/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * 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.exoplatform.services.organization.auth;

import org.exoplatform.container.component.ComponentRequestLifecycle;
import org.exoplatform.container.component.RequestLifeCycle;
import org.exoplatform.services.log.ExoLogger;
import org.exoplatform.services.log.Log;
import org.exoplatform.services.organization.DisabledUserException;
import org.exoplatform.services.organization.ExtendedUserHandler;
import org.exoplatform.services.organization.Membership;
import org.exoplatform.services.organization.OrganizationService;
import org.exoplatform.services.organization.UserHandler;
import org.exoplatform.services.security.Authenticator;
import org.exoplatform.services.security.Credential;
import org.exoplatform.services.security.DigestPasswordEncrypter;
import org.exoplatform.services.security.Identity;
import org.exoplatform.services.security.MembershipEntry;
import org.exoplatform.services.security.MembershipHashSet;
import org.exoplatform.services.security.PasswordCredential;
import org.exoplatform.services.security.PasswordEncrypter;
import org.exoplatform.services.security.RolesExtractor;
import org.exoplatform.services.security.UsernameCredential;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

import javax.security.auth.login.LoginException;

/**
 * Created by The eXo Platform SAS . An authentication wrapper over Organization
 * service
 * 
 * @author Gennady Azarenkov
 * @version $Id:$
 */

public class OrganizationAuthenticatorImpl implements Authenticator
{

   protected static final Log LOG =
      ExoLogger.getLogger("exo.core.component.organization.api.OrganizationUserRegistry");

   /**
    * The thread local in which we store the last exception that occurs while calling the method 
    * validateUser
    */
   private final ThreadLocal<Exception> lastExceptionOnValidateUser = new ThreadLocal<Exception>();

   private final OrganizationService orgService;

   private final PasswordEncrypter encrypter;

   private final RolesExtractor rolesExtractor;

   public OrganizationAuthenticatorImpl(OrganizationService orgService, RolesExtractor rolesExtractor,
      PasswordEncrypter encrypter)
   {
      this.orgService = orgService;
      this.encrypter = encrypter;
      this.rolesExtractor = rolesExtractor;
   }

   public OrganizationAuthenticatorImpl(OrganizationService orgService, RolesExtractor rolesExtractor)
   {
      this(orgService, rolesExtractor, null);
   }

   public OrganizationAuthenticatorImpl(OrganizationService orgService)
   {
      this(orgService, null, null);
   }

   public OrganizationService getOrganizationService()
   {
      return orgService;
   }

   /*
    * (non-Javadoc)
    * @see
    * org.exoplatform.services.security.Authenticator#createIdentity(java.lang
    * .String)
    */
   public Identity createIdentity(String userId) throws Exception
   {
      Set<MembershipEntry> entries = new MembershipHashSet();
      Collection<Membership> memberships;
      begin(orgService);
      try
      {
         memberships = orgService.getMembershipHandler().findMembershipsByUser(userId);
      }
      finally
      {
         end(orgService);
      }
      if (memberships != null)
      {
         for (Membership membership : memberships)
            entries.add(new MembershipEntry(membership.getGroupId(), membership.getMembershipType()));
      }
      if (rolesExtractor == null)
         return new Identity(userId, entries);
      return new Identity(userId, entries, rolesExtractor.extractRoles(userId, entries));
   }

   /*
    * (non-Javadoc)
    * @see
    * org.exoplatform.services.security.Authenticator#validateUser(org.exoplatform
    * .services.security.Credential[])
    */
   public String validateUser(Credential[] credentials) throws LoginException, Exception
   {
      String username = null;
      String password = null;
      Map<String, String> passwordContext= null;
      for (Credential cred : credentials)
      {
         if (cred instanceof UsernameCredential)
         {
            username = ((UsernameCredential)cred).getUsername();
         }
         if (cred instanceof PasswordCredential)
         {
            password = ((PasswordCredential)cred).getPassword();
            passwordContext = ((PasswordCredential)cred).getPasswordContext();
         }
      }
      if (username == null || password == null)
         throw new LoginException("Username or Password is not defined");

      if (this.encrypter != null)
         password = new String(encrypter.encrypt(password.getBytes()));

      begin(orgService);
      boolean success;
      try
      {
         UserHandler userHandler = orgService.getUserHandler();
         if (passwordContext != null && userHandler instanceof ExtendedUserHandler)
         {
            PasswordEncrypter pe = new DigestPasswordEncrypter(username, passwordContext);
            success = ((ExtendedUserHandler)userHandler).authenticate(username, password, pe);
         }
         else
         {
            success = userHandler.authenticate(username, password);
         }
         // No exception occurred
         lastExceptionOnValidateUser.remove();
      }
      catch (DisabledUserException e)
      {
         lastExceptionOnValidateUser.set(e);
         throw new LoginException("The user account " + username.replace("\n", " ").replace("\r", " ") + " is disabled");
      }
      catch (Exception e)
      {
         lastExceptionOnValidateUser.set(e);
         throw e;
      }
      finally
      {
         end(orgService);
      }

      if (!success)
         throw new LoginException("Login failed for " + username.replace("\n", " ").replace("\r", " "));

      return username;
   }

   public void begin(OrganizationService orgService) throws Exception
   {
      if (orgService instanceof ComponentRequestLifecycle)
      {
         RequestLifeCycle.begin((ComponentRequestLifecycle)orgService);
      }
   }

   public void end(OrganizationService orgService) throws Exception
   {
      if (orgService instanceof ComponentRequestLifecycle)
      {
         RequestLifeCycle.end();
      }
   }

   /**
    * {@inheritDoc}
    */
   public Exception getLastExceptionOnValidateUser()
   {
      Exception e = lastExceptionOnValidateUser.get();
      if (e != null)
      {
         // To prevent a memory leak, we apply an auto-cleanup strategy
         lastExceptionOnValidateUser.remove();
      }
      return e;
   }
}
