/**
 * 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 1999-2003 (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.Form;
import org.exolab.castor.xml.schema.SchemaContext;
import org.exolab.castor.xml.schema.Schema;
import org.exolab.castor.xml.schema.SchemaNames;
import org.exolab.castor.xml.schema.SimpleType;

/**
 * The Unmarshaller for Attribute declarations
 *
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
 **/
public class AttributeUnmarshaller 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 AttributeDecl _attribute = null;

  private Schema _schema = null;

  private boolean foundAnnotation = false;
  private boolean foundSimpleType = false;


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

  public AttributeUnmarshaller(final SchemaContext schemaContext, final Schema schema,
      final AttributeSet atts) {
    super(schemaContext);
    this._schema = schema;

    _attribute = new AttributeDecl(schema);

    // --@ref
    String attValue = atts.getValue(SchemaNames.REF_ATTR);
    if (attValue != null) {
      _attribute.setReference(attValue);
    }

    // -- @name
    attValue = atts.getValue(SchemaNames.NAME_ATTR);
    if (attValue != null) {
      if (_attribute.isReference()) {
        String err =
            "An attribute cannot have a 'name' attribute and a 'ref' attribute at the same time.";
        throw new IllegalStateException(err);
      }
      _attribute.setName(attValue);
    }

    // -- @default
    attValue = atts.getValue(SchemaNames.DEFAULT_ATTR);
    if (attValue != null) {
      _attribute.setDefaultValue(attValue);
    }

    // -- @id
    _attribute.setId(atts.getValue(SchemaNames.ID_ATTR));

    // -- @fixed
    attValue = atts.getValue(SchemaNames.FIXED_ATTR);
    if (attValue != null) {
      _attribute.setFixedValue(attValue);
    }

    // -- @form
    attValue = atts.getValue(SchemaNames.FORM);
    if (attValue != null) {
      if (_attribute.isReference()) {
        String err = "An attribute reference cannot have a 'form' attribute.";
        throw new IllegalArgumentException(err);
      }
      _attribute.setForm(Form.valueOf(attValue));
    }

    // -- @type
    attValue = atts.getValue(SchemaNames.TYPE_ATTR);
    if (attValue != null) {
      if (_attribute.isReference()) {
        String err = "An attribute reference cannot have a 'type' attribute.";
        throw new IllegalArgumentException(err);
      }
      _attribute.setSimpleTypeReference(attValue);
    }

    // -- @use
    attValue = atts.getValue(SchemaNames.USE_ATTR);
    if (attValue != null) {
      if (_attribute.isDefault() && (!attValue.equals(AttributeDecl.USE_OPTIONAL)))
        throw new IllegalArgumentException(
            "When 'default' is present, the 'use' attribute must have the value 'optional'.");
      _attribute.setUse(attValue);
    }

  } // -- AttributeUnmarshaller

  // -----------/
  // - 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;
  } // -- elementName

  /**
   *
  **/
  public AttributeDecl getAttribute() {
    return _attribute;
  } // -- getAttribute

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

    if (SchemaNames.ANNOTATION.equals(name)) {

      if (foundAnnotation)
        error("Only one (1) annotation is allowed as a child of " + "an attribute declaration.");

      if (foundSimpleType)
        error("An annotation may only appear as the first child of " + "an attribute declaration.");

      foundAnnotation = true;
      unmarshaller = new AnnotationUnmarshaller(getSchemaContext(), atts);
    } else if (SchemaNames.SIMPLE_TYPE.equals(name)) {
      if (foundSimpleType)
        error("Only one (1) simpleType is allowed as a child of " + "an attribute declaration.");

      foundSimpleType = true;
      unmarshaller = new SimpleTypeUnmarshaller(getSchemaContext(), _schema, 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;
    }

    // -- call unmarshaller finish to perform any necessary cleanup
    unmarshaller.finish();

    if (SchemaNames.ANNOTATION.equals(name)) {
      Annotation ann = (Annotation) unmarshaller.getObject();
      _attribute.addAnnotation(ann);
    } else if (SchemaNames.SIMPLE_TYPE.equals(name)) {
      SimpleType simpleType = ((SimpleTypeUnmarshaller) unmarshaller).getSimpleType();
      _attribute.setSimpleType(simpleType);
    }

    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

} // -- AttributeUnmarshaller
