/*
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright (c) 2006 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.  All rights reserved.
 */

package org.pentaho.reporting.libraries.xmlns.parser;

import org.xml.sax.Attributes;

/**
 * A SAX-Attributes implementation that fixes missing namespace-URIs. Attributes that define no namespace URIs on
 * their own will receive the defined default namespace.
 *
 * @author Thomas Morgner
 */
public class FixNamespaceUriAttributes implements Attributes
{
  private Attributes attributes;
  private String defaultNSUri;

  /**
   * Creates a new FixNamespaceUriAttributes wrapper.
   *
   * @param defaultNSUri the default namespace that is used if no explicit namespace is defined for an attribute.
   * @param attributes   the original attributes.
   */
  public FixNamespaceUriAttributes(final String defaultNSUri,
                                   final Attributes attributes)
  {
    this.attributes = attributes;
    this.defaultNSUri = defaultNSUri;
  }

  /**
   * Return the number of attributes in the list.
   * <p/>
   * <p>Once you know the number of attributes, you can iterate through the
   * list.</p>
   *
   * @return The number of attributes in the list.
   * @see #getURI(int)
   * @see #getLocalName(int)
   * @see #getQName(int)
   * @see #getType(int)
   * @see #getValue(int)
   */
  public int getLength()
  {
    return attributes.getLength();
  }

  /**
   * Look up an attribute's Namespace URI by index.
   *
   * @param index The attribute index (zero-based).
   * @return The Namespace URI, or the empty string if none is available, or
   *         null if the index is out of range.
   * @see #getLength
   */
  public String getURI(final int index)
  {
    final String uri = attributes.getURI(index);
    if (uri == null || "".equals(uri))
    {
      return defaultNSUri;
    }
    return uri;
  }

  /**
   * Look up an attribute's local name by index.
   *
   * @param index The attribute index (zero-based).
   * @return The local name, or the empty string if Namespace processing is not
   *         being performed, or null if the index is out of range.
   * @see #getLength
   */
  public String getLocalName(final int index)
  {
    final String name = attributes.getLocalName(index);
    if (name == null || "".equals(name))
    {
      return attributes.getQName(index);
    }
    return name;
  }

  /**
   * Look up an attribute's XML qualified (prefixed) name by index.
   *
   * @param index The attribute index (zero-based).
   * @return The XML qualified name, or the empty string if none is available,
   *         or null if the index is out of range.
   * @see #getLength
   */
  public String getQName(final int index)
  {
    return attributes.getQName(index);
  }

  /**
   * Look up an attribute's type by index.
   * <p/>
   * <p>The attribute type is one of the strings "CDATA", "ID", "IDREF",
   * "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES", or "NOTATION"
   * (always in upper case).</p>
   * <p/>
   * <p>If the parser has not read a declaration for the attribute, or if the
   * parser does not report attribute types, then it must return the value
   * "CDATA" as stated in the XML 1.0 Recommendation (clause 3.3.3,
   * "Attribute-Value Normalization").</p>
   * <p/>
   * <p>For an enumerated attribute that is not a notation, the parser will
   * report the type as "NMTOKEN".</p>
   *
   * @param index The attribute index (zero-based).
   * @return The attribute's type as a string, or null if the index is out of
   *         range.
   * @see #getLength
   */
  public String getType(final int index)
  {
    return attributes.getType(index);
  }

  /**
   * Look up an attribute's value by index.
   * <p/>
   * <p>If the attribute value is a list of tokens (IDREFS, ENTITIES, or
   * NMTOKENS), the tokens will be concatenated into a single string with each
   * token separated by a single space.</p>
   *
   * @param index The attribute index (zero-based).
   * @return The attribute's value as a string, or null if the index is out of
   *         range.
   * @see #getLength
   */
  public String getValue(final int index)
  {
    return attributes.getValue(index);
  }

  /**
   * Look up the index of an attribute by Namespace name.
   *
   * @param uri       The Namespace URI, or the empty string if the name has no
   *                  Namespace URI.
   * @param localName The attribute's local name.
   * @return The index of the attribute, or -1 if it does not appear in the
   *         list.
   */
  public int getIndex(final String uri, final String localName)
  {
    final int idx = attributes.getIndex(uri, localName);
    if (idx >= 0)
    {
      return idx;
    }
    if (defaultNSUri.equals(uri))
    {
      final int index = attributes.getIndex("", localName);
      if (index != -1)
      {
        return index;
      }
      try
      {
        final int value2 = attributes.getIndex(null, localName);
        if (value2 != -1)
        {
          return value2;
        }
      }
      catch (Exception e)
      {
        // ignore. Heck, Xerces breaks the SAX-Specs so we have to take weird steps to mess around their mess.
      }

      return attributes.getIndex(localName);
    }
    return -1;
  }

  /**
   * Look up the index of an attribute by XML qualified (prefixed) name.
   *
   * @param qName The qualified (prefixed) name.
   * @return The index of the attribute, or -1 if it does not appear in the
   *         list.
   */
  public int getIndex(final String qName)
  {
    return attributes.getIndex(qName);
  }

  /**
   * Look up an attribute's type by Namespace name.
   * <p/>
   * <p>See {@link #getType(int) getType(int)} for a description of the possible
   * types.</p>
   *
   * @param uri       The Namespace URI, or the empty String if the name has no
   *                  Namespace URI.
   * @param localName The local name of the attribute.
   * @return The attribute type as a string, or null if the attribute is not in
   *         the list or if Namespace processing is not being performed.
   */
  public String getType(final String uri, final String localName)
  {
    final String type = attributes.getType(uri, localName);
    if (type != null)
    {
      return type;
    }
    if (defaultNSUri.equals(uri))
    {
      final String type1 = attributes.getType("", localName);
      if (type1 != null)
      {
        return type1;
      }
      try
      {
        final String value2 = attributes.getType(null, localName);
        if (value2 != null)
        {
          return value2;
        }
      }
      catch (Exception e)
      {
        // ignore. Heck, Xerces breaks the SAX-Specs so we have to take weird steps to mess around their mess.
      }

      return attributes.getType(localName);
    }
    return null;

  }

  /**
   * Look up an attribute's type by XML qualified (prefixed) name.
   * <p/>
   * <p>See {@link #getType(int) getType(int)} for a description of the possible
   * types.</p>
   *
   * @param qName The XML qualified name.
   * @return The attribute type as a string, or null if the attribute is not in
   *         the list or if qualified names are not available.
   */
  public String getType(final String qName)
  {
    return attributes.getType(qName);
  }

  /**
   * Look up an attribute's value by Namespace name.
   * <p/>
   * <p>See {@link #getValue(int) getValue(int)} for a description of the
   * possible values.</p>
   *
   * @param uri       The Namespace URI, or the empty String if the name has no
   *                  Namespace URI.
   * @param localName The local name of the attribute.
   * @return The attribute value as a string, or null if the attribute is not in
   *         the list.
   */
  public String getValue(final String uri, final String localName)
  {
    final String value = attributes.getValue(uri, localName);
    if (value != null)
    {
      return value;
    }
    if (defaultNSUri.equals(uri))
    {
      final String value1 = attributes.getValue("", localName);
      if (value1 != null)
      {
        return value1;
      }
      try
      {
        final String value2 = attributes.getValue(null, localName);
        if (value2 != null)
        {
          return value2;
        }
      }
      catch (Exception e)
      {
        // ignore. Heck, Xerces breaks the SAX-Specs so we have to take weird steps to mess around their mess.
      }
      return attributes.getValue(localName);
    }
    return null;

  }

  /**
   * Look up an attribute's value by XML qualified (prefixed) name.
   * <p/>
   * <p>See {@link #getValue(int) getValue(int)} for a description of the
   * possible values.</p>
   *
   * @param qName The XML qualified name.
   * @return The attribute value as a string, or null if the attribute is not in
   *         the list or if qualified names are not available.
   */
  public String getValue(final String qName)
  {
    return attributes.getValue(qName);
  }
}