Aelia - Support

/*
Plugin Name: Aelia - Currency Price Sorting
Plugin URI: https://aelia.co/
Description: Alters the logic used by WooCommerce to sort by price, to use the currency-specific prices
Version: 1.0.1.230329
Author: Aelia
Author URI: https://aelia.co
License: GPLv3
*/
namespace Aelia\WC\Customisation;

use \WC_Product;
use \WC_Product_Variable;

/**
 * Implements a custom sorting logic to use currency-specific prices.
 */
class WC_Aelia_Currency_Price_Sorting {
	protected static $_sorting_by_price = false;
	protected static $_sort_order = 'ASC';

	const TEXT_DOMAIN = 'aelia-currency-price-sorting';

	/**
	 * Initialises the class.
	 *
	 * @return void
	 */
	public static function init(): void {
		add_filter('woocommerce_product_query_meta_query', [__CLASS__, 'woocommerce_product_query_meta_query'], 99, 2);
		add_filter('woocommerce_product_get_price', [__CLASS__, 'woocommerce_product_get_price'], 3, 2);
	}

	/**
	 * Indicates if the current query should be sorted based on the currency-specific prices.
	 *
	 * @return boolean
	 */
	protected static function should_sort_query_by_currency_prices(): bool {
		return (!is_admin() || defined('DOING_AJAX')) && static::$_sorting_by_price;
	}

	/**
	 * Intercepts the meta query being prepared by WooCommerce. This method uses the
	 * "woocommerce_product_query_meta_query" filter as an entry point to determine if
	 * the sorting logic should be altered. It doesn't modify the meta query passed to it.
	 *
	 * @param array $meta_query
	 * @param WC_Query $query
	 * @return array
	 */
	public static function woocommerce_product_query_meta_query($meta_query, $query) {
		$catalog_ordering_args = $query->get_catalog_ordering_args();

		static::$_sorting_by_price = in_array('price', explode(' ', $catalog_ordering_args['orderby'] ?? ''));
		static::$_sort_order = $catalog_ordering_args['order'] ?? 'ASC';

		if(!static::should_sort_query_by_currency_prices()) {
			return $meta_query;
		}

		// Remove the sorting logic used by WooCommerce to "sort by price, ascending" and
		// replace it with the custom one
		if(has_filter('posts_clauses', [$query, 'order_by_price_desc_post_clauses'])) {
			remove_filter('posts_clauses', [$query, 'order_by_price_desc_post_clauses']);

			add_filter('posts_clauses', [__CLASS__, 'posts_clauses'], 999, 2);
		}

		// Remove the sorting logic used by WooCommerce to "sort by price, decending" and
		// replace it with the custom one
		if(has_filter('posts_clauses', [$query, 'order_by_price_asc_post_clauses'])) {
			remove_filter('posts_clauses', [$query, 'order_by_price_asc_post_clauses']);

			add_filter('posts_clauses', [__CLASS__, 'posts_clauses'], 999, 2);
		}

		// Return the meta, untouched. We only used this event to hook into the flow at the right time
		return $meta_query;
	}

	/**
	 * Intercepts the post clauses used to build the product query, adding the JOIN and ORDER BY
	 * clauses needed to sort the products correctly.
	 *
	 * @param array $args
	 * @param WP_Query $wp_query
	 * @return array
	 */
	public static function posts_clauses($args, $wp_query) {
		// Remove this filter, to prevent it from running again for other queries that don't
		// need to be altered
		//remove_filter('posts_clauses', [__CLASS__, 'posts_clauses'], 999, 2);

		if(!static::should_sort_query_by_currency_prices() || !$wp_query->is_main_query()) {
			return $args;
		}

		global $wpdb;

		if(!strstr($args['join'], 'product_currency_price_sorting')) {
			$active_currency = get_woocommerce_currency();
			$price_meta_key = (self::$_sort_order === 'DESC') ? '_aelia_max_price' : '_aelia_min_price';

			$args['join'] .= trim("
				LEFT JOIN {$wpdb->postmeta} AS product_currency_price_sorting ON
					(product_currency_price_sorting.post_id = {$wpdb->posts}.ID) AND
					(product_currency_price_sorting.meta_key = '{$price_meta_key}_{$active_currency}')
			");

			$args['orderby'] = implode(",\n", [
				"CAST(product_currency_price_sorting.meta_value AS DECIMAL(10,6)) " . static::$_sort_order,
				"product_currency_price_sorting.post_id ASC",
			]);
		}

		return $args;
	}

	/**
	 * Intercepts the price of a product in the active currency and stores it in the database, so
	 * that it can be used for sorting.
	 *
	 * @param float|string $price
	 * @param WC_Product $product
	 * @return float|string
	 */
	public static function woocommerce_product_get_price($price, $product) {
		static $saved_product_prices = [];
		$active_currency = get_woocommerce_currency();

		if(($saved_product_prices[$product->get_id()] ?? '') !== $price) {
			// Find the callback to use for the product type
			$product_price_update_callback = static::get_price_update_callback($product);

			if(is_callable($product_price_update_callback)) {
				call_user_func($product_price_update_callback, $product, $price, $active_currency);
			}

			$saved_product_prices[$product->get_id()] = $price;
		}

		return $price;
	}

	/**
	 * Returns the callback that should be used to update the product price in the active currency.
	 *
	 * @param WC_Product $product
	 * @return callable
	 */
	protected static function get_price_update_callback(WC_Product $product): callable {
		$callbacks = [
			'variable' => [__CLASS__, 'update_variable_product_currency_prices'],
			'default' => [__CLASS__, 'update_product_currency_prices'],
		];

		$callback = apply_filters('wc_aelia_cps_product_price_update_callback', $callbacks[$product->get_type()] ?? $callbacks['default'], $product);

		// Handle condition in which the filter returns an invalid callback
		if(!is_callable($callback)) {
			trigger_error(__('Filter "wc_aelia_cps_product_price_update_callback" did not return a valid callback. Using default callback.', self::TEXT_DOMAIN), E_USER_WARNING);
			$callback = $callbacks[$product->get_type()] ?? $callbacks['default'];
		}

		return $callback;
	}

	/**
	 * Updates the currency specific prices for a generic product (e.g. simple, external, grouped).
	 *
	 * @param WC_Product $product
	 * @param float|string $product_price
	 * @param string $currency
	 * @return void
	 */
	protected static function update_product_currency_prices(WC_Product $product, $product_price, string $currency): void {
		$product->update_meta_data("_aelia_min_price_{$currency}", $product_price);
		$product->update_meta_data("_aelia_max_price_{$currency}", $product_price);
		$product->save_meta_data();
	}

	/**
	 * Updates the currency specific prices for a variable product.
	 *
	 * @param WC_Product_Variable $product
	 * @param float $product_price
	 * @param string $currency
	 * @return void
	 */
	protected static function update_variable_product_currency_prices(WC_Product_Variable $product, $product_price, string $currency): void {
		global $wpdb;

		// Load the list of prices of all product's variations
		// @see WC_Product_Variable_Data_Store_CPT::sync_price()
		$children = $product->get_visible_children();
		if(!empty($children)) {
			$format = array_fill( 0, count( $children ), '%d');
			$query_in = '(' . implode( ',', $format ) . ')';
			$prices = array_unique( $wpdb->get_col( $wpdb->prepare( "SELECT meta_value FROM $wpdb->postmeta WHERE meta_key = '_price' AND post_id IN {$query_in}", $children ) ) ); // @codingStandardsIgnoreLine.
			sort($prices, SORT_NUMERIC);
		} else {
			$prices = [];
		}

		$product->update_meta_data("_aelia_min_price_{$currency}", reset($prices));
		$product->update_meta_data("_aelia_max_price_{$currency}", end($prices));
		$product->save_meta_data();
	}

	/**
	 * Performs the activation operations.
	 *
	 * @return void
	 */
	public static function activate(): void {
		register_uninstall_hook(__FILE__, [__CLASS__, 'uninstall']);
	}

	/**
	 * Performs the uninstallation operations.
	 *
	 * @return void
	 */
	public static function uninstall(): void {
		global $wpdb;

		$SQL = trim("
			DELETE FROM {$wpdb->postmeta}
			WHERE
				(meta_key like '_aelia_min_price%') OR
				(meta_key like '_aelia_max_price%')
		");
		$wpdb->query($SQL);
	}
}

WC_Aelia_Currency_Price_Sorting::init();
register_activation_hook(__FILE__, [WC_Aelia_Currency_Price_Sorting::class, 'activate']);