<?php
/**
 * The attributes of a WooCommerce variation, as shown to shoppers.
 *
 * @package Fitzaro
 */

namespace Fitzaro\Prompt;

defined( 'ABSPATH' ) || exit;

/**
 * Global attributes (taxonomies) are turned into their term names, custom ones are used as typed.
 * "Any" values (empty) are skipped: the shopper's choice is not known.
 */
final class VariantAttributes {

	/**
	 * Attribute labels and selected values of a variation.
	 *
	 * @param int $variation_id Variation ID.
	 * @return array<string, string>
	 */
	public static function for_variation( int $variation_id ): array {
		$variation = wc_get_product( $variation_id );
		if ( ! $variation instanceof \WC_Product_Variation ) {
			return array();
		}

		$parent     = wc_get_product( $variation->get_parent_id() );
		$attributes = array();

		foreach ( $variation->get_attributes() as $taxonomy => $value ) {
			$value = (string) $value;
			if ( '' === $value ) {
				continue;
			}

			if ( taxonomy_exists( (string) $taxonomy ) ) {
				$term  = get_term_by( 'slug', $value, (string) $taxonomy );
				$value = $term instanceof \WP_Term ? $term->name : $value;
			}

			$label                = $parent instanceof \WC_Product ? wc_attribute_label( (string) $taxonomy, $parent ) : wc_attribute_label( (string) $taxonomy );
			$attributes[ $label ] = $value;
		}

		/**
		 * Filters the variant attributes named in the try-on prompt (size is always left out).
		 *
		 * @since 1.0.0
		 *
		 * @param array<string, string> $attributes   Attribute labels and values.
		 * @param int                   $variation_id Variation ID.
		 */
		$filtered = apply_filters( 'fitzaro/variant_attributes', $attributes, $variation_id );

		return self::only_strings( $filtered );
	}

	/**
	 * Keeps string keys and scalar values. A filter can return anything.
	 *
	 * @param mixed $attributes Filter result.
	 * @return array<string, string>
	 */
	private static function only_strings( $attributes ): array {
		$clean = array();
		foreach ( is_array( $attributes ) ? $attributes : array() as $name => $value ) {
			if ( is_string( $name ) && is_scalar( $value ) ) {
				$clean[ $name ] = (string) $value;
			}
		}

		return $clean;
	}
}