<?php
/**
 * Trigger configuration stored on an automation (docs/20 §2).
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Automation;

use Bookline\Domain\Shared\DomainException;

/**
 * Immutable trigger definition.
 *
 * @since 0.1.0
 */
final class TriggerDefinition {

	/**
	 * Constructor.
	 *
	 * @param TriggerKind          $kind                         Kind.
	 * @param string               $event                        Event or relative identifier.
	 * @param int|null             $offset_minutes               Relative offset; negative = before.
	 * @param int|null             $skip_if_lead_time_lt_minutes Skip window in minutes.
	 * @param array<string, mixed> $schedule                     Schedule payload.
	 *
	 * @throws DomainException When the definition is empty.
	 */
	public function __construct(
		private readonly TriggerKind $kind,
		private readonly string $event,
		private readonly ?int $offset_minutes = null,
		private readonly ?int $skip_if_lead_time_lt_minutes = null,
		private readonly array $schedule = [],
	) {
		if ( '' === trim( $this->event ) ) {
			throw new DomainException( 'automation.trigger_empty', 'Trigger event must not be empty.' );
		}
	}

	/**
	 * Kind.
	 *
	 * @since 0.1.0
	 */
	public function kind(): TriggerKind {
		return $this->kind;
	}

	/**
	 * Event or relative identifier.
	 *
	 * @since 0.1.0
	 */
	public function event(): string {
		return $this->event;
	}

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

	/**
	 * Skip-if-too-close window.
	 *
	 * @since 0.1.0
	 */
	public function skip_if_lead_time_lt_minutes(): ?int {
		return $this->skip_if_lead_time_lt_minutes;
	}

	/**
	 * Schedule payload.
	 *
	 * @return array<string, mixed>
	 *
	 * @since 0.1.0
	 */
	public function schedule(): array {
		return $this->schedule;
	}

	/**
	 * Serialise for JSON storage.
	 *
	 * @return array<string, mixed>
	 *
	 * @since 0.1.0
	 */
	public function to_array(): array {
		return [
			'kind'                         => $this->kind->value,
			'event'                        => $this->event,
			'offset_minutes'               => $this->offset_minutes,
			'skip_if_lead_time_lt_minutes' => $this->skip_if_lead_time_lt_minutes,
			'schedule'                     => $this->schedule,
		];
	}

	/**
	 * Hydrate from JSON.
	 *
	 * @param array<string, mixed> $data Data.
	 *
	 * @since 0.1.0
	 */
	public static function from_array( array $data ): self {
		$kind_raw = isset( $data['kind'] ) ? (string) $data['kind'] : TriggerKind::Event->value;
		$event    = isset( $data['event'] ) ? (string) $data['event'] : '';
		$offset   = isset( $data['offset_minutes'] ) ? (int) $data['offset_minutes'] : null;
		$skip     = isset( $data['skip_if_lead_time_lt_minutes'] ) ? (int) $data['skip_if_lead_time_lt_minutes'] : null;
		$schedule = isset( $data['schedule'] ) && is_array( $data['schedule'] ) ? $data['schedule'] : [];

		return new self(
			TriggerKind::from( $kind_raw ),
			$event,
			$offset,
			$skip,
			$schedule
		);
	}
}