//
   //  ========================================================================
   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.security;
  
  import java.io.IOException;
  import java.security.Principal;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.servlet.http.HttpSessionEvent;
  import javax.servlet.http.HttpSessionListener;
  
  import org.eclipse.jetty.security.authentication.DeferredAuthentication;
  import org.eclipse.jetty.server.AbstractHttpConnection;
  import org.eclipse.jetty.server.Authentication;
  import org.eclipse.jetty.server.Handler;
  import org.eclipse.jetty.server.Request;
  import org.eclipse.jetty.server.Response;
  import org.eclipse.jetty.server.UserIdentity;
  import org.eclipse.jetty.server.handler.ContextHandler;
  import org.eclipse.jetty.server.handler.ContextHandler.Context;
  import org.eclipse.jetty.server.handler.HandlerWrapper;
  import org.eclipse.jetty.server.session.AbstractSessionManager;
  import org.eclipse.jetty.util.component.LifeCycle;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /**
   * Abstract SecurityHandler.
   * Select and apply an {@link Authenticator} to a request.
   * <p>
   * The Authenticator may either be directly set on the handler
   * or will be create during {@link #start()} with a call to
   * either the default or set AuthenticatorFactory.
   * <p>
   * SecurityHandler has a set of initparameters that are used by the 
   * Authentication.Configuration. At startup, any context init parameters
   * that start with "org.eclipse.jetty.security." that do not have 
   * values in the SecurityHandler init parameters, are copied.  
   * 
   */
  public abstract class SecurityHandler extends HandlerWrapper implements Authenticator.AuthConfiguration
  {
      private static final Logger LOG = Log.getLogger(SecurityHandler.class);
  
      /* ------------------------------------------------------------ */
      private boolean _checkWelcomeFiles = false;
      private Authenticator _authenticator;
      private Authenticator.Factory _authenticatorFactory=new DefaultAuthenticatorFactory();
      private String _realmName;
      private String _authMethod;
      private final Map<String,String> _initParameters=new HashMap<String,String>();
      private LoginService _loginService;
      private boolean _loginServiceShared;
      private IdentityService _identityService;
      private boolean _renewSession=true;
  
      /* ------------------------------------------------------------ */
      protected SecurityHandler()
      {
      }
      
      /* ------------------------------------------------------------ */
      /** Get the identityService.
       * @return the identityService
       */
      public IdentityService getIdentityService()
      {
          return _identityService;
      }
  
      /* ------------------------------------------------------------ */
      /** Set the identityService.
       * @param identityService the identityService to set
       */
      public void setIdentityService(IdentityService identityService)
      {
         if (isStarted())
             throw new IllegalStateException("Started");
         _identityService = identityService;
     }
 
     /* ------------------------------------------------------------ */
     /** Get the loginService.
      * @return the loginService
      */
     public LoginService getLoginService()
     {
         return _loginService;
     }
 
     /* ------------------------------------------------------------ */
     /** Set the loginService.
      * @param loginService the loginService to set
      */
     public void setLoginService(LoginService loginService)
     {
         if (isStarted())
             throw new IllegalStateException("Started");
         _loginService = loginService;
         _loginServiceShared=false;
     }
 
 
     /* ------------------------------------------------------------ */
     public Authenticator getAuthenticator()
     {
         return _authenticator;
     }
 
     /* ------------------------------------------------------------ */
     /** Set the authenticator.
      * @param authenticator
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public void setAuthenticator(Authenticator authenticator)
     {
         if (isStarted())
             throw new IllegalStateException("Started");
         _authenticator = authenticator;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return the authenticatorFactory
      */
     public Authenticator.Factory getAuthenticatorFactory()
     {
         return _authenticatorFactory;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param authenticatorFactory the authenticatorFactory to set
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public void setAuthenticatorFactory(Authenticator.Factory authenticatorFactory)
     {
         if (isRunning())
             throw new IllegalStateException("running");
         _authenticatorFactory = authenticatorFactory;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return the realmName
      */
     public String getRealmName()
     {
         return _realmName;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param realmName the realmName to set
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public void setRealmName(String realmName)
     {
         if (isRunning())
             throw new IllegalStateException("running");
         _realmName = realmName;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @return the authMethod
      */
     public String getAuthMethod()
     {
         return _authMethod;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param authMethod the authMethod to set
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public void setAuthMethod(String authMethod)
     {
         if (isRunning())
             throw new IllegalStateException("running");
         _authMethod = authMethod;
     }
     
     /* ------------------------------------------------------------ */
     /**
      * @return True if forwards to welcome files are authenticated
      */
     public boolean isCheckWelcomeFiles()
     {
         return _checkWelcomeFiles;
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @param authenticateWelcomeFiles True if forwards to welcome files are
      *                authenticated
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public void setCheckWelcomeFiles(boolean authenticateWelcomeFiles)
     {
         if (isRunning())
             throw new IllegalStateException("running");
         _checkWelcomeFiles = authenticateWelcomeFiles;
     }
 
     /* ------------------------------------------------------------ */
     public String getInitParameter(String key)
     {
         return _initParameters.get(key);
     }
     
     /* ------------------------------------------------------------ */
     public Set<String> getInitParameterNames()
     {
         return _initParameters.keySet();
     }
     
     /* ------------------------------------------------------------ */
     /** Set an initialization parameter.
      * @param key
      * @param value
      * @return previous value
      * @throws IllegalStateException if the SecurityHandler is running
      */
     public String setInitParameter(String key, String value)
     {
         if (isRunning())
             throw new IllegalStateException("running");
         return _initParameters.put(key,value);
     }
     
     /* ------------------------------------------------------------ */
     protected LoginService findLoginService()
     {
         List<LoginService> list = getServer().getBeans(LoginService.class);
         
         String realm=getRealmName();
         if (realm!=null)
         {
             for (LoginService service : list)
                 if (service.getName()!=null && service.getName().equals(realm))
                     return service;
         }
         else if (list.size()==1)
             return list.get(0);
         return null;
     }
     
     /* ------------------------------------------------------------ */
     protected IdentityService findIdentityService()
     {
         return getServer().getBean(IdentityService.class);
     }
     
     /* ------------------------------------------------------------ */
     /** 
      */
     @Override
     protected void doStart()
         throws Exception
     {
         // copy security init parameters
         ContextHandler.Context context =ContextHandler.getCurrentContext();
         if (context!=null)
         {
             Enumeration<String> names=context.getInitParameterNames();
             while (names!=null && names.hasMoreElements())
             {
                 String name =names.nextElement();
                 if (name.startsWith("org.eclipse.jetty.security.") &&
                         getInitParameter(name)==null)
                     setInitParameter(name,context.getInitParameter(name));
             }
             
             //register a session listener to handle securing sessions when authentication is performed
             context.getContextHandler().addEventListener(new HttpSessionListener()
             {
                 
                 public void sessionDestroyed(HttpSessionEvent se)
                 {
                    
                 }
                 
                 public void sessionCreated(HttpSessionEvent se)
                 {
                     //if current request is authenticated, then as we have just created the session, mark it as secure, as it has not yet been returned to a user
                     AbstractHttpConnection connection = AbstractHttpConnection.getCurrentConnection();
                     if (connection == null)
                         return;
                     Request request = connection.getRequest();
                     if (request == null)
                         return;
                     
                     if (request.isSecure())
                     {
                         se.getSession().setAttribute(AbstractSessionManager.SESSION_KNOWN_ONLY_TO_AUTHENTICATED, Boolean.TRUE);
                     }
                 }
             });
         }
         
         // complicated resolution of login and identity service to handle
         // many different ways these can be constructed and injected.
         
         if (_loginService==null)
         {
             _loginService=findLoginService();
             if (_loginService!=null)
                 _loginServiceShared=true;
         }
         
         if (_identityService==null)
         {
             if (_loginService!=null)
                 _identityService=_loginService.getIdentityService();
 
             if (_identityService==null)
                 _identityService=findIdentityService();
             
             if (_identityService==null && _realmName!=null)
                 _identityService=new DefaultIdentityService();
         }
         
         if (_loginService!=null)
         {
             if (_loginService.getIdentityService()==null)
                 _loginService.setIdentityService(_identityService);
             else if (_loginService.getIdentityService()!=_identityService)
                 throw new IllegalStateException("LoginService has different IdentityService to "+this);
         }
 
         if (!_loginServiceShared && _loginService instanceof LifeCycle)
             ((LifeCycle)_loginService).start();        
         
         if (_authenticator==null && _authenticatorFactory!=null && _identityService!=null)
         {
             _authenticator=_authenticatorFactory.getAuthenticator(getServer(),ContextHandler.getCurrentContext(),this, _identityService, _loginService);
             if (_authenticator!=null)
                 _authMethod=_authenticator.getAuthMethod();
         }
 
         if (_authenticator==null)
         {
             if (_realmName!=null)
             {
                 LOG.warn("No ServerAuthentication for "+this);
                 throw new IllegalStateException("No ServerAuthentication");
             }
         }
         else
         {
             _authenticator.setConfiguration(this);
             if (_authenticator instanceof LifeCycle)
                 ((LifeCycle)_authenticator).start();
         }
 
         super.doStart();
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @see org.eclipse.jetty.server.handler.HandlerWrapper#doStop()
      */
     @Override
     protected void doStop() throws Exception
     {
         super.doStop();
         
         if (!_loginServiceShared && _loginService instanceof LifeCycle)
             ((LifeCycle)_loginService).stop();
         
     }
 
     /* ------------------------------------------------------------ */
     protected boolean checkSecurity(Request request)
     {
         switch(request.getDispatcherType())
         {
             case REQUEST:
             case ASYNC:
                 return true;
             case FORWARD:
                 if (_checkWelcomeFiles && request.getAttribute("org.eclipse.jetty.server.welcome") != null)
                 {
                     request.removeAttribute("org.eclipse.jetty.server.welcome");
                     return true;
                 }
                 return false;
             default:
                 return false;
         }
     }
     
     /* ------------------------------------------------------------ */
     /**
      * @see org.eclipse.jetty.security.Authenticator.AuthConfiguration#isSessionRenewedOnAuthentication()
      */
     public boolean isSessionRenewedOnAuthentication()
     {
         return _renewSession;
     }
     
     /* ------------------------------------------------------------ */
     /** Set renew the session on Authentication.
      * <p>
      * If set to true, then on authentication, the session associated with a reqeuest is invalidated and replaced with a new session.
      * @see org.eclipse.jetty.security.Authenticator.AuthConfiguration#isSessionRenewedOnAuthentication()
      */
     public void setSessionRenewedOnAuthentication(boolean renew)
     {
         _renewSession=renew;
     }
     
     /* ------------------------------------------------------------ */
     /*
      * @see org.eclipse.jetty.server.Handler#handle(java.lang.String,
      *      javax.servlet.http.HttpServletRequest,
      *      javax.servlet.http.HttpServletResponse, int)
      */
     @Override
     public void handle(String pathInContext, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
     {
         final Response base_response = baseRequest.getResponse();
         final Handler handler=getHandler();
         
         if (handler==null)
             return;
 
         final Authenticator authenticator = _authenticator;
         
         if (checkSecurity(baseRequest))
         {
             Object constraintInfo = prepareConstraintInfo(pathInContext, baseRequest);
             
             // Check data constraints
             if (!checkUserDataPermissions(pathInContext, baseRequest, base_response, constraintInfo))
             {
                 if (!baseRequest.isHandled())
                 {
                     response.sendError(Response.SC_FORBIDDEN);
                     baseRequest.setHandled(true);
                 }
                 return;
             }
 
             // is Auth mandatory?
             boolean isAuthMandatory = 
                 isAuthMandatory(baseRequest, base_response, constraintInfo);
 
             if (isAuthMandatory && authenticator==null)
             {
                 LOG.warn("No authenticator for: "+constraintInfo);
                 if (!baseRequest.isHandled())
                 {
                     response.sendError(Response.SC_FORBIDDEN);
                     baseRequest.setHandled(true);
                 }
                 return;
             }
             
             // check authentication
             Object previousIdentity = null;
             try
             {
                 Authentication authentication = baseRequest.getAuthentication();
                 if (authentication==null || authentication==Authentication.NOT_CHECKED)
                     authentication=authenticator==null?Authentication.UNAUTHENTICATED:authenticator.validateRequest(request, response, isAuthMandatory);
 
                 if (authentication instanceof Authentication.Wrapped)
                 {
                     request=((Authentication.Wrapped)authentication).getHttpServletRequest();
                     response=((Authentication.Wrapped)authentication).getHttpServletResponse();
                 }
 
                 if (authentication instanceof Authentication.ResponseSent)
                 {
                     baseRequest.setHandled(true);
                 }
                 else if (authentication instanceof Authentication.User)
                 {
                     Authentication.User userAuth = (Authentication.User)authentication;
                     baseRequest.setAuthentication(authentication);
                     if (_identityService!=null)
                         previousIdentity = _identityService.associate(userAuth.getUserIdentity());
 
                     if (isAuthMandatory)
                     {
                         boolean authorized=checkWebResourcePermissions(pathInContext, baseRequest, base_response, constraintInfo, userAuth.getUserIdentity());
                         if (!authorized)
                         {
                             response.sendError(Response.SC_FORBIDDEN, "!role");
                             baseRequest.setHandled(true);
                             return;
                         }
                     }
                          
                     handler.handle(pathInContext, baseRequest, request, response);
                     if (authenticator!=null)
                         authenticator.secureResponse(request, response, isAuthMandatory, userAuth);
                 }
                 else if (authentication instanceof Authentication.Deferred)
                 {
                     DeferredAuthentication deferred= (DeferredAuthentication)authentication;
                     baseRequest.setAuthentication(authentication);
 
                     try
                     {
                         handler.handle(pathInContext, baseRequest, request, response);
                     }
                     finally
                     {
                         previousIdentity = deferred.getPreviousAssociation();
                     }
 
                     if (authenticator!=null)
                     {
                         Authentication auth=baseRequest.getAuthentication();
                         if (auth instanceof Authentication.User)
                         {
                             Authentication.User userAuth = (Authentication.User)auth;
                             authenticator.secureResponse(request, response, isAuthMandatory, userAuth);
                         }
                         else
                             authenticator.secureResponse(request, response, isAuthMandatory, null);
                     }
                 }
                 else
                 {
                     baseRequest.setAuthentication(authentication);
                     if (_identityService!=null)
                         previousIdentity = _identityService.associate(null);
                     handler.handle(pathInContext, baseRequest, request, response);
                     if (authenticator!=null)
                         authenticator.secureResponse(request, response, isAuthMandatory, null);
                 }
             }
             catch (ServerAuthException e)
             {
                 // jaspi 3.8.3 send HTTP 500 internal server error, with message
                 // from AuthException
                 response.sendError(Response.SC_INTERNAL_SERVER_ERROR, e.getMessage());
             }
             finally
             {
                 if (_identityService!=null)
                     _identityService.disassociate(previousIdentity);
             }
         }
         else
             handler.handle(pathInContext, baseRequest, request, response);
     }
 
 
     /* ------------------------------------------------------------ */
     public static SecurityHandler getCurrentSecurityHandler()
     {
         Context context = ContextHandler.getCurrentContext();
         if (context==null)
             return null;
         
         SecurityHandler security = context.getContextHandler().getChildHandlerByClass(SecurityHandler.class);
         return security;
     }
 
     /* ------------------------------------------------------------ */
     public void logout(Authentication.User user)
     {
         LOG.debug("logout {}",user);
         LoginService login_service=getLoginService();
         if (login_service!=null)
         {
             login_service.logout(user.getUserIdentity());
         }
         
         IdentityService identity_service=getIdentityService();
         if (identity_service!=null)
         {
             // TODO recover previous from threadlocal (or similar)
             Object previous=null;
             identity_service.disassociate(previous);
         }
     }
     
     /* ------------------------------------------------------------ */
     protected abstract Object prepareConstraintInfo(String pathInContext, Request request);
 
     /* ------------------------------------------------------------ */
     protected abstract boolean checkUserDataPermissions(String pathInContext, Request request, Response response, Object constraintInfo) throws IOException;
 
     /* ------------------------------------------------------------ */
     protected abstract boolean isAuthMandatory(Request baseRequest, Response base_response, Object constraintInfo);
 
     /* ------------------------------------------------------------ */
     protected abstract boolean checkWebResourcePermissions(String pathInContext, Request request, Response response, Object constraintInfo,
                                                            UserIdentity userIdentity) throws IOException;
 
     
     /* ------------------------------------------------------------ */
     /* ------------------------------------------------------------ */
     public class NotChecked implements Principal
     {
         public String getName()
         {
             return null;
         }
 
         @Override
         public String toString()
         {
             return "NOT CHECKED";
         }
 
         public SecurityHandler getSecurityHandler()
         {
             return SecurityHandler.this;
         }
     }
 
     
     /* ------------------------------------------------------------ */
     /* ------------------------------------------------------------ */
     public static Principal __NO_USER = new Principal()
     {
         public String getName()
         {
             return null;
         }
 
         @Override
         public String toString()
         {
             return "No User";
         }
     };
     
     /* ------------------------------------------------------------ */
     /* ------------------------------------------------------------ */
     /**
      * Nobody user. The Nobody UserPrincipal is used to indicate a partial state
      * of authentication. A request with a Nobody UserPrincipal will be allowed
      * past all authentication constraints - but will not be considered an
      * authenticated request. It can be used by Authenticators such as
      * FormAuthenticator to allow access to logon and error pages within an
      * authenticated URI tree.
      */
     public static Principal __NOBODY = new Principal()
     {
         public String getName()
         {
             return "Nobody";
         }
 
         @Override
         public String toString()
         {
             return getName();
         }
     };
 
 }