/*
    * 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.myfaces.view.facelets.tag;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import javax.faces.view.facelets.TagAttribute;
  import javax.faces.view.facelets.TagAttributes;
  
  /**
   * A set of TagAttributes, usually representing all attributes on a Tag.
   * 
   * TODO: PROFILE - Explore the possibility of using HashMap instead of sorted arrays. 
   *       The footprint should be higher, but the instanciation and access speed should be faster 
   *       Instanciation: from O(n log n) to O(1)
   *       Access: from O(log n) to O(1)
   * 
   * @see org.apache.myfaces.view.facelets.tag.Tag
   * @see org.apache.myfaces.view.facelets.tag.TagAttributeImpl
   * @author Jacob Hookom
   * @version $Id$
   */
  public final class TagAttributesImpl extends TagAttributes
  {
      private final static TagAttribute[] EMPTY = new TagAttribute[0];
  
      private final TagAttribute[] _attributes;
  
      private final String[] _namespaces;
  
      private final List<TagAttribute[]> _nsattrs;
  
      /**
       * 
       */
      public TagAttributesImpl(TagAttribute[] attrs)
      {
          _attributes = attrs;
  
          // grab namespaces
          Set<String> set = new HashSet<String>();
          for (TagAttribute attribute : _attributes)
          {
              set.add(attribute.getNamespace());
          }
          
          _namespaces = set.toArray(new String[set.size()]);
          Arrays.sort(_namespaces);
  
          // assign attrs
          int size = _namespaces.length;
          List<List<TagAttribute>> temp = new ArrayList<List<TagAttribute>>(size);
          for (int i = 0; i < size; i++)
          {
              temp.add(new ArrayList<TagAttribute>());
          }
          
          for (TagAttribute attribute : _attributes)
          {
              temp.get(Arrays.binarySearch(_namespaces, attribute.getNamespace())).add(attribute);
          }
          
          _nsattrs = new ArrayList<TagAttribute[]>(size);
          for (int i = 0; i < size; i++)
          {
              List<TagAttribute> l = temp.get(i);
              _nsattrs.add(l.toArray(new TagAttribute[l.size()]));
          }
      }
  
      /**
       * Return an array of all TagAttributes in this set
       * 
       * @return a non-null array of TagAttributes
       */
      public TagAttribute[] getAll()
      {
          return _attributes;
      }
 
     /**
      * Using no namespace, find the TagAttribute
      * 
      * @see #get(String, String)
      * @param localName
      *            tag attribute name
      * @return the TagAttribute found, otherwise null
      */
     public TagAttribute get(String localName)
     {
         return get("", localName);
     }
 
     /**
      * Find a TagAttribute that matches the passed namespace and local name.
      * 
      * @param ns
      *            namespace of the desired attribute
      * @param localName
      *            local name of the attribute
      * @return a TagAttribute found, otherwise null
      */
     public TagAttribute get(String ns, String localName)
     {
         if (ns != null && localName != null)
         {
             int idx = Arrays.binarySearch(_namespaces, ns);
             if (idx >= 0)
             {
                 for (TagAttribute attribute : _nsattrs.get(idx))
                 {
                     if (localName.equals(attribute.getLocalName()))
                     {
                         return attribute;
                     }
                 }
             }
         }
         
         return null;
     }
 
     /**
      * Get all TagAttributes for the passed namespace
      * 
      * @param namespace
      *            namespace to search
      * @return a non-null array of TagAttributes
      */
     public TagAttribute[] getAll(String namespace)
     {
         int idx = 0;
         if (namespace == null)
         {
             idx = Arrays.binarySearch(_namespaces, "");
         }
         else
         {
             idx = Arrays.binarySearch(_namespaces, namespace);
         }
         
         if (idx >= 0)
         {
             return _nsattrs.get(idx);
         }
         
         return EMPTY;
     }
 
     /**
      * A list of Namespaces found in this set
      * 
      * @return a list of Namespaces found in this set
      */
     public String[] getNamespaces()
     {
         return _namespaces;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString()
     {
         StringBuffer sb = new StringBuffer();
         for (TagAttribute attribute : _attributes)
         {
             sb.append(attribute);
             sb.append(' ');
         }
         
         if (sb.length() > 1)
         {
             sb.setLength(sb.length() - 1);
         }
         
         return sb.toString();
     }
 }