services/billing-aws/src/main/java/com/epam/dlab/core/aggregate/DataAggregator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package com.epam.dlab.core.aggregate;

import com.epam.dlab.model.aws.ReportLine;
import org.apache.commons.lang3.StringUtils;

import java.util.Collections;
import java.util.Comparator;
import java.util.Vector;

/**
 * Aggregate billing report and summarizes column usage and cost.
 */
public class DataAggregator {
	/**
	 * List of the report lines.
	 */
	private final Vector<ReportLine> reportLines = new Vector<>(1000);

	/**
	 * Comparator for aggregation.
	 */
	private final Comparator<ReportLine> aggComparator = new AggComparator();

	/**
	 * Granularity for aggregation.
	 */
	private AggregateGranularity granularity;

	/**
	 * Length of date for truncate.
	 */
	private int truncateDateLength;


	public DataAggregator(AggregateGranularity granularity) {
		switch (granularity) {
			case DAY:
				truncateDateLength = 10;
				break;
			case MONTH:
				truncateDateLength = 7;
				break;
			default:
				throw new IllegalArgumentException("Invalid value of granularity argument: expected DAY or MONTH, " +
						"actual is " + granularity);
		}
		this.granularity = granularity;
	}

	/**
	 * Return granularity for aggregation.
	 */
	public AggregateGranularity getGranularity() {
		return granularity;
	}

	/**
	 * Appends the report line to the list and returns it.
	 *
	 * @param row the line of report.
	 * @return Instance of the aggregated report line.
	 */
	public ReportLine append(ReportLine row) {
		synchronized (this) {
			String usageInterval = truncDate(row.getUsageDate());
			row.setUsageDate(usageInterval);
			int index = Collections.binarySearch(reportLines, row, aggComparator);
			if (index < 0) {
				index = -index;
				if (index > reportLines.size()) {
					reportLines.add(row);
				} else {
					reportLines.add(index - 1, row);
				}
			} else {
				ReportLine found = reportLines.get(index);
				found.setUsage(found.getUsage() + row.getUsage());
				found.setCost(found.getCost() + row.getCost());
				return found;
			}
		}

		return row;
	}

	/**
	 * Truncate given date for aggregates.
	 *
	 * @param date the date.
	 * @return truncated date.
	 */
	private String truncDate(String date) {
		if (date == null || date.length() <= truncateDateLength) {
			return date;
		}
		return date.substring(0, truncateDateLength);
	}

	/**
	 * Returns the number of the report lines in list.
	 */
	public int size() {
		return reportLines.size();
	}

	/**
	 * Returns the report line.
	 *
	 * @param index index of the report line.
	 */
	public ReportLine get(int index) {
		return reportLines.get(index);
	}

	/**
	 * Removes all of the elements from list.
	 */
	public void clear() {
		reportLines.clear();
	}

	/**
	 * Comparator for aggregation.
	 */
	private class AggComparator implements Comparator<ReportLine> {
		@Override
		public int compare(ReportLine o1, ReportLine o2) {
			if (o1 == null) {
				return (o2 == null ? 0 : -1);
			} else if (o2 == null) {
				return 1;
			}

			int result = StringUtils.compare(o1.getResourceId(), o2.getResourceId());
			if (result == 0) {
				result = StringUtils.compare(o1.getUsageType(), o2.getUsageType());
				if (result == 0) {
					result = StringUtils.compare(o1.getUsageDate(), o2.getUsageDate());
					if (result == 0) {
						result = StringUtils.compare(o1.getProduct(), o2.getProduct());
						if (result == 0) {
							result = StringUtils.compare(o1.getUser(), o2.getUser());
							if (result == 0) {
								return StringUtils.compare(o1.getDlabId(), o2.getDlabId());
							}
						}
					}
				}
			}
			return result;
		}
	}
}