package at.gv.egiz.bku.online.webapp;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.gv.egiz.bku.binding.BindingProcessor;
import at.gv.egiz.bku.binding.Id;
import at.gv.egiz.bku.binding.IdFactory;
import at.gv.egiz.bku.slexceptions.SLRuntimeException;
import at.gv.egiz.bku.utils.StreamUtil;
import at.gv.egiz.stal.HashDataInput;
import at.gv.egiz.stal.STAL;
import at.gv.egiz.stal.service.impl.STALRequestBroker;

public class HashDataInputServlet extends SpringBKUServlet {

  private static Log log = LogFactory.getLog(HashDataInputServlet.class);

  public HashDataInputServlet() {

  }

  private STALRequestBroker getSTAL(Id id) {
    BindingProcessor bp = getBindingProcessorManager().getBindingProcessor(id);
    if (bp == null) {
      return null;
    }
    STAL stal = bp.getSTAL();
    if (stal instanceof STALRequestBroker) {
      return (STALRequestBroker) stal;
    } else {
      throw new SLRuntimeException("Unexpected STAL type");
    }
  }

  private static boolean isMSIE(HttpServletRequest req) {
    String useragent = req.getHeader("User-Agent");
    String user = useragent.toLowerCase();
    return (user.indexOf("msie") != -1);
  }

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    if ((req.getSession() == null) && (req.getSession().getId() != null)) {
      log.warn("Got request for hashdatainput without session info");
      resp.sendRedirect("expired.html");
      return;
    }
    Id sessionId = IdFactory.getInstance().createId(req.getSession().getId());
    log.debug("Got request for hashdata for session " + sessionId);
    STALRequestBroker rb = getSTAL(sessionId);
    if (rb == null) {
      log.info("STAL instance not found for session: " + sessionId);
      resp.sendRedirect("expired.html");
      return;
    }
    List<HashDataInput> hdi = rb.getHashDataInput();
    log.debug("Got hashdata list with " + hdi.size() + " entries");
    String param = req.getParameter("refId");
    log.debug("Got request for refId:" + param);
    if ((param == null) && (hdi.size() > 1)) {
      resp.sendRedirect("multiHashDataInput.html");
      return;
    }

    if ((param == null) && (hdi.size() == 1)) {
      param = hdi.get(0).getReferenceId();
      log.debug("Request parameter not set, setting to: " + param);
    }
    for (HashDataInput hd : hdi) {
      if (hd.getReferenceId().equals(param)) {
        log.debug("Found hashdatainput for refId:" + param);
        resp.setContentType(hd.getMimeType());

        String charSet = hd.getEncoding();
        if (charSet == null) {
          charSet = "UTF-8";
        }
        resp.setCharacterEncoding(charSet);
        if (isMSIE(req)) {
          String fileExt = hd.getMimeType().equalsIgnoreCase("text/plain") ? ".txt"
              : ".xhtml";
          if (fileExt.equals(".xhtml")) {
            if (req.getParameter("ieCType") == null) {
              resp.sendRedirect("ieView.html");
              return;
            } else {
              resp.setContentType(req.getParameter("ieCType"));
              if (req.getParameter("ieCType").equals("application/xhtml+xml")) {
                resp.addHeader("content-disposition", "attachment; filename="
                    + param + ".xhtml");
              }
            }
          }
        }
        Reader r = new InputStreamReader(hd.getHashDataInput(), charSet);
        Writer w = new OutputStreamWriter(resp.getOutputStream(), charSet);
        StreamUtil.copyStream(r, w);
        w.flush();
        return;

      }
    }
    log.error("Cannot find hashdata for id:" + param);
    resp.sendError(404);
    return;
  }

  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    doGet(req, resp);
  }

}