package org.madore.damlengine;

import java.util.Properties;
import java.util.regex.Pattern;
import java.security.MessageDigest;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.xpath.*;
import org.w3c.dom.*;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;
// import org.xml.sax.EntityResolver;
import org.apache.xerces.jaxp.DocumentBuilderFactoryImpl;
import org.apache.xerces.dom.DOMImplementationSourceImpl;
import org.postgresql.Driver;

public final class WeblogPopulate {

    private WeblogPopulate() { // Forbid instantiation
	throw new AssertionError("WeblogPopulate cannot be instantiated");
    }

    public static final String toHex(byte[] digest) {
	StringBuilder sb = new StringBuilder();
	for ( byte b : digest )
	    sb.append(String.format("%02x", b));
	return sb.toString();
    }

    public static void main(String[] args)
	throws Exception {

	final Resolver resolver = new Resolver();
        final DocumentBuilderFactory dbf = new DocumentBuilderFactoryImpl();
        dbf.setNamespaceAware(true);
        dbf.setValidating(false);
	final DocumentBuilder db = dbf.newDocumentBuilder();
	db.setEntityResolver(resolver);

	if ( args.length == 0 ) {
	    System.err.println("expecting filename as argument");
	}

        final DOMImplementationSource domisrc
	    = new DOMImplementationSourceImpl();
	final DOMImplementationLS domi
	    = (DOMImplementationLS)(domisrc.getDOMImplementation("LS"));
	LSSerializer ser = domi.createLSSerializer();
	ser.getDomConfig().setParameter("xml-declaration", false);

	MessageDigest sha1 = MessageDigest.getInstance("SHA-1");

	final String dbUrl = "jdbc:postgresql://localhost/weblog";
	final Properties dbProps = new Properties();
	dbProps.setProperty("user", "david");
	dbProps.setProperty("password", "IHATETHISWHYCANTIUSEUNIXDOMAINSOCKETS");
	dbProps.setProperty("ssl", "true");
	dbProps.setProperty("sslfactory", "org.postgresql.ssl.NonValidatingFactory");
	final Connection conn = (new Driver()).connect(dbUrl, dbProps);

	final PreparedStatement checkSt
	    = conn.prepareStatement("SELECT sha1 FROM entries WHERE id=?");
	final PreparedStatement insertSt
	    = conn.prepareStatement("INSERT INTO entries(id,edate,lang,title,title_xml,content,sha1) VALUES (?,?,?,?,?::xml,?::xml,?)");
	final PreparedStatement updateSt
	    = conn.prepareStatement("UPDATE entries SET (edate,mdate,lang,title,title_xml,content,sha1)=(?,DEFAULT,?,?,?::xml,?::xml,?) WHERE id=?");
	final PreparedStatement clearCatSt
	    = conn.prepareStatement("DELETE FROM incat WHERE id=?");
	final PreparedStatement setCatSt
	    = conn.prepareStatement("INSERT INTO incat(id,code) VALUES (?,?)");

	for (String fname : args) {
	    Document doc = db.parse(fname);
	    XPathFactory xpf = XPathFactory.newInstance();
	    XPath xp = xpf.newXPath();
	    xp.setNamespaceContext(new DamlEngine.DamlNSMapping());
	    XPathExpression expr = xp.compile("//d:weblog/d:entry");
	    XPathExpression texpr = xp.compile("d:title");
	    NodeList entries = (NodeList)(expr.evaluate(doc, XPathConstants.NODESET));
	    for ( int i=0 ; i<entries.getLength() ; i++ ) {
		Element ent = (Element)(entries.item(i));
		String idStr = ent.getAttributeNS(null, "number");
		if ( ! Pattern.matches("^\\d{4}$", idStr) )
		    throw new IllegalArgumentException("entry number attribute must be of the form NNNN");
		int id = Integer.parseInt(idStr);
		String date = ent.getAttributeNS(null, "date");
		if ( ! Pattern.matches("^\\d{4}-\\d{2}-\\d{2}$", date) )
		    throw new IllegalArgumentException("entry date attribute must be of the form YYYY-MM-DD");
		String catStr = ent.getAttributeNS(null, "cat");
		String[] catList = catStr.split("\\s+");
		String lang = LangHelper.getLangRec(ent);
		String content = ser.writeToString(ent);
		sha1.reset();
		String digest = toHex(sha1.digest(content.getBytes("UTF-8")));
		
		checkSt.setInt(1, id);
		ResultSet checkRes = checkSt.executeQuery();
		boolean exists = checkRes.next();
		if ( exists && checkRes.getString(1).equals(digest) )
		    continue;
		Node titleNode = (Node)(texpr.evaluate(ent, XPathConstants.NODE));
		String titleTxt = (titleNode != null) ? titleNode.getTextContent() : null;
		String titleXml = ser.writeToString(titleNode);
		conn.setAutoCommit(false);
		if ( exists ) {
		    System.err.println("Updating entry "+id);
		    updateSt.setString(1, date);
		    updateSt.setString(2, lang);
		    updateSt.setString(3, titleTxt);
		    updateSt.setString(4, titleXml);
		    updateSt.setString(5, content);
		    updateSt.setString(6, digest);
		    updateSt.executeUpdate();
		} else {
		    System.err.println("Registering entry "+id);
		    insertSt.setInt(1, id);
		    insertSt.setString(2, date);
		    insertSt.setString(3, lang);
		    insertSt.setString(4, titleTxt);
		    insertSt.setString(5, titleXml);
		    insertSt.setString(6, content);
		    insertSt.setString(7, digest);
		    insertSt.executeUpdate();
		}
		clearCatSt.setInt(1, id);
		clearCatSt.executeUpdate();
		for ( String cat : catList ) {
		    if ( ! cat.equals("") ) {
			setCatSt.setInt(1, id);
			setCatSt.setString(2, cat);
			setCatSt.executeUpdate();
		    }
		}
		conn.commit();
	    }
	}

	checkSt.close();
	insertSt.close();
	updateSt.close();
	clearCatSt.close();
	setCatSt.close();
	conn.close();

    }

}