<?php
/**
 * WooCommerce webhook delivery failures.
 *
 * @package Keepwatch
 */

namespace Keepwatch\WooCommerce;

use Keepwatch\Checks\Check;
use Keepwatch\Checks\Result;

defined( 'ABSPATH' ) || exit;

/**
 * WooCommerce disables a webhook after repeated delivery failures, silently stopping order sync to ERPs, shipping or
 * accounting tools. Reads counts from the webhooks table only; delivery URLs and secrets are never read.
 */
final class WebhooksCheck implements Check {

	/** WooCommerce disables a webhook once its failure count passes 5. */
	public const AUTO_DISABLE_FAILURES = 5;

	/**
	 * {@inheritDoc}
	 */
	public function group(): string {
		return 'woocommerce';
	}

	/**
	 * {@inheritDoc}
	 */
	public function run(): array {
		$counts = $this->counts();
		return null === $counts ? array() : self::evaluate( $counts['active'], $counts['failing'], $counts['disabled'] );
	}

	/**
	 * Pure evaluation.
	 *
	 * @param int $active   Active webhooks.
	 * @param int $failing  Active webhooks with recent delivery failures.
	 * @param int $disabled Webhooks WooCommerce disabled after repeated failures.
	 * @return Result[]
	 */
	public static function evaluate( int $active, int $failing, int $disabled ): array {
		if ( 0 === $active + $disabled ) {
			return array();
		}
		$link  = admin_url( 'admin.php?page=wc-settings&tab=advanced&section=webhooks' );
		$label = __( 'View webhooks', 'keepwatch' );

		if ( $disabled > 0 ) {
			return array(
				new Result(
					'woocommerce.webhooks',
					Result::CRITICAL,
					/* translators: %d: number of webhooks */
					sprintf( _n( '%d webhook was switched off after repeated failures', '%d webhooks were switched off after repeated failures', $disabled, 'keepwatch' ), $disabled ),
					__( 'WooCommerce stops a webhook after it fails several times in a row. The service it fed (for example shipping, accounting or an ERP) no longer receives orders. Fix the receiving address, then set the webhook to Active again.', 'keepwatch' ),
					$link,
					$label
				),
			);
		}
		if ( $failing > 0 ) {
			return array(
				new Result(
					'woocommerce.webhooks',
					Result::RECOMMENDED,
					/* translators: %d: number of webhooks */
					sprintf( _n( '%d webhook is failing to deliver', '%d webhooks are failing to deliver', $failing, 'keepwatch' ), $failing ),
					__( 'Recent deliveries failed. If it keeps failing, WooCommerce will switch the webhook off.', 'keepwatch' ),
					$link,
					$label
				),
			);
		}

		return array( new Result( 'woocommerce.webhooks', Result::GOOD, __( 'Webhooks deliver without errors', 'keepwatch' ) ) );
	}

	/**
	 * Webhook counts, or null if the table does not exist.
	 *
	 * @return array{active: int, failing: int, disabled: int}|null
	 */
	private function counts(): ?array {
		global $wpdb;

		$table = $wpdb->prefix . 'wc_webhooks';
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- read-only counts, cached by the check schedule.
		if ( $table !== $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) ) ) {
			return null;
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- see above.
		$row = $wpdb->get_row(
			$wpdb->prepare(
				'SELECT SUM(status = %s) AS active, SUM(status = %s AND failure_count > 0) AS failing, SUM(status = %s AND failure_count > %d) AS disabled FROM %i',
				'active',
				'active',
				'disabled',
				self::AUTO_DISABLE_FAILURES,
				$table
			),
			ARRAY_A
		);

		return is_array( $row ) ? array(
			'active'   => (int) $row['active'],
			'failing'  => (int) $row['failing'],
			'disabled' => (int) $row['disabled'],
		) : null;
	}
}