/*
    * ====================================================================
    * 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.BitSet;
  
  import org.apache.hc.core5.http.ParseException;
  import org.apache.hc.core5.http.ProtocolVersion;
  import org.apache.hc.core5.http.message.ParserCursor;
  import org.apache.hc.core5.http.message.TokenParser;
  
  final class TlsVersionParser {
  
      public final static TlsVersionParserrsionParser.html#TlsVersionParser">TlsVersionParser INSTANCE = new TlsVersionParser();
  
      private final TokenParser tokenParser;
  
      TlsVersionParser() {
          this.tokenParser = TokenParser.INSTANCE;
      }
  
      ProtocolVersion parse(
              final CharSequence buffer,
              final ParserCursor cursor,
              final BitSet delimiters) 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);
          }
          final String s = this.tokenParser.parseToken(buffer, cursor, delimiters);
          final int idx = s.indexOf('.');
          if (idx == -1) {
              final int major;
              try {
                  major = Integer.parseInt(s);
              } catch (final NumberFormatException e) {
                  throw new ParseException("Invalid TLS major version", buffer, lowerBound, upperBound, pos);
              }
              return new ProtocolVersion("TLS", major, 0);
          } else {
              final String s1 = s.substring(0, idx);
              final int major;
              try {
                  major = Integer.parseInt(s1);
              } catch (final NumberFormatException e) {
                  throw new ParseException("Invalid TLS major version", buffer, lowerBound, upperBound, pos);
              }
              final String s2 = s.substring(idx + 1);
              final int minor;
              try {
                  minor = Integer.parseInt(s2);
              } catch (final NumberFormatException e) {
                  throw new ParseException("Invalid TLS minor version", buffer, lowerBound, upperBound, pos);
              }
              return new ProtocolVersion("TLS", major, minor);
          }
      }
  
      ProtocolVersion parse(final String s) throws ParseException {
          if (s == null) {
              return null;
          }
         final ParserCursorsage/ParserCursor.html#ParserCursor">ParserCursor cursor = new ParserCursor(0, s.length());
         return parse(s, cursor, null);
     }
 
 }