package jpos.config.simple.xml;

///////////////////////////////////////////////////////////////////////////////
//
// This software is provided "AS IS".  The JavaPOS working group (including
// each of the Corporate members, contributors and individuals)  MAKES NO
// REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE SOFTWARE,
// EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED 
// WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
// NON-INFRINGEMENT. The JavaPOS working group shall not be liable for
// any damages suffered as a result of using, modifying or distributing this
// software or its derivatives. Permission to use, copy, modify, and distribute
// the software and its documentation for any purpose is hereby granted. 
//
// The JavaPOS Config/Loader (aka JCL) is now under the CPL license, which 
// is an OSS Apache-like license.  The complete license is located at:
//    http://oss.software.ibm.com/developerworks/opensource/license-cpl.html
//
///////////////////////////////////////////////////////////////////////////////

import java.io.*;
import java.util.*;
import java.net.URL;
import java.text.DateFormat;

import java.io.PrintWriter;

import org.apache.xerces.dom.DOMImplementationImpl;
import org.apache.xerces.parsers.DOMParser;
import org.apache.xml.serialize.OutputFormat;
import org.apache.xml.serialize.XMLSerializer;

import org.w3c.dom.*;
                  
import jpos.config.*;
import jpos.config.simple.*;
import jpos.util.*;
import jpos.util.tracing.Tracer;
import jpos.util.tracing.TracerFactory;

/**
 * This class is an abstract super class for all Xerces based parser/reg 
 * populator with functionality to serialize an enumeration of JposEntry 
 * objects into XML 
 * <p>
 * <b>NOTE</b>: this class must define a public no-argument ctor so that it may be 
 * created via reflection when its defined in the jpos.properties as the 
 * jpos.config.regPopulatorClass
 * </p>
 * @see jpos.util.JposProperties#JPOS_REG_POPULATOR_CLASS_PROP_NAME
 * @since 2.1.0
 * @author E. Michael Maximilien (maxim@us.ibm.com)
 */
public abstract class AbstractXercesRegPopulator 
				  extends AbstractRegPopulator 
				  implements XmlRegPopulator
{
    //-------------------------------------------------------------------------
    // Ctor(s)
    //

    /**
     * 1-arg constructor that takes the unique ID
	 * @param s the unique ID string
     * @since 1.3 (Washington DC 2001)
     */
    public AbstractXercesRegPopulator( String s ) { super( s ); }

    //-------------------------------------------------------------------------
    // Public methods
    //

    /**
     * Tell the populator to save the current entries 
     * @param entries an enumeration of JposEntry objects
     * @since 1.2 (NY 2K meeting)
     * @throws java.lang.Exception if any error occurs while saving
     */
    public void save( Enumeration entries ) throws Exception
    {
        if( isPopulatorFileDefined() )
            convertJposEntriesToXml( entries, getPopulatorFileOS() );
        else
            convertJposEntriesToXml( entries, 
       		new FileOutputStream( getDefaultXmlFileName() ) );
    }

    /**
     * Tell the populator to save the current entries in the file specified 
     * @param entries an enumeration of JposEntry objects
     * @param xmlFileName the XML file name to save entries
     * @since 1.3 (SF 2K meeting)
     * @throws java.lang.Exception if any error occurs while saving
     */
    public void save( Enumeration entries, String xmlFileName ) 
    throws Exception
    { 
		File xmlFile = new File( xmlFileName );
		FileOutputStream fos = new FileOutputStream( xmlFile );

		convertJposEntriesToXml( entries, fos ); 

		fos.close();
	}

    /**
     * @return the URL pointing to the entries file loaded or saved
     * @since 1.2 (NY 2K meeting)
     */
    public URL getEntriesURL()
    {
        URL url = null;

        if( getPopulatorFileURL() != null && 
        	!getPopulatorFileURL().equals( "" ) )
            try
            { url =  new URL( getPopulatorFileURL() ); }
            catch( Exception e ) 
            {
            	tracer.println( "getEntriesURL: Exception.message=" + 
            					e.getMessage() );
            }
        else
            url = createURLFromFile( new File( getPopulatorFileName() ) );
            
		//<temp>            
		tracer.println( "getPopulatorFileURL()=" + getPopulatorFileURL() );
		tracer.println( "getPopulatorFileName()=" + getPopulatorFileName() );
		//</temp>

        return url;
    }

    //--------------------------------------------------------------------------
    // Protected methods
    //

	/** @return the Tracer object */
	protected Tracer getTracer() { return tracer; }
	
	/** 
	 * @return the default XML file name that this populator will save 
	 * entries to 
	 */
	protected String getDefaultXmlFileName() { return xmlFileName; }
	    
    /**
     * Converts an Enumeration of JposEntry objects to XML
     * @param entries an Enumeration of JposEntry objects
     * @param os the OutputStream to stream the entries to
     * @exception java.lang.Exception if something goes wrong serializing
     * @since 1.2 (NY 2K meeting)
     */
    protected void convertJposEntriesToXml( Enumeration entries,
                                              OutputStream os ) 
    throws Exception
    {
        Document document = getParser().getDocument();
        serializeDocument( document, entries, os );
    }
    
    /**
     * @return the DOM parser object
     * @since 1.2 (NY 2K meeting)
     */
    protected DOMParser getParser() { return domParser; }

    /**
     * Serializes the JposEntry objects to an XML document and save to OutputStream
     * @param document the XML document object
     * @param entries an Enumeration of JposEntry objects
     * @param os the OuputStream object
     * @exception java.lang.Exception anything goes wrong while saving
     * @since 1.2 (NY 2K meeting)
     */
    protected void serializeDocument( Document document, 
    									Enumeration entries, 
    									OutputStream os ) throws Exception
    {
        Document newDoc = createEmptyDocument();

        insertJposEntriesInDoc( newDoc, entries );

        insertDateSavedComment( newDoc );

        OutputFormat outFormat = new OutputFormat( "xml", "UTF-8", true );

        outFormat.setStandalone( false );
        outFormat.setIndenting( true );
        outFormat.setIndent( 4 );
        outFormat.setPreserveSpace( true );
        outFormat.setLineWidth( 0 );

        insertDTDInfo( newDoc, outFormat );

        PrintWriter outWriter = null;
		try
		{
			outWriter = new PrintWriter
			(new BufferedWriter(new OutputStreamWriter(os, "UTF-8")));
		}
		catch( UnsupportedEncodingException ex )
		{ 
			tracer.println( "Error making PrintWriter: " + 
			                "UnsupportedEncodingException.message = " + 
			                ex.getMessage() );
		}

		if( outWriter != null )
		{
			XMLSerializer xmlSerializer = new XMLSerializer( outWriter, outFormat );
			xmlSerializer.serialize( newDoc );
		}
    }

	/**
	 * @return a String with the document type definition value.  For DTD this
	 * would be the DTD relative path/file and for schemas the XSD 
	 * relative path/file
	 * @since 2.1.0
	 */
	protected String getDoctypeValue() { return "jpos/res/jcl.dtd"; }

    /**
     * Inset DTD information in the XML Document object
     * @param doc the XML Document object
     * @param outFormat the OuputFormat object
     * @exception java.lang.Exception in case something goes wrong
     * @since 1.2 (NY 2K meeting)
     */
    protected void insertDTDInfo( Document doc, OutputFormat outFormat ) throws Exception
    {
        String publicId = OutputFormat.whichDoctypePublic( doc );
        String systemId = OutputFormat.whichDoctypeSystem( doc );

        outFormat.setDoctype( "JposEntries", getDoctypeValue() );
    }

    /**
     * @return an empty XML Document object
     * @since 1.2 (NY 2K meeting)
     */
    protected Document createEmptyDocument()
    {
        DOMImplementationImpl domImpImpl = (DOMImplementationImpl)
        					  DOMImplementationImpl.getDOMImplementation();
        DocumentType docType = domImpImpl.
        					   createDocumentType( "JposEntries", 
        					   					   "-//JavaPOS//DTD//EN", 
        					   					   getDoctypeValue() );
        					   					   
        Document doc = domImpImpl.createDocument( null, "JposEntries", docType );

        return doc;
    }
    
    /**
     * Inserts date and info saved in the XML Document object
     * @param document the XML Document object
     * @exception java.lang.Exception in case something goes wrong
     * @since 1.2 (NY 2K meeting)
     */
    protected void insertDateSavedComment( Document document ) 
    throws Exception
    {
        String dateString = DateFormat.getInstance().
                            format( new Date( System.currentTimeMillis() ) );

        String commentString = 
        "Saved by JavaPOS jpos.config/loader (JCL) version " + 
        Version.getVersionString() + " on " + dateString;

        Comment comment = document.createComment( commentString );