import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URI;
import java.util.Date;
import java.util.Enumeration;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


public class ShardulFilter implements Filter {

    public void doFilter(ServletRequest req0, ServletResponse res0, FilterChain chain) throws IOException,
                                                                                     ServletException {

        HttpServletRequest req = (HttpServletRequest)req0;
        HttpServletResponse res = (HttpServletResponse)res0;
        String ref = req.getHeader("Referer");
        if (ref != null) {
            try {
                URI refUri = new URI(ref);
                String host = refUri.getHost();
                if (host != null && host.toLowerCase().endsWith(".wordpress.com")) {
                    logRequest("redirect", req, null);
                    res.sendRedirect("http://www.forkalsrud.org/stalker.jpg");
                    return;
                }
            } catch (Exception e) {
                logRequest("error", req, e);
            }
        }
        chain.doFilter(req, res);
    }

    private void logRequest(String string, HttpServletRequest req, Exception e) {

        try {
            File logfile = new File(System.getProperty("user.home"), "stalker.log");
            FileWriter fw = new FileWriter(logfile, true);
            fw.write("--------------------\n");
            fw.write("" + new Date() + "\n");
            fw.write("IP: " + req.getRemoteAddr() + " " + req.getRemoteHost() + " " + req.getRequestURL().toString() + "\n");
            Enumeration enm = req.getParameterNames();
            while (enm.hasMoreElements()) {
                String param = (String)enm.nextElement();
                String[] val = req.getParameterValues(param);
                for (String s : val) {
                    fw.write("param " + param + ": " + s + "\n");
                }
            }
            fw.write("\n");
            enm = req.getHeaderNames();
            while (enm.hasMoreElements()) {
                String header = (String)enm.nextElement();
                String val = req.getHeader(header);
                fw.write(header + ": " + val + "\n");
            }
            fw.write("\n");
            if (e != null) {
                e.printStackTrace(new PrintWriter(fw, true));
            }
            fw.write("\n");
            fw.flush();
            fw.close();
        } catch (IOException e1) {
            e1.printStackTrace();
        } 
    }

    public void init(FilterConfig arg0) throws ServletException {
        // noop
    }

    public void destroy() {
        // noop
    }

}