/* Copyright © 2013 Matthew Champion

 All rights reserved.

 Redistribution and use in source and binary forms, with or without

 modification, are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright

       notice, this list of conditions and the following disclaimer.

  * 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.

  * Neither the name of mattunderscore.com nor the

       names of its contributors may be used to endorse or promote products

       derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND

 ANY EXPRESS 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 MATTHEW CHAMPION 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. */

 package com.mattunderscore.filter.contentnegotiation.variantsource;

 import java.io.InputStream;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Stack;

 import javax.xml.XMLConstants;

 import javax.xml.transform.stream.StreamSource;

 import javax.xml.validation.Schema;

 import javax.xml.validation.SchemaFactory;

 import org.xml.sax.Attributes;

 import org.xml.sax.SAXException;

 import org.xml.sax.SAXParseException;

 import com.mattunderscore.filter.contentnegotiation.parser.Header;

 import com.mattunderscore.filter.contentnegotiation.parser.HeaderPart;

 import com.mattunderscore.filter.contentnegotiation.parser.Output;

 import com.mattunderscore.filter.contentnegotiation.parser.Redirect;

 import com.mattunderscore.filter.contentnegotiation.parser.Variant;

 /**

  * Parser for the Negotiation XML file.

  * <P>

  * It is not intended to be called directly. This parser is called by {@link FilterVariantXMLSource}

  * and that should be used to get variants from an XML file. This returns the schema

  * "http://www.mattunderscore.com/schema/negotiation.xsd".

  * 

  * @author Matt Champion

  * @since 0.2.0

  */

 public final  class VariantXMLParser extends VariantSAXHandler

 {

     private Stack<StringBuilder> elementCharacterData = new Stack<StringBuilder>();

     private List<Variant> variants;

     private Variant currentVariant;

     private Output currentOutput;

     private Header currentHeader;

     private Redirect currentRedirect;

     private HeaderPart currentHeaderPart;

     private StringBuilder tempString;

     private List<HeaderPart> currentHeaderParts;

     public VariantXMLParser()

     {

     }

     @Override

     public void startElement(String s, String s1, String elementName, Attributes attributes)

             throws SAXException

     {

         tempString = new StringBuilder(50);

         elementCharacterData.push(tempString);

         if ("variants".equals(elementName))

         {

             variants = new ArrayList<Variant>();

         }

         else if ("variant".equals(elementName))

         {

             currentVariant = new Variant();

         }

         else if ("output".equals(elementName))

         {

             currentOutput = new Output();

         }

         else if ("header".equals(elementName))

         {

             currentHeader = new Header();

             currentHeaderParts = new ArrayList<HeaderPart>();

         }

         else if ("redirect".equals(elementName))

         {

             currentRedirect = new Redirect();

         }

         else if ("fail".equals(elementName))

         {

             currentOutput.setFail(true);

         }

         else if ("part".equals(elementName))

         {

             currentHeaderPart = new HeaderPart();

         }

     }

     @Override

     public void endElement(String prefix, String localName, String qualifiedName)

             throws SAXException

     {

         if ("variant".equals(qualifiedName))

         {

             variants.add(currentVariant);

         }

         else if ("urlPattern".equals(qualifiedName))

         {

             currentVariant.setUrlPattern(tempString.toString());

         }

         else if ("content-type".equals(qualifiedName))

         {

             currentVariant.setContentType(tempString.toString());

         }

         else if ("language".equals(qualifiedName))

         {

             currentVariant.setLanguage(tempString.toString());

         }

         else if ("output".equals(qualifiedName))

         {

             currentVariant.setOutput(currentOutput);

         }

         else if ("forward".equals(qualifiedName))

         {

             currentOutput.setForward(tempString.toString());

         }

         else if ("redirect".equals(qualifiedName))

         {

             currentOutput.setRedirect(currentRedirect);

         }

         else if ("header".equals(qualifiedName))

         {

             currentHeader.setPart(currentHeaderParts);

             currentOutput.setHeader(currentHeader);

         }

         else if ("fail".equals(qualifiedName))

         {

             currentOutput.setFail(true);

         }

         else if ("part".equals(qualifiedName))

         {

             currentHeaderParts.add(currentHeaderPart);

         }

         else if ("code".equals(qualifiedName))

         {

             int code = Integer.parseInt(tempString.toString());

             if (currentRedirect != null)

             {

                 currentRedirect.setCode(code);

             }

             else if (currentHeader != null)

             {

                 currentHeader.setCode(code);

             }

         }

         else if ("location".equals(qualifiedName))

         {

             currentRedirect.setLocation(tempString.toString());

         }

         else if ("name".equals(qualifiedName))

         {

             currentHeaderPart.setName(tempString.toString());

         }

         else if ("value".equals(qualifiedName))

         {

             currentHeaderPart.setValue(tempString.toString());

         }

         elementCharacterData.pop();

         if (!elementCharacterData.isEmpty())

         {

             tempString = elementCharacterData.peek();

         }

     }

     @Override

     public void characters(char[] chars, int start, int length)

     {

         tempString.append(new String(chars, start, length));

     }

     @Override

     public List<Variant> getVariants()

     {

         return variants;

     }

     @Override

     public void error(SAXParseException exception) throws SAXParseException

     {

         throw exception;

     }

     @Override

     public void fatalError(SAXParseException exception) throws SAXParseException

     {

         throw exception;

     }

     @Override

     public void warning(SAXParseException exception) throws SAXParseException

     {

         throw exception;

     }

     @Override

     public Schema getSchema() throws NoSchemaException

     {

         try

         {

             InputStream inputStream = VariantXMLParser.class

                     .getResourceAsStream("/negotiation.xsd");

             StreamSource source = new StreamSource(inputStream);

             SchemaFactory schemaFactory = SchemaFactory

                     .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

             return schemaFactory.newSchema(source);

         }

         catch (SAXException exception)

         {

             throw new NoSchemaException(exception);

         }

     }

 }