<?php
/**
 * Schema.org / JSON-LD generator for the Markdown response front matter.
 *
 * Emits a compact JSON-LD object (Article / BlogPosting / WebPage) inside a
 * fenced ```json block — this way both LLMs and regular tools parse it equally
 * well. Data is pulled from post fields (title, dates, author, cover image,
 * manual excerpt) and site settings (publisher, language). Writes nothing to
 * the DB — a pure function of WP_Post.
 *
 * @package ADG_AI_Markdown
 */

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

class ADG_AIM_Schema {

	/**
	 * Build the JSON-LD fenced block for a post.
	 *
	 * @param WP_Post $post Post.
	 * @return string The ```json ... ``` block (with trailing newline) or ''.
	 */
	public static function build_block( WP_Post $post ) {
		if ( ! (bool) ADG_AIM_Plugin::get_setting( 'schema_enabled', true ) ) {
			return '';
		}

		$data = self::build_data( $post );
		if ( empty( $data ) ) {
			return '';
		}

		$json = wp_json_encode(
			$data,
			JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT
		);
		if ( false === $json ) {
			return '';
		}

		return "```json\n" . $json . "\n```\n";
	}

	/**
	 * Build the Schema.org data array.
	 *
	 * @param WP_Post $post Post.
	 * @return array
	 */
	private static function build_data( WP_Post $post ) {
		$type_map = array(
			'post' => 'BlogPosting',
			'page' => 'WebPage',
		);
		$schema_type = isset( $type_map[ $post->post_type ] ) ? $type_map[ $post->post_type ] : 'Article';

		/**
		 * Schema.org type for the post (overridable for custom post types).
		 *
		 * @param string  $schema_type Type.
		 * @param WP_Post $post        Post.
		 */
		$schema_type = (string) apply_filters( 'adg_aim_schema_type', $schema_type, $post );

		$permalink = get_permalink( $post );

		$data = array(
			'@context'         => 'https://schema.org',
			'@type'            => $schema_type,
			'@id'              => $permalink,
			'url'              => $permalink,
			'mainEntityOfPage' => $permalink,
		);

		// Title: WebPage uses name, Article-like types use headline.
		$title = wp_strip_all_tags( get_the_title( $post ) );
		if ( '' !== $title ) {
			if ( false !== stripos( $schema_type, 'page' ) ) {
				$data['name'] = $title;
			} else {
				$data['headline'] = $title;
			}
		}

		// Dates in ISO 8601 (respecting the site timezone).
		$published = get_post_time( 'c', false, $post );
		$modified  = get_post_modified_time( 'c', false, $post );
		if ( $published ) {
			$data['datePublished'] = $published;
		}
		if ( $modified ) {
			$data['dateModified'] = $modified;
		}

		// Excerpt — manual only, to avoid duplicating the body and running auto-generation.
		if ( has_excerpt( $post ) ) {
			$excerpt = wp_strip_all_tags( get_the_excerpt( $post ) );
			if ( '' !== $excerpt ) {
				$data['description'] = $excerpt;
			}
		}

		// Author.
		$author = get_the_author_meta( 'display_name', $post->post_author );
		if ( is_string( $author ) && '' !== $author ) {
			$data['author'] = array(
				'@type' => 'Person',
				'name'  => $author,
			);
		}

		// Cover image.
		$image = get_the_post_thumbnail_url( $post, 'full' );
		if ( $image ) {
			$data['image'] = $image;
		}

		// Publisher (site) + logo from the site icon, if set.
		$publisher = array(
			'@type' => 'Organization',
			'name'  => get_bloginfo( 'name' ),
			'url'   => home_url( '/' ),
		);
		$logo = get_site_icon_url( 512 );
		if ( $logo ) {
			$publisher['logo'] = array(
				'@type' => 'ImageObject',
				'url'   => $logo,
			);
		}
		$data['publisher'] = $publisher;

		// Post/site language.
		$lang = get_bloginfo( 'language' );
		if ( '' !== $lang ) {
			$data['inLanguage'] = $lang;
		}

		/**
		 * Final JSON-LD array (for extension by third-party code).
		 *
		 * @param array   $data Schema.org data.
		 * @param WP_Post $post Post.
		 */
		return (array) apply_filters( 'adg_aim_schema_data', $data, $post );
	}
}