#!/usr/bin/perl -w
use strict;

use Test::More qw(no_plan);
use XML::SemanticDiff;
use File::Slurp;
use Getopt::Std;

my %opt;

# -v is verbose, it displays the generated string for each test
getopts( 'v', \%opt); 



# XML::SemanticDiff seems to only compare files, not strings
my $tmp_expected= "tmp.expected"; # temp file with expected result
my $tmp_result  = "tmp.result";   # temp file with result

my %tests=( 'XML::Simple' => { sub     => \&test_xml_simple, },
            'XML::Writer' => { extra_modules => [ 'IO::Scalar' ],
                               sub     => \&test_xml_writer,
                             },
            'XML::Handler::YAWriter'
                          =>  { sub    => \&test_xml_handler_yawriter, },
            'XML::Twig'   =>  { sub    => \&test_xml_twig, },
          );

write_file( $tmp_expected, <DATA>);
my $sem_diff= XML::SemanticDiff->new;

foreach my $module ( keys %tests)
  { my $test= $tests{$module};
    my @modules= ($module);
    push @modules, @{$test->{extra_modules}} if( $test->{extra_modules});
    if( load_modules( @modules))
      { my $result= $test->{sub}->();
        write_file( $tmp_result, $result);
        my $diff= $sem_diff->compare( $tmp_expected, $tmp_result);
        ok( ! $diff, $module) or diag( "got $result") ;
        diag( "\n", $result, "\n\n") if( $opt{v});
      }
    else
      { SKIP: { skip( "$module not available", 1); }
      }
  }

unlink $tmp_expected, $tmp_result;

sub test_xml_simple
  { my $xml= { entry => { att1 => 'value1', att2 => 'value2', path => { content => 'path & text'} } }; 
    return XMLout( $xml, keeproot => 1); 
  }

sub test_xml_writer
  { my $result;
    my $output = IO::Scalar->new( \$result);
    my $writer = XML::Writer->new(OUTPUT => $output);

    $writer->startTag( entry => att1 => 'value1', att2 => 'value2');
    $writer->dataElement( path => 'path & text');
    $writer->endTag( 'entry');

    $writer->end();
    $output->close();
    return $result;
  }

sub test_xml_handler_yawriter
  { my $writer= XML::Handler::YAWriter->new( AsString => 1);
    $writer->start_document;

    $writer->start_element( { Name => 'entry', Attributes => { att1 => 'value1', att2 => 'value2'} } );
    $writer->start_element( { Name => 'path' } );
    $writer->characters(    { Data => 'path & text' } );
    $writer->end_element(   { Name => 'path'} );
    $writer->end_element(   { Name => 'entry'} );

    return $writer->end_document;
  }

sub test_xml_twig
  { my $root= XML::Twig::Elt->new( entry => { att1 => 'value1', att2 => 'value2' });
    $root->insert_new_elt( path => "path & text");
    return $root->sprint;
  }

# a simple way of importing modules at run time
  
#sub load_modules
#  { foreach (@_)
#      { if(eval "require $_") { import $_; }
#        else                  { return 0; }
#      }
#    return 1;
#  }

# fun way
sub load_modules
  { ((eval "require $_" and import $_ or 1)  or return 0) foreach (@_); 1}

__DATA__
<entry att1="value1" att2="value2">
  <!-- the &amp; is here to test escaping -->
  <path>path &amp; text</path>
</entry>