<?php
/**
 * Product schema for WooCommerce products.
 *
 * @package OrbitstemSEO
 */

namespace Orbitstem\SEO\Schema;

use Orbitstem\SEO\Content\TemplateEngine;
use WP_Post;

defined( 'ABSPATH' ) || exit;

/**
 * Builds a Product node from WooCommerce's own data: price (or price range
 * for variable products), currency, stock status, SKU, brand, GTIN, ratings
 * and the newest reviews. WooCommerce prints its own, simpler product markup;
 * while Orbitstem prints this node, WooCommerce's is turned off so search
 * engines see one Product, not two.
 */
class Woo {

	/**
	 * Whether WooCommerce is active.
	 *
	 * @return bool
	 */
	public static function active() {
		return function_exists( 'wc_get_product' );
	}

	/**
	 * WooCommerce's cart, checkout and account pages: personal pages that are
	 * no use in search results, sitemaps or llms.txt.
	 *
	 * @return int[]
	 */
	public static function private_page_ids() {
		if ( ! function_exists( 'wc_get_page_id' ) ) {
			return array();
		}
		$ids = array();
		foreach ( array( 'cart', 'checkout', 'myaccount' ) as $page ) {
			$id = (int) wc_get_page_id( $page );
			if ( $id > 0 ) {
				$ids[] = $id;
			}
		}
		return $ids;
	}

	/**
	 * Turns off WooCommerce markup that Orbitstem's graph already has. Call it
	 * only while Orbitstem prints schema.
	 *
	 * @param bool $products Also turn off WooCommerce's product and breadcrumb
	 *                       markup (Orbitstem prints fuller ones when the
	 *                       WooCommerce schema setting is on).
	 */
	public static function register( $products = true ) {
		// A Shop page used as the front page gets a WebSite node from WooCommerce; Orbitstem's graph has one on every page.
		add_filter( 'woocommerce_structured_data_website', '__return_empty_array', 99 );
		if ( ! $products ) {
			return;
		}
		add_filter( 'woocommerce_structured_data_product', '__return_empty_array', 99 );
		// Orbitstem's graph already has the BreadcrumbList; a second one from WooCommerce would compete with it.
		add_filter( 'woocommerce_structured_data_breadcrumblist', '__return_empty_array', 99 );
	}

	/**
	 * Product node, or null when the post is not a WooCommerce product.
	 *
	 * @param WP_Post $post     Post.
	 * @param array   $resolved Resolver output.
	 * @param string  $page_id  WebPage @id.
	 * @return array|null
	 */
	public static function product_node( WP_Post $post, array $resolved, $page_id ) {
		if ( ! self::active() || 'product' !== $post->post_type ) {
			return null;
		}
		$product = wc_get_product( $post->ID );
		if ( ! $product ) {
			return null;
		}
		$url  = $resolved['url'];
		$node = array(
			'@type'            => 'Product',
			'@id'              => $url . '#product',
			'name'             => TemplateEngine::plain( $product->get_name() ),
			'url'              => $url,
			'mainEntityOfPage' => array( '@id' => $page_id ),
		);
		$desc = TemplateEngine::plain( $product->get_short_description() ? $product->get_short_description() : $product->get_description() );
		if ( '' !== $desc ) {
			$node['description'] = mb_substr( $desc, 0, 5000 );
		}
		$images = array();
		foreach ( array_merge( array( $product->get_image_id() ), $product->get_gallery_image_ids() ) as $image_id ) {
			$src = $image_id ? wp_get_attachment_image_url( (int) $image_id, 'full' ) : '';
			if ( $src ) {
				$images[] = $src;
			}
		}
		if ( $images ) {
			$node['image'] = array_slice( array_values( array_unique( $images ) ), 0, 10 );
		} elseif ( '' !== $resolved['image'] ) {
			$node['image'] = $resolved['image'];
		}
		if ( $product->get_sku() ) {
			$node['sku'] = $product->get_sku();
		}
		if ( method_exists( $product, 'get_global_unique_id' ) && $product->get_global_unique_id() ) {
			$node['gtin'] = $product->get_global_unique_id();
		}
		$brand = self::brand( $product );
		if ( '' !== $brand ) {
			$node['brand'] = array(
				'@type' => 'Brand',
				'name'  => $brand,
			);
		}

		$currency     = strtoupper( (string) get_woocommerce_currency() );
		$availability = 'https://schema.org/' . ( $product->is_in_stock() ? ( $product->is_on_backorder() ? 'BackOrder' : 'InStock' ) : 'OutOfStock' );
		// A shop currency changed by a filter to a made-up code (or a crypto symbol) is not a valid
		// price for search engines: the offer is left out, ratings and reviews are still shown.
		$valid = in_array( $currency, RichTypes::currencies(), true );
		if ( $valid && $product->is_type( 'variable' ) ) {
			$prices = $product->get_variation_prices( true );
			if ( ! empty( $prices['price'] ) ) {
				$node['offers'] = array(
					'@type'         => 'AggregateOffer',
					'lowPrice'      => wc_format_decimal( min( $prices['price'] ), wc_get_price_decimals() ),
					'highPrice'     => wc_format_decimal( max( $prices['price'] ), wc_get_price_decimals() ),
					'offerCount'    => count( $prices['price'] ),
					'priceCurrency' => $currency,
					'availability'  => $availability,
					'url'           => $url,
				);
			}
		} elseif ( $valid && ! $product->is_type( 'variable' ) && '' !== $product->get_price() ) {
			$offer = array(
				'@type'         => 'Offer',
				'price'         => wc_format_decimal( wc_get_price_to_display( $product ), wc_get_price_decimals() ),
				'priceCurrency' => $currency,
				'availability'  => $availability,
				'url'           => $url,
			);
			if ( $product->is_on_sale() && $product->get_date_on_sale_to() ) {
				$offer['priceValidUntil'] = $product->get_date_on_sale_to()->date( 'Y-m-d' );
			}
			$node['offers'] = $offer;
		}

		$count = (int) $product->get_review_count();
		if ( $count > 0 && wc_review_ratings_enabled() ) {
			$node['aggregateRating'] = array(
				'@type'       => 'AggregateRating',
				'ratingValue' => (float) $product->get_average_rating(),
				'reviewCount' => $count,
			);
			$reviews                 = get_comments(
				array(
					'post_id' => $post->ID,
					'status'  => 'approve',
					'type'    => 'review',
					'number'  => 5,
				)
			);
			foreach ( $reviews as $review ) {
				$rating = (int) get_comment_meta( $review->comment_ID, 'rating', true );
				if ( $rating < 1 ) {
					continue;
				}
				$node['review'][] = array(
					'@type'         => 'Review',
					'reviewRating'  => array(
						'@type'       => 'Rating',
						'ratingValue' => $rating,
						'bestRating'  => 5,
					),
					'author'        => array(
						'@type' => 'Person',
						'name'  => TemplateEngine::plain( $review->comment_author ),
					),
					'datePublished' => gmdate( 'c', (int) strtotime( $review->comment_date_gmt . ' UTC' ) ),
					'reviewBody'    => TemplateEngine::plain( $review->comment_content ),
				);
			}
		}
		// Google only shows product results with an offer, rating or review.
		return isset( $node['offers'] ) || isset( $node['aggregateRating'] ) ? $node : null;
	}

	/**
	 * Brand from a "brand" taxonomy (WooCommerce Brands and similar) or attribute.
	 *
	 * @param \WC_Product $product Product.
	 * @return string
	 */
	private static function brand( $product ) {
		foreach ( array( 'product_brand', 'pwb-brand', 'yith_product_brand' ) as $taxonomy ) {
			if ( taxonomy_exists( $taxonomy ) ) {
				$terms = get_the_terms( $product->get_id(), $taxonomy );
				if ( is_array( $terms ) && $terms ) {
					return TemplateEngine::plain( $terms[0]->name );
				}
			}
		}
		$attribute = $product->get_attribute( 'brand' );
		return is_string( $attribute ) ? TemplateEngine::plain( $attribute ) : '';
	}
}