<?php
/**
 * AEO Bob Lite - post schema (v1.5.92)
 *
 * "Generate llms.txt" in the AEO BOB Score box also builds this post's JSON-LD, like AEO Bob Pro's
 * Generate: an Article, plus an FAQPage built from the questions and answers in the post's FAQ
 * section (the real answers, read from the post). It is stored in post meta, printed in the page
 * head on the post's own page, and rebuilt when the post is saved, so it follows FAQ edits.
 *
 * When Yoast SEO, Rank Math, All in One SEO or SEOPress is active, that plugin already prints the
 * Article schema, so Lite adds only the FAQPage (no duplicate Article). No external calls.
 */

if (!defined('ABSPATH')) {
    exit;
}

class AEO_Bob_Lite_Schema {

    const META = '_aeo_bob_lite_schema';

    private static $instance = null;

    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        add_action('wp_head', array($this, 'output'), 20);
        add_action('save_post', array($this, 'refresh_on_save'), 15, 2); // before the queued rescore runs
    }

    /** The active SEO plugin that prints Article schema itself, or ''. */
    public static function seo_plugin() {
        $by = '';
        if (defined('WPSEO_VERSION')) {
            $by = 'Yoast SEO';
        } elseif (defined('RANK_MATH_VERSION')) {
            $by = 'Rank Math';
        } elseif (defined('AIOSEO_VERSION')) {
            $by = 'All in One SEO';
        } elseif (defined('SEOPRESS_VERSION')) {
            $by = 'SEOPress';
        }
        return (string) apply_filters('aeo_bob_lite_schema_seo_plugin', $by);
    }

    /**
     * @return array {graph, article_by, questions}
     */
    public function build($post) {
        $by = self::seo_plugin();
        $graph = array();
        if ('' === $by) {
            $graph[] = $this->article($post);
        }
        $pairs = AEO_Bob_Lite_Text::get_instance()->faq_pairs((string) $post->post_content);
        if ($pairs) {
            $questions = array();
            foreach ($pairs as $pair) {
                $questions[] = array(
                    '@type'          => 'Question',
                    'name'           => $pair[0],
                    'acceptedAnswer' => array('@type' => 'Answer', 'text' => $pair[1]),
                );
            }
            $graph[] = array('@type' => 'FAQPage', 'mainEntity' => $questions);
        }
        return array('graph' => $graph, 'article_by' => $by, 'questions' => count($pairs));
    }

    private function article($post) {
        $description = '';
        foreach (array('_aeo_bob_meta_description', '_yoast_wpseo_metadesc', '_aioseo_description', '_rank_math_description') as $key) {
            $value = get_post_meta($post->ID, $key, true);
            if (!empty($value) && is_string($value)) {
                $description = $value;
                break;
            }
        }
        if ('' === $description) {
            $description = wp_trim_words(wp_strip_all_tags(strip_shortcodes((string) $post->post_content)), 25);
        }
        $article = array(
            '@type'            => 'Article',
            'headline'         => wp_strip_all_tags((string) $post->post_title),
            'description'      => $description,
            'author'           => array('@type' => 'Person', 'name' => get_the_author_meta('display_name', $post->post_author)),
            'publisher'        => array('@type' => 'Organization', 'name' => get_bloginfo('name')),
            'datePublished'    => get_the_date('c', $post->ID),
            'dateModified'     => get_the_modified_date('c', $post->ID),
            'mainEntityOfPage' => array('@type' => 'WebPage', '@id' => get_permalink($post->ID)),
        );
        $icon = get_site_icon_url();
        if ($icon) {
            $article['publisher']['logo'] = array('@type' => 'ImageObject', 'url' => $icon);
        }
        if (has_post_thumbnail($post->ID)) {
            $image = wp_get_attachment_image_url(get_post_thumbnail_id($post->ID), 'full');
            if ($image) {
                $article['image'] = array('@type' => 'ImageObject', 'url' => $image);
            }
        }
        return $article;
    }

    /**
     * Build, store and describe this post's schema.
     *
     * @return string one-line result for the box, '' when the post does not exist
     */
    public function generate($post_id) {
        $post = get_post($post_id);
        if (!$post) {
            return '';
        }
        $b = $this->build($post);
        $stored = array('@context' => 'https://schema.org', '@graph' => $b['graph'], 'article_by' => $b['article_by']);
        update_post_meta($post->ID, self::META, wp_slash(wp_json_encode($stored)));

        $parts = array();
        if ('' === $b['article_by']) {
            $parts[] = 'Article';
        }
        if ($b['questions']) {
            /* translators: %d: number of FAQ questions in the schema */
            $parts[] = sprintf(_n('FAQPage (%d question)', 'FAQPage (%d questions)', $b['questions'], 'aeo-bob-lite'), $b['questions']);
        }
        $line = $parts
            /* translators: %s: schema types, e.g. "Article + FAQPage (3 questions)" */
            ? sprintf(__('Schema added: %s', 'aeo-bob-lite'), implode(' + ', $parts))
            : __('Schema: no FAQ section found for FAQPage', 'aeo-bob-lite');
        if ('' !== $b['article_by']) {
            /* translators: %s: SEO plugin name, e.g. "Yoast SEO" */
            $line .= ' · ' . sprintf(__('Article schema comes from %s', 'aeo-bob-lite'), $b['article_by']);
        }
        return $line;
    }

    /** Keep stored schema in step with the post (only for posts that already have it). */
    public function refresh_on_save($post_id, $post = null) {
        if (wp_is_post_revision($post_id) || (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)) {
            return;
        }
        if ('' === (string) get_post_meta($post_id, self::META, true)) {
            return;
        }
        $this->generate($post_id);
    }

    /** The stored schema of a post, decoded, or null. */
    public static function stored($post_id) {
        $data = json_decode((string) get_post_meta($post_id, self::META, true), true);
        return is_array($data) ? $data : null;
    }

    /** JSON-LD in the head of the post's own page. */
    public function output() {
        if (!is_singular()) {
            return;
        }
        $data = self::stored(get_queried_object_id());
        if (!$data || empty($data['@graph']) || !is_array($data['@graph'])) {
            return;
        }
        $json = wp_json_encode(array('@context' => 'https://schema.org', '@graph' => $data['@graph']), JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP);
        if ($json) {
            echo "\n<!-- AEO Bob Lite schema -->\n<script type=\"application/ld+json\">" . $json . "</script>\n"; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- JSON encoded with JSON_HEX_TAG
        }
    }
}