<?php
declare(strict_types=1);

namespace Kafka;


use RdKafka\Conf;
use RdKafka\Consumer;
use RdKafka\ConsumerTopic;
use RdKafka\Exception;
use RdKafka\KafkaConsumer;
use RdKafka\TopicConf;
use Snowflake\Snowflake;
use Swoole\Coroutine\Channel;
use Swoole\Process;
use Throwable;

/**
 * Class Queue
 * @package Queue
 */
class Kafka extends \Snowflake\Process\Process
{

	protected Channel $channel;

	private int $maxLength = 5000;


	/**
	 * @param Process $process
	 * @throws \Exception
	 */
	public function onHandler(Process $process): void
	{
		$this->waite(swoole_unserialize($process->read()));
	}


	/**
	 * @param array $kafkaServer
	 * @throws \Exception
	 */
	private function waite(array $kafkaServer)
	{
		try {
			name($this->pid, 'Kafka Consumer ' . $kafkaServer['topic']);

			[$config, $topic, $conf] = $this->kafkaConfig($kafkaServer);
			if (empty($config) && empty($topic) && empty($conf)) {
				return;
			}
			$objRdKafka = new Consumer($config);
			$topic = $objRdKafka->newTopic($kafkaServer['topic'], $topic);

			$topic->consumeStart(0, RD_KAFKA_OFFSET_STORED);
			do {
				$this->resolve($topic, $conf['interval'] ?? 1000);
			} while (true);
		} catch (Throwable $exception) {
			logger()->addError($exception, 'throwable');
		}
	}


	/**
	 * @param ConsumerTopic $topic
	 * @param $interval
	 * @throws \Exception
	 */
	private function resolve(ConsumerTopic $topic, $interval)
	{
		try {
			$message = $topic->consume(0, $interval);
			if (empty($message)) {
				return;
			}
			if ($message->err == RD_KAFKA_RESP_ERR_NO_ERROR) {
				$this->handlerExecute($message->topic_name, $message);
			} else if ($message->err == RD_KAFKA_RESP_ERR__PARTITION_EOF) {
				$this->application->warning('No more messages; will wait for more');
			} else if ($message->err == RD_KAFKA_RESP_ERR__TIMED_OUT) {
				$this->application->error('Kafka Timed out');
			} else {
				$this->application->error($message->errstr());
			}
		} catch (Throwable $exception) {
			logger()->addError($exception, 'throwable');
		}
	}


	/**
	 * @param $topic
	 * @param $message
	 * @throws \Exception
	 */
	protected function handlerExecute($topic, $message)
	{
		go(function () use ($topic, $message) {
			try {
				$topic = str_replace('-', '_', $topic);

				$namespace = 'App\\Kafka\\' . ucfirst($topic) . 'Consumer';
				if (!class_exists($namespace)) {
					return;
				}
				$class = Snowflake::createObject($namespace);
				if (!($class instanceof ConsumerInterface)) {
					return;
				}
				$class->onHandler(Snowflake::createObject(Struct::class, [$topic, $message]));
			} catch (Throwable $exception) {
				logger()->addError($exception, 'throwable');
			}
		});
	}


	/**
	 * @param $kafka
	 * @return array
	 * @throws \Exception
	 */
	private function kafkaConfig($kafka): array
	{
		try {
			$conf = new Conf();
			$conf->setRebalanceCb([$this, 'rebalanced_cb']);
			$conf->set('group.id', $kafka['groupId']);
			$conf->set('metadata.broker.list', $kafka['brokers']);
			$conf->set('socket.timeout.ms', '30000');

			$this->application->debug('kafka listen groupId ' . $kafka['groupId']);
			$this->application->debug('kafka listen brokers ' . $kafka['brokers']);

			if (function_exists('pcntl_sigprocmask')) {
				pcntl_sigprocmask(SIG_BLOCK, array(SIGIO));
				$conf->set('internal.termination.signal', (string)SIGIO);
			}

			$topicConf = new TopicConf();
			$topicConf->set('auto.commit.enable', '1');
			$topicConf->set('auto.commit.interval.ms', '100');

			//smallest：简单理解为从头开始消费，
			//largest：简单理解为从最新的开始消费
			$topicConf->set('auto.offset.reset', 'smallest');
			$topicConf->set('offset.store.path', 'kafka_offset.log');
			$topicConf->set('offset.store.method', 'broker');

			return [$conf, $topicConf, $kafka];
		} catch (Throwable $exception) {
			logger()->addError($exception, 'throwable');

			return [null, null, null];
		}

	}


	/**
	 * @param KafkaConsumer $kafka
	 * @param $err
	 * @param array|null $partitions
	 * @throws Exception
	 * @throws \Exception
	 */
	public function rebalanced_cb(KafkaConsumer $kafka, $err, array $partitions = null)
	{
		if ($err == RD_KAFKA_RESP_ERR__ASSIGN_PARTITIONS) {
			$kafka->assign($partitions);
		} else if ($err == RD_KAFKA_RESP_ERR__REVOKE_PARTITIONS) {
			$kafka->assign(NULL);
		} else {
			throw new \Exception($err);
		}
	}


}