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

declare( strict_types=1 );

namespace Bookline\Domain\Service;

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

/**
 * Bookable service with capacity, buffers and deposit rules.
 *
 * @since 0.1.0
 */
final class Service {

	/**
	 * Constructor.
	 *
	 * @param int|null                  $id                 Database id (null before persist).
	 * @param Uuid                      $uuid               Public identifier.
	 * @param int|null                  $category_id        Category FK.
	 * @param string                    $name               Display name.
	 * @param string                    $slug               URL slug.
	 * @param string|null               $description        Full description.
	 * @param string|null               $short_description  Short blurb.
	 * @param int|null                  $image_id           Attachment id.
	 * @param string|null               $colour             #RRGGBB.
	 * @param ServiceStatus             $status             Lifecycle status.
	 * @param int                       $capacity_min       Minimum attendees.
	 * @param int                       $capacity_max       Maximum attendees.
	 * @param int                       $buffer_before_min  Buffer before start.
	 * @param int                       $buffer_after_min   Buffer after end.
	 * @param int|null                  $lead_time_min      Lead time override.
	 * @param int|null                  $horizon_days       Horizon override.
	 * @param int|null                  $slot_step_min      Slot step override.
	 * @param DepositType               $deposit_type       Deposit mode.
	 * @param int                       $deposit_value      Fixed minor units or percent 0–100.
	 * @param string|null               $tax_class          Tax class key.
	 * @param bool                      $requires_approval  Manual approval flag.
	 * @param int                       $sort_order         Sort weight.
	 * @param array<string, mixed>|null $meta           Opaque meta.
	 * @param DateTimeImmutable         $created_at         Created (UTC).
	 * @param DateTimeImmutable         $updated_at         Updated (UTC).
	 * @param DateTimeImmutable|null    $deleted_at        Soft-delete instant.
	 *
	 * @throws \Bookline\Domain\Shared\DomainException When invariants fail.
	 */
	public function __construct(
		private ?int $id,
		private Uuid $uuid,
		private ?int $category_id,
		private string $name,
		private string $slug,
		private ?string $description,
		private ?string $short_description,
		private ?int $image_id,
		private ?string $colour,
		private ServiceStatus $status,
		private int $capacity_min,
		private int $capacity_max,
		private int $buffer_before_min,
		private int $buffer_after_min,
		private ?int $lead_time_min,
		private ?int $horizon_days,
		private ?int $slot_step_min,
		private DepositType $deposit_type,
		private int $deposit_value,
		private ?string $tax_class,
		private bool $requires_approval,
		private int $sort_order,
		private ?array $meta,
		private DateTimeImmutable $created_at,
		private DateTimeImmutable $updated_at,
		private ?DateTimeImmutable $deleted_at = null,
	) {
		$this->assert_invariants();
	}

	/**
	 * Validate entity invariants.
	 *
	 * @throws DomainException On invariant breach.
	 */
	private function assert_invariants(): void {
		if ( '' === trim( $this->name ) ) {
			throw new DomainException( 'service.name_empty', 'Service name must not be empty.' );
		}
		if ( '' === trim( $this->slug ) ) {
			throw new DomainException( 'service.slug_empty', 'Service slug must not be empty.' );
		}
		if ( $this->capacity_min < 1 ) {
			throw new DomainException( 'service.capacity_min', 'capacity_min must be at least 1.' );
		}
		if ( $this->capacity_max < $this->capacity_min ) {
			throw new DomainException( 'service.capacity_max', 'capacity_max must be >= capacity_min.' );
		}
		if ( $this->buffer_before_min < 0 || $this->buffer_after_min < 0 ) {
			throw new DomainException( 'service.buffer_negative', 'Buffers must not be negative.' );
		}
		if ( null !== $this->colour && 1 !== preg_match( '/^#[0-9A-Fa-f]{6}$/', $this->colour ) ) {
			throw new DomainException( 'service.colour_invalid', 'Colour must be #RRGGBB.' );
		}
		if ( DepositType::Percent === $this->deposit_type && ( $this->deposit_value < 0 || $this->deposit_value > 100 ) ) {
			throw new DomainException( 'service.deposit_percent', 'Percent deposit must be 0–100.' );
		}
		if ( DepositType::Fixed === $this->deposit_type && $this->deposit_value < 0 ) {
			throw new DomainException( 'service.deposit_fixed', 'Fixed deposit must not be negative.' );
		}
		if ( DepositType::None === $this->deposit_type && 0 !== $this->deposit_value ) {
			throw new DomainException( 'service.deposit_none', 'Deposit value must be 0 when type is none.' );
		}
	}

	/**
	 * 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;
	}

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

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

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

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

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

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

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

	/**
	 * Buffer before min.
	 *
	 * @since 0.1.0
	 */
	public function buffer_before_min(): int {
		return $this->buffer_before_min;
	}

	/**
	 * Buffer after min.
	 *
	 * @since 0.1.0
	 */
	public function buffer_after_min(): int {
		return $this->buffer_after_min;
	}

	/**
	 * Lead time min.
	 *
	 * @since 0.1.0
	 */
	public function lead_time_min(): ?int {
		return $this->lead_time_min;
	}

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

	/**
	 * Slot step min.
	 *
	 * @since 0.1.0
	 */
	public function slot_step_min(): ?int {
		return $this->slot_step_min;
	}

	/**
	 * Deposit type.
	 *
	 * @since 0.1.0
	 */
	public function deposit_type(): DepositType {
		return $this->deposit_type;
	}

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

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

	/**
	 * Requires approval.
	 *
	 * @since 0.1.0
	 */
	public function requires_approval(): bool {
		return $this->requires_approval;
	}

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

	/**
	 * Opaque meta payload.
	 *
	 * @return array<string, mixed>|null
	 *
	 * @since 0.1.0
	 */
	public function meta(): ?array {
		return $this->meta;
	}

	/**
	 * 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;
	}

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

	/**
	 * Whether soft-deleted.
	 *
	 * @since 0.1.0
	 */
	public function is_deleted(): bool {
		return null !== $this->deleted_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( 'service.id_assigned', 'Service id is already assigned.' );
		}
		if ( $id < 1 ) {
			throw new DomainException( 'service.id_invalid', 'Service id must be positive.' );
		}
		$this->id = $id;
	}

	/**
	 * Soft-delete at the given UTC instant.
	 *
	 * @param DateTimeImmutable $when Deletion instant (UTC).
	 *
	 * @since 0.1.0
	 */
	public function soft_delete( DateTimeImmutable $when ): void {
		if ( null !== $this->deleted_at ) {
			return;
		}
		$this->deleted_at = $when;
		$this->updated_at = $when;
		$this->status     = ServiceStatus::Archived;
	}
}