/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe 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 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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 MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.frontend.servlets;
  
  import java.security.Principal;
  import java.util.Optional;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mycore.common.MCRSession;
  import org.mycore.common.MCRSessionMgr;
  import org.mycore.common.MCRSystemUserInformation;
  import org.mycore.common.MCRUserInformation;
  import org.mycore.frontend.MCRFrontendUtil;
  
  import jakarta.servlet.http.HttpServletRequest;
  
  /**
   * @author Thomas Scheffler (yagee)
   *
   */
  public class MCRContainerLoginServlet extends MCRServlet {
  
      private static final long serialVersionUID = 1L;
  
      private static final Logger LOGGER = LogManager.getLogger(MCRContainerLoginServlet.class);
  
      /* (non-Javadoc)
       * @see org.mycore.frontend.servlets.MCRServlet#think(org.mycore.frontend.servlets.MCRServletJob)
       */
      @Override
      protected void think(MCRServletJob job) throws Exception {
          MCRSession session = MCRSessionMgr.getCurrentSession();
          session.setUserInformation(new ContainerUserInformation(session));
          LOGGER.info("Logged in: {}", session.getUserInformation().getUserID());
      }
  
      /* (non-Javadoc)
       * @see org.mycore.frontend.servlets.MCRServlet#render(org.mycore.frontend.servlets.MCRServletJob, java.lang.Exception)
       */
      @Override
      protected void render(MCRServletJob job, Exception ex) throws Exception {
          String backToUrl = getProperty(job.getRequest(), "url");
  
          if (backToUrl == null) {
              String referer = job.getRequest().getHeader("Referer");
              backToUrl = (referer != null) ? referer : MCRFrontendUtil.getBaseURL();
          }
          job.getResponse().sendRedirect(job.getResponse().encodeRedirectURL(backToUrl));
      }
  
      protected static class ContainerUserInformation implements MCRUserInformation {
          protected MCRSession session;
  
          String lastUser;
  
          public ContainerUserInformation(MCRSession session) {
              this.session = session;
          }
  
          @Override
          public String getUserID() {
              lastUser = getCurrentRequest()
                  .flatMap(r -> Optional.ofNullable(r.getUserPrincipal()))
                  .map(Principal::getName)
                  .orElseGet(() -> Optional.ofNullable(lastUser)
                      .orElseGet(MCRSystemUserInformation.getGuestInstance()::getUserID));
              return lastUser;
          }
  
          @Override
          public boolean isUserInRole(String role) {
              return getCurrentRequest().map(r -> r.isUserInRole(role)).orElse(Boolean.FALSE);
          }
  
          @Override
          public String getUserAttribute(String attribute) {
              return null;
          }
  
          protected Optional<HttpServletRequest> getCurrentRequest() {
              LogManager.getLogger(getClass()).debug("Getting request from session: {}", session.getID());
              return MCRFrontendUtil.getCurrentServletJob()
                 .map(MCRServletJob::getRequest);
         }
     }
 
 }