/**
 * 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 1999-2002 (C) Intalio Inc. All Rights Reserved.
 *
 * $Id$
 */

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

import org.exolab.castor.xml.AttributeSet;
import org.exolab.castor.xml.Namespaces;
import org.exolab.castor.xml.XMLException;
import org.exolab.castor.xml.schema.Annotation;
import org.exolab.castor.xml.schema.AttributeDecl;
import org.exolab.castor.xml.schema.AttributeGroup;
import org.exolab.castor.xml.schema.AttributeGroupDecl;
import org.exolab.castor.xml.schema.AttributeGroupReference;
import org.exolab.castor.xml.schema.SchemaContext;
import org.exolab.castor.xml.schema.Schema;
import org.exolab.castor.xml.schema.SchemaException;
import org.exolab.castor.xml.schema.SchemaNames;
import org.exolab.castor.xml.schema.Wildcard;

/**
 * A class for Unmarshalling AttributeGroups
 * 
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2005-12-13 14:58:48 -0700 (Tue, 13 Dec 2005) $
 **/
public class AttributeGroupUnmarshaller extends ComponentReader {


  // --------------------/
  // - Member Variables -/
  // --------------------/

  /**
   * The current ComponentReader
   **/
  private ComponentReader unmarshaller;

  /**
   * The current branch depth
   **/
  private int depth = 0;

  /**
   * The AttributeGroup we are constructing
   **/
  private AttributeGroup _attributeGroup = null;

  private boolean allowAnnotation = true;
  private boolean foundAnyAttribute = false;
  private boolean isRef = false;

  private Schema _schema = null;

  // ----------------/
  // - Constructors -/
  // ----------------/

  /**
   * Creates a new AttributeGroupUnmarshaller.
   * 
   * @param schemaContext the schema context to get some configuration settings from
   * @param schema the Schema to which the AttributeGroup belongs
   * @param atts the AttributeList
   **/
  public AttributeGroupUnmarshaller(final SchemaContext schemaContext, final Schema schema,
      final AttributeSet atts) throws XMLException {
    super(schemaContext);
    this._schema = schema;


    String ref = atts.getValue(SchemaNames.REF_ATTR);
    if (ref != null) {
      if (ref.length() > 0) {
        isRef = true;
        _attributeGroup = new AttributeGroupReference(schema, ref);
      } else {
        String err = "The value of the '" + SchemaNames.REF_ATTR
            + "' attribute for attribute group must contain a " + "valid value.";
        throw new SchemaException(err);
      }
    } else {
      AttributeGroupDecl attDecl = new AttributeGroupDecl(schema);
      _attributeGroup = attDecl;

      // -- handle attributes
      attDecl.setName(atts.getValue(SchemaNames.NAME_ATTR));
      attDecl.setId(atts.getValue(SchemaNames.ID_ATTR));
    }



  } // -- AttributeGroupUnmarshaller

  // -----------/
  // - Methods -/
  // -----------/

  /**
   * Returns the name of the element that this ComponentReader handles
   * 
   * @return the name of the element that this ComponentReader handles
   **/
  public String elementName() {
    return SchemaNames.ATTRIBUTE_GROUP;
  } // -- elementName

  /**
   * Returns the AttributeGroup created by this AttributeGroupUnmarshaller
   *
   * @return the AttributeGroup created by this AttributeGroupUnmarshaller
   **/
  public AttributeGroup getAttributeGroup() {
    return _attributeGroup;
  } // -- getAttributeGroup

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

  /**
   * Signals the start of an element with the given name.
   *
   * @param name the NCName of the element. It is an error if the name is a QName (ie. contains a
   *        prefix).
   * @param namespace the namespace of the element. This may be null. Note: A null namespace is not
   *        the same as the default namespace unless the default namespace is also null.
   * @param atts the AttributeSet containing the attributes associated with the element.
   * @param nsDecls the namespace declarations being declared for this element. This may be null.
   **/
  public void startElement(String name, String namespace, AttributeSet atts, Namespaces nsDecls)
      throws XMLException {
    // -- Do delagation if necessary
    if (unmarshaller != null) {
      unmarshaller.startElement(name, namespace, atts, nsDecls);
      ++depth;
      return;
    }

    // -- <anyAttribute>
    if (SchemaNames.ANY_ATTRIBUTE.equals(name)) {
      if (foundAnyAttribute)
        error(
            "an anyAttribute element can appear only once as a child " + "of an 'AttributeGroup'.");
      foundAnyAttribute = true;
      allowAnnotation = true;
      unmarshaller =
          new WildcardUnmarshaller(getSchemaContext(), _attributeGroup, _schema, name, atts);
    }
    // -- attribute declarations
    else if (SchemaNames.ATTRIBUTE.equals(name)) {
      allowAnnotation = false;

      if (isRef)
        error("AttributeGroup references may not have children.");

      unmarshaller = new AttributeUnmarshaller(getSchemaContext(), _schema, atts);
    }
    // -- element declarations
    else if (SchemaNames.ATTRIBUTE_GROUP.equals(name)) {
      allowAnnotation = false;
      if (isRef)
        error("AttributeGroup references may not have children.");
      unmarshaller = new AttributeGroupUnmarshaller(getSchemaContext(), _schema, atts);
    } else if (name.equals(SchemaNames.ANNOTATION)) {
      if (!allowAnnotation)
        outOfOrder(name);
      unmarshaller = new AnnotationUnmarshaller(getSchemaContext(), atts);
    } else
      illegalElement(name);

  } // -- startElement

  /**
   * Signals to end of the element with the given name.
   *
   * @param name the NCName of the element. It is an error if the name is a QName (ie. contains a
   *        prefix).
   * @param namespace the namespace of the element.
   **/
  public void endElement(String name, String namespace) throws XMLException {

    // -- Do delagation if necessary
    if ((unmarshaller != null) && (depth > 0)) {
      unmarshaller.endElement(name, namespace);
      --depth;
      return;
    }

    // -- have unmarshaller perform any necessary clean up
    unmarshaller.finish();

    // -- <anyAttribute>
    if (SchemaNames.ANY_ATTRIBUTE.equals(name)) {
      Wildcard wildcard = ((WildcardUnmarshaller) unmarshaller).getWildcard();
      try {
        ((AttributeGroupDecl) _attributeGroup).setAnyAttribute(wildcard);
      } catch (SchemaException e) {
        throw new IllegalArgumentException(e.getMessage());
      }
    }


    // -- attribute declarations
    else if (SchemaNames.ATTRIBUTE.equals(name)) {
      AttributeDecl attrDecl = ((AttributeUnmarshaller) unmarshaller).getAttribute();

      ((AttributeGroupDecl) _attributeGroup).addAttribute(attrDecl);
    }
    // -- attribute group references
    else if (SchemaNames.ATTRIBUTE_GROUP.equals(name)) {

      Object obj = unmarshaller.getObject();

      try {
        ((AttributeGroupDecl) _attributeGroup).addReference((AttributeGroupReference) obj);
      } catch (ClassCastException ex) {
        String err = "AttributeGroups cannot contain new "
            + "AttributeGroup definitions, only references to "
            + "top-level AttributeGroups are allowed.";
        error(err);
      }
    }
    // -- annotation
    else if (SchemaNames.ANNOTATION.equals(name)) {
      Annotation ann = ((AnnotationUnmarshaller) unmarshaller).getAnnotation();
      _attributeGroup.addAnnotation(ann);
    }

    unmarshaller = null;
  } // -- endElement

  public void characters(char[] ch, int start, int length) throws XMLException {
    // -- Do delagation if necessary
    if (unmarshaller != null) {
      unmarshaller.characters(ch, start, length);
    }
  } // -- characters

} // -- AttributeGroupUnmarshaller
