/*
 * 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.opennlp.ml.model;

import java.util.Iterator;

/**
 * Class which turns a sequence stream into an event stream. 
 *
 */
public class SequenceStreamEventStream implements EventStream {

  private Iterator<Sequence> sequenceIterator;
  int eventIndex = -1;
  Event[] events;
  
  public SequenceStreamEventStream(SequenceStream sequenceStream) {
    this.sequenceIterator = sequenceStream.iterator();
  }
  
  public boolean hasNext() {
    if (events != null && eventIndex < events.length) {
      return true;
    }
    else {
      if (sequenceIterator.hasNext()) {
        Sequence s = sequenceIterator.next();
        eventIndex = 0;
        events = s.getEvents();
        return true;
      }
      else {
        return false;
      }
    }
  }

  public Event next() {
    return events[eventIndex++];
  }

  public void remove() {
    throw new UnsupportedOperationException();
  }

}