/*
    * Copyright 2018 Hippo B.V. (http://www.onehippo.com)
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *         http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.onehippo.forge.hst.spring.support.session.servlet;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpSession;
  
  import org.springframework.session.SessionRepository;
  
  /**
   * {@link SessionRepository} implementation simply by delegating call to the underlying servlet container's {@link HttpSession}.
   */
  public class HttpSessionDelegatingRepository implements SessionRepository<HttpSessionDelegatingSession> {
  
      @Override
      public HttpSessionDelegatingSession createSession() {
          final HttpServletRequest request = HttpSessionDelegatingContext.getCurrentServletRequest();
  
          if (request == null) {
              throw new IllegalStateException("HttpServletRequest not found yet.");
          }
  
          final HttpSession httpSession = request.getSession(true);
          final HttpSessionDelegatingSession session = new HttpSessionDelegatingSession(httpSession);
          httpSession.setAttribute(HttpSessionDelegatingSession.NAME, session);
  
          return session;
      }
  
      @Override
      public void save(HttpSessionDelegatingSession session) {
          // Nothing to do as container's session management does care of it.
      }
  
      @Override
      public HttpSessionDelegatingSession findById(String id) {
          final HttpServletRequest request = HttpSessionDelegatingContext.getCurrentServletRequest();
          final HttpSession httpSession = (request != null) ? request.getSession(false) : null;
  
          if (httpSession == null) {
              return null;
          }
  
          HttpSessionDelegatingSession session = (HttpSessionDelegatingSession) httpSession.getAttribute(HttpSessionDelegatingSession.NAME);
  
          if (session != null) {
              // If previous JSESSIONID cookie in browser's in-memory session remains while tomcat gets restarted,
              // then we need to recreate Session again.
              if (!httpSession.getId().equals(id)) {
                  session = new HttpSessionDelegatingSession(httpSession);
                  httpSession.setAttribute(HttpSessionDelegatingSession.NAME, session);
              }
          }
  
          return session;
      }
  
      @Override
      public void deleteById(String id) {
          final HttpServletRequest request = HttpSessionDelegatingContext.getCurrentServletRequest();
          final HttpSession httpSession = (request != null) ? request.getSession(false) : null;
  
          if (httpSession == null) {
              return;
          }
  
          HttpSessionDelegatingSession session = (HttpSessionDelegatingSession) httpSession.getAttribute(HttpSessionDelegatingSession.NAME);
  
          if (session != null) {
              if (session.getId().equals(id)) {
                  httpSession.invalidate();
              }
          }
      }
  }