/**
    * Waffle (https://github.com/dblock/waffle)
    *
    * Copyright (c) 2010 - 2015 Application Security, Inc.
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     Application Security, Inc.
   */
  package waffle.apache;
  
  import java.io.IOException;
  import java.security.Principal;
  import java.util.Arrays;
  import java.util.LinkedHashSet;
  import java.util.Locale;
  import java.util.Set;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.catalina.authenticator.AuthenticatorBase;
  import org.apache.catalina.connector.Request;
  import org.slf4j.Logger;
  
  import waffle.windows.auth.IWindowsAuthProvider;
  import waffle.windows.auth.IWindowsIdentity;
  import waffle.windows.auth.PrincipalFormat;
  import waffle.windows.auth.impl.WindowsAuthProviderImpl;
  
  /**
   * The Class WaffleAuthenticatorBase.
   *
   * @author dblock[at]dblock[dot]org
   */
  abstract class WaffleAuthenticatorBase extends AuthenticatorBase {
  
      /** The Constant SUPPORTED_PROTOCOLS. */
      private static final Set<String> SUPPORTED_PROTOCOLS = new LinkedHashSet<String>(Arrays.asList("Negotiate", "NTLM"));
  
      /** The info. */
      protected String                 info;
      
      /** The log. */
      protected Logger                 log;
      
      /** The principal format. */
      protected PrincipalFormat        principalFormat     = PrincipalFormat.FQN;
      
      /** The role format. */
      protected PrincipalFormat        roleFormat          = PrincipalFormat.FQN;
      
      /** The allow guest login. */
      protected boolean                allowGuestLogin     = true;
      
      /** The protocols. */
      protected Set<String>            protocols           = WaffleAuthenticatorBase.SUPPORTED_PROTOCOLS;
  
      /** The auth. */
      protected IWindowsAuthProvider   auth                = new WindowsAuthProviderImpl();
  
      /**
       * Windows authentication provider.
       * 
       * @return IWindowsAuthProvider.
       */
      public IWindowsAuthProvider getAuth() {
          return this.auth;
      }
  
      /**
       * Set Windows auth provider.
       * 
       * @param provider
       *            Class implements IWindowsAuthProvider.
       */
      public void setAuth(final IWindowsAuthProvider provider) {
          this.auth = provider;
      }
  
      /* (non-Javadoc)
       * @see org.apache.catalina.authenticator.AuthenticatorBase#getInfo()
       */
      @Override
      public String getInfo() {
          return this.info;
      }
  
      /**
       * Set the principal format.
       * 
       * @param format
       *            Principal format.
       */
      public void setPrincipalFormat(final String format) {
         this.principalFormat = PrincipalFormat.valueOf(format.toUpperCase(Locale.ENGLISH));
         this.log.debug("principal format: {}", this.principalFormat);
     }
 
     /**
      * Principal format.
      * 
      * @return Principal format.
      */
     public PrincipalFormat getPrincipalFormat() {
         return this.principalFormat;
     }
 
     /**
      * Set the principal format.
      * 
      * @param format
      *            Role format.
      */
     public void setRoleFormat(final String format) {
         this.roleFormat = PrincipalFormat.valueOf(format.toUpperCase(Locale.ENGLISH));
         this.log.debug("role format: {}", this.roleFormat);
     }
 
     /**
      * Principal format.
      * 
      * @return Role format.
      */
     public PrincipalFormat getRoleFormat() {
         return this.roleFormat;
     }
 
     /**
      * True if Guest login permitted.
      * 
      * @return True if Guest login permitted, false otherwise.
      */
     public boolean isAllowGuestLogin() {
         return this.allowGuestLogin;
     }
 
     /**
      * Set whether Guest login is permitted. Default is true, if the Guest account is enabled, an invalid
      * username/password results in a Guest login.
      * 
      * @param value
      *            True or false.
      */
     public void setAllowGuestLogin(final boolean value) {
         this.allowGuestLogin = value;
     }
 
     /**
      * Set the authentication protocols. Default is "Negotiate, NTLM".
      * 
      * @param value
      *            Authentication protocols
      */
     public void setProtocols(final String value) {
         this.protocols = new LinkedHashSet<String>();
         final String[] protocolNames = value.split(",");
         for (String protocolName : protocolNames) {
             protocolName = protocolName.trim();
             if (!protocolName.isEmpty()) {
                 this.log.debug("init protocol: {}", protocolName);
                 if (WaffleAuthenticatorBase.SUPPORTED_PROTOCOLS.contains(protocolName)) {
                     this.protocols.add(protocolName);
                 } else {
                     this.log.error("unsupported protocol: {}", protocolName);
                     throw new RuntimeException("Unsupported protocol: " + protocolName);
                 }
             }
         }
     }
 
     /**
      * Send a 401 Unauthorized along with protocol authentication headers.
      * 
      * @param response
      *            HTTP Response
      */
     protected void sendUnauthorized(final HttpServletResponse response) {
         try {
             for (final String protocol : this.protocols) {
                 response.addHeader("WWW-Authenticate", protocol);
             }
             response.setHeader("Connection", "close");
             response.sendError(HttpServletResponse.SC_UNAUTHORIZED);
             response.flushBuffer();
         } catch (final IOException e) {
             throw new RuntimeException(e);
         }
     }
 
     /**
      * Send an error code.
      * 
      * @param response
      *            HTTP Response
      * @param code
      *            Error Code
      */
     protected void sendError(final HttpServletResponse response, final int code) {
         try {
             response.sendError(code);
         } catch (final IOException e) {
             this.log.error(e.getMessage());
             this.log.trace("{}", e);
             throw new RuntimeException(e);
         }
     }
 
     /* (non-Javadoc)
      * @see org.apache.catalina.authenticator.AuthenticatorBase#getAuthMethod()
      */
     @Override
     protected String getAuthMethod() {
         return null;
     }
 
     /* (non-Javadoc)
      * @see org.apache.catalina.authenticator.AuthenticatorBase#doLogin(org.apache.catalina.connector.Request, java.lang.String, java.lang.String)
      */
     @Override
     protected Principal doLogin(final Request request, final String username, final String password)
             throws ServletException {
         this.log.debug("logging in: {}", username);
         IWindowsIdentity windowsIdentity;
         try {
             windowsIdentity = this.auth.logonUser(username, password);
         } catch (final Exception e) {
             this.log.error(e.getMessage());
             this.log.trace("{}", e);
             return super.doLogin(request, username, password);
         }
         // disable guest login
         if (!this.allowGuestLogin && windowsIdentity.isGuest()) {
             this.log.warn("guest login disabled: {}", windowsIdentity.getFqn());
             return super.doLogin(request, username, password);
         }
         try {
             this.log.debug("successfully logged in {} ({})", username, windowsIdentity.getSidString());
             final GenericWindowsPrincipal windowsPrincipal = new GenericWindowsPrincipal(windowsIdentity,
                     this.principalFormat, this.roleFormat);
             this.log.debug("roles: {}", windowsPrincipal.getRolesString());
             return windowsPrincipal;
         } finally {
             windowsIdentity.dispose();
         }
     }
 
 }