<?php
/**
 * Post-meta backed SEO storage.
 *
 * @package CortexCommerce
 */

namespace CortexCommerce\Seo;

defined( 'ABSPATH' ) || exit;

/**
 * Every supported SEO plugin keeps the two fields in post meta; only the keys differ.
 */
abstract class MetaKeyAdapter implements SeoAdapter {

	abstract protected function title_key(): string;

	abstract protected function description_key(): string;

	public function get( int $post_id ): array {
		return array(
			'title'       => (string) get_post_meta( $post_id, $this->title_key(), true ),
			'description' => (string) get_post_meta( $post_id, $this->description_key(), true ),
		);
	}

	public function set( int $post_id, ?string $title, ?string $description ): void {
		if ( null !== $title ) {
			self::write( $post_id, $this->title_key(), $title );
		}
		if ( null !== $description ) {
			self::write( $post_id, $this->description_key(), $description );
		}
	}

	private static function write( int $post_id, string $key, string $value ): void {
		if ( '' === $value ) {
			delete_post_meta( $post_id, $key );
			return;
		}
		// update_post_meta() unslashes; slash first so backslashes survive.
		update_post_meta( $post_id, $key, wp_slash( $value ) );
	}
}