/*
    * Copyright 2006-2013 the original author or authors.
    *
    * Licensed 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.springframework.batch.core;
  
  import java.io.Serializable;
  import java.util.Date;
  
  /**
   * Domain representation of a parameter to a batch job. Only the following types
   * can be parameters: String, Long, Date, and Double.
   *
   * @author Lucas Ward
   * @author Dave Syer
   * @since 2.0
   *
   */
  @SuppressWarnings("serial")
  public class JobParameter implements Serializable {
  
  	private final Object parameter;
  
  	private final ParameterType parameterType;
  
  	/**
  	 * Construct a new JobParameter as a String.
  	 */
  	public JobParameter(String parameter) {
  		this.parameter = parameter;
  		parameterType = ParameterType.STRING;
  	}
  
  	/**
  	 * Construct a new JobParameter as a Long.
  	 *
  	 * @param parameter
  	 */
  	public JobParameter(Long parameter) {
  		this.parameter = parameter;
  		parameterType = ParameterType.LONG;
  	}
  
  	/**
  	 * Construct a new JobParameter as a Date.
  	 *
  	 * @param parameter
  	 */
  	public JobParameter(Date parameter) {
  		this.parameter = parameter;
  		parameterType = ParameterType.DATE;
  	}
  
  	/**
  	 * Construct a new JobParameter as a Double.
  	 *
  	 * @param parameter
  	 */
  	public JobParameter(Double parameter) {
  		this.parameter = parameter;
  		parameterType = ParameterType.DOUBLE;
  	}
  
  	/**
  	 * @return the value contained within this JobParameter.
  	 */
  	public Object getValue() {
  
  		if (parameter != null && parameter.getClass().isInstance(Date.class)) {
  			return new Date(((Date) parameter).getTime());
  		}
  		else {
  			return parameter;
  		}
  	}
  
  	/**
  	 * @return a ParameterType representing the type of this parameter.
  	 */
  	public ParameterType getType() {
  		return parameterType;
  	}
  
  	@Override
  	public boolean equals(Object obj) {
  		if (obj instanceof JobParameter == false) {
  			return false;
 		}
 
 		if (this == obj) {
 			return true;
 		}
 
 		JobParameter rhs = (JobParameter) obj;
 		return parameter==null ? rhs.parameter==null && parameterType==rhs.parameterType: parameter.equals(rhs.parameter);
 	}
 
 	@Override
 	public String toString() {
 		return parameter == null ? null : (parameterType == ParameterType.DATE ? "" + ((Date) parameter).getTime()
 				: parameter.toString());
 	}
 
 	@Override
 	public int hashCode() {
 		return 7 + 21 * (parameter == null ? parameterType.hashCode() : parameter.hashCode());
 	}
 
 	/**
 	 * Enumeration representing the type of a JobParameter.
 	 */
 	public enum ParameterType {
 
 		STRING, DATE, LONG, DOUBLE;
 	}
 }