package fr.ifremer.quadrige3.core.security.remote;
   
   /*-
    * #%L
    * Quadrige3 Core :: Quadrige3 Client Core
    * $Id:$
    * $HeadURL:$
    * %%
    * Copyright (C) 2017 Ifremer
   * %%
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Affero General Public License as published by
   * the Free Software Foundation, either version 3 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 Affero General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   * #L%
   */
  
  import fr.ifremer.quadrige3.core.config.QuadrigeCoreConfiguration;
  import fr.ifremer.quadrige3.core.security.AuthenticationInfo;
  import fr.ifremer.quadrige3.core.service.administration.user.UserService;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.http.HttpStatus;
  import org.apache.http.auth.AuthScope;
  import org.apache.http.auth.UsernamePasswordCredentials;
  import org.apache.http.client.CredentialsProvider;
  import org.apache.http.client.config.RequestConfig;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.impl.client.BasicCredentialsProvider;
  import org.apache.http.impl.client.CloseableHttpClient;
  import org.apache.http.impl.client.HttpClients;
  import org.apache.http.util.EntityUtils;
  import org.nuiton.i18n.I18n;
  import org.springframework.stereotype.Service;
  
  import javax.annotation.Resource;
  import java.io.IOException;
  import java.net.URISyntaxException;
  import java.net.URL;
  
  import static org.nuiton.i18n.I18n.t;
  
  /**
   * <p>AuthenticationRemoteServiceImpl class.</p>
   *
   */
  @Service("authenticationRemoteService")
  public class AuthenticationRemoteServiceImpl implements AuthenticationRemoteService {
  
      private static final Log log = LogFactory.getLog(AuthenticationRemoteServiceImpl.class);
  
      @Resource(name = "userService")
      protected UserService userService;
      
      @Resource
      protected QuadrigeCoreConfiguration config;
      
      /** {@inheritDoc} */
      @Override
      public boolean canAuthenticate(AuthenticationInfo authenticationInfo) throws AuthenticationRemoteException {
          boolean authenticated = false;
          Boolean isExtranet = userService.isLoginExtranet(authenticationInfo.getLogin());
  
          try {
              // if we known username origin (intranet or extranet), authenticate only once on the origin server 
              if (isExtranet != null) {
                  authenticated = authenticate(isExtranet, authenticationInfo);
              }
              
              // if we don't known the username origin:
              else {
                  // try extranet first
                  authenticated = authenticate(true/*extranet*/, authenticationInfo);
                  
                  // then try intranet
                  if (!authenticated) {
                      authenticated = authenticate(false/*intranet*/, authenticationInfo);
                  }
              }
              
          } catch (IOException e) {
              log.error(I18n.t("quadrige3.error.authenticate.failed", e.getMessage()), e);
          } catch (URISyntaxException e) {
              throw new AuthenticationRemoteException(t("quadrige3.error.authenticate.failed", e, e.getMessage()));
          }
          return authenticated;
      }
      
      /* -- Internal methods -- */   
      
     private boolean authenticate(boolean isExtranet, AuthenticationInfo authenticationInfo) throws IOException, URISyntaxException {
         URL url = isExtranet ? config.getAuthenticationExtranetSiteUrl() : config.getAuthenticationIntranetSiteUrl();
         Integer timeOut = isExtranet ? config.getAuthenticationExtranetSiteTimeout() : config.getAuthenticationIntranetSiteTimeout();
         return authenticate(url, timeOut, authenticationInfo);
     }
     
     private boolean authenticate(URL url, Integer timeOut, AuthenticationInfo authenticationInfo) throws IOException, URISyntaxException {
         boolean success;
         
         if (log.isDebugEnabled()) {
             log.debug(String.format("try to authenticate on [%s]", url));
         }
 
         // build credentials information
         CredentialsProvider credentialProvider = new BasicCredentialsProvider();
         credentialProvider.setCredentials(new AuthScope(url.getHost(), url.getPort()),
             new UsernamePasswordCredentials(authenticationInfo.getLogin(), authenticationInfo.getPassword()));
 
         // build request config for timeout 
         RequestConfig config = RequestConfig.custom().setSocketTimeout(timeOut).setConnectTimeout(timeOut).build();
 
         // build http client (don't use HttpService because of use of different url and timeout)
         try (CloseableHttpClient httpclient = HttpClients.custom().setDefaultRequestConfig(config).setDefaultCredentialsProvider(credentialProvider).build()) {
             HttpGet httpget = new HttpGet(url.toURI());
             if (log.isDebugEnabled()) {
                 log.debug("Executing request : " + httpget.getRequestLine());
             }
 
             // execute request
             try (CloseableHttpResponse response = httpclient.execute(httpget)) {
                 if (log.isDebugEnabled()) {
                     log.debug("Received response : " + response.getStatusLine());
                 }
                 int statusCode = response.getStatusLine().getStatusCode();
                 success = statusCode == HttpStatus.SC_OK;
                 EntityUtils.consume(response.getEntity());
             }            
         }
         
         return success;
     }
 }