<?php

/**
 * @file plugins/generic/dublinCoreMeta/DublinCoreMetaPlugin.inc.php
 *
 * Copyright (c) 2014-2021 Simon Fraser University
 * Copyright (c) 2003-2021 John Willinsky
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class DublinCoreMetaPlugin
 * @ingroup plugins_generic_dublinCoreMeta
 *
 * @brief Inject Dublin Core meta tags into article views to facilitate indexing.
 */

import('lib.pkp.classes.plugins.GenericPlugin');

class DublinCoreMetaPlugin extends GenericPlugin {
	/**
	 * @copydoc Plugin::register()
	 */
	function register($category, $path, $mainContextId = null) {
		if (parent::register($category, $path, $mainContextId)) {
			if ($this->getEnabled($mainContextId)) {
				HookRegistry::register('ArticleHandler::view',array(&$this, 'articleView'));
			}
			return true;
		}
		return false;
	}

	/**
	 * Get the name of the settings file to be installed on new context
	 * creation.
	 * @return string
	 */
	function getContextSpecificPluginSettingsFile() {
		return $this->getPluginPath() . '/settings.xml';
	}

	/**
	 * Inject Dublin Core metadata into article view
	 * @param $hookName string
	 * @param $args array
	 * @return boolean
	 */
	function articleView($hookName, $args) {
		$request = $args[0];
		$issue = $args[1];
		$article = $args[2];
		$publication = $article->getCurrentPublication();
		$requestArgs = $request->getRequestedArgs();
		$journal = $request->getContext();

		// Only add Dublin Core metadata tags to the canonical URL for the latest version
		// See discussion: https://github.com/pkp/pkp-lib/issues/4870
		if (count($requestArgs) > 1 && $requestArgs[1] === 'version') {
			return;
		}

		$templateMgr = TemplateManager::getManager($request);
		$templateMgr->addHeader('dublinCoreSchema', '<link rel="schema.DC" href="http://purl.org/dc/elements/1.1/" />');

		$i=0;
		if ($sponsors = $article->getSponsor(null)) foreach ($sponsors as $locale => $sponsor) {
			$templateMgr->addHeader('dublinCoreSponsor' . $i++, '<meta name="DC.Contributor.Sponsor" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars(strip_tags($sponsor)) . '"/>');
		}

		$i=0;
		if ($coverages = $article->getCoverage(null)) foreach($coverages as $locale => $coverage) {
			$templateMgr->addHeader('dublinCoreCoverage' . $i++, '<meta name="DC.Coverage" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars(strip_tags($coverage)) . '"/>');
		}

		$i=0;
		foreach ($article->getAuthors(true) as $author) {
			$templateMgr->addHeader('dublinCoreAuthor' . $i++, '<meta name="DC.Creator.PersonalName" content="' . htmlspecialchars($author->getFullName(false)) . '"/>');
		}

		if (is_a($article, 'Submission') && ($datePublished = $article->getDatePublished())) {
			$templateMgr->addHeader('dublinCoreDateCreated', '<meta name="DC.Date.created" scheme="ISO8601" content="' . strftime('%Y-%m-%d', strtotime($datePublished)) . '"/>');
		}
		$templateMgr->addHeader('dublinCoreDateSubmitted', '<meta name="DC.Date.dateSubmitted" scheme="ISO8601" content="' . strftime('%Y-%m-%d', strtotime($article->getDateSubmitted())) . '"/>');
		if ($issue && ($datePublished = $issue->getDatePublished())) {
			$templateMgr->addHeader('dublinCoreDateIssued', '<meta name="DC.Date.issued" scheme="ISO8601" content="' . strftime('%Y-%m-%d', strtotime($issue->getDatePublished())) . '"/>');
		}
		if ($dateModified = $article->getCurrentPublication()->getData('lastModified')) $templateMgr->addHeader('dublinCoreDateModified', '<meta name="DC.Date.modified" scheme="ISO8601" content="' . strftime('%Y-%m-%d', strtotime($dateModified)) . '"/>');

		if ($publication) {
			$i=0;
			if ($abstracts = (array) $publication->getData('abstract')) foreach($abstracts as $locale => $abstract) {
				$templateMgr->addHeader('dublinCoreAbstract' . $i++, '<meta name="DC.Description" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars(strip_tags($abstract)) . '"/>');
			}
		}

		$i=0;
		if (is_a($article, 'Submission')) foreach($article->getGalleys() as $galley) {
			$templateMgr->addHeader('dublinCoreFormat' . $i++, '<meta name="DC.Format" scheme="IMT" content="' . htmlspecialchars($galley->getFileType()) . '"/>');
		}

		$templateMgr->addHeader('dublinCoreIdentifier', '<meta name="DC.Identifier" content="' . htmlspecialchars($article->getBestId()) . '"/>');

		if ($pages = $article->getPages()) {
			$templateMgr->addHeader('dublinCorePages', '<meta name="DC.Identifier.pageNumber" content="' . htmlspecialchars($pages) . '"/>');
		}

		foreach((array) $templateMgr->getTemplateVars('pubIdPlugins') as $pubIdPlugin) {
			if ($pubId = $article->getStoredPubId($pubIdPlugin->getPubIdType())) {
				$templateMgr->addHeader('dublinCorePubId' . $pubIdPlugin->getPubIdDisplayType(), '<meta name="DC.Identifier.' . htmlspecialchars($pubIdPlugin->getPubIdDisplayType()) . '" content="' . htmlspecialchars($pubId) . '"/>');
			}
		}

		$templateMgr->addHeader('dublinCoreUri', '<meta name="DC.Identifier.URI" content="' . $request->url(null, 'article', 'view', array($article->getBestId())) . '"/>');
		$templateMgr->addHeader('dublinCoreLanguage', '<meta name="DC.Language" scheme="ISO639-1" content="' . substr($article->getLocale(), 0, 2) . '"/>');
		$templateMgr->addHeader('dublinCoreCopyright', '<meta name="DC.Rights" content="' . htmlspecialchars(__('submission.copyrightStatement', array('copyrightHolder' => $article->getCopyrightHolder($article->getLocale()), 'copyrightYear' => $article->getCopyrightYear()))) . '"/>');
		$templateMgr->addHeader('dublinCorePagesLicenseUrl', '<meta name="DC.Rights" content="' . htmlspecialchars($article->getLicenseURL()) . '"/>');
		$templateMgr->addHeader('dublinCoreSource', '<meta name="DC.Source" content="' . htmlspecialchars($journal->getName($journal->getPrimaryLocale())) . '"/>');
		if (($issn = $journal->getData('onlineIssn')) || ($issn = $journal->getData('printIssn')) || ($issn = $journal->getData('issn'))) {
			$templateMgr->addHeader('dublinCoreIssn', '<meta name="DC.Source.ISSN" content="' . htmlspecialchars($issn) . '"/>');
		}

		if ($issue) {
			if ($issue->getShowNumber()) $templateMgr->addHeader('dublinCoreIssue', '<meta name="DC.Source.Issue" content="' . htmlspecialchars($issue->getNumber()) . '"/>');
			if ($issue->getShowVolume()) $templateMgr->addHeader('dublinCoreVolume', '<meta name="DC.Source.Volume" content="' . htmlspecialchars($issue->getVolume()) . '"/>');
		}

		$templateMgr->addHeader('dublinCoreSourceUri', '<meta name="DC.Source.URI" content="' . $request->url($journal->getPath()) . '"/>');

		$dao = DAORegistry::getDAO('SubmissionKeywordDAO');
		$keywords = $dao->getKeywords($article->getCurrentPublication()->getId(), array(AppLocale::getLocale()));
		foreach ($keywords as $locale => $localeKeywords) {
			foreach ($localeKeywords as $keyword) {
				$templateMgr->addHeader('dublinCoreSubject' . $locale, '<meta name="DC.Subject" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars($keyword) . '"/>');
			}
		}

		if ($publication) {
			$templateMgr->addHeader('dublinCoreTitle', '<meta name="DC.Title" content="' . htmlspecialchars($publication->getLocalizedTitle()) . '"/>');
			foreach ($publication->getData('title') as $locale => $title) {
				if (empty($title) || $locale === $publication->getData('locale')) continue;
				$templateMgr->addHeader('dublinCoreAltTitle' . $locale, '<meta name="DC.Title.Alternative" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars($publication->getLocalizedTitle($locale)) . '"/>');
			}
		}

		$templateMgr->addHeader('dublinCoreType', '<meta name="DC.Type" content="Text.Serial.Journal"/>');
		if ($types = $article->getType(null)) foreach($types as $locale => $type) {
			$templateMgr->addHeader('dublinCoreType' . $locale, '<meta name="DC.Type" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars(strip_tags($type)) . '"/>');
		}

		$publication = $article->getCurrentPublication();
		if ($publication) {
			$sectionDao = DAORegistry::getDAO('SectionDAO'); /* @var $sectionDao SectionDAO */
			$section = $sectionDao->getById($publication->getData('sectionId'));
			$templateMgr->addHeader('dublinCoreArticleType', '<meta name="DC.Type.articleType" content="' . htmlspecialchars($section->getTitle($journal->getPrimaryLocale())) . '"/>');
		}

		return false;
	}

	/**
	 * Get the display name of this plugin
	 * @return string
	 */
	function getDisplayName() {
		return __('plugins.generic.dublinCoreMeta.name');
	}

	/**
	 * Get the description of this plugin
	 * @return string
	 */
	function getDescription() {
		return __('plugins.generic.dublinCoreMeta.description');
	}
}