use strict;

package Adapters::ParallelFiles;

sub new {
    my $class = shift;
    my ($src_path, $trg_path) = @_;
    
    my $self = {
        src_path => $src_path,
        trg_path => $trg_path,
        
        src_handle => undef,
        trg_handle => undef,
        
        current_src => undef,
        current_trg => undef,
        
        line_no => -1,
    };
    
    open($self->{src_handle}, "<:utf8", $src_path) or die;
    open($self->{trg_handle}, "<:utf8", $trg_path) or die;
    
    bless $self, $class;
    return $self;
}

sub HasNext() {
    my $self = shift;
    
    my $src_handle = $self->{src_handle};
    my $trg_handle = $self->{trg_handle};
    
    if(defined($self->{current_src} = <$src_handle>)
       and defined($self->{current_trg} = <$trg_handle>)) {
       
        chomp($self->{current_src}, $self->{current_trg});
       
        $self->{line_no}++;
        return 1;
    
    }
    else {
        return 0;
    }
}

sub CurrentSource {
    my $self = shift;
    return $self->{current_src};
}

sub CurrentTarget {
    my $self = shift;    
    return $self->{current_trg};    
}

sub LineNo {
    my $self = shift;
    return $self->{line_no};
}

sub Reset {
    my $self = shift;
    
    close($self->{src_handle}) or die;
    close($self->{trg_handle}) or die;

    open($self->{src_handle}, "<:utf8", $self->{src_path}) or die;
    open($self->{trg_handle}, "<:utf8", $self->{trg_path}) or die;
    
    $self->{current_src} = undef;
    $self->{current_trg} = undef;

    $self->{line_no} = -1;
}

1;