<?php

/**
 * @package     MokoJoomOpenGraph
 * @subpackage  plg_system_mokoog
 * @author      Moko Consulting <hello@mokoconsulting.tech>
 * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
 * @license     GNU General Public License version 3 or later; see LICENSE
 */

namespace Joomla\Plugin\System\MokoOG\Extension;

defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\Plugin\CMSPlugin;
use Joomla\CMS\Uri\Uri;
use Joomla\Event\Event;
use Joomla\Event\SubscriberInterface;
use Joomla\Plugin\System\MokoOG\Helper\ImageHelper;
use Joomla\Plugin\System\MokoOG\Helper\JsonLdBuilder;

final class MokoOG extends CMSPlugin implements SubscriberInterface
{
    /**
     * @var bool
     */
    protected $autoloadLanguage = true;

    /**
     * Returns the events this plugin subscribes to.
     *
     * @return  array<string, string>
     */
    public static function getSubscribedEvents(): array
    {
        return [
            'onAfterRoute'        => 'onAfterRoute',
            'onBeforeCompileHead' => 'onBeforeCompileHead',
        ];
    }

    /**
     * Run admin-side license key check after routing.
     *
     * @param   Event  $event  The event object
     *
     * @return  void
     */
    public function onAfterRoute(Event $event): void
    {
        $app = $this->getApplication();

        if ($app->isClient('administrator')) {
            $this->warnMissingLicenseKey();
        }
    }

    /**
     * Inject Open Graph and Twitter Card meta tags before the document head is compiled.
     *
     * @param   Event  $event  The event object
     *
     * @return  void
     */
    public function onBeforeCompileHead(Event $event): void
    {
        $app = $this->getApplication();

        // Only run on the site frontend
        if (!$app->isClient('site')) {
            return;
        }

        $doc = $app->getDocument();

        if ($doc->getType() !== 'html') {
            return;
        }

        $input  = $app->getInput();
        $option = $input->getCmd('option', '');
        $view   = $input->getCmd('view', '');
        $id     = $input->getInt('id', 0);

        // Try to load custom OG data from the database
        $ogData = $this->loadOgData($option, $view, $id);

        // For category views, also try category-level OG data as fallback
        if ($option === 'com_content' && $view === 'category' && $id > 0) {
            $catOg = $this->loadOgDataByType('com_content.category', $id);

            if ($catOg) {
                // Merge: category fills any gaps in the content-level data
                foreach (['og_title', 'og_description', 'og_image', 'og_type', 'seo_title', 'meta_description', 'robots', 'canonical_url'] as $field) {
                    if (empty($ogData->$field) && !empty($catOg->$field)) {
                        $ogData->$field = $catOg->$field;
                    }
                }
            }
        }

        // --- SEO meta tags (set first, before OG) ---
        $this->applySeoTags($doc, $ogData);

        // Build tag values — custom OG data → site-wide defaults → auto-generated
        $defaultTitle = $this->params->get('default_og_title', '');
        $defaultDesc  = $this->params->get('default_og_description', '');

        $title       = $ogData->og_title ?: ($doc->getTitle() ?: $defaultTitle);
        $description = $ogData->og_description ?: ($this->buildDescription($doc) ?: $defaultDesc);
        $image       = $ogData->og_image ?: $this->findImage($option, $view, $id);
        $url         = Uri::getInstance()->toString();
        $siteName    = $this->params->get('og_site_name', $app->get('sitename', ''));
        $type        = $ogData->og_type ?: 'article';

        // Open Graph tags
        $doc->setMetaData('og:title', $title, 'property');
        $doc->setMetaData('og:description', $description, 'property');
        $doc->setMetaData('og:url', $url, 'property');
        $doc->setMetaData('og:type', $type, 'property');
        $doc->setMetaData('og:site_name', $siteName, 'property');

        if ($image) {
            $imageUrl = $this->resolveImageUrl($image);
            $doc->setMetaData('og:image', $imageUrl, 'property');

            // Emit actual image dimensions when detectable
            $imageDims = $this->getImageDimensions($image);

            if ($imageDims) {
                $doc->setMetaData('og:image:width', (string) $imageDims[0], 'property');
                $doc->setMetaData('og:image:height', (string) $imageDims[1], 'property');
            }
        }

        // og:locale from current language
        $langTag   = Factory::getLanguage()->getTag();
        $ogLocale  = str_replace('-', '_', $langTag);
        $doc->setMetaData('og:locale', $ogLocale, 'property');

        // Facebook App ID
        $fbAppId = $this->params->get('fb_app_id', '');

        if ($fbAppId) {
            $doc->setMetaData('fb:app_id', $fbAppId, 'property');
        }

        // Twitter Card tags
        $cardType    = $this->params->get('twitter_card_type', 'summary_large_image');
        $twitterSite = $this->params->get('twitter_site', '');

        $doc->setMetaData('twitter:card', $cardType);
        $doc->setMetaData('twitter:title', $title);
        $doc->setMetaData('twitter:description', $description);

        if ($image) {
            $doc->setMetaData('twitter:image', $this->resolveImageUrl($image));
        }

        if ($twitterSite) {
            $doc->setMetaData('twitter:site', $twitterSite);
        }

        // Telegram channel tag
        $telegramChannel = $this->params->get('telegram_channel', '');

        if ($telegramChannel) {
            $doc->setMetaData('telegram:channel', $telegramChannel);
        }

        // Discord embed color (theme-color meta tag)
        $discordColor = $this->params->get('discord_color', '');

        if ($discordColor) {
            $doc->setMetaData('theme-color', $discordColor);
        }

        // LinkedIn article tags
        if ($option === 'com_content' && $view === 'article' && $id > 0) {
            $doc->setMetaData('article:published_time', $this->getArticleDate($id, 'publish_up'), 'property');
            $doc->setMetaData('article:modified_time', $this->getArticleDate($id, 'modified'), 'property');

            $author = $this->getArticleAuthor($id);

            if ($author) {
                $doc->setMetaData('article:author', $author, 'property');
            }
        }

        // Fire event so third-party plugins can add custom OG/social tags
        $eventData = [
            'subject' => $doc,
            'title'   => $title,
            'description' => $description,
            'image'   => $image ? $this->resolveImageUrl($image) : '',
            'url'     => $url,
            'type'    => $type,
            'option'  => $option,
            'view'    => $view,
            'id'      => $id,
        ];
        $app->getDispatcher()->dispatch('onMokoOGAfterRender', new Event('onMokoOGAfterRender', $eventData));

        // JSON-LD structured data
        if ($this->params->get('jsonld_enabled', 1)) {
            $imageUrl  = $image ? $this->resolveImageUrl($image) : '';

            if ($option === 'com_content' && $view === 'article' && $id > 0) {
                $schema = JsonLdBuilder::buildArticle($id, $title, $description, $imageUrl);
            } else {
                $schema = JsonLdBuilder::buildWebPage($title, $description);
            }

            if ($schema) {
                $doc->addCustomTag(JsonLdBuilder::toScriptTag($schema));
            }

            if ($this->params->get('jsonld_breadcrumbs', 1)) {
                $breadcrumbs = JsonLdBuilder::buildBreadcrumbs();

                if ($breadcrumbs) {
                    $doc->addCustomTag(JsonLdBuilder::toScriptTag($breadcrumbs));
                }
            }
        }
    }

    /**
     * Apply SEO meta tags (title, description, robots, canonical) to the document.
     *
     * @param   \Joomla\CMS\Document\HtmlDocument  $doc     The document
     * @param   object                              $ogData  The loaded OG/SEO data
     *
     * @return  void
     */
    private function applySeoTags($doc, object $ogData): void
    {
        // Custom SEO title overrides the page <title>
        if (!empty($ogData->seo_title)) {
            $doc->setTitle($ogData->seo_title);
        }

        // Custom meta description
        if (!empty($ogData->meta_description)) {
            $doc->setDescription($ogData->meta_description);
        }

        // Robots directive
        if (!empty($ogData->robots)) {
            $doc->setMetaData('robots', $ogData->robots);
        }

        // Canonical URL
        if (!empty($ogData->canonical_url)) {
            // Remove any existing canonical link first
            foreach ($doc->_links as $link => $attribs) {
                if (isset($attribs['relation']) && $attribs['relation'] === 'canonical') {
                    unset($doc->_links[$link]);
                }
            }

            $doc->addHeadLink($ogData->canonical_url, 'canonical');
        }
    }

    /**
     * Load custom OG data from the database for the current page.
     *
     * @param   string  $option  Component option
     * @param   string  $view    View name
     * @param   int     $id      Content ID
     *
     * @return  object
     */
    private function loadOgData(string $option, string $view, int $id): object
    {
        $empty = (object) [
            'og_title'         => '',
            'og_description'   => '',
            'og_image'         => '',
            'og_type'          => '',
            'seo_title'        => '',
            'meta_description' => '',
            'robots'           => '',
            'canonical_url'    => '',
        ];

        if (!$id) {
            // Try menu-item-based lookup
            $menuItem = $this->getApplication()->getMenu()->getActive();

            if (!$menuItem) {
                return $empty;
            }

            return $this->loadOgDataByMenu((int) $menuItem->id) ?: $empty;
        }

        $db    = Factory::getDbo();
        $query = $db->getQuery(true)
            ->select('*')
            ->from($db->quoteName('#__mokoog_tags'))
            ->where($db->quoteName('content_type') . ' = ' . $db->quote($option))
            ->where($db->quoteName('content_id') . ' = ' . (int) $id)
            ->where($db->quoteName('published') . ' = 1')
            ->where('(' . $db->quoteName('language') . ' = ' . $db->quote(Factory::getLanguage()->getTag())
                . ' OR ' . $db->quoteName('language') . ' = ' . $db->quote('*') . ')')
            ->order('CASE WHEN ' . $db->quoteName('language') . ' = ' . $db->quote('*') . ' THEN 1 ELSE 0 END ASC');

        $db->setQuery($query, 0, 1);

        return $db->loadObject() ?: $empty;
    }

    /**
     * Load OG data by content type and ID.
     *
     * @param   string  $contentType  Content type identifier
     * @param   int     $contentId    Content ID
     *
     * @return  object|null
     */
    private function loadOgDataByType(string $contentType, int $contentId): ?object
    {
        $db    = Factory::getDbo();
        $query = $db->getQuery(true)
            ->select('*')
            ->from($db->quoteName('#__mokoog_tags'))
            ->where($db->quoteName('content_type') . ' = ' . $db->quote($contentType))
            ->where($db->quoteName('content_id') . ' = ' . $contentId)
            ->where($db->quoteName('published') . ' = 1');

        $db->setQuery($query);

        return $db->loadObject();
    }

    /**
     * Load OG data by menu item ID.
     *
     * @param   int  $menuId  Menu item ID
     *
     * @return  object|null
     */
    private function loadOgDataByMenu(int $menuId): ?object
    {
        $db    = Factory::getDbo();
        $query = $db->getQuery(true)
            ->select('*')
            ->from($db->quoteName('#__mokoog_tags'))
            ->where($db->quoteName('content_type') . ' = ' . $db->quote('menu'))
            ->where($db->quoteName('content_id') . ' = ' . $menuId)
            ->where($db->quoteName('published') . ' = 1');

        $db->setQuery($query);

        return $db->loadObject();
    }

    /**
     * Build a description from the document metadata or page content.
     *
     * @param   \Joomla\CMS\Document\HtmlDocument  $doc  The document
     *
     * @return  string
     */
    private function buildDescription($doc): string
    {
        $description = $doc->getDescription();
        $maxLength   = (int) $this->params->get('desc_length', 160);

        if ($this->params->get('strip_html', 1)) {
            $description = strip_tags($description);
        }

        $description = trim(preg_replace('/\s+/', ' ', $description));

        if (mb_strlen($description) > $maxLength) {
            $description = mb_substr($description, 0, $maxLength - 3) . '...';
        }

        return $description;
    }

    /**
     * Attempt to find the first image for the given content.
     *
     * @param   string  $option  Component option
     * @param   string  $view    View name
     * @param   int     $id      Content ID
     *
     * @return  string
     */
    private function findImage(string $option, string $view, int $id): string
    {
        if (!$this->params->get('auto_generate', 1)) {
            return $this->params->get('default_image', '');
        }

        // For Joomla articles, look at the intro/full image fields
        if ($option === 'com_content' && $id > 0) {
            $db    = Factory::getDbo();
            $query = $db->getQuery(true)
                ->select($db->quoteName('images'))
                ->from($db->quoteName('#__content'))
                ->where($db->quoteName('id') . ' = ' . (int) $id);

            $db->setQuery($query);
            $images = $db->loadResult();

            if ($images) {
                $imagesData = json_decode($images, true);

                if (!empty($imagesData['image_fulltext'])) {
                    return $imagesData['image_fulltext'];
                }

                if (!empty($imagesData['image_intro'])) {
                    return $imagesData['image_intro'];
                }
            }

            // Fallback: check the article's category for an image
            if ($view === 'article') {
                $catQuery = $db->getQuery(true)
                    ->select($db->quoteName('cat.params'))
                    ->from($db->quoteName('#__categories', 'cat'))
                    ->join('INNER', $db->quoteName('#__content', 'a') . ' ON ' . $db->quoteName('a.catid') . ' = ' . $db->quoteName('cat.id'))
                    ->where($db->quoteName('a.id') . ' = ' . (int) $id);

                $db->setQuery($catQuery);
                $catParams = $db->loadResult();

                if ($catParams) {
                    $catData = json_decode($catParams, true);

                    if (!empty($catData['image'])) {
                        return $catData['image'];
                    }
                }
            }
        }

        return $this->params->get('default_image', '');
    }

    /**
     * Resolve a relative image path to a full URL, resizing for OG if needed.
     *
     * @param   string  $image  Image path
     *
     * @return  string
     */
    private function resolveImageUrl(string $image): string
    {
        if (str_starts_with($image, 'http://') || str_starts_with($image, 'https://')) {
            return $image;
        }

        // Auto-resize to OG recommended dimensions if enabled
        if ($this->params->get('auto_resize', 1)) {
            $image = ImageHelper::resize($image);
        }

        return rtrim(Uri::root(), '/') . '/' . ltrim($image, '/');
    }

    /**
     * Get a date field from an article.
     *
     * @param   int     $id     Article ID
     * @param   string  $field  Date field name (publish_up, modified, created)
     *
     * @return  string  ISO 8601 date string
     */
    private function getArticleDate(int $id, string $field): string
    {
        $db    = Factory::getDbo();
        $query = $db->getQuery(true)
            ->select($db->quoteName($field))
            ->from($db->quoteName('#__content'))
            ->where($db->quoteName('id') . ' = ' . $id);

        $db->setQuery($query);
        $date = $db->loadResult();

        return $date ?: '';
    }

    /**
     * Get the author name for an article.
     *
     * @param   int  $id  Article ID
     *
     * @return  string
     */
    private function getArticleAuthor(int $id): string
    {
        $db    = Factory::getDbo();
        $query = $db->getQuery(true)
            ->select($db->quoteName('u.name'))
            ->from($db->quoteName('#__content', 'a'))
            ->join('LEFT', $db->quoteName('#__users', 'u') . ' ON ' . $db->quoteName('u.id') . ' = ' . $db->quoteName('a.created_by'))
            ->where($db->quoteName('a.id') . ' = ' . $id);

        $db->setQuery($query);

        return $db->loadResult() ?: '';
    }

    /**
     * Warn administrators once per session when no license key is configured.
     *
     * @return  void
     */
    private function warnMissingLicenseKey(): void
    {
        $session = Factory::getSession();

        if ($session->get('mokoog.license_warned', false)) {
            return;
        }

        $user = Factory::getUser();

        if ($user->guest || !$user->authorise('core.manage')) {
            return;
        }

        try {
            $db = Factory::getDbo();

            $query = $db->getQuery(true)
                ->select($db->quoteName('extra_query'))
                ->from($db->quoteName('#__update_sites'))
                ->where($db->quoteName('name') . ' = ' . $db->quote('MokoJoomOpenGraph Updates'))
                ->setLimit(1);
            $db->setQuery($query);
            $extraQuery = (string) $db->loadResult();

            // Mark as checked only after the DB query succeeds
            $session->set('mokoog.license_warned', true);

            if (!empty($extraQuery)) {
                parse_str($extraQuery, $parsed);

                if (!empty($parsed['dlid']) && preg_match('/^MOKO-[A-Z0-9]{4}-[A-Z0-9]{4}-[A-Z0-9]{4}-[A-Z0-9]{4}$/', $parsed['dlid'])) {
                    return;
                }
            }

            $this->getApplication()->enqueueMessage(
                '<strong>Moko Consulting License Key Required</strong> — '
                . 'No download key is configured. Updates will not be available until a valid license key is entered. '
                . 'Go to <a href="index.php?option=com_installer&view=updatesites">System → Update Sites</a> '
                . 'and enter your license key (<code>MOKO-XXXX-XXXX-XXXX-XXXX</code>) in the Download Key field '
                . 'for the MokoJoomOpenGraph update site.',
                'warning'
            );
        } catch (\Throwable $e) {
            // Don't break admin over a license check
        }
    }

    /**
     * Get the actual pixel dimensions of a local image.
     *
     * Returns [width, height] or null for external URLs or unreadable images.
     *
     * @param   string  $image  Image path (relative or absolute URL)
     *
     * @return  array{0: int, 1: int}|null
     */
    private function getImageDimensions(string $image): ?array
    {
        // Cannot determine dimensions for external URLs
        if (str_starts_with($image, 'http://') || str_starts_with($image, 'https://')) {
            return null;
        }

        // If auto-resize is on, the resized image lives in the generated dir
        if ($this->params->get('auto_resize', 1)) {
            $resolved = ImageHelper::resize($image);
        } else {
            $resolved = $image;
        }

        $absPath = JPATH_ROOT . '/' . ltrim($resolved, '/');

        if (!is_file($absPath)) {
            return null;
        }

        $info = @getimagesize($absPath);

        if (!$info) {
            return null;
        }

        return [$info[0], $info[1]];
    }
}