<?php
/**
 * Coupon material-change revision hash (PRD 9.10.2).
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Application\MaterialChange;

/**
 * Stable hash over material coupon fields only.
 * Description, usage_count, and presentational meta are excluded.
 */
final class CouponMaterialHasher {

	/**
	 * Hash from a WC_Coupon.
	 *
	 * @param \WC_Coupon $coupon Coupon.
	 * @return string
	 */
	public static function hash_coupon( $coupon ) {
		$payload = array(
			'amount'                      => self::norm_decimal( (string) $coupon->get_amount() ),
			'discount_type'               => (string) $coupon->get_discount_type(),
			'product_ids'                 => array_map( 'intval', (array) $coupon->get_product_ids() ),
			'excluded_product_ids'        => array_map( 'intval', (array) $coupon->get_excluded_product_ids() ),
			'product_categories'          => array_map( 'intval', (array) $coupon->get_product_categories() ),
			'excluded_product_categories' => array_map( 'intval', (array) $coupon->get_excluded_product_categories() ),
			'individual_use'              => (bool) $coupon->get_individual_use(),
			'free_shipping'               => (bool) $coupon->get_free_shipping(),
			'minimum_amount'              => self::norm_decimal( (string) $coupon->get_minimum_amount() ),
			'maximum_amount'              => self::norm_decimal( (string) $coupon->get_maximum_amount() ),
			'date_expires'                => $coupon->get_date_expires() ? (string) $coupon->get_date_expires()->date( 'Y-m-d H:i:s' ) : '',
			'usage_limit'                 => (int) $coupon->get_usage_limit(),
			'usage_limit_per_user'        => (int) $coupon->get_usage_limit_per_user(),
			'limit_usage_to_x_items'      => (int) $coupon->get_limit_usage_to_x_items(),
			'exclude_sale_items'          => (bool) $coupon->get_exclude_sale_items(),
			'status'                      => method_exists( $coupon, 'get_status' ) ? (string) $coupon->get_status() : '',
		);

		return self::hash_payload( $payload );
	}

	/**
	 * @param array $payload Material payload.
	 * @return string
	 */
	public static function hash_payload( array $payload ) {
		return hash( 'sha256', (string) wp_json_encode( self::normalize_payload( $payload ) ) );
	}

	/**
	 * @param array $payload Raw.
	 * @return array
	 */
	public static function normalize_payload( array $payload ) {
		$sort_ints = static function ( array $ids ) {
			$ids = array_values( array_unique( array_map( 'intval', $ids ) ) );
			sort( $ids, SORT_NUMERIC );
			return $ids;
		};

		return array(
			'amount'                      => self::norm_decimal( isset( $payload['amount'] ) ? (string) $payload['amount'] : '0' ),
			'discount_type'               => isset( $payload['discount_type'] ) ? (string) $payload['discount_type'] : '',
			'product_ids'                 => $sort_ints( isset( $payload['product_ids'] ) ? (array) $payload['product_ids'] : array() ),
			'excluded_product_ids'        => $sort_ints( isset( $payload['excluded_product_ids'] ) ? (array) $payload['excluded_product_ids'] : array() ),
			'product_categories'          => $sort_ints( isset( $payload['product_categories'] ) ? (array) $payload['product_categories'] : array() ),
			'excluded_product_categories' => $sort_ints( isset( $payload['excluded_product_categories'] ) ? (array) $payload['excluded_product_categories'] : array() ),
			'individual_use'              => ! empty( $payload['individual_use'] ),
			'free_shipping'               => ! empty( $payload['free_shipping'] ),
			'minimum_amount'              => self::norm_decimal( isset( $payload['minimum_amount'] ) ? (string) $payload['minimum_amount'] : '' ),
			'maximum_amount'              => self::norm_decimal( isset( $payload['maximum_amount'] ) ? (string) $payload['maximum_amount'] : '' ),
			'date_expires'                => isset( $payload['date_expires'] ) ? (string) $payload['date_expires'] : '',
			'usage_limit'                 => isset( $payload['usage_limit'] ) ? (int) $payload['usage_limit'] : 0,
			'usage_limit_per_user'        => isset( $payload['usage_limit_per_user'] ) ? (int) $payload['usage_limit_per_user'] : 0,
			'limit_usage_to_x_items'      => isset( $payload['limit_usage_to_x_items'] ) ? (int) $payload['limit_usage_to_x_items'] : 0,
			'exclude_sale_items'          => ! empty( $payload['exclude_sale_items'] ),
			'status'                      => isset( $payload['status'] ) ? (string) $payload['status'] : '',
		);
	}

	/**
	 * @param string $value Raw.
	 * @return string
	 */
	public static function norm_decimal( $value ) {
		return OrderMaterialHasher::norm_decimal( $value );
	}
}