/**
    * - Digitalis Internal Framework v2.0 - (C) 2007, Digitalis Informatica. 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.objects;
   
   import java.util.HashMap;
   import java.util.Map;
  import java.util.Map.Entry;
  
  import pt.digitalis.dif.controller.interfaces.INavigationHistory;
  import pt.digitalis.dif.controller.interfaces.IPrivateDIFSession;
  import pt.digitalis.dif.ioc.DIFIoCRegistry;
  import pt.digitalis.dif.startup.DIFGeneralConfigurationParameters;
  import pt.digitalis.dif.utils.ObjectFormatter;
  
  /**
   * Base implementation of a DIF Session. Should be extended by each specific channel session. (i.e. DIFSessionHTTPImpl)
   * 
   * @author Rodrigo Gonçalves <a href="mailto:rgoncalves@digitalis.pt">rgoncalves@digitalis.pt</a>
   * @author Pedro Viegas <a href="mailto:pviegas@digitalis.pt">pviegas@digitalis.pt</a>
   * @created Nov 29, 2007
   */
  public class DIFSession implements IPrivateDIFSession {
  
      /** The session key indicating that authentication was performed by a remote provider */
      public static final String REMOTE_AUTHENTICATION_PROVIDER_LOGIN = "remote_authentication_provider_login";
  
      /** The session key indicating that authentication was performed by a remote provider */
      public static final String REMOTE_AUTHENTICATION_PROVIDER_LOGOUT = "remote_authentication_provider_logout";
  
      /** Session attributes. */
      private Map<String, Object> attributes = new HashMap<String, Object>();
  
      /** Keeps record of session creation time. */
      private long firstAccessTime = 0;
  
      /** The current session navigation history */
      private INavigationHistory history = null;
  
      /** The current session user language */
      private String language = null;
  
      /** Keeps record of last session access. */
      private long lastAccessTime = 0;
  
      /** If the session been marked for removal */
      private Boolean markedForRemoval = false;
  
      /** The session unique ID */
      private final String sessionID;
  
      /** The defined time out value for the session. */
      private long sessionTimeOut = 0;
  
      /** The user associated to the session. */
      private DIFUserInSession user;
  
      /**
       * Default constructor. Sets the first access time.
       * 
       * @param sessionID
       *            the session unique identifier
       */
      public DIFSession(String sessionID)
      {
          this.firstAccessTime = System.currentTimeMillis();
          this.lastAccessTime = System.currentTimeMillis();
          this.sessionID = sessionID;
      }
  
      /**
       * One-argument constructor that receives an user.
       * 
       * @param sessionID
       *            the session unique identifier
       * @param user
       *            a DIF user
       */
      public DIFSession(String sessionID, DIFUserInSession user)
      {
          this(sessionID);
          this.user = user;
      }
  
      /**
       * @see pt.digitalis.dif.controller.interfaces.IDIFSession#addAttribute(java.lang.String, java.lang.Object)
       */
      public void addAttribute(String key, Object value)
      {
          attributes.put(key, value);
      }
  
      /**
       * @see pt.digitalis.dif.controller.interfaces.IDIFSession#containsAttribute(java.lang.String)
       */
      public boolean containsAttribute(String key)
      {
         return attributes.containsKey(key);
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IPrivateDIFSession#forceKeepAlive()
      */
     public void forceKeepAlive()
     {
         this.setLastAccessTime(System.currentTimeMillis());
 
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getAttribute(java.lang.String)
      */
     public Object getAttribute(String key)
     {
         return attributes.get(key);
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getAttributes()
      */
     public Map<String, Object> getAttributes()
     {
         return attributes;
     }
 
     /**
      * Inspector for the 'firstAccessTime' property.
      * 
      * @return the 'firstAccessTime' value
      */
     public long getFirstAccessTime()
     {
         return this.firstAccessTime;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getLanguage()
      */
     public String getLanguage()
     {
         return language;
     }
 
     /**
      * Inspector for the 'lastAccessTime' property.
      * 
      * @return the 'lastAccessTime' value
      */
     public long getLastAccessTime()
     {
         return this.lastAccessTime;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getNavigationHistory()
      */
     public INavigationHistory getNavigationHistory()
     {
         if (history == null)
             history = DIFIoCRegistry.getRegistry().getImplementation(INavigationHistory.class);
 
         return history;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getSessionID()
      */
     public String getSessionID()
     {
         return sessionID;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getSessionTimeOut()
      */
     public long getSessionTimeOut()
     {
         return this.sessionTimeOut;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#getUser()
      */
     public DIFUserInSession getUser()
     {
         return user;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IPrivateDIFSession#hasExpiredAfterTimeOut()
      */
     public boolean hasExpiredAfterTimeOut()
     {
         long currentTime = System.currentTimeMillis();
 
         return (this.getLastAccessTime() + this.getSessionTimeOut()
                 + DIFGeneralConfigurationParameters.getInstance().getSessionExpirationTimeAfterTimeout() < currentTime);
     }
 
     /**
      * The criteria for a timed out session is that the last access time plus the session time out must be higher than
      * the current time.
      * 
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#hasTimedOut()
      */
     public boolean hasTimedOut()
     {
 
         long currentTime = System.currentTimeMillis();
 
         return (this.getLastAccessTime() + this.getSessionTimeOut() < currentTime);
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#isLogged()
      */
     public boolean isLogged()
     {
         return (user != null);
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#isMarkedForRemoval()
      */
     public boolean isMarkedForRemoval()
     {
         return markedForRemoval;
     }
 
     /**
      * Sets the 'lastAccesTime' property to "now".
      * 
      * @see pt.digitalis.dif.controller.interfaces.IPrivateDIFSession#keepAlive()
      */
     public void keepAlive()
     {
         if (!isMarkedForRemoval() && !hasTimedOut())
             forceKeepAlive();
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#setAttributes(Map)
      */
     public void setAttributes(Map<String, Object> attributes)
     {
         this.attributes = attributes;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#setLanguage(java.lang.String)
      */
     public void setLanguage(String language)
     {
         this.language = language;
 
     }
 
     /**
      * Modifier for the 'lastAccessTime' property.
      * 
      * @param lastAccessTime
      *            the 'lastAccessTime' new value to set
      */
     public void setLastAccessTime(long lastAccessTime)
     {
         this.lastAccessTime = lastAccessTime;
     }
 
     /**
      * @param markedForRemoval
      */
     public void setMarkedForRemoval(Boolean markedForRemoval)
     {
         this.markedForRemoval = markedForRemoval;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#setSessionTimeOut(long)
      */
     public void setSessionTimeOut(long sessionTimeOut)
     {
         this.sessionTimeOut = sessionTimeOut;
     }
 
     /**
      * @see pt.digitalis.dif.controller.interfaces.IDIFSession#setUser(pt.digitalis.dif.controller.objects.DIFUserInSession)
      */
     public void setUser(DIFUserInSession user)
     {
         this.user = user;
     }
 
     /**
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString()
     {
         ObjectFormatter formatter = new ObjectFormatter();
 
         formatter.addItem("Session ID", sessionID);
         formatter.addItem("First Access Time", firstAccessTime);
         formatter.addItem("Last Access Time", lastAccessTime);
         formatter.addItem("language", language);
         formatter.addItem("User in session", getUser());
 
         Map<String, Object> parsedAttributes = new HashMap<String, Object>();
 
         for (Entry<String, Object> entry: attributes.entrySet())
             if (!entry.getKey().startsWith("JSONCache:"))
                 parsedAttributes.put(entry.getKey(), entry.getValue());
 
         formatter.addItemIfNotNull("Attributes", parsedAttributes);
 
         return formatter.getFormatedObject();
     }
 }