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/**
 * Copyright (C) 2015 Stubhub.
 */
package io.bigdime.handler.kafka;

import java.util.List;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;

import com.google.common.base.Preconditions;

import io.bigdime.core.InputDescriptor;
import io.bigdime.core.commons.PropertyHelper;
import io.bigdime.handler.constants.KafkaReaderHandlerConstants;

/**
 * Encapsulates the fields(topic, partition) that are needed to connect to
 * kafka.
 * 
 * @author Neeraj Jain
 *
 */
@Component
public class KafkaInputDescriptor implements InputDescriptor {

	private String topic;
	private int partition;
	private String entityName;
	

	public KafkaInputDescriptor() {

	}
	/**
	 * The default value of entity is derived from topic
	 * @param topic
	 * @param partition
	 */
	public KafkaInputDescriptor(String topic, int partition) {
		this.topic = topic;
		this.partition = partition;
		this.entityName = topic;
	}

	/**
	 * Gets the next topic:partition to process. For Kafka, we just need to
	 * return the same topic and partition.
	 * 
	 * @param availableInputs
	 *            list of available topic:partition, assumed to be in the order
	 *            in which they need to be processed
	 * @param lastInput
	 *            last topic:partition that was last processed, successfully or
	 *            unsuccessfully
	 * @return topic:partition to process next
	 */
	public String getNext(List availableInputs, String lastInput) {
		return lastInput;
	}

	@Override
	public void parseDescriptor(String descriptor) {
		if (StringUtils.isBlank(descriptor))
			throw new IllegalArgumentException("descriptor can't be null or empty");
		String[] stringParts = descriptor.split(":");
		if (stringParts == null || stringParts.length != 2) {
			throw new IllegalArgumentException("descriptor must be in topic:partition format");
		} else {
			topic = stringParts[0].trim();
			partition = Integer.valueOf(stringParts[1]);
		}
	}
	/**
	 * default value of entity derived from topic
	 * @param descriptor
	 */
	public void parseDescriptor(Map properties ) {
			topic = PropertyHelper.getStringProperty(properties, KafkaReaderHandlerConstants.TOPIC);
			partition = PropertyHelper.getIntProperty(properties, KafkaReaderHandlerConstants.PARTITION, -1);
			Preconditions.checkNotNull(topic,"Valid topic is required and cannot be null");
			if(partition < 0){
				throw new IllegalArgumentException("valid partition is required partition="+partition);
			}
			entityName = PropertyHelper.getStringProperty(properties, KafkaReaderHandlerConstants.ENTITY_NAME,topic);
	}

	@Override
	public String toString() {
		return topic + ":" + partition;
	}

	public String getTopic() {
		return topic;
	}

	public void setTopic(String topic) {
		this.topic = topic;
	}

	public int getPartition() {
		return partition;
	}

	public void setPartition(int partition) {
		this.partition = partition;
	}

	public String getEntityName() {
		return entityName;
	}

	public void setEntityName(String entityName) {
		this.entityName = entityName;
	}

}