<?php
/**
 * Busy interval returned by availability range queries.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Booking;

use DateTimeImmutable;

/**
 * Half-open busy window for an agent or location (UTC).
 *
 * @since 0.1.0
 */
final class BusyInterval {

	/**
	 * Constructor.
	 *
	 * @param int               $booking_id Booking id.
	 * @param DateTimeImmutable $start_utc  Buffer start UTC.
	 * @param DateTimeImmutable $end_utc    Buffer end UTC.
	 * @param int               $attendees  Attendee count (for capacity).
	 *
	 * @throws \Bookline\Domain\Shared\DomainException When invariants fail.
	 */
	public function __construct(
		private int $booking_id,
		private DateTimeImmutable $start_utc,
		private DateTimeImmutable $end_utc,
		private int $attendees = 1,
	) {
	}

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

	/**
	 * Start utc.
	 *
	 * @since 0.1.0
	 */
	public function start_utc(): DateTimeImmutable {
		return $this->start_utc;
	}

	/**
	 * End utc.
	 *
	 * @since 0.1.0
	 */
	public function end_utc(): DateTimeImmutable {
		return $this->end_utc;
	}

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