/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2008, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.jboss.ejb.plugins.cmp.jdbc.bridge;

import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;
import java.security.Principal;
import java.security.AccessController;
import java.security.PrivilegedActionException; 
import java.lang.reflect.UndeclaredThrowableException;

import javax.security.auth.Subject;
import javax.security.jacc.PolicyContext;
import javax.security.jacc.PolicyContextException;

import org.jboss.security.RunAs; 
import org.jboss.security.SecurityContext; 
import org.jboss.security.SecurityContextFactory;
import org.jboss.security.SecurityContextAssociation;
 

/** A collection of privileged actions for this package
 * @author Scott.Stark@jboss.org
 * @author <a href="mailto:alex@jboss.org">Alexey Loubyansky</a>
 * @author Anil.Saldhana@redhat.com
 * @version $Revison: $
 */
class SecurityActions
{
    
   interface RunAsIdentityActions
   {
      RunAsIdentityActions PRIVILEGED = new RunAsIdentityActions()
      {
         private final PrivilegedAction peekAction = new PrivilegedAction()
         {
            public Object run()
            {
               //return SecurityAssociation.peekRunAsIdentity();
               SecurityContext sc = SecurityContextAssociation.getSecurityContext();
               if(sc == null)
                  throw new IllegalStateException("Security Context is null");
               return sc.getOutgoingRunAs();
            }
         };

         private final PrivilegedAction popAction = new PrivilegedAction()
         {
            public Object run()
            {
               //return SecurityAssociation.popRunAsIdentity();
               SecurityContext sc = SecurityContextAssociation.getSecurityContext();
               if(sc == null)
                  throw new IllegalStateException("Security Context is null"); 
               RunAs ra = sc.getOutgoingRunAs();
               sc.setOutgoingRunAs(null); 
               return ra;
            }
         };

         public RunAs peek()
         {
            return (RunAs)AccessController.doPrivileged(peekAction);
         }

         public void push(final RunAs id)
         {
            AccessController.doPrivileged(
               new PrivilegedAction()
               {
                  public Object run()
                  {
                     //SecurityAssociation.pushRunAsIdentity((RunAsIdentity)id);
                     SecurityContext sa = SecurityContextAssociation.getSecurityContext(); 
                     if(sa == null)
                        throw new IllegalStateException("Security Context is null to push runas"); 
                     sa.setOutgoingRunAs(id);
                     return null;
                  }
               }
            );
         }

         public RunAs pop()
         { 
            return (RunAs)AccessController.doPrivileged(popAction);
         }
      };

      RunAsIdentityActions NON_PRIVILEGED = new RunAsIdentityActions()
      {
         public RunAs peek()
         {
            //return SecurityAssociation.peekRunAsIdentity();
            SecurityContext sc = SecurityContextAssociation.getSecurityContext();
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            return sc.getOutgoingRunAs();
         }

         public void push(RunAs id)
         {
            //SecurityAssociation.pushRunAsIdentity(id); 
            SecurityContext sc = SecurityContextAssociation.getSecurityContext();
            if(sc == null)
               throw new IllegalStateException("Security Context is null to push runas");  
            sc.setOutgoingRunAs(id);
         }

         public RunAs pop()
         { 
            //Pop the RAI 
            // return SecurityAssociation.popRunAsIdentity(); 
            SecurityContext sc = SecurityContextAssociation.getSecurityContext();  
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            RunAs ra = null; 
            ra = sc.getOutgoingRunAs();
            sc.setOutgoingRunAs(null); 
            return ra;
         }
      };

      RunAs peek();

      void push(RunAs id);

      RunAs pop();
   }

    

   interface PolicyContextActions
   {
      /** The JACC PolicyContext key for the current Subject */
      static final String SUBJECT_CONTEXT_KEY = "javax.security.auth.Subject.container";
      PolicyContextActions PRIVILEGED = new PolicyContextActions()
      {
         private final PrivilegedExceptionAction exAction = new PrivilegedExceptionAction()
         {
            public Object run() throws Exception
            {
               return (Subject) PolicyContext.getContext(SUBJECT_CONTEXT_KEY);
            }
         };
         public Subject getContextSubject()
            throws PolicyContextException
         {
            try
            {
               return (Subject) AccessController.doPrivileged(exAction);
            }
            catch(PrivilegedActionException e)
            {
               Exception ex = e.getException();
               if( ex instanceof PolicyContextException )
                  throw (PolicyContextException) ex;
               else
                  throw new UndeclaredThrowableException(ex);
            }
         }
      };

      PolicyContextActions NON_PRIVILEGED = new PolicyContextActions()
      {
         public Subject getContextSubject()
            throws PolicyContextException
         {
            return (Subject) PolicyContext.getContext(SUBJECT_CONTEXT_KEY);
         }
      };

      Subject getContextSubject()
         throws PolicyContextException;
   }
   
   static ClassLoader getContextClassLoader()
   {
      return TCLAction.UTIL.getContextClassLoader();
   }

   static void setContextClassLoader(ClassLoader loader)
   {
      TCLAction.UTIL.setContextClassLoader(loader);
   }

    

   static RunAs peekRunAsIdentity()
   {
      if(System.getSecurityManager() == null)
      {
         return RunAsIdentityActions.NON_PRIVILEGED.peek();
      }
      else
      {
         return RunAsIdentityActions.PRIVILEGED.peek();
      }
   }

   static void pushRunAsIdentity(RunAs principal)
   {
      if(System.getSecurityManager() == null)
      {
         RunAsIdentityActions.NON_PRIVILEGED.push(principal);
      }
      else
      {
         RunAsIdentityActions.PRIVILEGED.push(principal);
      }
   }

   static RunAs popRunAsIdentity()
   {
      if(System.getSecurityManager() == null)
      {
         return RunAsIdentityActions.NON_PRIVILEGED.pop();
      }
      else
      {
         return RunAsIdentityActions.PRIVILEGED.pop();
      }
   } 
    

   static Subject getContextSubject()
      throws PolicyContextException
   {
      if(System.getSecurityManager() == null)
      {
         return PolicyContextActions.NON_PRIVILEGED.getContextSubject();
      }
      else
      {
         return PolicyContextActions.PRIVILEGED.getContextSubject();
      }      
   }

   interface TCLAction
   {
      class UTIL
      {
         static TCLAction getTCLAction()
         {
            return System.getSecurityManager() == null ? NON_PRIVILEGED : PRIVILEGED;
         }

         static ClassLoader getContextClassLoader()
         {
            return getTCLAction().getContextClassLoader();
         }

         static ClassLoader getContextClassLoader(Thread thread)
         {
            return getTCLAction().getContextClassLoader(thread);
         }

         static void setContextClassLoader(ClassLoader cl)
         {
            getTCLAction().setContextClassLoader(cl);
         }

         static void setContextClassLoader(Thread thread, ClassLoader cl)
         {
            getTCLAction().setContextClassLoader(thread, cl);
         }
      }

      TCLAction NON_PRIVILEGED = new TCLAction()
      {
         public ClassLoader getContextClassLoader()
         {
            return Thread.currentThread().getContextClassLoader();
         }

         public ClassLoader getContextClassLoader(Thread thread)
         {
            return thread.getContextClassLoader();
         }

         public void setContextClassLoader(ClassLoader cl)
         {
            Thread.currentThread().setContextClassLoader(cl);
         }

         public void setContextClassLoader(Thread thread, ClassLoader cl)
         {
            thread.setContextClassLoader(cl);
         }
      };

      TCLAction PRIVILEGED = new TCLAction()
      {
         private final PrivilegedAction getTCLPrivilegedAction = new PrivilegedAction()
         {
            public Object run()
            {
               return Thread.currentThread().getContextClassLoader();
            }
         };

         public ClassLoader getContextClassLoader()
         {
            return (ClassLoader)AccessController.doPrivileged(getTCLPrivilegedAction);
         }

         public ClassLoader getContextClassLoader(final Thread thread)
         {
            return (ClassLoader)AccessController.doPrivileged(new PrivilegedAction()
            {
               public Object run()
               {
                  return thread.getContextClassLoader();
               }
            });
         }

         public void setContextClassLoader(final ClassLoader cl)
         {
            AccessController.doPrivileged(
               new PrivilegedAction()
               {
                  public Object run()
                  {
                     Thread.currentThread().setContextClassLoader(cl);
                     return null;
                  }
               }
            );
         }

         public void setContextClassLoader(final Thread thread, final ClassLoader cl)
         {
            AccessController.doPrivileged(
               new PrivilegedAction()
               {
                  public Object run()
                  {
                     thread.setContextClassLoader(cl);
                     return null;
                  }
               }
            );
         }
      };

      ClassLoader getContextClassLoader();

      ClassLoader getContextClassLoader(Thread thread);

      void setContextClassLoader(ClassLoader cl);

      void setContextClassLoader(Thread thread, ClassLoader cl);
   }
   
   
   
   static void createAndSetSecurityContext(final Principal p, final Object cred, final String domain) 
   throws PrivilegedActionException
   {
      AccessController.doPrivileged(new PrivilegedExceptionAction(){

         public Object run() throws Exception
         {
            SecurityContext sc = SecurityContextFactory.createSecurityContext(p, cred, null, domain);
            SecurityContextAssociation.setSecurityContext(sc);
            return null;
         }});
   }
   
   static void createAndSetSecurityContext(final Principal p, final Object cred, final String domain,
         final Subject subject) throws PrivilegedActionException
   {
      AccessController.doPrivileged(new PrivilegedExceptionAction(){

         public Object run() throws Exception
         {
            SecurityContext sc = SecurityContextFactory.createSecurityContext(domain); 
            sc.getUtil().createSubjectInfo(p, cred, subject);
            SecurityContextAssociation.setSecurityContext(sc);
            return null;
         }});
   } 
   
   static void clearSecurityContext()
   { 
      AccessController.doPrivileged(new PrivilegedAction(){

         public Object run()
         { 
            SecurityContextAssociation.setSecurityContext(null);
            return null;
         }});
   }
   
   static SecurityContext getSecurityContext()
   { 
      return (SecurityContext)AccessController.doPrivileged(new PrivilegedAction(){
         public Object run()
         {
            return SecurityContextAssociation.getSecurityContext();
         }
      });
   }
   
   static Exception getContextException()
   {
      return (Exception)AccessController.doPrivileged(new PrivilegedAction()
      {
         static final String EX_KEY = "org.jboss.security.exception";
         public Object run()
         { 
            SecurityContext sc = getSecurityContext();
            return sc.getData().get(EX_KEY); 
         }
      });
   }
   
   static void pushSubjectContext(final Principal p, final Object cred, final Subject s)
   {
      AccessController.doPrivileged(new PrivilegedAction(){

         public Object run()
         {
            SecurityContext sc = getSecurityContext(); 
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            sc.getUtil().createSubjectInfo(p, cred, s); 
            return null;
         }}
      );
   } 
   
   static void popSubjectContext()
   {
      AccessController.doPrivileged(new PrivilegedAction(){

         public Object run()
         {
            SecurityContext sc = getSecurityContext();
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            Principal p = sc.getUtil().getUserPrincipal();
            Object cred = sc.getUtil().getCredential();
            sc.getUtil().createSubjectInfo(p, cred,null);
            return null;
         }}
      );
   } 
   
   static void pushCallerRunAsIdentity(final RunAs ra)
   {
      AccessController.doPrivileged(new PrivilegedAction(){ 
         public Object run()
         {
            SecurityContext sc = SecurityContextAssociation.getSecurityContext();
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            sc.setIncomingRunAs(ra);
            return null;
         } 
      }); 
   } 

   static void popCallerRunAsIdentity()
   {
      AccessController.doPrivileged(new PrivilegedAction(){ 
         public Object run()
         {
            SecurityContext sc = SecurityContextAssociation.getSecurityContext();
            if(sc == null)
               throw new IllegalStateException("Security Context is null");
            sc.setIncomingRunAs(null);
            return null;
         } 
      }); 
   }
}
