/*
    * 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.lang3.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;
    }
  
  }