/**
    * 2007, Digitalis Informatica. All rights reserved. Distribuicao e Gestao de Informatica, Lda. Estrada de Paco de Arcos
    * num.9 - Piso -1 2780-666 Paco de Arcos Telefone: (351) 21 4408990 Fax: (351) 21 4408999 http://www.digitalis.pt
    */
   
   package pt.digitalis.dif.controller.security.managers.impl;
   
   import java.util.HashMap;
   import java.util.Map;
  
  import pt.digitalis.dif.controller.security.managers.IAuthenticationManager;
  import pt.digitalis.dif.controller.security.managers.IIdentityManager;
  import pt.digitalis.dif.controller.security.objects.IDIFUser;
  import pt.digitalis.dif.exception.security.AuthenticationManagerException;
  import pt.digitalis.dif.exception.security.IdentityManagerException;
  import pt.digitalis.dif.utils.ObjectFormatter;
  
  import com.google.inject.Inject;
  
  /**
   * DIF's default implementation of an authentication manager. This implementation will manage authentication records for
   * the DIF localy. No central authentication process is supported.
   * 
   * @author Pedro Viegas <a href="mailto:pviegas@digitalis.pt">pviegas@digitalis.pt</a>
   * @author Rodrigo Gonçalves <a href="mailto:rgoncalves@digitalis.pt">rgoncalves@digitalis.pt</a><br/>
   * @created 2007/12/03
   */
  public class AuthenticationManagerStaticImpl implements IAuthenticationManager {
  
      /** List of logged clients and their users Map<K=clientIdentifier, V=userID>. */
      private Map<String, String> loggedClients = new HashMap<String, String>();
  
      /** The identity manager. */
      @Inject
      private IIdentityManager theIDManager;
  
      /**
       * @see pt.digitalis.dif.controller.security.managers.IAuthenticationManager#disconnectClient(java.lang.String)
       */
      public void disconnectClient(String clientIdentifier)
      {
          // Our implementation is for DIF usage only. So when a DIF client disconnects the authentication is terminated
          logOut(clientIdentifier);
      }
  
      /**
       * @see pt.digitalis.dif.controller.security.managers.IAuthenticationManager#getLoggedUser(java.lang.String)
       */
      public IDIFUser getLoggedUser(String clientIdentifier) throws AuthenticationManagerException
      {
          try
          {
              String userID = loggedClients.get(clientIdentifier);
  
              if (userID == null)
                  return null;
              else
                  return theIDManager.getUser(userID);
          }
          catch (IdentityManagerException identityManagerException)
          {
              throw new AuthenticationManagerException("Could not access the identity manager for user authentication!",
                      identityManagerException);
          }
      }
  
      /**
       * @see pt.digitalis.dif.controller.security.managers.IAuthenticationManager#isClientLogged(java.lang.String)
       */
      public boolean isClientLogged(String clientIdentifier)
      {
          return loggedClients.containsKey(clientIdentifier);
      }
  
      /**
       * @see pt.digitalis.dif.controller.security.managers.IAuthenticationManager#logIn(java.lang.String,
       *      java.lang.String, java.lang.String)
       */
      public IDIFUser logIn(String clientSpecificID, String userID, String password)
              throws AuthenticationManagerException
      {
          try
          {
              if (loggedClients.containsKey(clientSpecificID))
              {
  
                  // Already authenticated. No validation required.
                  String presentUserID = loggedClients.get(clientSpecificID);
  
                  if (presentUserID.equals(userID))
                      return theIDManager.getUser(userID);
              }
  
              // No authentication. Validate user and authenticate.
              if (theIDManager.isIdentityValid(userID, password))
              {
  
                  // Valid user/pass. Register login and return the user. User is now authenticated.
                  loggedClients.put(clientSpecificID, userID);
 
                 return theIDManager.getUser(userID);
             }
             else
                 // Invalid user/password
                 return null;
         }
         catch (IdentityManagerException identityManagerException)
         {
             throw new AuthenticationManagerException("Could not access the identity manager for user authentication!",
                     identityManagerException);
         }
     }
 
     /**
      * @see pt.digitalis.dif.controller.security.managers.IAuthenticationManager#logOut(java.lang.String)
      */
     public void logOut(String clientIdentifier)
     {
         loggedClients.remove(clientIdentifier);
     }
 
     /**
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString()
     {
         ObjectFormatter formatter = new ObjectFormatter();
         formatter.addItem("Logged Clients", loggedClients);
 
         return formatter.getFormatedObject();
     }
 }