package org.appfuse.webapp.services.impl;
   
   import org.appfuse.Constants;
   import org.appfuse.model.Role;
   import org.appfuse.model.User;
   import org.appfuse.webapp.services.SecurityContext;
   import org.springframework.security.authentication.AuthenticationTrustResolver;
   import org.springframework.security.authentication.AuthenticationTrustResolverImpl;
   import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
  import org.springframework.security.core.Authentication;
  import org.springframework.security.core.context.SecurityContextHolder;
  import org.springframework.security.core.userdetails.UserDetails;
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.regex.Pattern;
  
  /**
   * Security context implementation based on Spring Security
   *
   * @author Serge Eby
   */
  public class SpringSecurityContext implements SecurityContext {
  
      private final static Pattern COMMA_PATTERN = Pattern.compile("\\s*,\\s*");
  
      public boolean isLoggedIn() {
  
          Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
          if (authentication != null && authentication.getPrincipal() != null) {
              if ("anonymousUser".equals(authentication.getName())) {
                  return false;
              }
              return authentication.isAuthenticated();
          }
          return false;
      }
  
      public UserDetails getUserDetails() {
  
          UserDetails userDetails = null;
          if (isLoggedIn()) {
              Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
              if (principal instanceof UserDetails) {
                  userDetails = (UserDetails) principal;
              }
          }
          return userDetails;
      }
  
  
      public User getUser() {
          User user = null;
          if (isLoggedIn()) {
              Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
              if (principal instanceof UserDetails) {
                  user = (User) principal;
              }
          }
          return user;
      }
  
      public String getUsername() {
          User user = getUser();
          return user != null ? user.getUsername() : null;
      }
  
      public boolean hasRoles(String roleName) {
          // If no role defined, return true
          if (roleName == null) {
              return true;
          }
  
          User user = getUser();
          //TODO: User InternalUtils class??
          List<String> allowedRoles = Arrays.asList(COMMA_PATTERN.split(roleName.trim()));
          if (user != null) {
              for (Role role : user.getRoles()) {
                  if (allowedRoles.contains(role.getName())) {
                      return true;
                  }
              }
          }
          return false;
      }
  
  
      public boolean isAdmin() {
          return hasRoles(Constants.ADMIN_ROLE);
      }
  
      public void logout() {
          // NYI
      }
  
      public boolean isRememberMe() {
          AuthenticationTrustResolver resolver = new AuthenticationTrustResolverImpl();
          Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
  
         return resolver.isRememberMe(authentication);
     }
 
     public void login(User user) {
         if (user == null) {
             throw new IllegalArgumentException("User cannot be null");
         }
 
         UsernamePasswordAuthenticationToken loggedIn = new UsernamePasswordAuthenticationToken(
                 user,
                 user.getConfirmPassword(),
                 user.getAuthorities());
 
         loggedIn.setDetails(user);
         SecurityContextHolder.getContext().setAuthentication(loggedIn);
 
     }
 
 }