// Append repository
repositories {
    mavenCentral()
}

// Append dependency
implementation("com.icerockdev.service:kafka-service:0.1.1")

// Producer
single(TestProducerService(
    appConf.getString("kafka.servers"),
    appConf.getString("kafka.clientId"),
    "topicName"
))

// Consumer
single(TestKafkaConsumer(
    appConf.getString("kafka.servers"),
    appConf.getString("kafka.groupId"),
    appConf.getString("kafka.clientId")
))

// Executor
single {
    KafkaConsumerExecutionPool(Dispatchers.IO)
}

// application.conf
kafka {
    servers = ${KAFKA_BROKERS}
    clientId = "auth_service"
}

class TestProducerService(servers: String, clientId: String, private val topic: String) : AutoCloseable {
    private val producer = KafkaProducerBuilder()
//        .applyTransactional(KAFKA_TRANSACTION_ID) // supported only for 3 brokers and more
        .applyIdempotence()
        .applyTimeout()
        .applyBuffering()
        .build<Long, String>(
            servers = servers,
            clientId = clientId,
            keySerializer = LongSerializer(),
            valueSerializer = ObjectSerializer()
        )

    fun sendData(model: String): Boolean {
        val time = System.currentTimeMillis()
        return KafkaSender.send(producer, topic, time, model)
    }

    fun sendAsyncData(model: String) {
        val time = System.currentTimeMillis()
        KafkaSender.sendAsync(producer, topic, time, model)
    }

    override fun close() {
        producer.flush()
        producer.close()
    }
}

class TestKafkaConsumer(servers: String, groupId: String, clientId: String) : IKafkaConsumer {

    private val consumer =
        KafkaConsumerBuilder()
            .applyReadOpt()
            .applyIsolation(KafkaConsumerBuilder.IsolationLevel.READ_COMMITTED)
            .apply {
                with(props) {
                    this[ConsumerConfig.FETCH_MAX_BYTES_CONFIG] = 50 * 1024 * 1024
                    this[ConsumerConfig.AUTO_OFFSET_RESET_CONFIG] = KafkaConsumerBuilder.Offset.LATEST.value
                }
            }
            .build<String, String>(
                servers,
                groupId,
                clientId,
                StringDeserializer(),
                ObjectDeserializer(jacksonTypeRef())
            )


    override fun run(executor: KafkaConsumerExecutionPool, topic: String) {
        executor.runExecutor(
            consumer = consumer,
            topicList = Collections.singletonList(topic),
            pollWait = Duration.ofMillis(100)
        ) {
            this.forEach { record ->
                // apply values
                println("Read value: ${record.value()}")
            }
            true
        }

    }

    override fun close() {
        consumer.close()
    }
}

Copyright 2019 IceRock MAG Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.