package Catmandu::Importer::Multi;

use Catmandu::Sane;

our $VERSION = '1.0002_01';

use Catmandu::Util qw(is_string);
use Catmandu;
use Catmandu::MultiIterator;
use Moo;
use namespace::clean;

with 'Catmandu::Importer';

has importers => (
    is => 'ro',
    default => sub { [] },
    coerce => sub {
        my $importers = $_[0];
        return [ map {
            if (is_string($_)) {
                Catmandu->importer($_);
            } else {
                $_;
            }
        } @$importers ];
    },
);

sub generator {
    my ($self) = @_;
    sub {
        state $generators = [ map { $_->generator } @{$self->importers} ];
        while (@$generators) {
            my $data = $generators->[0]->();
            return $data if defined $data;
            shift @$generators;
        }
        return;
    };
}

1;

__END__

=pod

=head1 NAME

Catmandu::Importer::Multi - Chain multiple importers together

=head1 SYNOPSIS

    use Catmandu::Importer::Multi;

    my $importer = Catmandu::Importer::Multi->new(importers => [
        Catmandu::Importer::Mock->new,
        Catmandu::Importer::Mock->new,
    ]);

    my $importer = Catmandu::Importer::Multi->new(
        'importer1',
        'importer2',
    );

    # return all the items of each importer in turn
    $importer->each(sub {
        # ...
    });

=head1 METHODS

Every L<Catmandu::Importer> is a L<Catmandu::Iterable> all its methods are
inherited.

=cut
