<?php

declare(strict_types=1);

namespace KupShop\SynchronizationBundle\Util\Rabbit;

use KupShop\KupShopBundle\Util\Logging\SentryLogger;
use KupShop\SynchronizationBundle\Exception\RabbitRetryMessageException;
use KupShop\SynchronizationBundle\Rabbit\RabbitConsumerConfiguration;
use Symfony\Component\Messenger\Bridge\Amqp\Transport\AmqpStamp;
use Symfony\Component\Messenger\Bridge\Amqp\Transport\Connection;

class RabbitConsumer
{
    public function __construct(private readonly SentryLogger $sentryLogger)
    {
    }

    /**
     * @param callable(\AMQPEnvelope): bool $fn
     */
    public function consume(RabbitConsumerConfiguration $configuration, callable $fn): bool
    {
        $connection = $this->createConnection($configuration);

        if (!($messagesCount = $connection->countMessagesInQueues())) {
            $this->closeConnection($connection);

            return false;
        }

        $moreMessages = true;
        $processedCount = 0;

        $startTime = microtime(true);

        // zacnu zpracovavat zmeny
        $this->processMessages($configuration, $connection, function (\AMQPEnvelope $envelope) use ($fn, $connection, $configuration, $startTime, $messagesCount, &$processedCount, &$moreMessages) {
            // pokud vyprsel limit pro zpracovani zmen, tak to ukoncim
            if ((microtime(true) - $startTime) >= $configuration->timeout) {
                return false;
            }

            $wasAckedEarly = false;
            // pokud ma na sobe message header s `x-ack-on-start`, tak provedu acknuti message hned na zacatku
            if ($envelope->hasHeader('x-ack-on-start')) {
                $connection->ack($envelope, $configuration->queue);
                $wasAckedEarly = true;
            }

            // podle celkoveho poctu a zpracovaneho poctu odetekuju, zda ve fronte jsou jeste nejake messages, ktere jsem nezpracoval
            $moreMessages = ++$processedCount < $messagesCount;

            try {
                $result = $fn($envelope);
            } catch (RabbitRetryMessageException) {
                $this->handleRetryMessage($envelope, $configuration, $connection);

                return $moreMessages;
            } catch (\Throwable $e) {
                if (isLocalDevelopment()) {
                    throw $e;
                }

                $this->sentryLogger->captureException($e, [
                    'extra' => [
                        'body' => $envelope->getBody(),
                    ],
                ]);

                $result = false;
            }

            // pokud mi umrela connectiona, tak zastavim consume, protoze stejnak nefunguje ackovani atd... kdyz jsem uz odpojenej
            if (!$this->isConnectionAlive($connection)) {
                return false;
            }

            // pokud byla message uz acknuta, tak vracim vysledek, protoze logika dole uz neni potreba
            if ($wasAckedEarly) {
                return $moreMessages;
            }

            // pokud nastala chyba a nebo jsem na locale, tak message vratim zpatky do fronty
            if (!$result || isLocalDevelopment()) {
                $connection->nack($envelope, $configuration->queue, AMQP_REQUEUE);

                return $moreMessages;
            }

            // vse probehlo uspesne, takze provedu potvrzeni message
            $connection->ack($envelope, $configuration->queue);

            return $moreMessages;
        });

        $this->closeConnection($connection);

        return $moreMessages;
    }

    /**
     * Message processing handler.
     *
     * Handler is processing all queues that are configured by configuration (priority queues).
     */
    private function processMessages(RabbitConsumerConfiguration $configuration, Connection $connection, callable $fn): void
    {
        $processNext = true;

        // multiple queues can be configured when using priorities, so we need to iterate all of them
        foreach ($configuration->getQueues() as $options) {
            // process should be stopped because $fn told us
            if (!$processNext) {
                break;
            }

            // no messages in queue, so we can skip it
            if (!($messagesCount = $connection->queue($options['queueName'])->declareQueue())) {
                continue;
            }

            $processedCount = 0;

            // start queue consuming
            $connection->queue($options['queueName'])->consume(function (\AMQPEnvelope $envelope) use ($fn, $messagesCount, &$processedCount, &$processNext) {
                if (!$fn($envelope)) {
                    $processNext = false;

                    return false;
                }

                // no more messages in queue, so return false to stop consume
                return ++$processedCount < $messagesCount;
            });
        }
    }

    private function closeConnection(Connection $connection): void
    {
        $amqpConnection = $connection->channel()->getConnection();

        try {
            $connection->channel()->close();
        } catch (\Exception) {
        }

        try {
            $amqpConnection->disconnect();
        } catch (\Exception) {
        }
    }

    private function handleRetryMessage(\AMQPEnvelope $envelope, RabbitConsumerConfiguration $configuration, Connection $connection): void
    {
        // pokud je nastavena retry strategy, tak ji aplikuji
        if ($configuration->retryStrategy) {
            // pokud ji chci jeste opakovat, tak ji znovu poslu do delay fronty odkud se potom vrati do
            // normlani fronty a zkusi se zpracovat znovu
            if ($configuration->retryStrategy->isRetryable($envelope)) {
                $connection->publish(
                    $envelope->getBody(),
                    ['x-retry-count' => ($envelope->getHeaders()['x-retry-count'] ?? 0) + 1],
                    $configuration->retryStrategy->getWaitingTime($envelope),
                    // retry message should be routed to default queue when returning from delay queue (retry message becomes unprioritized)
                    AmqpStamp::createFromAmqpEnvelope($envelope, retryRoutingKey: $configuration->getDefaultQueue())
                );
            }
        }

        // potvrdim message, aby zmizela z fronty
        $connection->ack($envelope, $configuration->queue);
    }

    private function createConnection(RabbitConsumerConfiguration $configuration): Connection
    {
        $options = [
            'auto_setup' => false,
            'queues' => $configuration->getQueuesConfiguration(),
        ];

        if ($configuration->hasPriorityQueuesWithExchange()) {
            $options['exchange'] = [
                'name' => $configuration->priorityOptions['exchange'],
                'type' => 'direct',
            ];
        }

        $connection = Connection::fromDsn(
            rtrim($configuration->dsn, '/').'/'.$configuration->queue,
            $options
        );

        // priority options are configured, so setup priority queues with exchange
        if ($configuration->hasPriorityQueuesWithExchange()) {
            $connection->exchange()->declareExchange();
            foreach ($configuration->getQueues() as $config) {
                $connection->queue($config['queueName'])->declareQueue();
                $connection->queue($config['queueName'])->bind($configuration->priorityOptions['exchange'], $config['priorityName']);
            }
        }

        $connection->channel()->setPrefetchCount($configuration->prefetchCount);

        return $connection;
    }

    private function isConnectionAlive(Connection $connection): bool
    {
        return $connection->channel()->isConnected();
    }
}