/* 
 * 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.
 */

using System;

namespace Lucene.Net.Search.Payloads
{
	
	
	/// <summary> Returns the maximum payload score seen, else 1 if there are no payloads on the doc.
	/// <p/>
	/// Is thread safe and completely reusable.
	/// 
	/// 
	/// </summary>
	[Serializable]
	public class MaxPayloadFunction:PayloadFunction
	{
		public override float CurrentScore(int docId, System.String field, int start, int end, int numPayloadsSeen, float currentScore, float currentPayloadScore)
		{
            if (numPayloadsSeen == 0)
            {
                return currentPayloadScore;
            }
            else
            {
                return System.Math.Max(currentPayloadScore, currentScore);
            }
		}
		
		public override float DocScore(int docId, System.String field, int numPayloadsSeen, float payloadScore)
		{
			return numPayloadsSeen > 0?payloadScore:1;
		}
		
		public override int GetHashCode()
		{
			int prime = 31;
			int result = 1;
			result = prime * result + this.GetType().GetHashCode();
			return result;
		}
		
		public  override bool Equals(System.Object obj)
		{
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (GetType() != obj.GetType())
				return false;
			return true;
		}
	}
}