/*
    * Copyright 2011 FatWire Corporation. All Rights Reserved.
    *
    * 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 com.fatwire.gst.foundation.controller.action.support;
  
  import java.lang.reflect.Constructor;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.logging.Log;
  
  import COM.FutureTense.Interfaces.ICS;
  
  import com.fatwire.gst.foundation.controller.action.Factory;
  import com.fatwire.gst.foundation.controller.action.FactoryProducer;
  import com.fatwire.gst.foundation.facade.logging.LogUtil;
  
  /**
   * Producer for a {@link Factory} that makes use of reflection to construct the
   * Factory.
   * 
   * @author Dolf.Dijkstra
   * 
   */
  public class ReflectionFactoryProducer implements FactoryProducer {
      protected static final Log LOG = LogUtil.getLog(ReflectionFactoryProducer.class);
      private Constructor<Factory> constructor;
  
      public Factory getFactory(final ICS ics) {
          Factory factory = null;
          try {
              factory = getInjectionFactory(ics);
          } catch (final Exception e) {
              LOG.warn(e);
          }
          if (factory == null) {
              factory = new IcsBackedObjectFactoryTemplate(ics);
          }
          return factory;
      }
  
      public final Factory getInjectionFactory(final ICS ics) throws Exception {
          Factory factory = null;
          if (constructor != null) {
              factory = constructor.newInstance(ics);
          }
          return factory;
      }
  
      @SuppressWarnings("unchecked")
      private void findConstructor(final String factoryClassname) throws ClassNotFoundException, NoSuchMethodException,
              SecurityException {
          if (StringUtils.isNotBlank(factoryClassname)) {
              final Class<Factory> c = (Class<Factory>) Class.forName(factoryClassname);
              constructor = c.getConstructor(ICS.class);
          } else {
              throw new IllegalArgumentException("factoryClassname cannot be blank.");
          }
      }
  
      /**
       * @param factoryClassname the factoryClassname to set
       */
      public void setFactoryClassname(final String factoryClassname) {
          try {
              findConstructor(factoryClassname);
          } catch (final RuntimeException e) {
              throw e;
          } catch (final Exception e) {
              throw new IllegalArgumentException("factoryClassname: " + factoryClassname + " is illegal. "
                      + e.getMessage(), e);
          }
      }
  }