/*
    * Copyright 2020 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.codec.quic;
  
  import io.netty.util.internal.ObjectUtil;
  
  import java.nio.ByteBuffer;
  import java.security.SecureRandom;
  
  final class SecureRandomQuicConnectionIdGenerator implements QuicConnectionIdGenerator {
      private static final SecureRandom RANDOM = new SecureRandom();
  
      static final QuicConnectionIdGenerator INSTANCE = new SecureRandomQuicConnectionIdGenerator();
  
      private SecureRandomQuicConnectionIdGenerator() {
      }
  
      @Override
      public ByteBuffer newId(int length) {
          ObjectUtil.checkInRange(length, 0, maxConnectionIdLength(), "length");
          byte[] bytes = new byte[length];
          RANDOM.nextBytes(bytes);
          return ByteBuffer.wrap(bytes);
      }
  
      @Override
      public ByteBuffer newId(ByteBuffer buffer, int length) {
          return newId(length);
      }
  
      @Override
      public int maxConnectionIdLength() {
          return Quiche.QUICHE_MAX_CONN_ID_LEN;
      }
  
      @Override
      public boolean isIdempotent() {
          return false;
      }
  }