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

import java.io.IOException;
import java.io.PrintWriter;

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.lt.text.transcode.Transcoder;

public class Transcode extends HttpServlet {
  private static final long serialVersionUID = 1L;
  private Transcoder transcoder;

  public Transcode() {
    super();
  }

  public void init(ServletConfig config) throws ServletException  {
    super.init(config);
    transcoder = Transcoder.getInstance();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");
    String inputString = request.getParameter("inputString");
    String srcEncoding = request.getParameter("srcEncoding");
    String destEncoding = request.getParameter("destEncoding");
    if (destEncoding == null)
      destEncoding = "unicode";
    String result = null;
    try {
      response.setContentType("text/html");
      PrintWriter out = response.getWriter();
      if (inputString == null || inputString.isEmpty()) {
        out.print("request parameter \"inputString\" is empty. Please specify \"inputString\"");
        out.close();
        return;
      }
      if (srcEncoding == null || srcEncoding.isEmpty()) {
        out.print("request parameter \"srcEncoding\" is empty. Please specify \"srcEncoding\"");
        out.close();
        return;
      }
      if (destEncoding == null || destEncoding.isEmpty()) {
        out.print("request parameter \"destEncoding\" is empty. Please specify \"destEncoding\"");
        out.close();
        return;
      }
      if (srcEncoding.equals("buckwalter") && destEncoding.equals("unicode")) {
        result = transcoder.transcodeFromBuckwalter2Unicode(inputString);
      } else if (srcEncoding.equals("betacode") && destEncoding.equals("unicode")) {
        result = transcoder.transcodeFromBetaCode2Unicode(inputString);
      } else if (srcEncoding.equals("unicode") && destEncoding.equals("betacode")) {
        result = transcoder.transcodeFromUnicode2BetaCode(inputString);
      } else if (srcEncoding.equals("unicode") && destEncoding.equals("buckwalter")) {
        result = transcoder.transcodeFromUnicode2Buckwalter(inputString);
      } else {
        result = "your combination of \"srcEncoding\" and \"destEncoding\" is not yet supported";
      }
      if (result != null)
        out.print(result);
      out.close();
    } catch (ApplicationException e) { 
      throw new ServletException(e);
    }
  }

  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doGet(request, response);
  }  
}