/**
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 1999-2004 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */

package org.exolab.castor.xml.schema.reader;

import org.exolab.castor.net.URILocation;
import org.exolab.castor.net.URIResolver;
import org.exolab.castor.xml.AttributeSet;
import org.exolab.castor.xml.XMLException;
import org.exolab.castor.xml.schema.Schema;
import org.exolab.castor.xml.schema.SchemaContext;
import org.exolab.castor.xml.schema.SchemaException;
import org.exolab.castor.xml.schema.SchemaNames;
import org.xml.sax.Locator;
import org.xml.sax.Parser;

/**
 * A simple unmarshaller to read included schemas. Included schemas can be cached in the original
 * parent Schema or can be inlined in that same XML Schema as recommended by the XML Schema
 * specification.
 * 
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @author <a href="mailto:blandin@intalio.com">Arnaud Blandin</a>
 * @version $Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
 **/
public class IncludeUnmarshaller extends ComponentReader {


  public IncludeUnmarshaller(final SchemaContext schemaContext, final Schema schema,
      final AttributeSet atts, final URIResolver uriResolver, final Locator locator,
      final SchemaUnmarshallerState state) throws XMLException {
    super(schemaContext);

    setURIResolver(uriResolver);
    URILocation uri = null;
    // -- Get schemaLocation
    String include = atts.getValue("schemaLocation");
    if (include == null)
      throw new SchemaException("'schemaLocation' attribute missing on 'include'");

    if (include.indexOf("\\") != -1) {
      String err = include + " is not a valid URI as defined by IETF RFC 2396.";
      err += "The URI must not contain '\\'.";
      throw new SchemaException(err);
    }

    uri = derive(locator, include);
    if (uri != null)
      include = uri.getAbsoluteURI();

    // -- Has this schema location been included yet?
    if (schema.includeProcessed(include)) {
      return;
    } else if (include.equals(schema.getSchemaLocation())) {
      return;
    }

    Schema includedSchema = null;
    boolean alreadyLoaded = false;

    // -- caching is on
    if (state.cacheIncludedSchemas) {
      if (uri instanceof SchemaLocation) {
        includedSchema = ((SchemaLocation) uri).getSchema();
        schema.cacheIncludedSchema(includedSchema);
        alreadyLoaded = true;
      }
      // -- Have we already imported this XML Schema file?
      if (state.processed(include)) {
        includedSchema = state.getSchema(include);
        schema.cacheIncludedSchema(includedSchema);
        alreadyLoaded = true;
      }
    }

    if (includedSchema == null) {
      includedSchema = new Schema();
    } else {
      state.markAsProcessed(include, includedSchema);
    }

    // -- keep track of the schemaLocation
    schema.addInclude(include);

    if (alreadyLoaded) {
      return;
    }

    Parser parser = createParser("include");

    SchemaUnmarshaller schemaUnmarshaller =
        new SchemaUnmarshaller(getSchemaContext(), true, state, getURIResolver());

    if (state.cacheIncludedSchemas) {
      schemaUnmarshaller.setSchema(includedSchema);
    } else {
      schemaUnmarshaller.setSchema(schema);
    }

    parseSchema(parser, schemaUnmarshaller, uri, include, "include");

    if (state.cacheIncludedSchemas) {
      String ns = includedSchema.getTargetNamespace();
      if (ns == null || ns == "")
        includedSchema.setTargetNamespace(schema.getTargetNamespace());
      else if (!ns.equals(schema.getTargetNamespace()))
        throw new SchemaException(
            "The target namespace of the included components must be the same as the target namespace of the including schema");
      schema.cacheIncludedSchema(includedSchema);
    }
  }


  /**
   * Sets the name of the element that this UnknownUnmarshaller handles
   **/
  public String elementName() {
    return SchemaNames.INCLUDE;
  }

  /**
   * Returns the Object created by this ComponentReader
   * 
   * @return the Object created by this ComponentReader
   **/
  public Object getObject() {
    return null;
  }

}
