/*
 * 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 org.apache.iotdb.db.query.udf.example;

import org.apache.iotdb.udf.api.UDTF;
import org.apache.iotdb.udf.api.access.Row;
import org.apache.iotdb.udf.api.collector.PointCollector;
import org.apache.iotdb.udf.api.customizer.config.UDTFConfigurations;
import org.apache.iotdb.udf.api.customizer.parameter.UDFParameters;
import org.apache.iotdb.udf.api.customizer.strategy.RowByRowAccessStrategy;
import org.apache.iotdb.udf.api.type.Type;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class TerminateTester implements UDTF {

  private static final Logger logger = LoggerFactory.getLogger(TerminateTester.class);

  private Long maxTime;
  private int count;

  @Override
  public void beforeStart(UDFParameters parameters, UDTFConfigurations configurations) {
    logger.debug("TerminateTester#beforeStart");
    configurations.setOutputDataType(Type.INT32).setAccessStrategy(new RowByRowAccessStrategy());
    maxTime = null;
    count = 0;
  }

  @Override
  public void transform(Row row, PointCollector collector) throws Exception {
    maxTime = row.getTime();
    ++count;

    collector.putInt(maxTime, 1);
  }

  @Override
  public void terminate(PointCollector collector) throws Exception {
    if (maxTime != null) {
      collector.putInt(maxTime + 1, count);
    }
  }

  @Override
  public void beforeDestroy() {
    logger.debug("TerminateTester#beforeDestroy");
  }
}
