<?php
/**
 * Product.
 *
 * @package ElevenRank
 * @since   1.0.0
 */

namespace ElevenRank\Modules\Schema;

use WP_Post;

defined( 'ABSPATH' ) || exit;

/**
 * A product needs a name and an offer or a rating (Google's Product snippet rules). The offer needs
 * a price and a currency; the rating needs a value and a count.
 *
 * @since 1.0.0
 */
final class Product_Node extends Content_Node {

	/**
	 * Builds the node.
	 *
	 * @since 1.0.0
	 *
	 * @param string               $type   Product.
	 * @param array<string, mixed> $fields Field values.
	 * @param WP_Post              $post   The post.
	 * @param Node_Context         $c      Page information.
	 * @param Graph                $graph  The graph.
	 * @return array<string, mixed>|null
	 */
	public function build( string $type, array $fields, WP_Post $post, Node_Context $c, Graph $graph ): ?array {
		$name   = $this->text( $fields, 'name', $this->title( $post ) );
		$offer  = $this->offer( $fields, '', $c->url );
		$rating = $this->aggregate_rating( $fields );

		if ( '' === $name || ( null === $offer && null === $rating ) ) {
			return null;
		}

		$brand = $this->text( $fields, 'brand' );

		return array(
			'@type'            => 'Product',
			'@id'              => $c->id( 'product' ),
			'mainEntityOfPage' => array( '@id' => $c->id( 'webpage' ) ),
			'url'              => $c->url,
			'name'             => $name,
			'description'      => $this->text( $fields, 'description', $this->description( $post, $c ) ),
			'image'            => $this->image_url( $fields, 'image', $post ),
			'brand'            => '' !== $brand ? array(
				'@type' => 'Brand',
				'name'  => $brand,
			) : null,
			'sku'              => $this->text( $fields, 'sku' ),
			'gtin'             => $this->text( $fields, 'gtin' ),
			'mpn'              => $this->text( $fields, 'mpn' ),
			'offers'           => $offer,
			'aggregateRating'  => $rating,
		);
	}
}