package de.mpg.mpiwg.berlin.mpdl.servlets.xml;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;

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

import de.mpg.mpiwg.berlin.mpdl.exception.ApplicationException;
import de.mpg.mpiwg.berlin.mpdl.xml.xquery.XQueryEvaluator;

public class XQuery extends HttpServlet {
  private static final long serialVersionUID = 1L;
  private XQueryEvaluator xqueryEvaluator;

  public XQuery() {
    super();
  }

  public void init(ServletConfig config) throws ServletException  {
    super.init(config);
    xqueryEvaluator = new XQueryEvaluator();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    String result = null; 
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");
    String inputString = request.getParameter("inputString");
    String srcUrlStr = request.getParameter("srcUrl");
    String xqueryStr = request.getParameter("xquery");
    try {
      if (inputString != null) {
        result = xqueryEvaluator.evaluateAsString(inputString, xqueryStr);
      } else if (srcUrlStr != null) {
        URL srcUrl = new URL(srcUrlStr);
        result = xqueryEvaluator.evaluateAsString(srcUrl, xqueryStr);
      }
      response.setContentType("text/xml");
      PrintWriter out = response.getWriter();
      out.print("<result>" + result + "</result>"); 
      out.close(); 
    } catch (ApplicationException e) {
      throw new ServletException(e);
    }
  }

}