<?php
/**
 * Adds group flat fee plus per-attendee pricing.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Pricing\Modifiers;

use Bookline\Domain\Pricing\Money;
use Bookline\Domain\Pricing\PriceContext;
use Bookline\Domain\Pricing\PriceModifier;

/**
 * Priority 40 — group booking fees.
 *
 * @since 0.1.0
 */
final class GroupBaseFee implements PriceModifier {

	/**
	 * Priority.
	 *
	 * @since 0.1.0
	 */
	public function priority(): int {
		return 40;
	}

	/**
	 * Add flat fee and per-attendee amounts.
	 *
	 * @param PriceContext $ctx     Context.
	 * @param Money        $running Running total.
	 *
	 * @since 0.1.0
	 */
	public function apply( PriceContext $ctx, Money $running ): Money {
		$running = $running->add( $ctx->group_flat_fee() );
		$per     = $ctx->group_per_attendee();
		if ( ! $per->is_zero() ) {
			$running = $running->add( $per->multiply( $ctx->attendees() ) );
		}
		return $running;
	}
}