package org.madore.damlengine;

import java.util.regex.Pattern;
import java.util.regex.Matcher;
import java.io.InputStream;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.BufferedReader;
import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
// import org.xml.sax.EntityResolver;
import org.apache.xerces.jaxp.DocumentBuilderFactoryImpl;

public final class DamlEngine {

    public static final String XMLNS_NS = XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
    public static final String XML_NS = XMLConstants.XML_NS_URI;
    public static final String XHTML_NS = "http://www.w3.org/1999/xhtml";
    public static final String DAML_NS = "http://www.madore.org/~david/NS/daml/";
    public static final String RDF_NS = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
    public static final String RSS10_NS = "http://purl.org/rss/1.0/";
    public static final String DUBLINCORE_NS = "http://purl.org/dc/elements/1.1/";
    public static final String SYNDICATION_NS = "http://purl.org/rss/1.0/modules/syndication/";

    public static final class DamlNSMapping implements NamespaceContext {
	// This is used for XPath resolution (_not_ for parsing the document).
	public String getNamespaceURI(String prefix) {
	    if ( prefix == null )
		throw new IllegalArgumentException("getNamespaceURI() called with null prefix");
	    else if ( prefix.equals("") )
		return XHTML_NS;
	    else if ( prefix.equals("d") )
		return DAML_NS;
	    else if ( prefix.equals("xml") )
		return XML_NS;
	    else if ( prefix.equals("xmlns") )
		return XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
	    else
		return XMLConstants.NULL_NS_URI;
	}
	public String getPrefix(String uri) {
	    throw new UnsupportedOperationException("getPrefix() not implemented");
	}
	public java.util.Iterator<String> getPrefixes(String uri) {
	    throw new UnsupportedOperationException("getPrefixes() not implemented");
	}
    }

    public static final class GetDocumentBuilder {
	static final DocumentBuilder db;
	static {
	    final Resolver resolver = new Resolver();
	    final DocumentBuilderFactory dbf = new DocumentBuilderFactoryImpl();
	    dbf.setNamespaceAware(true);
	    dbf.setValidating(false);
	    try {
		db = dbf.newDocumentBuilder();
	    } catch (ParserConfigurationException e) {
		throw new RuntimeException(e);
	    }
	    db.setEntityResolver(resolver);
	}
    }

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

    public static class RootTodo extends TodoItem {
	public RootTodo(Context ctx) {
	    super(ctx, null);
	}
	public void handle() {
	    TodoItem it
		= TodoElement.getTodoElement(ctx.doc.getDocumentElement(),
					     ctx, this);
	    this.ownerDeque.registerAtEnd(it);
	}
    }

    public static void processDocument(Document doc,
				       Context.WeblogSelectionContext wsc) {
	TodoDeque todoDeque = new TodoDeque();
	Context ctx = new Context(doc);
	ctx.wsc = wsc;
	todoDeque.registerAtEnd(new RootTodo(ctx));
	todoDeque.dispatchLoop();
    }

    public static void processDocument(Document doc) {
	processDocument(doc, null);
    }

    public static void fullProcess(InputStream in, OutputStream out,
				   Context.WeblogSelectionContext wsc)
	throws Exception {

	final DocumentBuilder db = GetDocumentBuilder.db;

	Document doc = db.parse(in);
	processDocument(doc, wsc);
	doc.normalizeDocument();
	Unparser unparser
	    = new Unparser(doc, new OutputStreamWriter(out, "UTF-8"),
			   "html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\"");
	unparser.unparse();

    }

    public static void fullProcess(InputStream in, OutputStream out)
	throws Exception {
	fullProcess(in, out, null);
    }

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

	BufferedReader buf = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
	String line;
	Matcher matcher;

	while ( ( line = buf.readLine() ) != null ) {
	    if ( Pattern.matches("^\\s+$", line) )
		continue;
	    System.err.println(line);
	    if ( (matcher=Pattern.compile("process\\s+(\\S+)(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		String inf = matcher.group(1);
		String outf = matcher.group(2);
		InputStream in = new FileInputStream(inf);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		fullProcess(in, out);
	    } else if ( (matcher=Pattern.compile("process-weblog-month\\s+(\\d{4})\\-(\\d{2})(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		String year = matcher.group(1);
		String month = matcher.group(2);
		String outf = matcher.group(3);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		WeblogSelect.fullProcess(new Context.WeblogMonthSelectionContext(year,month),
					 out);
	    } else if ( (matcher=Pattern.compile("process-weblog-cat\\s+([a-z0-9\\-]+)(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		String code = matcher.group(1);
		String outf = matcher.group(2);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		WeblogSelect.fullProcess(new Context.WeblogCategorySelectionContext(code),
					 out);
	    } else if ( (matcher=Pattern.compile("process-weblog-recent\\s+(\\d+)(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		int count = Integer.parseInt(matcher.group(1));
		String outf = matcher.group(2);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		WeblogSelect.fullProcess(new Context.WeblogRecentSelectionContext(count),
					 out);
	    } else if ( (matcher=Pattern.compile("process-weblog-index(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		String outf = matcher.group(1);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		WeblogIndexSelect.fullProcess(out);
	    } else if ( (matcher=Pattern.compile("process-weblog-rss(?:\\s+\\>\\s*(\\S+))?\\s*").matcher(line)).matches() ) {
		String outf = matcher.group(1);
		OutputStream out = (outf != null)
		    ? new FileOutputStream(outf)
		    : System.out;
		WeblogRSS.fullProcess(out);
	    } else if ( (matcher=Pattern.compile("populate-weblog\\s+(\\S+)\\s*").matcher(line)).matches() ) {
		String inf = matcher.group(1);
		InputStream in = new FileInputStream(inf);
		WeblogPopulate.populate(in);
	    } else {
		throw new IllegalArgumentException("couldn't understand command");
	    }
	}

    }

}