<?php
/**
 * Yoast SEO integration: sermon description as meta/Open Graph description,
 * noindex for thin sermon taxonomy archives and sitemap exclusions.
 *
 * @package Kanzelbuch
 */

defined( 'ABSPATH' ) || exit;

/**
 * Short plain-text description of a sermon (excerpt, else content), max. 155 characters.
 *
 * @param int $post_id Sermon ID.
 * @return string
 */
function fegp_seo_description( $post_id ) {
	$p = get_post( $post_id );
	if ( ! $p ) {
		return '';
	}
	$text = '' !== trim( $p->post_excerpt ) ? $p->post_excerpt : $p->post_content;
	$text = trim( preg_replace( '/\s+/u', ' ', wp_strip_all_tags( strip_shortcodes( excerpt_remove_blocks( $text ) ) ) ) );
	if ( function_exists( 'mb_strlen' ) && mb_strlen( $text ) > 155 ) {
		$cut  = mb_substr( $text, 0, 154 );
		$pos  = mb_strrpos( $cut, ' ' );
		$text = rtrim( false !== $pos && $pos > 100 ? mb_substr( $cut, 0, $pos ) : $cut, " ,.;:–-" ) . '…';
	}
	return $text;
}

/**
 * Fill an empty Yoast description on single sermons.
 *
 * @param string $desc Description from Yoast.
 * @return string
 */
function fegp_seo_filter_desc( $desc ) {
	if ( '' !== trim( (string) $desc ) || ! is_singular( 'sermons' ) ) {
		return $desc;
	}
	$own = fegp_seo_description( get_queried_object_id() );
	return '' !== $own ? $own : $desc;
}

/**
 * Sermon taxonomies kept out of the index.
 *
 * @return string[]
 */
function fegp_seo_taxonomies() {
	return array( 'sermon_speaker', 'sermon_topics', 'sermon_book', 'sermon_series' );
}

/**
 * Whether the current request is one of these taxonomy archives.
 *
 * @return bool
 */
function fegp_seo_is_sermon_tax() {
	return is_tax( fegp_seo_taxonomies() );
}

/**
 * Robots as array (Yoast 14+).
 *
 * @param array $robots Robots values.
 * @return array
 */
function fegp_seo_robots_array( $robots ) {
	if ( fegp_seo_is_sermon_tax() ) {
		$robots['index']  = 'noindex';
		$robots['follow'] = 'follow';
	}
	return $robots;
}

/**
 * Robots as string (older Yoast versions).
 *
 * @param string $robots Robots string.
 * @return string
 */
function fegp_seo_robots( $robots ) {
	if ( ! fegp_seo_is_sermon_tax() ) {
		return $robots;
	}
	$parts = array_filter( array_map( 'trim', explode( ',', (string) $robots ) ) );
	$parts = array_diff( $parts, array( 'index', 'noindex', 'follow', 'nofollow' ) );
	return implode( ', ', array_merge( array( 'noindex', 'follow' ), $parts ) );
}

/**
 * Leave sermon taxonomies out of the Yoast sitemap.
 *
 * @param bool   $exclude  Excluded.
 * @param string $taxonomy Taxonomy.
 * @return bool
 */
function fegp_seo_sitemap_tax( $exclude, $taxonomy ) {
	return in_array( $taxonomy, fegp_seo_taxonomies(), true ) ? true : $exclude;
}

/**
 * Leave the 'archive_pages' post type (Advanced Sermons) out of the Yoast sitemap.
 *
 * @param bool   $exclude   Excluded.
 * @param string $post_type Post type.
 * @return bool
 */
function fegp_seo_sitemap_post_type( $exclude, $post_type ) {
	return 'archive_pages' === $post_type ? true : $exclude;
}

/**
 * Register the filters only when Yoast SEO is active.
 */
function fegp_seo_init() {
	if ( ! defined( 'WPSEO_VERSION' ) ) {
		return;
	}
	add_filter( 'wpseo_metadesc', 'fegp_seo_filter_desc' );
	add_filter( 'wpseo_opengraph_desc', 'fegp_seo_filter_desc' );
	$o = fegp_options();
	if ( ! empty( $o['seo_noindex_tax'] ) ) {
		add_filter( 'wpseo_robots_array', 'fegp_seo_robots_array' );
		add_filter( 'wpseo_robots', 'fegp_seo_robots' );
		add_filter( 'wpseo_sitemap_exclude_taxonomy', 'fegp_seo_sitemap_tax', 10, 2 );
		add_filter( 'wpseo_sitemap_exclude_post_type', 'fegp_seo_sitemap_post_type', 10, 2 );
	}
}
add_action( 'plugins_loaded', 'fegp_seo_init', 20 );