package org.madore.damlengine;

import java.util.regex.Pattern;
import java.util.regex.Matcher;
import org.w3c.dom.*;

public class TodoWrefAttr extends TodoAttr {

    public static class Factory extends TodoAttr.Factory {
	@Override
	public TodoWrefAttr newItem(Attr attr, Element owner,
				    Context ctx,
				    TodoItem caller) {
	    return new TodoWrefAttr(attr, owner, ctx, caller);
	}
    }

    public TodoWrefAttr(Attr attr, Element owner,
			Context ctx,
			TodoItem caller) {
	super(attr, owner, ctx, caller);
    }

    @Override
    public void handle() {
	String wrefStr = attr.getValue();
	Matcher wrefMatcher = Pattern.compile("^\\#d\\.(\\d{4})-(\\d{2})-(\\d{2})\\.(\\d{4})(|\\..*)$").matcher(wrefStr);
	if ( ! wrefMatcher.matches() )
	    throw new IllegalArgumentException("wref attribute must be of the form #d.YYYY-MM-DD.NNNN[.xxx]");
	String wrefYearStr = wrefMatcher.group(1);
	String wrefMonthStr = wrefMatcher.group(2);
	String wrefDayStr = wrefMatcher.group(3);
	String wrefNumberStr = wrefMatcher.group(4);
	String wrefSupplementStr = wrefMatcher.group(5);
	String targetFile = "";
	if ( true )
	    targetFile = wrefYearStr + "-" + wrefMonthStr + ".html";
	String targetFragment = "d." + wrefYearStr + "-" + wrefMonthStr
	    + "-" + wrefDayStr + "." + wrefNumberStr + wrefSupplementStr;
	String target = targetFile + "#" + targetFragment;
	this.owner.removeAttribute(this.attr.getName());
	this.owner.setAttributeNS(null, "href", target);
	if ( ! this.owner.hasAttributeNS(null, "class") )
	    this.owner.setAttributeNS(null, "class", "weblog-internal-link");
    }

}