/*
    * Copyright 2006-2007 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.sample.domain.order.internal.valang;
  
  import java.math.BigDecimal;
  import java.util.List;
  
  import org.springframework.batch.sample.domain.order.LineItem;
  import org.springmodules.validation.valang.functions.AbstractFunction;
  import org.springmodules.validation.valang.functions.Function;
  
  
  /**
   * @author peter.zozom
   *
   */
  public class ValidateDiscountsFunction extends AbstractFunction {
      private static final BigDecimal BD_0 = new BigDecimal(0.0);
      private static final BigDecimal BD_PERC_MAX = new BigDecimal(100.0);
  
      public ValidateDiscountsFunction(Function[] arguments, int line, int column) {
          super(arguments, line, column);
          definedExactNumberOfArguments(1);
      }
  
      /**
       * @see org.springmodules.validation.valang.functions.AbstractFunction#doGetResult(java.lang.Object)
       */
      @SuppressWarnings("unchecked")
  	protected Object doGetResult(Object target) throws Exception {
          List<LineItem> lineItems = (List<LineItem>) getArguments()[0].getResult(target);
  
          for (LineItem item : lineItems) {
  
              if (BD_0.compareTo(item.getDiscountPerc()) != 0) {
                  //DiscountPerc must be between 0.0 and 100.0
                  if ((BD_0.compareTo(item.getDiscountPerc()) > 0)
                          || (BD_PERC_MAX.compareTo(item.getDiscountPerc()) < 0)
                          || (BD_0.compareTo(item.getDiscountAmount()) != 0)) { //only one of DiscountAmount and DiscountPerc should be non-zero
  
                      return Boolean.FALSE;
                  }
              } else {
                  //DiscountAmount must be between 0.0 and item.price
                  if ((BD_0.compareTo(item.getDiscountAmount()) > 0)
                          || (item.getPrice().compareTo(item.getDiscountAmount()) < 0)) {
                      return Boolean.FALSE;
                  }
              }
          }
  
          return Boolean.TRUE;
      }
  }