/*
    * Copyright 2016 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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.
   */
  package io.netty.handler.ssl;
  
  import io.netty.util.internal.SuppressJava6Requirement;
  import io.netty.util.CharsetUtil;
  
  import javax.net.ssl.SNIHostName;
  import javax.net.ssl.SNIMatcher;
  import javax.net.ssl.SNIServerName;
  import javax.net.ssl.SSLParameters;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  
  @SuppressJava6Requirement(reason = "Usage guarded by java version check")
  final class Java8SslUtils {
  
      private Java8SslUtils() { }
  
      static List<String> getSniHostNames(SSLParameters sslParameters) {
          List<SNIServerName> names = sslParameters.getServerNames();
          if (names == null || names.isEmpty()) {
              return Collections.emptyList();
          }
          List<String> strings = new ArrayList<String>(names.size());
  
          for (SNIServerName serverName : names) {
              if (serverName instanceof SNIHostName) {
                  strings.add(((SNIHostName) serverName).getAsciiName());
              } else {
                  throw new IllegalArgumentException("Only " + SNIHostName.class.getName()
                          + " instances are supported, but found: " + serverName);
              }
          }
          return strings;
      }
  
      static void setSniHostNames(SSLParameters sslParameters, List<String> names) {
          sslParameters.setServerNames(getSniHostNames(names));
      }
  
      static boolean isValidHostNameForSNI(String hostname) {
          try {
              new SNIHostName(hostname);
              return true;
          } catch (IllegalArgumentException illegal) {
              return false;
          }
      }
  
      static List getSniHostNames(List<String> names) {
          if (names == null || names.isEmpty()) {
              return Collections.emptyList();
          }
          List<SNIServerName> sniServerNames = new ArrayList<SNIServerName>(names.size());
          for (String name: names) {
              sniServerNames.add(new SNIHostName(name.getBytes(CharsetUtil.UTF_8)));
          }
          return sniServerNames;
      }
  
      static List getSniHostName(byte[] hostname) {
          if (hostname == null || hostname.length == 0) {
              return Collections.emptyList();
          }
          return Collections.singletonList(new SNIHostName(hostname));
      }
  
      static boolean getUseCipherSuitesOrder(SSLParameters sslParameters) {
          return sslParameters.getUseCipherSuitesOrder();
      }
  
      static void setUseCipherSuitesOrder(SSLParameters sslParameters, boolean useOrder) {
          sslParameters.setUseCipherSuitesOrder(useOrder);
      }
  
      @SuppressWarnings("unchecked")
      static void setSNIMatchers(SSLParameters sslParameters, Collection<?> matchers) {
          sslParameters.setSNIMatchers((Collection<SNIMatcher>) matchers);
      }
  
      @SuppressWarnings("unchecked")
      static boolean checkSniHostnameMatch(Collection<?> matchers, byte[] hostname) {
         if (matchers != null && !matchers.isEmpty()) {
             SNIHostName name = new SNIHostName(hostname);
             Iterator<SNIMatcher> matcherIt = (Iterator<SNIMatcher>) matchers.iterator();
             while (matcherIt.hasNext()) {
                 SNIMatcher matcher = matcherIt.next();
                 // type 0 is for hostname
                 if (matcher.getType() == 0 && matcher.matches(name)) {
                     return true;
                 }
             }
             return false;
         }
         return true;
     }
 }