a parallel corpus." unless defined $aligned;

    $cname = uc $cname;
    $self->exec("$cname;");

    $self->annotation_show($aligned);
}


=head2 cat

This method uses the C<cat> method to return a result set. The first
mandatory argument is the name of the result set. 

B<NOT YET SUPPORTED:> Second and Third
arguments are optional, and correspond to the interval of matches to
return.

Returns empty list on any error.
On success returns list of pairs.

=cut

sub cat {
    my ($self, $id) = @_;  # , $from, $to) = @_;
#    my $extra = "";
 #   $extra = "$from $to" if defined($from) && defined($to);
    my @ans;
    try {
        @ans = $self->exec("cat $id;");  #" $extra;");
    } catch {
        @ans = ();
    };

    my @fans;
    while (@ans) {
        my $left  = shift @ans;
        my $right = shift @ans;
        push @fans, [$left,$right];
    }

    return @fans;
}

=head1 SEE ALSO

CWB::CQP::More

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2014 by Alberto Manuel Brandão Simões

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.2 or,
at your option, any later version of Perl 5 you may have available.

=cut



1;
__END__