<?php

declare( strict_types=1 );

namespace Senti\Subscription;

use Senti\Shared\WordPress\Identifiers;
use wpdb;

/**
 * Enqueues delivery events for active subscribers.
 */
final class NotificationQueue {

	private const ACTION = 'senti_process_notifications';

	public function __construct(
		private wpdb $wpdb,
		private SubscriptionService $subscriptions
	) {}

	public function enqueue_release( int $release_id ): int {
		if ( get_post_type( $release_id ) !== Identifiers::POST_TYPE_RELEASE || get_post_status( $release_id ) !== 'publish' ) {
			return 0;
		}

		$event_key        = hash( 'sha256', 'release:' . $release_id );
		$subscription_ids = $this->subscriptions->active_for_release( $release_id );

		return $this->enqueue_subject( $subscription_ids, $event_key, 'release', 'release', $release_id );
	}

	public function enqueue_feedback_status( int $feedback_id, string $status ): int {
		if ( get_post_type( $feedback_id ) !== Identifiers::POST_TYPE_FEEDBACK ) {
			return 0;
		}

		$event_key        = hash( 'sha256', 'feedback_status:' . $feedback_id . ':' . $status );
		$subscription_ids = $this->subscriptions->active_for_feedback( $feedback_id );

		return $this->enqueue_subject( $subscription_ids, $event_key, 'feedback_status', 'feedback', $feedback_id );
	}

	/**
	 * @param int[] $subscription_ids
	 */
	private function enqueue_subject( array $subscription_ids, string $event_key, string $event_type, string $subject_type, int $subject_id ): int {
		$queued = 0;
		$table  = "{$this->wpdb->prefix}senti_notifications";

		foreach ( $subscription_ids as $subscription_id ) {
			$query = $this->wpdb->prepare(
				'INSERT IGNORE INTO %i (subscription_id, event_key, event_type, subject_type, subject_id, state, attempt_count, scheduled_gmt, created_gmt) VALUES (%d, %s, %s, %s, %d, %s, 0, %s, %s)',
				$table,
				$subscription_id,
				$event_key,
				$event_type,
				$subject_type,
				$subject_id,
				'pending',
				current_time( 'mysql', true ),
				current_time( 'mysql', true )
			);
			// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- $query is prepared immediately above.
			$result  = is_string( $query ) ? $this->wpdb->query( $query ) : false;
			$queued += $result === 1 ? 1 : 0;
		}

		if ( $queued > 0 ) {
			$this->schedule_worker( time() + MINUTE_IN_SECONDS );
		}

		return $queued;
	}

	private function schedule_worker( int $timestamp ): void {
		$next = wp_next_scheduled( self::ACTION );
		if ( $next !== false && $next <= $timestamp ) {
			return;
		}
		wp_clear_scheduled_hook( self::ACTION );
		wp_schedule_single_event( $timestamp, self::ACTION );
	}
}