#!/usr/bin/env perl

use warnings;
use strict;
use lib '../lib';
use lib 'lib';

use Carp qw(croak);
use File::Spec;
use Getopt::Long;
use XML::Twig;

# gwybodaeth specific modules
use Gwybodaeth::Parsers::N3;
use Gwybodaeth::Read;

sub show_help {
    return system( "perldoc", "Gwybodaeth" );
}

my $data;
my $map;
my $in_type;
my $help;

GetOptions(
    'src|source=s' => \$data,
    'map=s'        => \$map,
    'input|in=s'   => \$in_type,
    'help|h'       => \$help
);

# Load help dialogue
if ( defined $help ) {
    show_help;
    exit 1;
}

# Load configuration
my $root = File::Spec->rootdir();
my $conf_file = File::Spec->catfile("$root",'etc','gwybodaeth','gwybodaeth.conf');
-e $conf_file or croak "you need a configuration file $conf_file: $!";

my $twig = XML::Twig->new();
$twig->parsefile($conf_file);

my @converters = $twig->root->children('converter');
my %convert    = ();

for my $conv (@converters) {
    my $name   = $conv->first_child_text('name');
    my $parser = $conv->first_child_text('parser');
    my $writer = $conv->first_child_text('writer');

    $convert{$name} = { parser => $parser, writer => $writer };
}

my $input = Gwybodaeth::Read->new();

my $len;
if ( -f $data ) {
    $len = $input->get_file_data($data);
}
else {
    $len = $input->get_url_data($data);
}

croak "Empty file." if ( $len < 1 );

my $mapping = Gwybodaeth::Read->new();

if ( -f $map ) {
    $len = $mapping->get_file_data($map);
}
else {
    $len = $mapping->get_url_data($map);
}

croak "Empty site." if ( $len < 1 );

my @data = @{ $mapping->get_input_data };

my $map_parser = Gwybodaeth::Parsers::N3->new();

my $map_triples = $map_parser->parse(@data);

unless ($map_triples) { croak 'Error while parsing map data'; }

my $parser;
my $writer;
my $write_mod;
my $parse_mod;
if ( defined( $convert{$in_type} ) ) {
    $write_mod = $convert{$in_type}->{'writer'};
    $parse_mod = $convert{$in_type}->{'parser'};
    eval {
        ( my $wpkg = $write_mod ) =~ s!::!/!gx;
        ( my $ppkg = $parse_mod ) =~ s!::!/!gx;
        require "$wpkg.pm";                        ## no critic
        require "$ppkg.pm";                        ## no critic
        import $parse_mod;
        import $write_mod;
        1;
    } or croak "Module loading failed: $!";
    $parser = $parse_mod->new();
    $writer = $write_mod->new();
}
else {
    croak "$in_type is not defined in the config file";
}
my $parsed_data_ref = $parser->parse( @{ $input->get_input_data } );

unless ($parsed_data_ref) { croak 'Error while parsing source data.'; }

$writer->write_rdf( $map_triples, $parsed_data_ref );
__END__

=head1 SEE ALSO

L<Gwybodaeth>

=head1 AUTHORS

Iestyn Pryce, <imp25@cam.ac.uk>

=head1 ACKNOWLEDGEMENTS

I'd like to thank the Ensemble project (www.ensemble.ac.uk) for funding me to
work on this project in the summer of 2009.

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2009 Iestyn Pryce <imp25@cam.ac.uk>

This library is free software; you can redistribute it and/or modify it under
the terms of the BSD license.