// XCatalogReader.java - Read XML Catalog files

/*
 * 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.xml.resolver.readers;

import java.util.Vector;
import org.apache.xml.resolver.Catalog;
import org.apache.xml.resolver.CatalogEntry;
import org.apache.xml.resolver.CatalogException;
import org.apache.xml.resolver.helpers.PublicId;

import org.xml.sax.*;

import javax.xml.parsers.*;

/**
 * Parse "XCatalog" XML Catalog files, this is the XML Catalog format
 * developed by John Cowan and supported by Apache.
 *
 * @see Catalog
 *
 * @author Norman Walsh
 * <a href="mailto:Norman.Walsh@Sun.COM">Norman.Walsh@Sun.COM</a>
 *
 * @version 1.0
 */
public class XCatalogReader extends SAXCatalogReader implements SAXCatalogParser {
  /** The catalog object needs to be stored by the object so that
   * SAX callbacks can use it.
   */
  protected Catalog catalog = null;

  /** Set the current catalog. */
  public void setCatalog (Catalog catalog) {
    this.catalog = catalog;
    debug = catalog.getCatalogManager().debug;
  }

  /** Get the current catalog. */
  public Catalog getCatalog () {
    return catalog;
  }

  /** Default constructor */
  public XCatalogReader() {
    super();
  }

  /** Constructor allowing for providing custom SAX parser factory */
  public XCatalogReader(SAXParserFactory parserFactory, Catalog catalog) {
    super(parserFactory);
    setCatalog(catalog);
  }

  // ----------------------------------------------------------------------
  // Implement the SAX ContentHandler interface

  /** The SAX <code>setDocumentLocator</code> method does nothing. */
  public void setDocumentLocator (Locator locator) {
    return;
  }

  /** The SAX <code>startDocument</code> method does nothing. */
  public void startDocument ()
    throws SAXException {
    return;
  }

  /** The SAX <code>endDocument</code> method does nothing. */
  public void endDocument ()
    throws SAXException {
    return;
  }

  /**
   * The SAX <code>startElement</code> method recognizes elements
   * from the plain catalog format and instantiates CatalogEntry
   * objects for them.
   *
   * @param namespaceURI The namespace name of the element.
   * @param localName The local name of the element.
   * @param qName The QName of the element.
   * @param atts The list of attributes on the element.
   *
   * @see CatalogEntry
   */
  public void startElement (String namespaceURI,
			    String localName,
			    String qName,
			    Attributes atts)
    throws SAXException {

    int entryType = -1;
    Vector entryArgs = new Vector();

    if (localName.equals("Base")) {
      entryType = catalog.BASE;
      entryArgs.add(atts.getValue("HRef"));

      debug.message(4, "Base", atts.getValue("HRef"));
    } else if (localName.equals("Delegate")) {
      entryType = catalog.DELEGATE_PUBLIC;
      entryArgs.add(atts.getValue("PublicID"));
      entryArgs.add(atts.getValue("HRef"));

      debug.message(4, "Delegate",
		    PublicId.normalize(atts.getValue("PublicID")),
		    atts.getValue("HRef"));
    } else if (localName.equals("Extend")) {
      entryType = catalog.CATALOG;
      entryArgs.add(atts.getValue("HRef"));

      debug.message(4, "Extend", atts.getValue("HRef"));
    } else if (localName.equals("Map")) {
      entryType = catalog.PUBLIC;
      entryArgs.add(atts.getValue("PublicID"));
      entryArgs.add(atts.getValue("HRef"));

      debug.message(4, "Map",
		    PublicId.normalize(atts.getValue("PublicID")),
		    atts.getValue("HRef"));
    } else if (localName.equals("Remap")) {
      entryType = catalog.SYSTEM;
      entryArgs.add(atts.getValue("SystemID"));
      entryArgs.add(atts.getValue("HRef"));

      debug.message(4, "Remap",
		    atts.getValue("SystemID"),
		    atts.getValue("HRef"));
    } else if (localName.equals("XCatalog")) {
      // nop, start of catalog
    } else {
      // This is equivalent to an invalid catalog entry type
      debug.message(1, "Invalid catalog entry type", localName);
    }

    if (entryType >= 0) {
      try {
	CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
	catalog.addEntry(ce);
      } catch (CatalogException cex) {
	if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
	  debug.message(1, "Invalid catalog entry type", localName);
	} else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
	  debug.message(1, "Invalid catalog entry", localName);
	}
      }
    }
  }

  /** The SAX <code>endElement</code> method does nothing. */
  public void endElement (String namespaceURI,
			  String localName,
			  String qName)
    throws SAXException {
    return;
  }

  /** The SAX <code>characters</code> method does nothing. */
  public void characters (char ch[], int start, int length)
    throws SAXException {
    return;
  }

  /** The SAX <code>ignorableWhitespace</code> method does nothing. */
  public void ignorableWhitespace (char ch[], int start, int length)
    throws SAXException {
    return;
  }

  /** The SAX <code>processingInstruction</code> method does nothing. */
  public void processingInstruction (String target, String data)
    throws SAXException {
    return;
  }

  /** The SAX <code>skippedEntity</code> method does nothing. */
  public void skippedEntity (String name)
    throws SAXException {
    return;
  }

  /** The SAX <code>startPrefixMapping</code> method does nothing. */
  public void startPrefixMapping(String prefix, String uri)
    throws SAXException {
    return;
  }

  /** The SAX <code>endPrefixMapping</code> method does nothing. */
  public void endPrefixMapping(String prefix)
    throws SAXException {
    return;
  }

}
