<?php
/**
 * Cart aggregate for an order intent.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\OrderIntent;

use Bookline\Domain\Shared\DomainException;
use Bookline\Domain\Shared\Uuid;
use DateTimeImmutable;
use DateTimeZone;

/**
 * Cart row linked to exactly one order intent.
 *
 * @since 0.1.0
 */
final class Cart {

	/**
	 * Constructor.
	 *
	 * @param int|null          $id              Database id.
	 * @param Uuid              $uuid            Public id.
	 * @param int               $order_intent_id Parent intent.
	 * @param CartStatus        $status          Status.
	 * @param DateTimeImmutable $created_at      Created UTC.
	 * @param DateTimeImmutable $updated_at      Updated UTC.
	 *
	 * @throws DomainException When invariants fail.
	 */
	public function __construct(
		private ?int $id,
		private Uuid $uuid,
		private int $order_intent_id,
		private CartStatus $status,
		private DateTimeImmutable $created_at,
		private DateTimeImmutable $updated_at,
	) {
		if ( $this->order_intent_id < 1 ) {
			throw new DomainException( 'cart.order_intent_id', 'order_intent_id must be positive.' );
		}
	}

	/**
	 * Database id.
	 *
	 * @since 0.1.0
	 */
	public function id(): ?int {
		return $this->id;
	}

	/**
	 * Public UUID.
	 *
	 * @since 0.1.0
	 */
	public function uuid(): Uuid {
		return $this->uuid;
	}

	/**
	 * Parent order intent id.
	 *
	 * @since 0.1.0
	 */
	public function order_intent_id(): int {
		return $this->order_intent_id;
	}

	/**
	 * Status.
	 *
	 * @since 0.1.0
	 */
	public function status(): CartStatus {
		return $this->status;
	}

	/**
	 * Created at.
	 *
	 * @since 0.1.0
	 */
	public function created_at(): DateTimeImmutable {
		return $this->created_at;
	}

	/**
	 * Updated at.
	 *
	 * @since 0.1.0
	 */
	public function updated_at(): DateTimeImmutable {
		return $this->updated_at;
	}

	/**
	 * Assign id after insert.
	 *
	 * @param int $id New id.
	 *
	 * @throws DomainException When already assigned.
	 *
	 * @since 0.1.0
	 */
	public function assign_id( int $id ): void {
		if ( null !== $this->id ) {
			throw new DomainException( 'cart.id_assigned', 'Cart id is already assigned.' );
		}
		if ( $id < 1 ) {
			throw new DomainException( 'cart.id_invalid', 'Cart id must be positive.' );
		}
		$this->id = $id;
	}

	/**
	 * Transition status.
	 *
	 * @param CartStatus        $status New status.
	 * @param DateTimeImmutable $now    Instant.
	 *
	 * @since 0.1.0
	 */
	public function set_status( CartStatus $status, DateTimeImmutable $now ): void {
		$this->status     = $status;
		$this->updated_at = $now->setTimezone( new DateTimeZone( 'UTC' ) );
	}
}