/*
 * WordListFileLoader.java
 *
 * Created on January 16, 2005, 8:57 PM
 */

package com.toy.anagrams.lib;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.Attributes;

/**
 *
 * @author bsuter
 */
public class WordListFileLoader {
    
    /** Creates a new instance of WordListFileLoader */
    public WordListFileLoader() {
        out = System.out;
    }
    
    public String[] loadList(String url)
    {
        InputStream is;
        try {
                URL u = new URL(url);
                is = u.openConnection().getInputStream();
        } catch (IOException ioe) {
            report("Unable to open or find the specified wordlist.");
            is = null;
        }
        
        if (is == null)
        {
            report("Unable to load the requested wordlist. An error occurred while opening the file.");
            return null;
        }
        
        SAXParserFactory parserFactory = SAXParserFactory.newInstance();
        SAXParser parser;
        try {
          parser = parserFactory.newSAXParser();
        } catch ( ParserConfigurationException pce ) {
            report("Error setting up the XML Parser. The parser is not properly configured. Loading aborted.");
            return null;
        } catch ( SAXException saxe ) {
            report("Error setting up the XML Parser. Loading aborted.");
            return null;
        }

        try {
            WordListHandler handler = new WordListHandler();
            parser.parse(is, handler);
        } catch ( Exception e ) {
            report("Unable to load the list, probably while performing SAX parsing.");
            return null;
        }
        
        return this.list;
    }
    
    public class WordListHandler extends DefaultHandler 
    {
        protected String nodeType;
        protected ArrayList al;
        
        public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException
        {
            if ( qName == "word" ) 
            {
                nodeType = "word";
            } else if ( qName == "wordlist" ) {
               al = new ArrayList();
            }
        }

        public void endElement(String uri, String localName, String qName) throws SAXException
        {
             if ( qName == "word" ) 
             {
                 nodeType = null;
             } else if (qName == "wordlist" ) {
                 /* Cast the ArrayList to a an array of String objects. */
                 list = (String[]) this.al.toArray(new String[al.size()]);
             }
        }
        
        public void characters(char[] chars, int start, int length) throws SAXException
        {
            if ( this.nodeType == "word" )
            {
                this.al.add(new String(chars, start, length).trim());
            }
        }
    }
    
    protected void report(String message)
    {
        this.out.println(message);
    }
    
    protected PrintStream out;
    protected String[] list;
}