<?php
/**
 * Service category entity.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Service;

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

/**
 * Hierarchical category for organising services.
 *
 * @since 0.1.0
 */
final class ServiceCategory {

	/**
	 * Constructor.
	 *
	 * @param int|null          $id          Database id.
	 * @param Uuid              $uuid        Public id.
	 * @param int|null          $parent_id   Parent category.
	 * @param string            $name        Name.
	 * @param string            $slug        Slug.
	 * @param string|null       $description Description.
	 * @param int|null          $image_id    Attachment.
	 * @param int               $sort_order  Sort.
	 * @param DateTimeImmutable $created_at  Created UTC.
	 * @param DateTimeImmutable $updated_at  Updated UTC.
	 *
	 * @throws \Bookline\Domain\Shared\DomainException When invariants fail.
	 */
	public function __construct(
		private ?int $id,
		private Uuid $uuid,
		private ?int $parent_id,
		private string $name,
		private string $slug,
		private ?string $description,
		private ?int $image_id,
		private int $sort_order,
		private DateTimeImmutable $created_at,
		private DateTimeImmutable $updated_at,
	) {
		if ( '' === trim( $this->name ) ) {
			throw new DomainException( 'category.name_empty', 'Category name must not be empty.' );
		}
		if ( '' === trim( $this->slug ) ) {
			throw new DomainException( 'category.slug_empty', 'Category slug must not be empty.' );
		}
		if ( null !== $this->parent_id && $this->parent_id < 1 ) {
			throw new DomainException( 'category.parent_id', 'parent_id must be positive when set.' );
		}
	}

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

	/**
	 * Name.
	 *
	 * @since 0.1.0
	 */
	public function name(): string {
		return $this->name;
	}

	/**
	 * Slug.
	 *
	 * @since 0.1.0
	 */
	public function slug(): string {
		return $this->slug;
	}

	/**
	 * Description.
	 *
	 * @since 0.1.0
	 */
	public function description(): ?string {
		return $this->description;
	}

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

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

	/**
	 * 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 the database id after insert.
	 *
	 * @param int $id New id.
	 *
	 * @throws \Bookline\Domain\Shared\DomainException When id is already set or invalid.
	 *
	 * @since 0.1.0
	 */
	public function assign_id( int $id ): void {
		if ( null !== $this->id ) {
			throw new DomainException( 'category.id_assigned', 'Category id is already assigned.' );
		}
		$this->id = $id;
	}
}