package com.atlassian.refapp.auth.internal;
   
   import com.atlassian.seraph.auth.AuthenticationContext;
   import com.atlassian.seraph.config.SecurityConfig;
   
   import javax.servlet.Filter;
   import javax.servlet.FilterChain;
   import javax.servlet.FilterConfig;
   import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import java.io.IOException;
  
  public class AuthenticationContextCopyFilter implements Filter {
      private final AuthenticationContext authenticationContext;
      private SecurityConfig securityConfig;
      private final ThreadLocal<Integer> entryCount = new ThreadLocal<Integer>();
  
      public AuthenticationContextCopyFilter(AuthenticationContext authenticationContext) {
          this.authenticationContext = authenticationContext;
      }
  
      public void init(FilterConfig filterConfig) throws ServletException {
          securityConfig = (SecurityConfig) filterConfig.getServletContext().getAttribute(SecurityConfig.STORAGE_KEY);
          if (securityConfig == null) {
              throw new ServletException("No SecurityConfig found in servlet context!");
          }
      }
  
      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
          authenticationContext.setUser(securityConfig.getAuthenticationContext().getUser());
          entryCount.set(entryCount.get() == null ? 1 : entryCount.get() + 1);
          try {
              chain.doFilter(request, response);
          } finally {
              entryCount.set(entryCount.get() - 1);
              if (entryCount.get() == 0) {
                  authenticationContext.clearUser();
              }
          }
      }
  
      public void destroy() {
      }
  }