/**
 * 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.AttributeGroupReference;
import org.exolab.castor.xml.schema.ComplexType;
import org.exolab.castor.xml.schema.ContentType;
import org.exolab.castor.xml.schema.ElementDecl;
import org.exolab.castor.xml.schema.SchemaContext;
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.SchemaException;
import org.exolab.castor.xml.schema.SchemaNames;
import org.exolab.castor.xml.schema.Wildcard;
import org.exolab.castor.xml.schema.XMLType;

/**
 * A class for unmarshalling XML Schema <complexType> definitions.
 * 
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $
 **/
public class ComplexTypeUnmarshaller extends ComponentReader {

  /**
   * Represents the textual representation of the value '0'
   */
  private static final String VALUE_0 = "0";

  /**
   * Represents the textual representation of the value '1'
   */
  private static final String VALUE_1 = "1";

  /**
   * Represents the textual representation of the value 'false'
   */
  private static final String VALUE_FALSE = "false";

  /**
   * Represents the textual representation of the value 'true'
   */
  private static final String VALUE_TRUE = "true";

  /**
   * Represents the XML schema keyword 'restrictions'
   */
  private static final String KEYWORD_RESTRICTIONS = "restrictions";

  /**
   * Represents the XML schema keyword 'extensions'
   */
  private static final String KEYWORD_EXTENSION = "extension";

  /**
   * Represents the XML schema keyword 'derivedBy'
   */
  private static final String KEYWORD_DERIVED_BY = "derivedBy";

  /**
   * 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 boolean allowAnnotation = true;
  private boolean foundAnnotation = false;
  private boolean foundAnyAttribute = false;
  private boolean foundAttributes = false;
  private boolean foundSimpleContent = false;
  private boolean foundComplexContent = false;
  private boolean foundModelGroup = false;

  private Schema _schema = null;

  /**
   * Creates a new {@link ComplexTypeUnmarshaller} instance.
   * 
   * @param schemaContext the {@link SchemaContext} instance to get some configuration settings from
   * @param schema the {@link Schema} to which the {@link ComplexType} belongs.
   * @param atts the attribute list associated with this {@link ComplexType}.
   * @see Schema
   **/
  public ComplexTypeUnmarshaller(final SchemaContext schemaContext, final Schema schema,
      final AttributeSet atts) throws XMLException {
    super(schemaContext);

    this._schema = schema;

    _complexType = schema.createComplexType();

    _complexType.useResolver(getResolver());

    // -- handle attributes
    String attValue = null;

    // -- read @name attribute
    _complexType.setName(atts.getValue(SchemaNames.NAME_ATTR));

    // -- read contentType
    String content = atts.getValue(SchemaNames.MIXED);
    if (content != null) {
      if (isTurnedOn(content)) {
        _complexType.setContentType(ContentType.mixed);
      }
      if (isTurnedOff(content)) {
        _complexType.setContentType(ContentType.elemOnly);
      }
    }

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

      String derivedBy = atts.getValue(KEYWORD_DERIVED_BY);
      _complexType.setDerivationMethod(derivedBy);
      if ((derivedBy == null) || (derivedBy.length() == 0)
          || (derivedBy.equals(KEYWORD_EXTENSION))) {
        XMLType baseType = schema.getType(base);
        if (baseType == null)
          _complexType.setBase(base); // the base type has not been read
        else
          _complexType.setBaseType(baseType);
      } else if (derivedBy.equals(KEYWORD_RESTRICTIONS)) {
        String err = "restrictions not yet supported for <type>.";
        throw new SchemaException(err);
      } else {
        String err = "invalid value for derivedBy attribute of ";
        err += "<type>: " + derivedBy;
        throw new SchemaException(err);
      }

    }

    // -- read @abstract attribute
    attValue = atts.getValue(SchemaNames.ABSTRACT);
    if (attValue != null) {
      Boolean bool = Boolean.valueOf(attValue);
      _complexType.setAbstract(bool.booleanValue());
    }

    // -- read @block attribute
    _complexType.setBlock(atts.getValue(SchemaNames.BLOCK_ATTR));

    // -- read @final attribute
    _complexType.setFinal(atts.getValue(SchemaNames.FINAL_ATTR));

    // -- read @id attribute
    _complexType.setId(atts.getValue(SchemaNames.ID_ATTR));

  }

  /**
   * Checks whether a given property is turned on, i.e. its value is set to 'false' or '0'.
   * 
   * @param property Property value
   * @return True of the property is 'turned off'.
   */
  private boolean isTurnedOff(String content) {
    return content.equals(VALUE_FALSE) || content.equals(VALUE_0);
  }

  /**
   * Checks whether a given property is turned on, i.e. its value is set to 'true' or '1'.
   * 
   * @param property Property value
   * @return True of the property is 'turned on'.
   */
  private boolean isTurnedOn(String property) {
    return property.equals(VALUE_TRUE) || property.equals(VALUE_1);
  }

  // -----------/
  // - 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.COMPLEX_TYPE;
  } // -- elementName

  /**
   *
  **/
  public ComplexType getComplexType() {
    return _complexType;
  } // -- getComplexType

  /**
   * Returns the Object created by this ComponentReader
   * 
   * @return the Object created by this ComponentReader
   **/
  public Object getObject() {
    return getComplexType();
  } // -- 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 (foundComplexContent)
        error("an anyAttribute element cannot appear as a child "
            + "of 'complexType' if 'complexContent' also exists");
      if (foundSimpleContent)
        error("an anyAttribute element cannot appear as a child "
            + "of 'complexType' if 'simpleContent' also exists");
      foundAnyAttribute = true;
      allowAnnotation = true;
      unmarshaller =
          new WildcardUnmarshaller(getSchemaContext(), _complexType, _schema, name, atts);
    }

    // -- attribute declarations
    else if (SchemaNames.ATTRIBUTE.equals(name)) {
      if (foundComplexContent)
        error("an attribute definition cannot appear as a child "
            + "of 'complexType' if 'complexContent' also exists");
      if (foundSimpleContent)
        error("an 'attribute' definition cannot appear as a child "
            + "of 'complexType' if 'simpleContent' also exists");
      if (foundAnyAttribute)
        error("an attribute definition cannot appear after "
            + "the definition of an 'anyAttribute' element");
      foundAttributes = true;
      allowAnnotation = false;
      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) {
        error("A 'complexType' may contain referring " + "attributeGroups, but not defining ones.");
      }
      if (foundComplexContent)
        error("an attributeGroup reference cannot appear as a child "
            + "of 'complexType' if 'complexContent' also exists");
      if (foundSimpleContent)
        error("an attributeGroup reference cannot appear as a child "
            + "of 'complexType' if 'simpleContent' also exists");
      if (foundAnyAttribute)
        error("an 'attributeGroup' reference cannot appear after "
            + "the definition of an 'anyAttribute' element");

      foundAttributes = true;
      allowAnnotation = false;
      unmarshaller = new AttributeGroupUnmarshaller(getSchemaContext(), _schema, atts);
    }
    // -- simpleContent
    else if (SchemaNames.SIMPLE_CONTENT.equals(name)) {

      if (foundAttributes)
        error("'simpleContent' and attribute definitions cannot both "
            + "appear as children of 'complexType' at the same time.");
      if (foundComplexContent)
        error("'simpleContent' and 'complexContent' cannot both "
            + "appear as children of 'complexType'.");
      if (foundSimpleContent)
        error("Only one (1) 'simpleContent' may appear as a child of " + "'complexType'.");
      if (foundModelGroup)
        error("'simpleContent' cannot appear as a child of "
            + "'complexType' if 'all', 'sequence', 'choice' or " + "'group' also exist");

      foundSimpleContent = true;
      allowAnnotation = false;
      _complexType.setSimpleContent(true);
      unmarshaller = new SimpleContentUnmarshaller(getSchemaContext(), _complexType, atts);
    }
    // -- complexContent
    else if (SchemaNames.COMPLEX_CONTENT.equals(name)) {

      if (foundAttributes)
        error("'complexContent' and attribute definitions cannot both "
            + "appear as children of 'complexType' at the same time.");
      if (foundSimpleContent)
        error("'simpleContent' and 'complexContent' cannot both "
            + "appear as children of 'complexType'.");
      if (foundComplexContent)
        error("Only one (1) 'complexContent' may appear as a child of " + "'complexType'.");
      if (foundModelGroup)
        error("'complexContent' cannot appear as a child of "
            + "'complexType' if 'all', 'sequence', 'choice' or " + "'group' also exist");

      foundComplexContent = true;
      allowAnnotation = false;

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

      foundModelGroup = true;
      allowAnnotation = false;
      unmarshaller = new ModelGroupUnmarshaller(getSchemaContext(), _schema, atts);
    }
    // -- ModelGroup declarations (choice, all, sequence)
    else if ((SchemaNames.isGroupName(name)) && (name != SchemaNames.GROUP)) {

      if (foundAttributes)
        error("'" + name + "' must appear before any attribute "
            + "definitions when a child of 'complexType'.");
      if (foundComplexContent)
        error("'" + name + "' and 'complexContent' cannot both "
            + "appear as children of 'complexType'.");
      if (foundSimpleContent)
        error("'" + name + "' and 'simpleContent' cannot both "
            + "appear as children of 'complexType'.");
      if (foundModelGroup)
        error("'" + name + "' cannot appear as a child of 'complexType' "
            + "if another 'all', 'sequence', 'choice' or " + "'group' also exists.");

      foundModelGroup = true;
      allowAnnotation = false;
      unmarshaller = new GroupUnmarshaller(getSchemaContext(), _schema, name, atts);
    } else if (name.equals(SchemaNames.ANNOTATION)) {
      if (allowAnnotation) {
        unmarshaller = new AnnotationUnmarshaller(getSchemaContext(), atts);
        allowAnnotation = false;
        foundAnnotation = true;
      } else {
        if (foundAnnotation) {
          error("Only one (1) annotation may appear as a child of " + "'complexType' elements");
        }
        error("An annotation must appear as the first child of " + "'complexType' elements.");
      }
    } 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
    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);
    }
    // -- element declarations
    else if (SchemaNames.ELEMENT.equals(name)) {

      ElementDecl element = ((ElementUnmarshaller) unmarshaller).getElement();
      _complexType.addElementDecl(element);
    }
    // --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

} // -- ComplexTypeUnmarshaller
