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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  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.  For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.abdera.factory;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.abdera.model.Base;
import org.apache.abdera.model.Document;
import org.apache.abdera.model.Element;

/**
 * A utility implementation of ExtensionFactory used internally by Abdera.
 * It maintains the collection ExtensionFactory instances discovered on 
 * the classpath and a cache of Internal-Wrapper mappings.
 */
public class ExtensionFactoryMap 
  implements ExtensionFactory {

  private final List factories;
  
  public ExtensionFactoryMap(List factories) {
    this.factories = Collections.synchronizedList(factories);
  }

  @SuppressWarnings("unchecked")
  public  T getElementWrapper(Element internal) {
    if (internal == null) return null;
    T t = null;
    synchronized(factories) {
      for (ExtensionFactory factory : factories) {
        t = (T) factory.getElementWrapper(internal);
        if (t != null && t != internal) {
          return t;
        }
      }
    }
    return (t != null) ? t : (T)internal;
  }
  
  public String[] getNamespaces() {
    List ns = new ArrayList();
    synchronized(factories) {
      for (ExtensionFactory factory : factories) {
        String[] namespaces = factory.getNamespaces();
        for (String uri : namespaces) {
          if (!ns.contains(uri)) ns.add(uri);
        }
      }
    }
    return ns.toArray(new String[ns.size()]);
  }

  public boolean handlesNamespace(String namespace) {
    synchronized(factories) {
      for (ExtensionFactory factory : factories) {
        if (factory.handlesNamespace(namespace)) return true;
      }
    }
    return false;
  }
  
  public ExtensionFactoryMap addFactory(ExtensionFactory factory) {
    if (!factories.contains(factory))
      factories.add(factory);
    return this;
  }

  public  String getMimeType(T base) {
    Element element = base instanceof Element ? (Element)base : ((Document)base).getRoot();
    String namespace = element.getQName().getNamespaceURI();
    synchronized(factories) {
      for (ExtensionFactory factory : factories) {
        if (factory.handlesNamespace(namespace)) 
          return factory.getMimeType(base);
      }
    }
    return null;
  }
  
  public String[] listExtensionFactories() {
    List names = new ArrayList();
    synchronized(factories) {
      for (ExtensionFactory factory : factories) {
        String name = factory.getClass().getName();
        if (!names.contains(name)) names.add(name);
      }
    }
    return names.toArray(new String[names.size()]);
  }
}