/*
    * Copyright 2005 Philipp Erlacher
    *
    * 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.exolab.castor.xml.parsing.primitive.objects;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  import org.apache.commons.lang.StringUtils;
  
  /**
   * This class is part of the command pattern implementation to instantiate an
   * object. It is used as a command by the command invoker {@link PrimitiveObject}.
   * 
   * @author <a href="mailto:philipp DOT erlacher AT gmail DOT com">Philipp
   *         Erlacher</a>
   * 
   */
  class PrimitiveEnum extends PrimitiveObject {
  
      @Override
      public Object getObject(Class<?> type, String value) {
          if (StringUtils.isEmpty(value)) {
              return null;
          }
  
          // discover the fromValue Method
          try {
              Method valueOfMethod = type.getMethod("fromValue",
                      new Class[] { String.class });
              return valueOfMethod.invoke(null, new Object[] { value });
  
          } catch (NoSuchMethodException e) {
              // do nothing, check valueOf method
          } catch (IllegalArgumentException e) {
              throw new IllegalStateException(e.toString());
          } catch (IllegalAccessException e) {
              throw new IllegalStateException(e.toString());
          } catch (InvocationTargetException e) {
              if (e.getTargetException() instanceof RuntimeException) {
                  throw (RuntimeException) e.getTargetException();
              }
          }
  
          // backwards compability, check valueOf method to support
          // "simple" enums without value object
          try {
              Method valueOfMethod = type.getMethod("valueOf",
                      new Class[] { String.class });
              return valueOfMethod.invoke(null, new Object[] { value });
  
          } catch (IllegalAccessException e) {
              throw new IllegalStateException(e.toString());
          } catch (InvocationTargetException e) {
              if (e.getTargetException() instanceof RuntimeException) {
                  throw (RuntimeException) e.getTargetException();
              }
          } catch (NoSuchMethodException e) {
              String err = type.getName()
                      + " does not contain the required method: public static "
                      + type.getName() + " valueOf(String);";
              throw new IllegalArgumentException(err);
          }
  
          return value;
      }
  
  }