/*
 * 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.pulsar.functions.api.examples.window;

import java.util.Collection;
import org.apache.pulsar.functions.api.Record;
import org.apache.pulsar.functions.api.WindowContext;
import org.apache.pulsar.functions.api.WindowFunction;

/**
 * Example function that wants to keep track of
 * the event time of each message sent.
 */
public class UserMetricWindowFunction implements WindowFunction<String, Void> {

    @Override
    public Void process(Collection<Record<String>> inputs, WindowContext context) throws Exception {

        for (Record<String> record : inputs) {
            if (record.getEventTime().isPresent()) {
                context.recordMetric("MessageEventTime", record.getEventTime().get().doubleValue());
            }
        }

        return null;
    }
}
