/*
    * $Id$
    *
    * 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.tiles.xmlDefinition;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import jakarta.servlet.ServletContext;
  import jakarta.servlet.ServletRequest;
  
  import org.apache.struts.tiles.ComponentDefinition;
  import org.apache.struts.tiles.DefinitionsFactoryException;
  import org.apache.struts.tiles.FactoryNotFoundException;
  import org.apache.struts.tiles.NoSuchDefinitionException;
  
  /**
   * Component Definitions factory.
   * This factory contains several factories identified by a key. The
   * getDefinition() method first looks for the factory key, retrieves or creates this
   * factory and then calls its getDefinition().
   */
  @SuppressWarnings("deprecation")
  public abstract class FactorySet implements org.apache.struts.tiles.ComponentDefinitionsFactory
  {
      private static final long serialVersionUID = -3005016733922480701L;
  
      /** Loaded factories */
    protected HashMap<Object, Object> factories = null;
  
    /**
     * Extract key that will be used to get the sub factory.
     * @param name Name of requested definition.
     * @param request Current servlet request.
     * @param servletContext Current servlet context.
     * @return Object.
     */
    abstract protected Object getDefinitionsFactoryKey(String name, ServletRequest request, ServletContext servletContext);
  
    /**
     * Get default factory.
     * @return Default factory.
     */
    abstract protected DefinitionsFactory getDefaultFactory();
  
    /**
     * Get a factory by its key.
     * If key is <code>null</code>, return defaultFactory.
     * Search in loaded factories. If not found, create factory and store return value in
     * loaded factories.
     * @param key Key of requested definition.
     * @param request Current servlet request.
     * @param servletContext Current servlet context.
     * @throws DefinitionsFactoryException If an error occur while creating factory.
     */
    protected DefinitionsFactory getFactory(Object key, ServletRequest request, ServletContext servletContext)
      throws DefinitionsFactoryException
    {
    if(key == null )
      return getDefaultFactory();
  
    Object factory = factories.get( key );
    if( factory == null )
      {
        // synchronize creation to avoid double creation by separate threads.
        // Also, check if factory hasn't been created while waiting for synchronized
        // section.
      synchronized(factories)
        {
        factory = factories.get( key );
        if( factory == null )
          {
          factory = createFactory( key, request, servletContext);
          factories.put( key, factory );
          } // end if
        } // end synchronized
      } // end if
    return (DefinitionsFactory)factory;
    }
  
    /**
    * Get a definition by its name.
    *
    * @param name Name of requested definition.
    * @param request Current servlet request.
    * @param servletContext Current servlet context.
    * @throws NoSuchDefinitionException No definition found for specified name
    * @throws DefinitionsFactoryException General exception
    */
   public ComponentDefinition getDefinition(String name, ServletRequest request, ServletContext servletContext)
     throws NoSuchDefinitionException, DefinitionsFactoryException
   {
   if( factories == null )
     throw new FactoryNotFoundException( "No definitions factory defined" );
 
   Object key = getDefinitionsFactoryKey( name, request, servletContext);
   DefinitionsFactory factory = getFactory( key, request, servletContext);
   return factory.getDefinition( name, request, servletContext );
   }
 
   /**
    * Create a factory for specified key.
    * This method is called by getFactory() when the requested factory doesn't already exist.
    * Must return a factory, or a default one.
    * Real implementation needs to provide this method.
    * @param key Key of requested definition.
    * @param request Current servlet request.
    * @param servletContext Current servlet context
    * @throws DefinitionsFactoryException If an error occur while creating factory.
    */
   abstract protected DefinitionsFactory createFactory(Object key, ServletRequest request, ServletContext servletContext)
           throws DefinitionsFactoryException;
 
   /**
    * Init factory set.
    * @param servletContext Current servlet context
    * @param properties properties used to initialized factory set;
    */
   abstract public void initFactory(ServletContext servletContext, Map<String, Object> properties)
     throws DefinitionsFactoryException;
 
   /**
    * Constructor.
    */
   public FactorySet()
   {
   factories = new HashMap<>();
   }
 
     /**
      * Return String representation.
      * @return String representation.
      */
   public String toString()
     {
     StringBuilder buff = new StringBuilder( "all FactorySet's factory : \n" );
     for (Object factory : factories.values())
       {
       buff.append( factory.toString() ).append("\n");
       }
     return buff.toString();
     }
 }