package water.api;

import water.DKV;
import water.JettyHTTPD;
import water.fvec.Frame;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 */
public class DatasetServlet extends HttpServlet {

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response) {
    String uri = JettyHTTPD.getDecodedUri(request);
    try {
      boolean use_hex = false;
      String f_name = request.getParameter("frame_id");
      String hex_string = request.getParameter("hex_string");
      if (f_name == null) {
        throw new RuntimeException("Cannot find value for parameter \'frame_id\'");
      }
      if (hex_string != null && hex_string.toLowerCase().equals("true")) {
        use_hex = true;
      }

      Frame dataset = DKV.getGet(f_name);
      // TODO: Find a way to determing the hex_string parameter. It should not always be false
      InputStream is = dataset.toCSV(true, use_hex);
      response.setContentType("application/octet-stream");
      // Clean up the file name
      int x = f_name.length() - 1;
      boolean dot = false;
      for (; x >= 0; x--)
        if (!Character.isLetterOrDigit(f_name.charAt(x)) && f_name.charAt(x) != '_')
          if (f_name.charAt(x) == '.' && !dot) dot = true;
          else break;
      String suggested_fname = f_name.substring(x + 1).replace(".hex", ".csv");
      if (!suggested_fname.endsWith(".csv"))
        suggested_fname = suggested_fname + ".csv";
      f_name = suggested_fname;
      response.addHeader("Content-Disposition", "attachment; filename=" + f_name);
      JettyHTTPD.setResponseStatus(response, HttpServletResponse.SC_OK);
      OutputStream os = response.getOutputStream();
      water.util.FileUtils.copyStream(is, os, 2048);
    } catch (Exception e) {
      JettyHTTPD.sendErrorResponse(response, e, uri);
    } finally {
      JettyHTTPD.logRequest("GET", request, response);
    }
  }

}