/*
    * ====================================================================
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.http.impl.client;
  
  import java.util.Locale;
  
  import org.apache.http.auth.AuthSchemeProvider;
  import org.apache.http.client.CredentialsProvider;
  import org.apache.http.client.config.AuthSchemes;
  import org.apache.http.config.Registry;
  import org.apache.http.config.RegistryBuilder;
  import org.apache.http.impl.auth.BasicSchemeFactory;
  import org.apache.http.impl.auth.DigestSchemeFactory;
  import org.apache.http.impl.auth.win.WindowsCredentialsProvider;
  import org.apache.http.impl.auth.win.WindowsNTLMSchemeFactory;
  import org.apache.http.impl.auth.win.WindowsNegotiateSchemeFactory;
  
  import com.sun.jna.platform.win32.Sspi;
  
  /**
   * Factory methods for {@link CloseableHttpClient} instances configured to use integrated
   * Windows authentication by default.
   *
   * @since 4.4
   */
  public class WinHttpClients {
  
      private WinHttpClients() {
          super();
      }
  
      public static boolean isWinAuthAvailable() {
          String os = System.getProperty("os.name");
          os = os != null ? os.toLowerCase(Locale.ROOT) : null;
          if (os != null && os.contains("windows")) {
              try {
                  return Sspi.MAX_TOKEN_SIZE > 0;
              } catch (final Exception ignore) { // Likely ClassNotFound
                  return false;
              }
          }
          return false;
      }
  
      private static HttpClientBuilder createBuilder() {
          if (isWinAuthAvailable()) {
              final Registry<AuthSchemeProvider> authSchemeRegistry = RegistryBuilder.<AuthSchemeProvider>create()
                      .register(AuthSchemes.BASIC, new BasicSchemeFactory())
                      .register(AuthSchemes.DIGEST, new DigestSchemeFactory())
                      .register(AuthSchemes.NTLM, new WindowsNTLMSchemeFactory(null))
                      .register(AuthSchemes.SPNEGO, new WindowsNegotiateSchemeFactory(null))
                      .build();
              final CredentialsProvider credsProvider = new WindowsCredentialsProvider(new SystemDefaultCredentialsProvider());
              return HttpClientBuilder.create()
                      .setDefaultCredentialsProvider(credsProvider)
                      .setDefaultAuthSchemeRegistry(authSchemeRegistry);
          } else {
              return HttpClientBuilder.create();
          }
      }
  
      /**
       * Creates builder object for construction of custom
       * {@link CloseableHttpClient} instances.
       */
      public static HttpClientBuilder custom() {
          return createBuilder();
      }
  
      /**
       * Creates {@link CloseableHttpClient} instance with default
       * configuration.
       */
      public static CloseableHttpClient createDefault() {
          return createBuilder().build();
     }
 
     /**
      * Creates {@link CloseableHttpClient} instance with default
      * configuration based on system properties.
      */
     public static CloseableHttpClient createSystem() {
         return createBuilder().useSystemProperties().build();
     }
 
 
 }