/**
 * 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
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 * 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 2000-2002 (C) Intalio Inc. All Rights Reserved.
 *
 * $Id$
 */

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

// -- imported classes and packages
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.AttributeGroupReference;
import org.exolab.castor.xml.schema.ComplexType;
import org.exolab.castor.xml.schema.Group;
import org.exolab.castor.xml.schema.ModelGroup;
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.exolab.castor.xml.schema.SimpleContent;
import org.exolab.castor.xml.schema.SimpleType;
import org.exolab.castor.xml.schema.Wildcard;
import org.exolab.castor.xml.schema.XMLType;

/**
 * A class for Unmarshalling extension elements
 * 
 * @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 ExtensionUnmarshaller extends ComponentReader {


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

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

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

  /**
   * The Attribute reference for the Attribute we are constructing
   **/
  private ComplexType _complexType = null;
  private Schema _schema = null;

  private boolean foundAnnotation = false;
  private boolean foundAttributes = false;
  private boolean foundModelGroup = false;


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

  /**
   * Creates a new ExtensionUnmarshaller.
   * 
   * @param schemaContext the {@link SchemaContext} to get some configuration settings from
   * @param complexType the ComplexType being unmarshalled
   * @param atts the AttributeList
   **/
  public ExtensionUnmarshaller(final SchemaContext schemaContext, final ComplexType complexType,
      final AttributeSet atts) throws XMLException {
    super(schemaContext);

    _complexType = complexType;
    _schema = complexType.getSchema();

    _complexType.setDerivationMethod(SchemaNames.EXTENSION);

    // -- base
    String base = atts.getValue(SchemaNames.BASE_ATTR);
    if ((base != null) && (base.length() > 0)) {

      XMLType baseType = _schema.getType(base);
      if (baseType == null) {
        _complexType.setBase(base); // the base type has not been read
        if (_complexType.isSimpleContent()) {
          _complexType.setContentType(new SimpleContent(_schema, base));
        }
      } else {
        // --we cannot extend a simpleType in <complexContent>
        if ((baseType.isSimpleType()) && (_complexType.isComplexContent())) {
          String err = "In a 'complexContent', the base attribute " + "must be a complexType but "
              + base + " is a simpleType.\n";
          error(err);
        }
        _complexType.setBase(base);
        _complexType.setBaseType(baseType);
        if (_complexType.isSimpleContent()) {
          // --set the content type
          if (baseType.isSimpleType()) {
            SimpleType simpleType = (SimpleType) baseType;
            _complexType.setContentType(new SimpleContent(simpleType));
          } else {
            ComplexType temp = (ComplexType) baseType;
            SimpleContent simpleContent = (SimpleContent) temp.getContentType();
            _complexType.setContentType(simpleContent.copy());
          }
        }

      }

    }

  } // -- ExtensionUnmarshaller

  // -----------/
  // - 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.EXTENSION;
  } // -- elementName

  /**
   * Returns the Object created by this ComponentReader
   * 
   * @return the Object created by this ComponentReader
   **/
  public Object getObject() {
    return null;
  } // -- 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)) {
      unmarshaller =
          new WildcardUnmarshaller(getSchemaContext(), _complexType, _schema, name, atts);
    }

    // -- attribute declarations
    else if (SchemaNames.ATTRIBUTE.equals(name)) {
      foundAttributes = true;
      unmarshaller = new AttributeUnmarshaller(getSchemaContext(), _schema, atts);
    }
    // -- attribute group declarations
    else if (SchemaNames.ATTRIBUTE_GROUP.equals(name)) {

      // -- make sure we have an attribute group
      // -- reference and not a definition

      if (atts.getValue(SchemaNames.REF_ATTR) == null) {
        String err =
            "A complexType may contain referring " + "attribute groups, but not defining ones.";
        error(err);
      }

      foundAttributes = true;
      unmarshaller = new AttributeGroupUnmarshaller(getSchemaContext(), _schema, atts);
    }
    // --<group>
    else if (name.equals(SchemaNames.GROUP)) {
      if (foundAttributes)
        error("'" + name + "' must appear before any attribute "
            + "definitions when a child of 'complexType'.");
      if (foundModelGroup)
        error("'" + name + "' cannot appear as a child of 'complexType' "
            + "if another 'all', 'sequence', 'choice' or " + "'group' also exists.");

      foundModelGroup = true;
      unmarshaller = new ModelGroupUnmarshaller(getSchemaContext(), _schema, atts);
    } else if (SchemaNames.isGroupName(name) && (name != SchemaNames.GROUP)) {
      if (foundAttributes)
        error("'" + name + "' must appear before attribute "
            + "definitions in an 'extension' element.");

      if (foundModelGroup)
        error("'" + name + "' cannot appear as a child of 'extension' "
            + "if another 'all', 'sequence', 'choice' or " + "'group' already exists.");

      if (_complexType.isSimpleContent())
        error("'" + name + "' may not appear in a 'extension' of " + "'simpleContent'.");

      foundModelGroup = true;
      unmarshaller = new GroupUnmarshaller(getSchemaContext(), _schema, name, atts);
    }
    // -- element declarations
    else if (SchemaNames.ANY_ATTRIBUTE.equals(name)) {
      // -- not yet supported....
      error("anyAttribute is not yet supported.");
    } else if (name.equals(SchemaNames.ANNOTATION)) {
      if (foundAttributes || foundModelGroup)
        error("An annotation must appear as the first child of an " + "'extension' element.");

      if (foundAnnotation)
        error("Only one (1) annotation may appear as the child of " + "an 'extension' element.");

      foundAnnotation = true;
      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 {
        _complexType.setAnyAttribute(wildcard);
      } catch (SchemaException e) {
        throw new IllegalArgumentException(e.getMessage());
      }
    }

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

      _complexType.addAttributeDecl(attrDecl);
    }
    // -- attribute groups
    else if (SchemaNames.ATTRIBUTE_GROUP.equals(name)) {
      AttributeGroupReference attrGroupRef = (AttributeGroupReference) unmarshaller.getObject();
      _complexType.addAttributeGroupReference(attrGroupRef);
    }
    // --group
    else if (name.equals(SchemaNames.GROUP)) {
      ModelGroup group = ((ModelGroupUnmarshaller) unmarshaller).getGroup();
      _complexType.addGroup(group);
    }

    // -- group declarations (all, choice, sequence)
    else if ((SchemaNames.isGroupName(name)) && (name != SchemaNames.GROUP)) {
      Group group = ((GroupUnmarshaller) unmarshaller).getGroup();
      _complexType.addGroup(group);
    }
    // -- annotation
    else if (SchemaNames.ANNOTATION.equals(name)) {
      Annotation ann = ((AnnotationUnmarshaller) unmarshaller).getAnnotation();
      _complexType.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

} // -- ExtensionUnmarshaller
