/*
    * 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.user2.login;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mycore.common.MCRSessionMgr;
  import org.mycore.common.MCRUserInformation;
  import org.mycore.frontend.servlets.MCRServlet;
  import org.mycore.frontend.servlets.MCRServletJob;
  import org.mycore.user2.MCRRealmFactory;
  import org.mycore.user2.MCRUser;
  import org.mycore.user2.MCRUserAttributeMapper;
  import org.mycore.user2.MCRUserManager;
  
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  
  /**
   * 
   * @author Ren\u00E9 Adler (eagle)
   */
  public class MCRShibbolethLoginServlet extends MCRServlet {
  
      private static final long serialVersionUID = 1L;
  
      private static Logger LOGGER = LogManager.getLogger(MCRShibbolethLoginServlet.class);
  
      public void doGetPost(MCRServletJob job) throws Exception {
          HttpServletRequest req = job.getRequest();
          HttpServletResponse res = job.getResponse();
  
          String msg = null;
  
          String uid = (String) req.getAttribute("uid");
          String userId = uid != null ? uid : req.getRemoteUser();
  
          if (userId != null) {
              final String realmId = userId.contains("@") ? userId.substring(userId.indexOf("@") + 1) : null;
              if (realmId != null && MCRRealmFactory.getRealm(realmId) != null) {
                  userId = realmId != null ? userId.replace("@" + realmId, "") : userId;
  
                  final Map<String, Object> attributes = new HashMap<>();
  
                  final MCRUserAttributeMapper attributeMapper = MCRRealmFactory.getAttributeMapper(realmId);
                  for (final String key : attributeMapper.getAttributeNames()) {
                      final Object value = req.getAttribute(key);
                      if (value != null) {
                          LOGGER.info("received {}:{}", key, value);
                          attributes.put(key, value);
                      }
                  }
  
                  MCRUserInformation userinfo;
  
                  MCRUser user = MCRUserManager.getUser(userId, realmId);
                  if (user != null) {
                      LOGGER.debug("login existing user \"{}\"", user.getUserID());
  
                      attributeMapper.mapAttributes(user, attributes);
                      user.setLastLogin();
                      MCRUserManager.updateUser(user);
  
                      userinfo = user;
                  } else {
                      userinfo = new MCRShibbolethUserInformation(userId, realmId, attributes);
                  }
  
                  MCRSessionMgr.getCurrentSession().setUserInformation(userinfo);
                  // MCR-1154
                  req.changeSessionId();
  
                  res.sendRedirect(res.encodeRedirectURL(req.getParameter("url")));
                  return;
              } else {
                  msg = "Login from realm \"" + realmId + "\" is not allowed.";
              }
          } else {
              msg = "Principal could not be received from IDP.";
          }
 
         job.getResponse().sendError(HttpServletResponse.SC_UNAUTHORIZED, msg);
     }
 }