package org.argeo.cms.auth;
   
   import java.net.InetAddress;
   import java.net.UnknownHostException;
   import java.security.Principal;
   import java.util.Map;
   import java.util.Set;
   
   import javax.naming.ldap.LdapName;
  import javax.security.auth.Subject;
  import javax.security.auth.callback.CallbackHandler;
  import javax.security.auth.kerberos.KerberosPrincipal;
  import javax.security.auth.login.LoginException;
  import javax.security.auth.spi.LoginModule;
  import javax.security.auth.x500.X500Principal;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.argeo.api.NodeConstants;
  import org.argeo.api.security.DataAdminPrincipal;
  import org.argeo.cms.internal.auth.ImpliedByPrincipal;
  import org.argeo.naming.LdapAttrs;
  import org.argeo.osgi.useradmin.IpaUtils;
  
  public class SingleUserLoginModule implements LoginModule {
  	private final static Log log = LogFactory.getLog(SingleUserLoginModule.class);
  
  	private Subject subject;
  	private Map<String, Object> sharedState = null;
  
  	@SuppressWarnings("unchecked")
  	@Override
  	public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState,
  			Map<String, ?> options) {
  		this.subject = subject;
  		this.sharedState = (Map<String, Object>) sharedState;
  	}
  
  	@Override
  	public boolean login() throws LoginException {
  		String username = System.getProperty("user.name");
  		if (!sharedState.containsKey(CmsAuthUtils.SHARED_STATE_NAME))
  			sharedState.put(CmsAuthUtils.SHARED_STATE_NAME, username);
  		return true;
  	}
  
  	@Override
  	public boolean commit() throws LoginException {
  		X500Principal principal;
  		KerberosPrincipal kerberosPrincipal = CmsAuthUtils.getSinglePrincipal(subject, KerberosPrincipal.class);
  		if (kerberosPrincipal != null) {
  			LdapName userDn = IpaUtils.kerberosToDn(kerberosPrincipal.getName());
  			principal = new X500Principal(userDn.toString());
  		} else {
  			Object username = sharedState.get(CmsAuthUtils.SHARED_STATE_NAME);
  			if (username == null)
  				throw new LoginException("No username available");
  			String hostname;
  			try {
  				hostname = InetAddress.getLocalHost().getHostName();
  			} catch (UnknownHostException e) {
  				log.warn("Using localhost as hostname", e);
  				hostname = "localhost";
  			}
  			String baseDn = ("." + hostname).replaceAll("\\.", ",dc=");
  			principal = new X500Principal(LdapAttrs.uid + "=" + username + baseDn);
  		}
  		Set<Principal> principals = subject.getPrincipals();
  		principals.add(principal);
  		principals.add(new ImpliedByPrincipal(NodeConstants.ROLE_ADMIN, principal));
  		principals.add(new DataAdminPrincipal());
  		return true;
  	}
  
  	@Override
  	public boolean abort() throws LoginException {
  		return true;
  	}
  
  	@Override
  	public boolean logout() throws LoginException {
  		// TODO Auto-generated method stub
  		return true;
  	}
  
  }