<?php
/**
 * doaprdfPlugin Class
 *
 * Copyright 2011, Olivier Berger & Institut Telecom
 * Copyright 2021, Franck Villaume - TrivialDev
 *
 * This program was developped in the frame of the COCLICO project
 * (http://www.coclico-project.org/) with financial support of the Paris
 * Region council.
 *
 * This file is part of FusionForge. FusionForge is free software;
 * you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the Licence, or (at your option)
 * any later version.
 *
 * FusionForge is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with FusionForge; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

require_once 'common/include/rdfutils.php';

class doaprdfPlugin extends Plugin {
	function __construct($id=0) {
		parent::__construct($id) ;
		$this->name = "doaprdf";
		$this->text = _("DoaPRDF!"); // To show in the tabs, use...
		$this->pkg_desc =
_("This plugin provides DOAP RDF documents for projects on /projects URLs
with content-negotiation (application/rdf+xml).");
		$this->_addHook("script_accepted_types");
		$this->_addHook("content_negociated_project_home");
		$this->_addHook("alt_representations");

	}

	/**
	 * Declares itself as accepting RDF XML on /projects/...
	 * @param unknown_type $params
	 */
	function script_accepted_types (&$params) {
		$script = $params['script'];
		if ($script == 'project_home') {
			$params['accepted_types'][] = 'application/rdf+xml';
			$params['accepted_types'][] = 'text/turtle';
		}
	}

	function doapNameSpaces() {
		// Construct an ARC2_Resource containing the project's RDF (DOAP) description
		$ns = array(
				'rdf' => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
				'rdfs' => 'http://www.w3.org/2000/01/rdf-schema#',
				'doap' => 'http://usefulinc.com/ns/doap#',
				'dcterms' => 'http://purl.org/dc/terms/'
		);
		return $ns;
	}

	function getProjectResourceIndex($group_id, &$ns, $detailed = false) {

		// connect to FusionForge internals
		$project = group_get_object($group_id);
		$projectname = $project->getUnixName();
		$project_shortdesc = $project->getPublicName();
		$project_description = $project->getDescription();
		$tags_list = NULL;
		if (forge_get_config('use_project_tags')) {
			$tags_list = $project->getTags();
		}

		$conf = array(
				'ns' => $ns
		);

		$res = ARC2::getResource($conf);
		$res->setURI(util_make_url_g($projectname).'#project');

		// $res->setRel('rdf:type', 'doap:Project');
		rdfutils_setPropToUri($res, 'rdf:type', 'doap:Project');

		$res->setProp('doap:name', $projectname);
		$res->setProp('doap:shortdesc', $project_shortdesc);
		if($project_description) {
			$res->setProp('doap:description', $project_description);
		}
		$homepages = array(util_make_url_g($projectname));
		$project_homepage = $project->getHomePage();
		if(!in_array($project_homepage, $homepages)) {
			$homepages[] = $project_homepage;
		}
		$res->setProp('doap:homepage', $homepages);
		$tags = array();
		if($tags_list) {
			$tags = explode(', ',$tags_list);
			$res->setProp('dcterms:subject', $tags);
		}

		// Now, we need to collect complementary RDF descriptiosn of the project via other plugins
		// invoke the 'project_rdf_metadata' hook so as to complement the RDF description
		$hook_params = array();
		$hook_params['prefixes'] = array();
		foreach($ns as $prefix => $url) {
			$hook_params['prefixes'][$url] = $prefix;
		}
		$hook_params['group'] = $group_id;
		// pass the resource in case it could be useful (read-only in principle)
		$hook_params['in_Resource'] = $res;
		$hook_params['out_Resources'] = array();
		if ($detailed) {
			$hook_params['details'] = 'full';
		}
		else {
			$hook_params['details'] = 'minimal';
		}
		plugin_hook_by_reference('project_rdf_metadata', $hook_params);

		// add new prefixes to the list
		foreach($hook_params['prefixes'] as $url => $prefix) {
			if (!isset($ns[$prefix])) {
				$ns[$prefix] = $url;
			}
		}

		// merge the two sets of triples
		$merged_index = $res->index;
		foreach($hook_params['out_Resources'] as $out_res) {
			$merged_index = ARC2::getMergedIndex($merged_index, $out_res->index);
		}

		return $merged_index;
	}

	/**
	 * Outputs project's DOAP profile
	 * @param unknown_type $params
	 */
	function content_negociated_project_home (&$params) {
		$projectname = $params['groupname'];
		$accept = $params['accept'];
		$group_id = $params['group_id'];

		if($accept == 'application/rdf+xml' || $accept == 'text/turtle') {

			// We will return RDF+XML
			$params['content_type'] = $accept;

			$ns = $this->doapNameSpaces();

			$merged_index = $this->getProjectResourceIndex($group_id, $ns, $detailed = true);

			$conf = array(
					'ns' => $ns,
					'serializer_type_nodes' => true
			);

			if($accept == 'application/rdf+xml') {
				$ser = ARC2::getRDFXMLSerializer($conf);
			}
			else {
				// text/turtle
				$ser = ARC2::getTurtleSerializer($conf);
			}
			/* Serialize a resource index */
			$doc = $ser->getSerializedIndex($merged_index);

			$params['content'] = $doc . "\n";
		}
	}

	/**
	 * Declares a link to itself in the link+meta HTML headers
	 * @param unknown_type $params
	 */
	function alt_representations (&$params) {
		$script_name = $params['script_name'];
		$php_self = $params['php_self'];
		// really trigger only for real projects descriptions, not for the projects index
		if ( ($script_name == '/projects') && (($php_self != '/projects') && ($php_self != '/projects/')) ) {
			$params['return'][] = '<link rel="alternate" type="application/rdf+xml" title="DOAP RDF Data" href=""/>';
			$params['return'][] = '<link rel="alternate" type="test/turtle" title="DOAP RDF Data" href=""/>';
		}
	}

}

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