/*
    * ====================================================================
    * 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.hc.core5.http2.ssl;
  
  import java.net.SocketAddress;
  
  import javax.net.ssl.SSLContext;
  import javax.net.ssl.SSLParameters;
  
  import org.apache.hc.core5.concurrent.FutureCallback;
  import org.apache.hc.core5.http.HttpHost;
  import org.apache.hc.core5.http.URIScheme;
  import org.apache.hc.core5.http.nio.ssl.TlsStrategy;
  import org.apache.hc.core5.net.NamedEndpoint;
  import org.apache.hc.core5.reactor.ssl.SSLBufferMode;
  import org.apache.hc.core5.reactor.ssl.SSLSessionInitializer;
  import org.apache.hc.core5.reactor.ssl.SSLSessionVerifier;
  import org.apache.hc.core5.reactor.ssl.TransportSecurityLayer;
  import org.apache.hc.core5.ssl.SSLContexts;
  import org.apache.hc.core5.util.Args;
  import org.apache.hc.core5.util.Timeout;
  
  /**
   * Basic client-side implementation of {@link TlsStrategy} that upgrades to TLS for all endpoints
   * with {@code HTTPS} scheme.
   *
   * @since 5.0
   */
  public class H2ClientTlsStrategy implements TlsStrategy {
  
      private final SSLContext sslContext;
      private final SSLBufferMode sslBufferMode;
      private final SSLSessionInitializer initializer;
      private final SSLSessionVerifier verifier;
  
      public H2ClientTlsStrategy(
              final SSLContext sslContext,
              final SSLBufferMode sslBufferMode,
              final SSLSessionInitializer initializer,
              final SSLSessionVerifier verifier) {
          this.sslContext = Args.notNull(sslContext, "SSL context");
          this.sslBufferMode = sslBufferMode;
          this.initializer = initializer;
          this.verifier = verifier;
      }
  
      public H2ClientTlsStrategy(
              final SSLContext sslContext,
              final SSLSessionInitializer initializer,
              final SSLSessionVerifier verifier) {
          this(sslContext, null, initializer, verifier);
      }
  
      public H2ClientTlsStrategy(
              final SSLContext sslContext,
              final SSLSessionVerifier verifier) {
          this(sslContext, null, null, verifier);
      }
  
      public H2ClientTlsStrategy(final SSLContext sslContext) {
          this(sslContext, null, null, null);
      }
  
      public H2ClientTlsStrategy() {
          this(SSLContexts.createSystemDefault());
      }
  
      /**
       * Constructor with the default SSL context based on system properties and custom {@link SSLSessionVerifier}.
       * @param verifier the custom {@link SSLSessionVerifier}.
       * @see SSLContext
       * @since 5.2
       */
      public H2ClientTlsStrategy( final SSLSessionVerifier verifier) {
         this(SSLContexts.createSystemDefault(), null, null, verifier);
     }
 
     @Override
     public void upgrade(
             final TransportSecurityLayer tlsSession,
             final NamedEndpoint endpoint,
             final Object attachment,
             final Timeout handshakeTimeout,
             final FutureCallback<TransportSecurityLayer> callback) {
         tlsSession.startTls(
                 sslContext,
                 endpoint,
                 sslBufferMode,
                 (e, sslEngine) -> {
                     final SSLParameters sslParameters = sslEngine.getSSLParameters();
                     sslParameters.setEndpointIdentificationAlgorithm(URIScheme.HTTPS.id);
                     sslEngine.setSSLParameters(H2TlsSupport.enforceRequirements(attachment, sslParameters));
                     if (initializer != null) {
                         initializer.initialize(e, sslEngine);
                     }
                 },
                 verifier,
                 handshakeTimeout,
                 callback);
     }
 
     /**
      * @deprecated use {@link #upgrade(TransportSecurityLayer, NamedEndpoint, Object, Timeout, FutureCallback)}
      */
     @Deprecated
     @Override
     public boolean upgrade(
             final TransportSecurityLayer tlsSession,
             final HttpHost host,
             final SocketAddress localAddress,
             final SocketAddress remoteAddress,
             final Object attachment,
             final Timeout handshakeTimeout) {
         final String scheme = host != null ? host.getSchemeName() : null;
         if (URIScheme.HTTPS.same(scheme)) {
             upgrade(tlsSession, host, attachment, handshakeTimeout, null);
             return true;
         }
         return false;
     }
 
 }