/*
    * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway
    * Copyright (C) 2010  Mickael Guessant
    *
    * This program is free software; you can redistribute it and/or
    * modify it under the terms of the GNU General Public License
    * as published by the Free Software Foundation; either version 2
    * of the License, or (at your option) any later version.
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   */
  
  package davmail.exchange.ews;
  
  import org.apache.http.Header;
  import org.apache.http.HttpResponse;
  import org.apache.http.client.ResponseHandler;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.entity.ContentType;
  import org.apache.http.entity.StringEntity;
  import org.apache.log4j.Logger;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.nio.charset.StandardCharsets;
  
  public class AutoDiscoverMethod extends HttpPost implements ResponseHandler {
  
      protected static final Logger LOGGER = Logger.getLogger(AutoDiscoverMethod.class);
  
      public AutoDiscoverMethod(String url, String userEmail) {
          super(url);
          setRequestEntity(userEmail);
      }
  
      private void setRequestEntity(String userEmail) {
          String body = "<Autodiscover xmlns=\"http://schemas.microsoft.com/exchange/autodiscover/outlook/requestschema/2006\">" +
                  "<Request>" +
                  "<EMailAddress>" + userEmail + "</EMailAddress>" +
                  "<AcceptableResponseSchema>http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a</AcceptableResponseSchema>" +
                  "</Request>" +
                  "</Autodiscover>";
          setEntity(new StringEntity(body, ContentType.create("text/xml", "UTF-8")));
      }
  
      @Override
      public Object handleResponse(HttpResponse response) throws IOException {
          String ewsUrl = null;
          try {
              Header contentTypeHeader = response.getFirstHeader("Content-Type");
              if (contentTypeHeader != null &&
                      ("text/xml; charset=utf-8".equals(contentTypeHeader.getValue())
                              || "text/html; charset=utf-8".equals(contentTypeHeader.getValue())
                      )) {
                  BufferedReader autodiscoverReader = null;
                  try {
                      autodiscoverReader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), StandardCharsets.UTF_8));
                      String line;
                      // find ews url
                      //noinspection StatementWithEmptyBody
                      while ((line = autodiscoverReader.readLine()) != null
                              && (!line.contains("<EwsUrl>"))
                              && (!line.contains("</EwsUrl>"))) {
                      }
                      if (line != null) {
                          ewsUrl = line.substring(line.indexOf("<EwsUrl>") + 8, line.indexOf("</EwsUrl>"));
                      }
                  } catch (IOException e) {
                      LOGGER.debug(e);
                  } finally {
                      if (autodiscoverReader != null) {
                          try {
                              autodiscoverReader.close();
                          } catch (IOException e) {
                              LOGGER.debug(e);
                          }
                      }
                  }
              }
  
          } finally {
              ((CloseableHttpResponse) response).close();
          }
          return ewsUrl;
      }
  }