package plugins.XMLLibrarian;

import java.util.HashMap;
import java.util.List;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import freenet.support.Logger;

/**
 * Required for using SAX parser on XML indices
 * 
 * @author swati
 * 
 */
public class LibrarianHandler extends DefaultHandler {
	private final String word;
	private final String md5;

	private int prefix;
	private boolean processingWord;
	private String prefixMatch;

	// now we need to adapt this to read subindexing 
	private boolean found_match;
	/** file id -> uri */
	private HashMap<String, String> uris;
	/** file id -> title */
	private HashMap<String, String> titles;
	private List<URIWrapper> fileuris;

	public LibrarianHandler(String word, List<URIWrapper> fileuris) throws Exception {
		this.fileuris = fileuris;
		this.word = word;
		md5 = XMLLibrarian.MD5(word);
	}

	public void setDocumentLocator(Locator value) {

	}

	public void endDocument() throws SAXException {
	}

	public void startDocument() throws SAXException {
		found_match = false;
		uris = new HashMap<String, String>();
		titles = new HashMap<String, String>();
	}

	public void startElement(String nameSpaceURI, String localName, String rawName, Attributes attrs)
	        throws SAXException {
		if (rawName == null) {
			rawName = localName;
		}
		String elt_name = rawName;
		/*
		 * Gives the maximum number of digits of md5 used for creating subindices
		 */
		if (elt_name.equals("prefix")) {
			prefix = Integer.parseInt(attrs.getValue("value"));
		}
		if (elt_name.equals("subIndex")) {
			try {
				//here we need to match and see if any of the subindices match the required substring of the word.
				for (int i = 0; i < prefix; i++) {
					if ((md5.substring(0, prefix - i)).equals(attrs.getValue("key"))) {
						prefixMatch = md5.substring(0, prefix - i);
						Logger.normal(this, "match found " + prefixMatch);
						Logger.minor(this, "word searched = " + word + " prefix matcheed = " + prefixMatch);
						break;
					}
				}
			}
			catch (Exception e) {
				Logger.error(this, "MD5 of the word" + word + "could not be calculated " + e.toString(), e);
			}
		}

		if (elt_name.equals("files"))
			processingWord = false;
		if (elt_name.equals("keywords"))
			processingWord = true;
		/*
		 * looks for the word in the given subindex file if the word is found then the parser
		 * fetches the corresponding fileElements
		 */
		if (elt_name.equals("word")) {
			try {
				found_match = false;
				String match = attrs.getValue("v");
				if (match.equals(word))
					found_match = true;
				//if((attrs.getValue("v")).equals(word)) found_match = true;
				Logger.minor(this, "word searched = " + word + " matched");
			} catch (Exception e) {
				Logger.error(this, "word key doesn't match" + e.toString(), e);
			}
		}

		if (elt_name.equals("file")) {
			//				try{
			//					FileWriter outp = new FileWriter("logfile",true);
			//				outp.write("word searched = "+word+" found_match = "+found_match+" processingWord "+processingWord+" \n");
			//				outp.close();
			//				}
			//				catch(Exception e){

			//				}
			if (processingWord == true && found_match == true) {
				URIWrapper uri = new URIWrapper();
				try{
					uri.URI = uris.get(attrs.getValue("id"));
					Logger.minor(this, "word searched = " + word + " file id = " + uri.URI);
					//uri.descr = "not available";
					synchronized(this){
						if(titles.containsKey(attrs.getValue("id")))
						{
							uri.descr = titles.get(attrs.getValue("id"));
							if ((uri.URI).equals(uri.descr))
								uri.descr = "not available";
						}
						else
							uri.descr = "not available";

						if (fileuris != null)
							fileuris.add(uri);
					}
				}
				catch (Exception e) {
					Logger.error(this, "Index format may be outdated " + e.toString(), e);
				}

			} else if (processingWord == false) {
				try {
					String id = attrs.getValue("id");
					String key = attrs.getValue("key");
					int l = attrs.getLength();
					String title;
					synchronized (this) {
						if (l >= 3) {
							try {
								title = attrs.getValue("title");
								//									FileWriter outp = new FileWriter("logfile",true);
								//									outp.write("found title "+title+" == \n");
								//									outp.close();
								titles.put(id, title);
							} catch (Exception e) {
								Logger.error(this, "Index Format not compatible " + e.toString(), e);
							}
						}

						uris.put(id, key);
					}
					//String[] words = (String[]) uris.values().toArray(new String[uris.size()]);
				}
				catch (Exception e) {
					Logger.error(this, "File id and key could not be retrieved. May be due to format clash", e);
				}
			}
		}
	}

	public String getPrefixMatch() {
		return prefixMatch;
	}

}