<?php
/**
 * Acknowledgment meta tags in <head>.
 *
 * @package Acknowledgify
 */

namespace Acknowledgify\Includes;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Outputs acknowledgment meta tags.
 */
class Meta_Tags {

	/**
	 * Setting key => meta name attribute.
	 *
	 * None of these names are emitted by Yoast SEO, Rank Math, All in One SEO
	 * or SEOPress in a stock configuration, so there is no duplicate-tag
	 * conflict. If a particular setup ever does collide, drop the offending
	 * key with the acknowledgify_meta_tags filter rather than editing here.
	 *
	 * @return array
	 */
	public static function get_tag_map() {
		$map = array(
			'meta_author'         => 'author',
			'meta_designer'       => 'designer',
			'meta_developer'      => 'developer',
			'meta_copyright'      => 'copyright',
			'meta_owner'          => 'owner',
			'meta_publisher'      => 'publisher',
			'meta_manage'         => 'managed-by',
			'meta_power'          => 'powered-by',
			'meta_acknowledgment' => 'acknowledgment',
		);

		/**
		 * Filters the acknowledgment meta tags that may be output.
		 *
		 * Unset a key to suppress that tag entirely, for example to avoid a
		 * clash with another plugin.
		 *
		 * @param array $map Setting key => meta name attribute.
		 */
		return (array) apply_filters( 'acknowledgify_meta_tags', $map );
	}

	/**
	 * Print the tags. Only settings with a value produce a tag.
	 *
	 * @return void
	 */
	public static function add_meta_tags() {
		if ( 1 !== (int) Helper::get_setting( 'enable_meta_tags', 0 ) ) {
			return;
		}

		$output = '';

		foreach ( self::get_tag_map() as $key => $meta_name ) {
			$output .= Helper::generate_meta_tag( $key, $meta_name );
		}

		if ( '' === $output ) {
			return;
		}

		// Each tag was built with esc_attr() on both attributes in
		// Helper::generate_meta_tag(); the allow-list here is a second gate
		// that guarantees nothing but meta name/content can ever be emitted.
		echo wp_kses(
			$output,
			array(
				'meta' => array(
					'name'    => array(),
					'content' => array(),
				),
			)
		);
	}
}