/**
    * 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 2004 (C) Intalio, Inc. All Rights Reserved.
   *
   * $Id$
   */
  
  package org.exolab.castor.xml.schema.reader;
  
  //-- imported classes and packages
  import org.exolab.castor.net.URIException;
  import org.exolab.castor.net.URILocation;
  import org.exolab.castor.net.URIResolver;
  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.AttributeGroup;
  import org.exolab.castor.xml.schema.AttributeGroupDecl;
  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.RedefineSchema;
  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.SimpleType;
  import org.exolab.castor.xml.schema.XMLType;
  import org.xml.sax.InputSource;
  import org.xml.sax.Locator;
  import org.xml.sax.Parser;
  
  /**
   * The purpose of this class is to read redefined elements in an XML schema.
   * The following xml schema structure can be redefined:
   * <ul>
   *     <li>Complextypes</li>
   *     <li>Simpletypes</li>
   *     <li>AttributeGroup</li>
   *     <li>Group</li>
   * </ul>
   * @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 RedefineUnmarshaller extends ComponentReader
  {
  
  	/**
  	 * The current ComponentReader used to read nested structures
  	 **/
  	private ComponentReader _unmarshaller;
  	
  	/**
  	 * The current branch depth
  	 **/
  	private int _depth = 0;
  	
  	/**
  	 * The parent XML schema
  	 */
 	private Schema _schema;
 	
 	/**
 	 * The imported XML Schema
 	 */
 	private Schema _importedSchema;
 	
 	private RedefineSchema _redefineSchema;
 	
 	/**
 	 * The XML Schema imported
 	 */
 	
     public RedefineUnmarshaller(
             final SchemaContext schemaContext,
             final Schema schema,
             final AttributeSet atts,
             final URIResolver uriResolver,
             final Locator locator,
             final SchemaUnmarshallerState state)
     throws XMLException {
         super(schemaContext);
         if (schema == null) {
         	String err = SchemaNames.REDEFINE + " must be used with an existing parent XML Schema.";
         	throw new SchemaException(err);
         }
         setURIResolver(uriResolver);
 
         URILocation uri = null;
 		//-- Get schemaLocation
 		String schemaLocation = atts.getValue(SchemaNames.SCHEMALOCATION_ATTR);
 		_schema = schema;
 		
 		if (schemaLocation == null) {
 		    //-- <redefine/> or <redefine> <annotation>(*) </redefine>
 		    _redefineSchema = new RedefineSchema(schema);
 		    _schema.addRedefineSchema(_redefineSchema);
 			return; 
 		}
 
         
         if (schemaLocation.indexOf("\\") != -1) {
             String err = "'" + schemaLocation + 
                 "' is not a valid URI as defined by IETF RFC 2396.";
             err += "The URI mustn't contain '\\'.";
             error(err);
 	    }
 
         try {
             String documentBase = locator.getSystemId();
             if (documentBase != null) {
                 if (!documentBase.endsWith("/"))
                     documentBase = documentBase.substring(0, documentBase.lastIndexOf('/') +1 );
             }
 	        uri = getURIResolver().resolve(schemaLocation, documentBase);
             if (uri != null) {
                 schemaLocation = uri.getAbsoluteURI();
             }
         } 
         catch (URIException urix) {
             throw new XMLException(urix);
         }
 
         //-- Schema object to hold import schema
 		boolean addSchema = false;
 		_redefineSchema = schema.getRedefineSchema(schemaLocation);
 		Schema importedSchema = null;
 		
 		boolean alreadyLoaded = false;
 		
         //-- The schema is not yet loaded
 		if (_redefineSchema == null) {
             if (uri instanceof SchemaLocation) {
                 importedSchema = ((SchemaLocation)uri).getSchema();
                 //-- set the main schema in order to handle 
                 //-- redefinition at runtime
                 
                 // importedSchema.addMainSchema(schema);
                 
                 _redefineSchema = new RedefineSchema(schema, importedSchema);
 			    schema.addRedefineSchema(_redefineSchema);
 			    alreadyLoaded = true;
             }
             else {
 			    importedSchema = new Schema();
 			    addSchema = true;
 			}
 		}
 		else {
 			//-- check schema location, if different, allow merge
 		    String tmpLocation = _redefineSchema.getOriginalSchema().getSchemaLocation();
 		    alreadyLoaded = schemaLocation.equals(tmpLocation);
 		}
 
         state.markAsProcessed(schemaLocation, importedSchema);
 
         if (alreadyLoaded) return;
         
         //-- Parser Schema
 		Parser parser = null;
 		try {
 		    parser = getSchemaContext().getParser();
 		}
 		catch(RuntimeException rte) {}
 		if (parser == null) {
 		    throw new SchemaException("Error failed to create parser for import");
 		}
 		//-- Create Schema object and setup unmarshaller
 		SchemaUnmarshaller schemaUnmarshaller = new SchemaUnmarshaller(getSchemaContext(), state);
 		schemaUnmarshaller.setURIResolver(getURIResolver());
 		schemaUnmarshaller.setSchema(importedSchema);
 		Sax2ComponentReader handler = new Sax2ComponentReader(schemaUnmarshaller);
 		parser.setDocumentHandler(handler);
 		parser.setErrorHandler(handler);
 
 		try {
 		    InputSource source = new InputSource(uri.getReader());
             source.setSystemId(uri.getAbsoluteURI());
             parser.parse(source);
 		}
 		catch(java.io.IOException ioe) {
 		    throw new SchemaException("Error reading import file '"+schemaLocation+"': "+ ioe);
 		}
 		catch(org.xml.sax.SAXException sx) {
 		    throw new SchemaException(sx);
 		}
 		
 		//-- namespace checking
 		String namespace = importedSchema.getTargetNamespace();
 		if ( namespace != null ) {
 			//-- Make sure targetNamespace is not the same as the
 			//-- importing schema, see section 4.2.2 in the
 			//-- XML Schema Recommendation
 			if (!namespace.equals(schema.getTargetNamespace()) ) {
 			    String err = "The 'namespace' attribute in the <redefine> element must be the same of the targetNamespace of the global schema.\n"
 			    	         +namespace+" is different from:"+schema.getTargetNamespace();
 			    error (err);
 			}
 		} else {
 			importedSchema.setTargetNamespace(schema.getTargetNamespace());
 		}
 		
         //-- set the main schema in order to handle 
 		//-- redefinition at runtime
 		
 		// importedSchema.addMainSchema(schema);
 		
 		_importedSchema = importedSchema;
 		_redefineSchema = new RedefineSchema(schema, _importedSchema);
 		//-- Add schema to list of redefine schemas (if not already present)
 		if (addSchema)
 		{
             importedSchema.setSchemaLocation(schemaLocation);
             _schema.addRedefineSchema(_redefineSchema);
 		}
 	}
 
     /**
      * 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
 	{
 
     	
     	
     	//-- DEBUG
     	//System.out.println("#startElement: " + name + " {" + namespace + "}");
     	//-- /DEBUG
 
     	//-- Do delagation if necessary
     	if (_unmarshaller != null) {
     		try {
     			_unmarshaller.startElement(name, namespace, atts, nsDecls);
     			_depth ++;
     			return;
     		} catch(RuntimeException rtx) {
     			error(rtx);
     		}
     	}
     	
     	//-- <annotation>
     	if (name.equals(SchemaNames.ANNOTATION)) {
     		_unmarshaller = new AnnotationUnmarshaller(getSchemaContext(), atts);
     	}
     	//-- <attributeGroup>
     	else if (name.equals(SchemaNames.ATTRIBUTE_GROUP)) {
     		_unmarshaller = new AttributeGroupUnmarshaller(getSchemaContext(), _schema, atts);
     	}
     	//-- <complexType>
     	else if (name.equals(SchemaNames.COMPLEX_TYPE)) {
     		_unmarshaller
 			= new ComplexTypeUnmarshaller(getSchemaContext(), _schema, atts);
     	}
     	//-- <simpleType>
     	else if (name.equals(SchemaNames.SIMPLE_TYPE)) {
     		_unmarshaller = new SimpleTypeUnmarshaller(getSchemaContext(), _schema, atts);
     	}
     	//-- <group>
     	else if (name.equals(SchemaNames.GROUP)) {
     		_unmarshaller = new ModelGroupUnmarshaller(getSchemaContext(), _schema, atts);
     	}
     	else {
     		//--Exception here
     		String err = "<" + name +"> elements cannot be used in a redefine.";
             error(err);
     	}
 
     	_unmarshaller.setDocumentLocator(getDocumentLocator());
 
     } //-- 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
 	{
     	
     	//-- DEBUG
     	//System.out.println("#endElement: " + name + " {" + namespace + "}");
     	//-- /DEBUG
 
     	//-- Do delagation if necessary
     	if ((_unmarshaller != null) && (_depth > 0)) {
     		_unmarshaller.endElement(name, namespace);
     		--_depth;
     		return;
     	}
 
 
     	//-- use internal JVM String
     	name = name.intern();
 
 
     	//-- check for name mismatches
     	if ((_unmarshaller != null)) {
     		if (!name.equals(_unmarshaller.elementName())) {
     			String err = "error: missing end element for ";
     			err += _unmarshaller.elementName();
     			error(err);
     		}
     	}
     	else {
     		String err = "error: missing start element for " + name;
     		throw new SchemaException(err);
     	}
 
     	//-- call unmarshaller.finish() to perform any necessary cleanup
     	_unmarshaller.finish();
 
     	//-- <annotation>
     	if (name.equals(SchemaNames.ANNOTATION)) {
     		_redefineSchema.addAnnotation((Annotation)_unmarshaller.getObject());
     	}
     	//-- <attributeGroup>
         else if (name.equals(SchemaNames.ATTRIBUTE_GROUP)) {
         	if (_redefineSchema.getSchemaLocation() == "") {
         		String err = "In a <redefine>, only annotations can be defined when no -schemaLocation- is specified.";
         		error(err);
         	}
         	
         	AttributeGroupDecl group = null;
         	group = (AttributeGroupDecl)(((AttributeGroupUnmarshaller)_unmarshaller).getAttributeGroup());
         	
         	String structureName = group.getName();
         	if (structureName == null) {
         		String err = "When redefining an AttributeGroup, the group must have a name.\n";
         		error(err);
         	}
         	
         	//1-- the attributeGroup must exist in the imported schema
         	AttributeGroup original = _importedSchema.getAttributeGroup(structureName);
         	if (original == null) {
         		String err = "When redefining an AttributeGroup, the AttributeGroup must be present in the imported XML schema.\n"
         			+"AttributeGroup: "+structureName+" is not defined in XML Schema:" + _importedSchema.getSchemaLocation();
         		error(err);
         	}
         	
         	//-- todo: add code to check the Derivation Valid (Restriction, Complex) constraint.
         	group.setRedefined();
     		_redefineSchema.addAttributeGroup(group);
     		
     	}
     	//-- <complexType>
     	else if (name.equals(SchemaNames.COMPLEX_TYPE)) {
     		if (_redefineSchema.getSchemaLocation() == "") {
     			String err = "In a <redefine>, only annotations can be defined when no -schemaLocation- is specified.";
     			error(err);
     		}
     		ComplexType complexType = null;
     		complexType = ((ComplexTypeUnmarshaller)_unmarshaller).getComplexType();
     		//-- Checks that the complexType exists in the imported schema
     		String structureName = complexType.getName();
     		if (structureName == null) {
     			String err = "When redefining a complexType, the complexType must have a name.\n";
     			error(err);
     		}
     		
     		//1-- the complexType must exist in the imported schema
     		ComplexType original = _importedSchema.getComplexType(structureName);
     		if (original == null) {
     		    String err = "When redefining a complexType, the complexType must be present in the imported XML schema.\n"
     		    	         +"ComplexType: "+structureName+" is not defined in XML Schema:" + _importedSchema.getSchemaLocation();
     		    error(err);
     		}
     		
     		//2-- the base type must be itself
     		XMLType baseType = complexType.getBaseType();
     		//--just check the names since a top level complexType can only be defined once.
     		if (baseType == null || !baseType.getName().equals(structureName)) {
     			String err = "When redefining a complexType, the complexType must use itself as the base type definition.\n"
     				+"ComplexType: "+structureName+" uses:" + baseType+ " as its base type.";
     			error(err);
     		}
     		
     		complexType.setRedefined();
     		_redefineSchema.addComplexType(complexType);
             getResolver().addResolvable(complexType.getReferenceId(), complexType);
     	}
     	//-- <simpleType>
     	else if (name.equals(SchemaNames.SIMPLE_TYPE)) {
     		if (_redefineSchema.getSchemaLocation() == "") {
     			String err = "In a <redefine>, only annotations can be defined when no -schemaLocation- is specified.";
     			error(err);
     		}
     		
     		SimpleType simpleType = null;
     		simpleType = ((SimpleTypeUnmarshaller)_unmarshaller).getSimpleType();
             //-- Checks that the simpleType exists in the imported schema
     		String structureName = simpleType.getName();
     		if (structureName == null) {
     			String err = "When redefining a simpleType, the simpleType must have a name.\n";
     			error(err);
     		}
     		
     		//1-- the simpleType must exist in the imported schema
     		SimpleType original = _importedSchema.getSimpleType(structureName,_schema.getTargetNamespace() );
     		if (original == null) {
     			String err = "When redefining a simpleType, the simpleType must be present in the imported XML schema.\n"
     				+"SimpleType: "+structureName+" is not defined in XML Schema:" + _importedSchema.getSchemaLocation();
     			error(err);
     		}
     		
     		//2-- the base type must be itself
     		XMLType baseType = simpleType.getBaseType();
     		//--just check the names since a top level complexType can only be defined once.
     		if (!baseType.getName().equals(structureName)) {
     			String err = "When redefining a simpleType, the simpleType must use itself as the base type definition.\n"
     				+"SimpleType: "+structureName+" uses:" + baseType.getName() + " as its base type.";
     			error(err);
     		}	
     		
     		simpleType.setRedefined();
     		_redefineSchema.addSimpleType(simpleType);
     		getResolver().addResolvable(simpleType.getReferenceId(), simpleType);
     	}
     	//--<group>
     	else if (name.equals(SchemaNames.GROUP)) {
     		if (_redefineSchema.getSchemaLocation() == "") {
     			String err = "In a <redefine>, only annotations can be defined when no -schemaLocation- is specified.";
     			error(err);
     		}
     		
     		ModelGroup group = null;
     		group = (((ModelGroupUnmarshaller)_unmarshaller).getGroup());
     		
     		String structureName = group.getName();
     		if (structureName == null) {
     			String err = "When redefining a group, the group must have a name.\n";
     			error(err);
     		}
     		
     		//1-- the group must exist in the imported schema
     		Group original = _importedSchema.getModelGroup(structureName);
     		if (original == null) {
     			String err = "When redefining a group, the group must be present in the imported XML schema.\n"
     				+"Group: "+structureName+" is not defined in XML Schema:" + _importedSchema.getSchemaLocation();
     			error(err);
     		}
     		
     		//-- code needs to be added to check the Particle Valid (Restriction) constraint
     		//--TBD
     		
     		group.setRedefined();
     		_redefineSchema.addGroup(group);
     	} else {
     		String err = "In a <redefine>, only complexTypes|simpleTypes|groups or attributeGroups can be redefined.";
 			error(err);	
     	}
 
     	_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
     
     
     /**
      * Sets the name of the element that this UnknownUnmarshaller handles
     **/
     public String elementName() {
         return SchemaNames.REDEFINE;
     } //-- elementName
 
     /**
      * Returns the Object created by this ComponentReader
      * @return the Object created by this ComponentReader
     **/
     public Object getObject() {
         return _redefineSchema;
     } //-- getObject
 
 }