######################################################################

=item $xhtmlfragment = eprint_render( $eprint, $session, $preview )

This subroutine takes an eprint object and renders the XHTML view
of this eprint for public viewing.

Takes two arguments: the L<$eprint|EPrints::DataObj::EPrint> to render and the current L<$session|EPrints::Session>.

Returns three XHTML DOM fragments (see L<EPrints::XML>): C<$page>, C<$title>, (and optionally) C<$links>.

If $preview is true then this is only being shown as a preview.
(This is used to stop the "edit eprint" link appearing when it makes
no sense.)

=cut

######################################################################

## NJS 2009-11-03
# Added sort subroutine to sort documents by position. This doesn't appear
# to happen by default!
sub bypos ($$) { $_[0]->get_value( "pos" ) <=> $_[1]->get_value( "pos" ); }
# END NJS 2009-11-03

$c->{eprint_render} = sub
{
	my( $eprint, $session, $preview ) = @_;

	my $succeeds_field = $session->get_repository->get_dataset( "eprint" )->get_field( "succeeds" );
	my $commentary_field = $session->get_repository->get_dataset( "eprint" )->get_field( "commentary" );
	my $has_multiple_versions = $eprint->in_thread( $succeeds_field );

	my( $page, $p, $a );

	$page = $session->make_doc_fragment;
	# Citation
	$p = $session->make_element( "p", style=>"margin-bottom: 1em" );
	$p->appendChild( $eprint->render_citation() );
	$page->appendChild( $p );

	# Put in a message describing how this document has other versions
	# in the repository if appropriate
	if( $has_multiple_versions )
	{
		my $latest = $eprint->last_in_thread( $succeeds_field );
		my $block = $session->make_element( "div", class=>"ep_block", style=>"margin-bottom: 1em" );
		$page->appendChild( $block );
		if( $latest->get_value( "eprintid" ) == $eprint->get_value( "eprintid" ) )
		{
			$block->appendChild( $session->html_phrase( 
						"page:latest_version" ) );
		}
		else
		{
			$block->appendChild( $session->render_message(
				"warning",
				$session->html_phrase( 
					"page:not_latest_version",
					link => $session->render_link( 
							$latest->get_url() ) ) ) );
		}
	}		

	# Contact email address
	my $has_contact_email = 0;
	if( $session->get_repository->can_call( "email_for_doc_request" ) )
	{
		if( defined( $session->get_repository->call( "email_for_doc_request", $session, $eprint ) ) )
		{
			$has_contact_email = 1;
		}
	}

	# Available documents
	## NJS 2009-11-03
	# Sort the documents by their "pos" field.
	my @documents = sort bypos $eprint->get_all_documents();
	## END 2009-11-03
# NJS 2009-11-03: !!! original code follows
# 	my @documents = $eprint->get_all_documents();

	my $docs_to_show = scalar @documents;
	
	## NJS 2008-07-24
	# Documents with security level staffonly are now invisible to normal
	# users, so we need to decrement $docs_to_show for each document with
	# security level staffonly. This could imply zero visible documents,
	# which is expected behaviour when all have staffonly security level.
	foreach my $doc ( @documents )
	{
		$docs_to_show-- if ( $doc->get_value( "security" ) eq "staffonly" );
	}
	## END NJS 2008-07-24

	$p = $session->make_element( "p", style=>"margin-bottom: 1em" );
	$page->appendChild( $p );

	if( $docs_to_show == 0 )
	{
		$p->appendChild( $session->html_phrase( "page:nofulltext" ) );
		if( $has_contact_email && $eprint->get_value( "eprint_status" ) eq "archive"  )
		{
			# "Request a copy" button
			my $form = $session->render_form( "get", $session->get_repository->get_conf( "perl_url" ) . "/request_doc" );
			$form->appendChild( $session->render_hidden_field( "eprintid", $eprint->get_id ) );
			$form->appendChild( $session->render_action_buttons( 
				"null" => $session->phrase( "request:button" )
			) );
			$p->appendChild( $form );
		}
	}
	else
	{
		$p->appendChild( $session->html_phrase( "page:fulltext" ) );

		my( $doctable, $doctr, $doctd );
		$doctable = $session->make_element( "table", style=>"margin-bottom: 1em" );

		foreach my $doc ( @documents )
		{
			## NJS 2008-07-24
			# Ignore the document if it has security level staffonly and the
			# current user doesn't have privileges to view it. Note that this
			# means that staffonly documents will _never_ appear in abstracts
			# regardless of the current user type. Staff will only be able to
			# see such documents through the item control page.
			next if ( $doc->get_value( "security" ) eq "staffonly" );
			## END NJS 2008-07-24
			
			$doctr = $session->make_element( "tr" );
	
			$doctd = $session->make_element( "td", valign=>"top", style=>"text-align:center" );
			$doctr->appendChild( $doctd );
			
			## NJS 2008-07-10: Add Google Analytics tracking code to icon link.
			my $rendered_icon = $doc->render_icon_link( preview => 1 );
			
			# Strip the front off the URL to get just the document path.
			my $doc_url = $doc->get_url;
			$doc_url =~ m|^http://[^/]+(/.+)$|;
			my $javascript = "javascript:urchinTracker( '$1' );";
			
			my $the_node;
			
			# NJS 2008-07-10
			# Find the first <a> element in the DocumentFragment and add the
			# onclick attribute to it.
			#
			# Need to check if it's defined, in case render_icon_link returns
			# nothing (probably because of document security restrictions).
			#
			# NJS 2008-07-15: Added test for GDOME. GDOME doesn't have
			# the getElementsByTagName method, and XML::DOM and XML::LibXML
			# don't have the findnodes method. D'oh!
			# DOM 2
			if ( $EPrints::SystemSettings::conf->{enable_gdome} )
			{
				my @nodes = $rendered_icon->findnodes( './/a' );
				$the_node = $nodes[0];
			}
			else
			# DOM 1
			# Note that the DOM 1 documentation says the NodeList is indexed
			# from 0, but item(0) gives the wrong element (?!?!).
			{
				$the_node = $rendered_icon->getElementsByTagName( 'a' )->item( 1 );
			}
			$the_node->setAttribute( 'onclick', $javascript ) if ( defined ( $the_node ) );
			
			$doctd->appendChild( $rendered_icon );
			## END NJS 2008-07-10
# NJS 2008-07-10: !!! original code follows
# 			$doctd->appendChild( $doc->render_icon_link( preview => 1 ) );
	
			$doctd = $session->make_element( "td", valign=>"top" );
			$doctr->appendChild( $doctd );
				
			## NJS 2007-07-30: Add Google Analytics tracking code to text link.
			my $rendered_cite = $doc->render_citation_link();
			
			# Ugh, DOM sucks...
			# NJS 2008-07-10: Updated to work with EPrints 3.
			# Find the first <a> element in the DocumentFragment and add the
			# onclick attribute to it. Note that the DOM documentation says
			# the NodeList is indexed from 0, but item(0) gives the last
			# element instead of the first one; item(1)->(4) give the results
			# we want here.
			#
			# Need to check if it's defined, in case render_icon_link returns
			# nothing (probably because of document security restrictions).
			# DOM 2
			if ( $EPrints::SystemSettings::conf->{enable_gdome} )
			{
				my @nodes = $rendered_cite->findnodes( './/a' );
				$the_node = $nodes[0];
			}
			else
			# DOM 1
			{
				$the_node = $rendered_cite->getElementsByTagName( 'a' )->item( 1 );
			}
			$the_node->setAttribute( 'onclick', $javascript ) if ( defined ( $the_node ) );
			
			$doctd->appendChild( $rendered_cite );
			## END NJS 2007-07-30
# NJS 2007-07-30: !!! original code follows
# 			$doctd->appendChild( $doc->render_citation_link() );
			my %files = $doc->files;
			if( defined $files{$doc->get_main} )
			{
				my $size = $files{$doc->get_main};
				$doctd->appendChild( $session->make_element( 'br' ) );
				$doctd->appendChild( $session->make_text( EPrints::Utils::human_filesize($size) ));
			}

			if( $has_contact_email && !$doc->is_public && $eprint->get_value( "eprint_status" ) eq "archive" )
			{
				# "Request a copy" button
				$doctd = $session->make_element( "td" );
				my $form = $session->render_form( "get", $session->get_repository->get_conf( "perl_url" ) . "/request_doc" );
				$form->appendChild( $session->render_hidden_field( "docid", $doc->get_id ) );
				$form->appendChild( $session->render_action_buttons( 
					"null" => $session->phrase( "request:button" )
				) );
				$doctd->appendChild( $form );
				$doctr->appendChild( $doctd );
			}

			$doctable->appendChild( $doctr );
		}
		$page->appendChild( $doctable );
	}	

	# Alternative locations
	if( $eprint->is_set( "official_url" ) )
	{
		$p = $session->make_element( "p", style=>"margin-bottom: 1em" );
		$page->appendChild( $p );
		$p->appendChild( $session->html_phrase( "eprint_fieldname_official_url" ) );
		$p->appendChild( $session->make_text( ": " ) );
		$p->appendChild( $eprint->render_value( "official_url" ) );
	}
	
	
	# Link to download statistics. [NJS 2005-12-08]
	# Note: highly dependent on the way that the UTas EPrintsStats package
	# structures things! In particular, this will break completely if the
	# URL format changes.
	$p = $session->make_element( "p" );
	$page->appendChild( $p );
	$p->appendChild( $session->html_phrase( "abstract/stats_link:prefix" ) );

	my $statslink = $session->make_element( "a", 
		href=>"/es/index.php?action=show_detail_eprint;id=" . $eprint->get_value( "eprintid" ) . ";year=0;month=0;range=4w" );
	$statslink->appendChild( $session->html_phrase( "abstract/stats_link:link_text" ) );

	$p->appendChild( $statslink );
	$p->appendChild( $session->html_phrase( "abstract/stats_link:suffix" ) );
	
	
	# Then the abstract
	if( $eprint->is_set( "abstract" ) )
	{
		my $div = $session->make_element( "div", class=>"ep_block" );
		$page->appendChild( $div );
		my $h2 = $session->make_element( "h2" );
		$h2->appendChild( 
			$session->html_phrase( "eprint_fieldname_abstract" ) );
		$div->appendChild( $h2 );

		$p = $session->make_element( "p", style=>"text-align: left; margin: 1em auto 0em auto" );
		$p->appendChild( $eprint->render_value( "abstract" ) );
		$div->appendChild( $p );
	}
	else
	{
		$page->appendChild( $session->make_element( 'br' ) );
	}
	
	my( $table, $tr, $td, $th );	# this table needs more class cjg
	$table = $session->make_element( "table",
					class=>"ep_block", style=>"margin-bottom: 1em",
					border=>"0",
					cellpadding=>"3" );
	$page->appendChild( $table );

	# Commentary
	if( $eprint->is_set( "commentary" ) )
	{
		my $target = EPrints::DataObj::EPrint->new( 
			$session,
			$eprint->get_value( "commentary" ),
			$session->get_repository()->get_dataset( "archive" ) );
		if( defined $target )
		{
			$table->appendChild( $session->render_row(
				$session->html_phrase( 
					"eprint_fieldname_commentary" ),
				$target->render_citation_link() ) );
		}
	}

	my $frag = $session->make_doc_fragment;
	$frag->appendChild( $eprint->render_value( "type"  ) );
	my $type = $eprint->get_value( "type" );
	if( $type eq "conference_item" )
	{
		$frag->appendChild( $session->make_text( " (" ));
		$frag->appendChild( $eprint->render_value( "pres_type"  ) );
		$frag->appendChild( $session->make_text( ")" ));
	}
	if( $type eq "monograph" )
	{
		$frag->appendChild( $session->make_text( " (" ));
		$frag->appendChild( $eprint->render_value( "monograph_type"  ) );
		$frag->appendChild( $session->make_text( ")" ));
	}
	if( $type eq "thesis" )
	{
		$frag->appendChild( $session->make_text( " (" ));
		$frag->appendChild( $eprint->render_value( "thesis_type"  ) );
		$frag->appendChild( $session->make_text( ")" ));
	}
	$table->appendChild( $session->render_row(
		$session->html_phrase( "eprint_fieldname_type" ),
		$frag ));

	# Additional Info
	if( $eprint->is_set( "note" ) )
	{
		$table->appendChild( $session->render_row(
			$session->html_phrase( "eprint_fieldname_note" ),
			$eprint->render_value( "note" ) ) );
	}


	# Keywords
	if( $eprint->is_set( "keywords" ) )
	{
		$table->appendChild( $session->render_row(
			$session->html_phrase( "eprint_fieldname_keywords" ),
			$eprint->render_value( "keywords" ) ) );
	}



	# NJS 2008-07-22
	# Affiliations...
	$table->appendChild( $session->render_row(
		$session->html_phrase( "eprint_fieldname_affiliations" ),
		$eprint->render_value( "affiliations" ) ) );

	# Subjects...
	$table->appendChild( $session->render_row(
		$session->html_phrase( "eprint_fieldname_subjects" ),
		$eprint->render_value( "subjects" ) ) );

	$table->appendChild( $session->render_row(
		$session->html_phrase( "page:id_code" ),
		$eprint->render_value( "eprintid" ) ) );

	my $user = new EPrints::DataObj::User( 
			$eprint->{session},
 			$eprint->get_value( "userid" ) );
	my $usersname;
	if( defined $user )
	{
		$usersname = $user->render_description();
	}
	else
	{
		$usersname = $session->html_phrase( "page:invalid_user" );
	}

	$table->appendChild( $session->render_row(
		$session->html_phrase( "page:deposited_by" ),
		$usersname ) );

	if( $eprint->is_set( "datestamp" ) )
	{
		$table->appendChild( $session->render_row(
			$session->html_phrase( "page:deposited_on" ),
			$eprint->render_value( "datestamp" ) ) );
	}

	if( $eprint->is_set( "lastmod" ) )
	{
		$table->appendChild( $session->render_row(
			$session->html_phrase( "eprint_fieldname_lastmod" ),
			$eprint->render_value( "lastmod" ) ) );
	}


	# Now show the version and commentary response threads
	if( $has_multiple_versions )
	{
		my $div = $session->make_element( "div", class=>"ep_block", style=>"margin-bottom: 1em" );
		$page->appendChild( $div );
		$div->appendChild( 
			$session->html_phrase( "page:available_versions" ) );
		$div->appendChild( 
			$eprint->render_version_thread( $succeeds_field ) );
	}
	
	if( $eprint->in_thread( $commentary_field ) )
	{
		my $div = $session->make_element( "div", class=>"ep_block", style=>"margin-bottom: 1em" );
		$page->appendChild( $div );
		$div->appendChild( 
			$session->html_phrase( "page:commentary_threads" ) );
		$div->appendChild( 
			$eprint->render_version_thread( $commentary_field ) );
	}

if(0){	
	# Experimental SFX Link
	my $url ="http://demo.exlibrisgroup.com:9003/demo?";
	#my $url = "http://aire.cab.unipd.it:9003/unipr?";
	$url .= "title=".$eprint->get_value( "title" );
	$url .= "&";
	my $authors = $eprint->get_value( "creators" );
	my $first_author = $authors->[0];
	$url .= "aulast=".$first_author->{name}->{family};
	$url .= "&";
	$url .= "aufirst=".$first_author->{name}->{family};
	$url .= "&";
	$url .= "date=".$eprint->get_value( "date" );
	my $sfx_block = $session->make_element( "p" );
	$page->appendChild( $sfx_block );
	my $sfx_link = $session->render_link( $url );
	$sfx_block->appendChild( $sfx_link );
	$sfx_link->appendChild( $session->make_text( "SFX" ) );
}

if(0){
	# Experimental OVID Link
	my $url ="http://linksolver.ovid.com/OpenUrl/LinkSolver?";
	$url .= "atitle=".$eprint->get_value( "title" );
	$url .= "&";
	my $authors = $eprint->get_value( "creators" );
	my $first_author = $authors->[0];
	$url .= "aulast=".$first_author->{name}->{family};
	$url .= "&";
	$url .= "date=".substr($eprint->get_value( "date" ),0,4);
	if( $eprint->is_set( "issn" ) )
	{
		$url .= "&issn=".$eprint->get_value( "issn" );
	}
	if( $eprint->is_set( "volume" ) )
	{
		$url .= "&volume=".$eprint->get_value( "volume" );
	}
	if( $eprint->is_set( "number" ) )
	{
		$url .= "&issue=".$eprint->get_value( "number" );
	}
	if( $eprint->is_set( "pagerange" ) )
	{
		my $pr = $eprint->get_value( "pagerange" );
		$pr =~ m/^([^-]+)-/;
		$url .= "&spage=$1";
	}

	my $ovid_block = $session->make_element( "p" );
	$page->appendChild( $ovid_block );
	my $ovid_link = $session->render_link( $url );
	$ovid_block->appendChild( $ovid_link );
	$ovid_link->appendChild( $session->make_text( "OVID" ) );
}


	unless( $preview )
	{
		# Add a link to the edit-page for this record. Handy for staff.
		my $edit_para = $session->make_element( "p", align=>"right" );
		$edit_para->appendChild( $session->html_phrase( 
			"page:edit_link",
			link => $session->render_link( $eprint->get_control_url ) ) );
		$page->appendChild( $edit_para );
	}

	my $title = $eprint->render_description();

	my $links = $session->make_doc_fragment();
	$links->appendChild( $session->plugin( "Export::Simple" )->dataobj_to_html_header( $eprint ) );
	$links->appendChild( $session->plugin( "Export::DC" )->dataobj_to_html_header( $eprint ) );

	return( $page, $title, $links );
};