<?php
/**
 * Enqueue selected-coupon preflight to Action Scheduler (avoid admin POST timeouts).
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Application\Audit;

use Kayvandra\MarginBeacon\Application\MaterialChange\CouponMaterialHasher;
use Kayvandra\MarginBeacon\Infrastructure\Persistence\FindingsRepository;
use Kayvandra\MarginBeacon\Infrastructure\Scheduler\SchedulerInterface;
use Kayvandra\MarginBeacon\Infrastructure\Scheduler\SchedulerResult;
use Kayvandra\MarginBeacon\Support\Constants;

/**
 * Validates request and queues background preflight run.
 */
final class PreflightJobService {

	/**
	 * @var SchedulerInterface
	 */
	private $scheduler;

	/**
	 * @var FindingsRepository
	 */
	private $repo;

	/**
	 * @param SchedulerInterface      $scheduler Scheduler.
	 * @param FindingsRepository|null $repo      Optional repository (tests may pass a duck-typed stub).
	 */
	public function __construct( SchedulerInterface $scheduler, $repo = null ) {
		$this->scheduler = $scheduler;
		$this->repo      = null !== $repo ? $repo : new FindingsRepository();
	}

	/**
	 * @param int $coupon_id Coupon ID.
	 * @return array{success:bool,scan_id?:int,error?:string}
	 */
	public function enqueue( $coupon_id ) {
		$coupon_id = (int) $coupon_id;
		$coupon    = function_exists( 'wc_get_coupon' ) ? wc_get_coupon( $coupon_id ) : new \WC_Coupon( $coupon_id );
		if ( ! $coupon || ! $coupon->get_id() ) {
			return array(
				'success' => false,
				'error'   => __( 'Coupon not found.', 'marginbeacon' ),
			);
		}

		$scan_id = (int) $this->repo->create_scan(
			array(
				'type'             => 'selected',
				'status'           => 'queued',
				'evaluation_scope' => 'selected_free',
				'input_revision'   => CouponMaterialHasher::hash_coupon( $coupon ),
				'cursor_json'      => wp_json_encode(
					array(
						'coupon_id'   => $coupon_id,
						'coupon_code' => $coupon->get_code(),
					)
				),
				'started_at_gmt'   => gmdate( 'Y-m-d H:i:s' ),
			)
		);

		// Fail-closed: require valid scan_id from persistence.
		if ( $scan_id <= 0 ) {
			return array(
				'success' => false,
				'error'   => __( 'Failed to create scan row.', 'marginbeacon' ),
			);
		}

		$action_id = $this->scheduler->enqueue(
			Constants::ACTION_RUN_SELECTED_PREFLIGHT,
			array(
				'scan_id'   => (int) $scan_id,
				'coupon_id' => $coupon_id,
			),
			Constants::SCHEDULER_GROUP,
			null,
			'preflight_' . $coupon_id . '_' . $scan_id
		);

		if ( ! SchedulerResult::is_enqueued( $action_id ) ) {
			$outcome = $this->repo->persist_scan(
				(int) $scan_id,
				array( 'status' => 'failed' ),
				array( 'queued' )
			);
			if ( 'fail' === $outcome ) {
				return array(
					'success' => false,
					'error'   => __( 'Could not queue preflight and failed to mark scan as failed.', 'marginbeacon' ),
				);
			}
			return array(
				'success' => false,
				'error'   => __( 'Could not queue preflight (Action Scheduler unavailable).', 'marginbeacon' ),
			);
		}

		return array(
			'success' => true,
			'scan_id' => (int) $scan_id,
		);
	}

	/**
	 * Background handler.
	 *
	 * @param int $scan_id   Scan ID.
	 * @param int $coupon_id Coupon ID.
	 * @return void
	 */
	public function run( $scan_id, $coupon_id ) {
		$scan_id   = (int) $scan_id;
		$coupon_id = (int) $coupon_id;
		if ( $scan_id <= 0 || $coupon_id <= 0 ) {
			return;
		}

		// CAS: ok → continue; noop → stop quietly (paused/cancelled/terminal won race); fail → retry via AS.
		// Accept queued + running so AS retries after a crash mid-run remain idempotent.
		$mark = $this->repo->persist_scan( $scan_id, array( 'status' => 'running' ), array( 'queued', 'running' ) );
		if ( 'noop' === $mark ) {
			return;
		}
		if ( 'fail' === $mark ) {
			throw new \RuntimeException(
				esc_html( sprintf( 'MarginBeacon preflight CAS failed for scan_id=%d (expected queued|running→running).', $scan_id ) )
			);
		}
		if ( 'ok' !== $mark ) {
			return;
		}

		try {
			$result = ( new SelectedCouponPreflightService() )->run(
				$coupon_id,
				array(
					'scan_id' => $scan_id,
				)
			);
			if ( empty( $result['success'] ) ) {
				$outcome = $this->repo->persist_scan(
					(int) $scan_id,
					array( 'status' => 'failed' ),
					array( 'running' )
				);
				if ( 'fail' === $outcome ) {
					throw new \RuntimeException(
						esc_html( sprintf( 'MarginBeacon failed to persist failed status for scan_id=%d', $scan_id ) )
					);
				}
			}
		} catch ( \Throwable $e ) {
			if ( $e instanceof \RuntimeException && false !== strpos( $e->getMessage(), 'failed to persist failed status' ) ) {
				throw $e;
			}
			$outcome = $this->repo->persist_scan(
				(int) $scan_id,
				array( 'status' => 'failed' ),
				array( 'running' )
			);
			if ( 'fail' === $outcome ) {
				throw new \RuntimeException(
					esc_html( sprintf( 'MarginBeacon failed to persist failed status for scan_id=%d after exception', $scan_id ) ),
					0,
					$e // phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped -- Throwable chaining, never rendered here.
				);
			}
			throw $e;
		}
	}
}