/*
    * $Id$
    *
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.struts.action;
  
  import java.io.Serializable;
  import java.lang.reflect.InvocationTargetException;
  import java.util.HashMap;
  
  import org.apache.commons.beanutils.DynaBean;
  import org.apache.commons.beanutils.DynaClass;
  import org.apache.commons.beanutils.DynaProperty;
  import org.apache.struts.config.FormBeanConfig;
  import org.apache.struts.config.FormPropertyConfig;
  import org.apache.struts.util.RequestUtils;
  
  /**
   * <p>Implementation of <code>DynaClass</code> for <code>DynaActionForm</code>
   * classes that allow developers to define ActionForms without having to
   * individually code all of the classes. <strong>NOTE</strong> - This class is
   * only used in the internal implementation of dynamic action form beans.
   * Application developers never need to consult this documentation.</p>
   *
   * @version $Rev$ $Date: 2006-01-17 07:26:20 -0500 (Tue, 17 Jan 2006)
   *          $
   * @since Struts 1.1
   */
  public class DynaActionFormClass implements DynaClass, Serializable {
      private static final long serialVersionUID = -2521119905360425245L;
  
      // ----------------------------------------------------- Instance Variables
  
      /**
       * <p>The <code>DynaActionForm</code> implementation <code>Class</code>
       * which we will use to create new bean instances.</p>
       */
      protected transient Class<? extends DynaActionForm> beanClass = null;
  
      /**
       * <p>The form bean configuration information for this class.</p>
       */
      protected FormBeanConfig config = null;
  
      /**
       * <p>The "dynamic class name" for this <code>DynaClass</code>.</p>
       */
      protected String name = null;
  
      /**
       * <p>The set of dynamic properties that are part of this DynaClass.</p>
       */
      protected DynaProperty[] properties = null;
  
      /**
       * <p>The set of dynamic properties that are part of this
       * <code>DynaClass</code>, keyed by the property name.  Individual
       * descriptor instances will be the same instances as those in the
       * <code>properties</code> list.
       */
      protected HashMap<String, DynaProperty> propertiesMap = new HashMap<>();
  
      // ----------------------------------------------------------- Constructors
  
      /**
       * <p>Construct a new <code>DynaActionFormClass</code> for the specified
       * form bean configuration.  This constructor is private;
       * <code>DynaActionFormClass</code> instances will be created as needed
       * via calls to the static <code>createDynaActionFormClass()</code>
       * method.</p>
       *
       * @param config The FormBeanConfig instance describing the properties of
       *               the bean to be created
       * @throws IllegalArgumentException if the bean implementation class
       *                                  specified in the configuration is not
       *                                  DynaActionForm (or a subclass of
       *                                  DynaActionForm)
       */
      public DynaActionFormClass(FormBeanConfig config) {
          introspect(config);
      }
  
      // ------------------------------------------------------ DynaClass Methods
 
     /**
      * <p>Return the name of this <code>DynaClass</code> (analogous to the
      * <code>getName()</code> method of <code>java.lang.Class</code>, which
      * allows the same <code>DynaClass</code> implementation class to support
      * different dynamic classes, with different sets of properties.
      *
      * @return The name of this <code>DynaClass</code>.
      */
     public String getName() {
         return (this.name);
     }
 
     /**
      * <p>Return a property descriptor for the specified property, if it
      * exists; otherwise, return <code>null</code>.</p>
      *
      * @param name Name of the dynamic property for which a descriptor is
      *             requested
      * @return A property descriptor for the specified property.
      * @throws IllegalArgumentException if no property name is specified
      */
     public DynaProperty getDynaProperty(String name) {
         if (name == null) {
             throw new IllegalArgumentException("No property name specified");
         }
 
         return (propertiesMap.get(name));
     }
 
     /**
      * <p>Return an array of <code>DynaProperty</code>s for the properties
      * currently defined in this <code>DynaClass</code>.  If no properties are
      * defined, a zero-length array will be returned.</p>
      *
      * @return An array of property instances for this class.
      */
     public DynaProperty[] getDynaProperties() {
         return (properties);
 
         // :FIXME: Should we really be implementing
         // getBeanInfo instead, which returns property descriptors
         // and a bunch of other stuff?
     }
 
     /**
      * <p>Instantiate and return a new {@link DynaActionForm} instance,
      * associated with this <code>DynaActionFormClass</code>.  The properties
      * of the returned {@link DynaActionForm} will have been initialized to
      * the default values specified in the form bean configuration
      * information.</p>
      *
      * @return A new {@link DynaActionForm} instance.
      * @throws IllegalAccessException if the Class or the appropriate
      *                                constructor is not accessible
      * @throws InstantiationException if this Class represents an abstract
      *                                class, an array class, a primitive type,
      *                                or void; or if instantiation fails for
      *                                some other reason
      */
     public DynaBean newInstance()
             throws IllegalAccessException, InstantiationException {
 
         DynaActionForm dynaBean;
         try {
             dynaBean = getBeanClass().getDeclaredConstructor().newInstance();
         } catch (IllegalArgumentException | InvocationTargetException
                 | NoSuchMethodException | SecurityException e) {
             InstantiationException e2 = new InstantiationException(
                 "Error creating DynaActionForm instance of type "
                 + getBeanClass());
             e2.initCause(e);
             throw e2;
         }
 
         dynaBean.setDynaActionFormClass(this);
 
         FormPropertyConfig[] props = config.findFormPropertyConfigs();
 
         for (int i = 0; i < props.length; i++) {
             dynaBean.set(props[i].getName(), props[i].initial());
         }
 
         return (dynaBean);
     }
 
     // --------------------------------------------------------- Public Methods
 
     /**
      * <p>Render a <code>String</code> representation of this object.</p>
      *
      * @return The string representation of this instance.
      */
     public String toString() {
         StringBuilder sb = new StringBuilder("DynaActionFormBean[name=");
 
         sb.append(name);
 
         DynaProperty[] props = getDynaProperties();
 
         if (props == null) {
             props = new DynaProperty[0];
         }
 
         for (int i = 0; i < props.length; i++) {
             sb.append(',');
             sb.append(props[i].getName());
             sb.append('/');
             sb.append(props[i].getType());
         }
 
         sb.append("]");
 
         return (sb.toString());
     }
 
     // --------------------------------------------------------- Static Methods
 
     /**
      * Return the <code>DynaActionFormClass</code> instance for the specified
      * form bean configuration instance.
      *
      * @param config The config for which the class should be created.
      * @return The instance for the specified form bean config.
      */
     public static DynaActionFormClass createDynaActionFormClass(
         FormBeanConfig config) {
         return config.getDynaActionFormClass();
     }
 
     // ------------------------------------------------------ Protected Methods
 
     /**
      * <p>Return the implementation class we are using to construct new
      * instances, re-introspecting our {@link FormBeanConfig} if necessary
      * (that is, after being deserialized, since <code>beanClass</code> is
      * marked transient).</p>
      *
      * @return The implementation class used to construct new instances.
      */
     protected Class<? extends DynaActionForm> getBeanClass() {
         if (beanClass == null) {
             introspect(config);
         }
 
         return (beanClass);
     }
 
     /**
      * <p>Introspect our form bean configuration to identify the supported
      * properties.</p>
      *
      * @param config The FormBeanConfig instance describing the properties of
      *               the bean to be created
      * @throws IllegalArgumentException if the bean implementation class
      *                                  specified in the configuration is not
      *                                  DynaActionForm (or a subclass of
      *                                  DynaActionForm)
      */
     protected void introspect(FormBeanConfig config) {
         this.config = config;
 
         // Validate the ActionFormBean implementation class
         final Class<?> clazz;
         try {
             clazz = RequestUtils.applicationClass(config.getType());
         } catch (Throwable t) {
             IllegalArgumentException t2 = new IllegalArgumentException(
                 "Cannot instantiate ActionFormBean class '" + config.getType()
                 + "'");
             t2.initCause(t);
             throw t2;
         }
 
         if (!DynaActionForm.class.isAssignableFrom(clazz)) {
             throw new IllegalArgumentException("Class '" + config.getType()
                 + "' is not a subclass of "
                 + "'org.apache.struts.action.DynaActionForm'");
         }
         beanClass = clazz.asSubclass(DynaActionForm.class);
 
         // Set the name we will know ourselves by from the form bean name
         this.name = config.getName();
 
         // Look up the property descriptors for this bean class
         FormPropertyConfig[] descriptors = config.findFormPropertyConfigs();
 
         if (descriptors == null) {
             descriptors = new FormPropertyConfig[0];
         }
 
         // Create corresponding dynamic property definitions
         properties = new DynaProperty[descriptors.length];
 
         for (int i = 0; i < descriptors.length; i++) {
             properties[i] =
                 new DynaProperty(descriptors[i].getName(),
                     descriptors[i].getTypeClass());
             propertiesMap.put(properties[i].getName(), properties[i]);
         }
     }
 
     // -------------------------------------------------------- Private Methods
 }