/*
    * ====================================================================
    * 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.http.ssl;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.hc.core5.annotation.Internal;
  import org.apache.hc.core5.http.ParseException;
  import org.apache.hc.core5.http.ProtocolVersion;
  import org.apache.hc.core5.http.ProtocolVersionParser;
  import org.apache.hc.core5.util.Tokenizer;
  
  /**
   * Supported {@code TLS} protocol versions.
   *
   * @since 5.0
   */
  public enum TLS {
  
      V_1_0("TLSv1",   new ProtocolVersion("TLS", 1, 0)),
      V_1_1("TLSv1.1", new ProtocolVersion("TLS", 1, 1)),
      V_1_2("TLSv1.2", new ProtocolVersion("TLS", 1, 2)),
      V_1_3("TLSv1.3", new ProtocolVersion("TLS", 1, 3));
  
      public final String id;
      public final ProtocolVersion version;
  
      TLS(final String id, final ProtocolVersion version) {
          this.id = id;
          this.version = version;
      }
  
      public boolean isSame(final ProtocolVersion protocolVersion) {
          return version.equals(protocolVersion);
      }
  
      public boolean isComparable(final ProtocolVersion protocolVersion) {
          return version.isComparable(protocolVersion);
      }
  
      /**
       * Gets the ID.
       * @return the ID.
       *
       * @since 5.2
       */
      public String getId() {
          return id;
      }
  
      /**
       * Gets the version.
       * @return the version.
       *
       * @since 5.2
       */
      public ProtocolVersion getVersion() {
          return version;
      }
  
      public boolean greaterEquals(final ProtocolVersion protocolVersion) {
          return version.greaterEquals(protocolVersion);
      }
  
      public boolean lessEquals(final ProtocolVersion protocolVersion) {
          return version.lessEquals(protocolVersion);
      }
  
      @Internal
      public static ProtocolVersion parse(
              final CharSequence buffer,
              final Tokenizer.Cursor cursor,
              final Tokenizer.Delimiter delimiterPredicate) throws ParseException {
         final int lowerBound = cursor.getLowerBound();
         final int upperBound = cursor.getUpperBound();
 
         int pos = cursor.getPos();
         if (pos + 4 > cursor.getUpperBound()) {
             throw new ParseException("Invalid TLS protocol version", buffer, lowerBound, upperBound, pos);
         }
         if (buffer.charAt(pos) != 'T' || buffer.charAt(pos + 1) != 'L' || buffer.charAt(pos + 2) != 'S'
                 || buffer.charAt(pos + 3) != 'v') {
             throw new ParseException("Invalid TLS protocol version", buffer, lowerBound, upperBound, pos);
         }
         pos = pos + 4;
         cursor.updatePos(pos);
         if (cursor.atEnd()) {
             throw new ParseException("Invalid TLS version", buffer, lowerBound, upperBound, pos);
         }
         return ProtocolVersionParser.INSTANCE.parse("TLS", null, buffer, cursor, delimiterPredicate);
     }
 
     public static ProtocolVersion parse(final String s) throws ParseException {
         if (s == null) {
             return null;
         }
         final Tokenizer.Cursor cursor = new Tokenizer.Cursor(0, s.length());
         final ProtocolVersion protocolVersion = parse(s, cursor, null);
         Tokenizer.INSTANCE.skipWhiteSpace(s, cursor);
         if (!cursor.atEnd()) {
             throw new ParseException("Invalid TLS protocol version; trailing content");
         }
         return protocolVersion;
     }
 
     public static String[] excludeWeak(final String... protocols) {
         if (protocols == null) {
             return null;
         }
         final List<String> enabledProtocols = new ArrayList<>();
         for (final String protocol : protocols) {
             if (isSecure(protocol)) {
                 enabledProtocols.add(protocol);
             }
         }
         if (enabledProtocols.isEmpty()) {
             enabledProtocols.add(V_1_2.id);
         }
         return enabledProtocols.toArray(new String[0]);
     }
 
     /**
      * Check if a given protocol is considered secure and is enabled by default.
      *
      * @return {@code true} if the given protocol is secure and enabled, otherwise return {@code
      * false}.
      * @since 5.2
      */
     public static boolean isSecure(final String protocol) {
         return !protocol.startsWith("SSL") && !protocol.equals(V_1_0.id) && !protocol.equals(V_1_1.id);
     }
 
 }