<?php

declare(strict_types=1);

namespace App\Controller\Webhook;

use App\Message\MailjetNewsletterEventMessage;
use Psr\Log\LoggerInterface;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Messenger\MessageBusInterface;
use Symfony\Component\Routing\Attribute\Route;

final class MailjetNewsletterWebhookController extends AbstractController
{
    private int $ignored = 0;

    /**
     * @param array<int, string> $mailjetLists
     */
    public function __construct(
        private readonly MessageBusInterface $messageBus,
        private readonly LoggerInterface $logger,
        private readonly array $mailjetLists = [],
    ) {
    }

    #[Route('/webhooks/mailjet/newsletter', name: 'app_webhook_mailjet_newsletter', methods: ['POST'])]
    public function index(Request $request): JsonResponse
    {
        $payload = json_decode($request->getContent(), true);
        if (JSON_ERROR_NONE !== json_last_error() || false === is_array($payload)) {
            return new JsonResponse(['success' => false, 'message' => 'Invalid JSON payload.'], Response::HTTP_BAD_REQUEST);
        }

        $events = $this->normalizeEvents($payload);
        $dispatched = 0;
        $this->ignored = 0;

        foreach ($events as $eventPayload) {
            $message = $this->createMessage($eventPayload);
            if (null === $message) {
                continue;
            }

            $this->messageBus->dispatch($message);
            ++$dispatched;
        }

        $this->logger->info('Processed Mailjet newsletter webhook payload', [
            'events' => count($events),
            'dispatched' => $dispatched,
            'ignored' => $this->ignored,
        ]);

        return new JsonResponse(['success' => true, 'dispatched' => $dispatched]);
    }

    /**
     * Mailjet may send one event or a batch of events, so normalize both shapes
     * into a list before dispatching.
     *
     * @param array<int|string, mixed> $payload
     *
     * @return list<array<string, mixed>>
     */
    private function normalizeEvents(array $payload): array
    {
        if ([] === $payload) {
            return [];
        }

        if (array_is_list($payload)) {
            $events = [];
            foreach ($payload as $entry) {
                if (true === is_array($entry)) {
                    $events[] = $entry;
                }
            }

            return $events;
        }

        return [$payload];
    }

    /**
     * @param array<string, mixed> $payload
     */
    private function createMessage(array $payload): ?MailjetNewsletterEventMessage
    {
        $event = isset($payload['event']) ? strtolower(trim((string) $payload['event'])) : '';
        if (MailjetNewsletterEventMessage::EVENT_UNSUBSCRIBE !== $event) {
            return null;
        }

        $email = isset($payload['email']) ? mb_strtolower(trim((string) $payload['email'])) : '';
        if (false === filter_var($email, FILTER_VALIDATE_EMAIL)) {
            return null;
        }

        $mailjetListId = $this->resolveListId($payload);
        if (null === $mailjetListId) {
            return null;
        }

        if (false === $this->isHandledListId($mailjetListId)) {
            ++$this->ignored;

            $this->logger->debug('Ignored Mailjet newsletter webhook event for unconfigured list', [
                'email' => $email,
                'mailjet_list_id' => $mailjetListId,
            ]);

            return null;
        }

        return new MailjetNewsletterEventMessage(
            email: $email,
            mailjetListId: $mailjetListId,
            event: $event,
            eventAt: $this->resolveEventAt($payload),
            payload: $payload,
        );
    }

    /**
     * @param array<string, mixed> $payload
     */
    private function resolveListId(array $payload): ?int
    {
        $value = $payload['mj_list_id'] ?? $payload['list_id'] ?? null;
        if (true === is_int($value)) {
            return $value > 0 ? $value : null;
        }

        if (true === is_string($value) && true === ctype_digit(trim($value))) {
            $listId = (int) trim($value);

            return $listId > 0 ? $listId : null;
        }

        return null;
    }

    private function isHandledListId(int $mailjetListId): bool
    {
        return array_key_exists($mailjetListId, $this->mailjetLists);
    }

    /**
     * @param array<string, mixed> $payload
     */
    private function resolveEventAt(array $payload): ?\DateTimeImmutable
    {
        $value = $payload['time'] ?? $payload['event_at'] ?? null;
        if (true === is_int($value) || true === is_float($value) || true === (is_string($value) && ctype_digit(trim($value)))) {
            return (new \DateTimeImmutable())->setTimestamp((int) $value);
        }

        if (true === is_string($value) && '' !== trim($value)) {
            try {
                return new \DateTimeImmutable($value);
            } catch (\Throwable $e) {
                $this->logger->debug('Could not parse event timestamp from Mailjet webhook payload', [
                    'value' => $value,
                    'error' => $e->getMessage(),
                ]);

                return null;
            }
        }

        return null;
    }
}