EpubJsViewerPlugin.php

<?php

/**
 * @file plugins/generic/epubJsViewer/EpubJsViewerPlugin.php
 *
 * Copyright (c) 2026 OJSBR (https://ojsbr.com.br)
 * Inspired by the original Bibi EPUB Viewer plugin by Lepidus Tecnologia,
 * discontinued in 2025 because the Bibi reader was no longer maintained.
 * Reader replaced by epub.js (FuturePress), which is actively maintained.
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class EpubJsViewerPlugin
 *
 * @brief Embedded viewing of EPUB galleys using epub.js.
 */

namespace APP\plugins\generic\epubJsViewer;

use APP\core\Application;
use APP\template\TemplateManager;
use Exception;
use PKP\plugins\Hook;

class EpubJsViewerPlugin extends \PKP\plugins\GenericPlugin
{
    public const EPUB_MIME_TYPE = 'application/epub+zip';

    /**
     * @copydoc Plugin::register()
     */
    public function register($category, $path, $mainContextId = null)
    {
        if (parent::register($category, $path, $mainContextId)) {
            if ($this->getEnabled($mainContextId)) {
                switch (Application::get()->getName()) {
                    case 'ojs2':
                        Hook::add('ArticleHandler::view::galley', $this->submissionCallback(...), Hook::SEQUENCE_LAST);
                        Hook::add('IssueHandler::view::galley', $this->issueCallback(...), Hook::SEQUENCE_LAST);
                        break;
                    case 'ops':
                        Hook::add('PreprintHandler::view::galley', $this->submissionCallback(...), Hook::SEQUENCE_LAST);
                        break;
                }
            }
            return true;
        }
        return false;
    }

    public function getDisplayName()
    {
        return __('plugins.generic.epubJsViewer.displayName');
    }

    public function getDescription()
    {
        return __('plugins.generic.epubJsViewer.description');
    }

    /**
     * Present an EPUB article galley inside the epub.js reader.
     */
    public function submissionCallback($hookName, $args)
    {
        $request = &$args[0];
        $application = Application::get();

        switch ($application->getName()) {
            case 'ojs2':
                $issue = &$args[1];
                $galley = &$args[2];
                $submission = &$args[3];
                $submissionNoun = 'article';
                break;
            case 'ops':
                $galley = &$args[1];
                $submission = &$args[2];
                $submissionNoun = 'preprint';
                $issue = null;
                break;
            default:
                throw new Exception('Unknown application!');
        }

        if (!$galley || $galley->getFileType() !== self::EPUB_MIME_TYPE) {
            return false;
        }

        $galleyPublication = null;
        foreach ($submission->getData('publications') as $publication) {
            if ($publication->getId() === $galley->getData('publicationId')) {
                $galleyPublication = $publication;
                break;
            }
        }
        if (!$galleyPublication) {
            return false;
        }

        $templateMgr = TemplateManager::getManager($request);

        $epubUrl = $request->url(
            null,
            $submissionNoun,
            'download',
            [$submission->getBestId(), $galley->getBestGalleyId(), $galley->getFile()->getId()]
        );
        $parentUrl = $request->url(null, $submissionNoun, 'view', [$submission->getBestId()]);

        $templateMgr->assign([
            'displayTemplateResource' => $this->getTemplateResource('display.tpl'),
            'pluginUrl' => $request->getBaseUrl() . '/' . $this->getPluginPath(),
            'galleyFile' => $galley->getFile(),
            'issue' => $issue,
            'submission' => $submission,
            'submissionNoun' => $submissionNoun,
            'bestId' => $galleyPublication->getData('urlPath') ?? $submission->getId(),
            'galley' => $galley,
            'galleyPublication' => $galleyPublication,
            'currentVersionString' => $application->getCurrentVersion()->getVersionString(false),
            'isLatestPublication' => $submission->getData('currentPublicationId') === $galley->getData('publicationId'),
            'title' => $galleyPublication->getLocalizedTitle(null, 'html'),
            'isTitleHtml' => true,
            'epubUrl' => $epubUrl,
            'parentUrl' => $parentUrl,
            'galleyTitle' => __('submission.representationOfTitle', [
                'representation' => $galley->getLabel(),
                'title' => $galleyPublication->getLocalizedFullTitle(),
            ]),
            'datePublished' => __('submission.outdatedVersion', [
                'datePublished' => $galleyPublication->getData('datePublished'),
                'urlRecentVersion' => $parentUrl,
            ]),
        ]);

        $templateMgr->display($this->getTemplateResource('display.tpl'));
        return true;
    }

    /**
     * Present an EPUB issue galley inside the epub.js reader.
     */
    public function issueCallback($hookName, $args)
    {
        $request = &$args[0];
        $issue = &$args[1];
        $galley = &$args[2];

        if (!$galley || $galley->getFileType() !== self::EPUB_MIME_TYPE) {
            return false;
        }

        $templateMgr = TemplateManager::getManager($request);
        $parentUrl = $request->url(null, 'issue', 'view', [$issue->getBestIssueId()]);

        $templateMgr->assign([
            'displayTemplateResource' => $this->getTemplateResource('display.tpl'),
            'pluginUrl' => $request->getBaseUrl() . '/' . $this->getPluginPath(),
            'issue' => $issue,
            'galley' => $galley,
            'galleyFile' => $galley->getFile(),
            'isLatestPublication' => true,
            'title' => $issue->getLocalizedTitle(),
            'isTitleHtml' => false,
            'epubUrl' => $request->url(null, 'issue', 'download', [$issue->getBestIssueId(), $galley->getBestGalleyId()]),
            'parentUrl' => $parentUrl,
            'galleyTitle' => $issue->getLocalizedTitle(),
        ]);

        $templateMgr->display($this->getTemplateResource('display.tpl'));
        return true;
    }
}