/*
 * 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.streampipes.processors.filters.jvm.processor.merge;

import org.apache.streampipes.model.runtime.Event;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public class StreamBuffer {
  private String timestampProperty;
  private List<Event> buffer;

  public StreamBuffer(String timestampProperty) {
    buffer = new LinkedList<>();
    this.timestampProperty = timestampProperty;
  }

  public void add(Event event) {
    buffer.add(event);
  }

  public int getLength() {
    return buffer.size();
  }

  public List<Event> getList() {
    return this.buffer;
  }

  public Event get(int i) {
    return this.buffer.get(i);
  }

  public void removeOldEvents(long timestamp) {
    Iterator itr = this.buffer.iterator();
    while (itr.hasNext()) {
      Event e = (Event) itr.next();
      if (e.getFieldBySelector(timestampProperty).getAsPrimitive().getAsLong() <= timestamp) {
        itr.remove();
      }
    }
  }

  public void reset() {
    this.buffer = new LinkedList<>();
  }
}
