/*
 * 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.solr.client.solrj.io.eval;

import java.io.IOException;
import java.util.UUID;

import org.apache.solr.client.solrj.io.Tuple;
import org.apache.solr.client.solrj.io.stream.expr.Explanation;
import org.apache.solr.client.solrj.io.stream.expr.Explanation.ExpressionType;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionParameter;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;

public class UuidEvaluator extends SimpleEvaluator {
  protected static final long serialVersionUID = 1L;

  public UuidEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{
    // no parameters are used
  }

  @Override
  public UUID evaluate(Tuple tuple) throws IOException {
    return UUID.randomUUID();
  }

  @Override
  public StreamExpressionParameter toExpression(StreamFactory factory) throws IOException {
    return new StreamExpression(factory.getFunctionName(getClass()));
  }

  @Override
  public Explanation toExplanation(StreamFactory factory) throws IOException {
    return new Explanation(nodeId.toString())
      .withExpressionType(ExpressionType.EVALUATOR)
      .withImplementingClass(getClass().getName())
      .withExpression(toExpression(factory).toString());
  }

}