/*
    * Copyright 2012 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.socks;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.util.CharsetUtil;
  import io.netty.util.internal.ObjectUtil;
  
  import java.nio.charset.CharsetEncoder;
  
  /**
   * An socks auth request.
   *
   * @see SocksAuthResponse
   * @see SocksAuthRequestDecoder
   */
  public final class SocksAuthRequest extends SocksRequest {
      private static final SocksSubnegotiationVersion SUBNEGOTIATION_VERSION = SocksSubnegotiationVersion.AUTH_PASSWORD;
      private final String username;
      private final String password;
  
      public SocksAuthRequest(String username, String password) {
          super(SocksRequestType.AUTH);
          ObjectUtil.checkNotNull(username, "username");
          ObjectUtil.checkNotNull(password, "password");
          final CharsetEncoder asciiEncoder = CharsetUtil.encoder(CharsetUtil.US_ASCII);
          if (!asciiEncoder.canEncode(username) || !asciiEncoder.canEncode(password)) {
              throw new IllegalArgumentException(
                      "username: " + username + " or password: **** values should be in pure ascii");
          }
          if (username.length() > 255) {
              throw new IllegalArgumentException("username: " + username + " exceeds 255 char limit");
          }
          if (password.length() > 255) {
              throw new IllegalArgumentException("password: **** exceeds 255 char limit");
          }
          this.username = username;
          this.password = password;
      }
  
      /**
       * Returns username that needs to be authenticated
       *
       * @return username that needs to be authenticated
       */
      public String username() {
          return username;
      }
  
      /**
       * Returns password that needs to be validated
       *
       * @return password that needs to be validated
       */
      public String password() {
          return password;
      }
  
      @Override
      public void encodeAsByteBuf(ByteBuf byteBuf) {
          byteBuf.writeByte(SUBNEGOTIATION_VERSION.byteValue());
          byteBuf.writeByte(username.length());
          byteBuf.writeCharSequence(username, CharsetUtil.US_ASCII);
          byteBuf.writeByte(password.length());
          byteBuf.writeCharSequence(password, CharsetUtil.US_ASCII);
      }
  }