/*
    * 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.buffer.ByteBufUtil;
  import io.netty.util.CharsetUtil;
  import io.netty.util.NetUtil;
  import io.netty.util.internal.ObjectUtil;
  
  import java.net.IDN;
  
  /**
   * An socks cmd request.
   *
   * @see SocksCmdResponse
   * @see SocksCmdRequestDecoder
   */
  public final class SocksCmdRequest extends SocksRequest {
      private final SocksCmdType cmdType;
      private final SocksAddressType addressType;
      private final String host;
      private final int port;
  
      public SocksCmdRequest(SocksCmdType cmdType, SocksAddressType addressType, String host, int port) {
          super(SocksRequestType.CMD);
          ObjectUtil.checkNotNull(cmdType, "cmdType");
          ObjectUtil.checkNotNull(addressType, "addressType");
          ObjectUtil.checkNotNull(host, "host");
  
          switch (addressType) {
              case IPv4:
                  if (!NetUtil.isValidIpV4Address(host)) {
                      throw new IllegalArgumentException(host + " is not a valid IPv4 address");
                  }
                  break;
              case DOMAIN:
                  String asciiHost = IDN.toASCII(host);
                  if (asciiHost.length() > 255) {
                      throw new IllegalArgumentException(host + " IDN: " + asciiHost + " exceeds 255 char limit");
                  }
                  host = asciiHost;
                  break;
              case IPv6:
                  if (!NetUtil.isValidIpV6Address(host)) {
                      throw new IllegalArgumentException(host + " is not a valid IPv6 address");
                  }
                  break;
              case UNKNOWN:
                  break;
          }
          if (port <= 0 || port >= 65536) {
              throw new IllegalArgumentException(port + " is not in bounds 0 < x < 65536");
          }
          this.cmdType = cmdType;
          this.addressType = addressType;
          this.host = host;
          this.port = port;
      }
  
      /**
       * Returns the {@link SocksCmdType} of this {@link SocksCmdRequest}
       *
       * @return The {@link SocksCmdType} of this {@link SocksCmdRequest}
       */
      public SocksCmdType cmdType() {
          return cmdType;
      }
  
      /**
       * Returns the {@link SocksAddressType} of this {@link SocksCmdRequest}
       *
       * @return The {@link SocksAddressType} of this {@link SocksCmdRequest}
       */
      public SocksAddressType addressType() {
          return addressType;
      }
  
      /**
       * Returns host that is used as a parameter in {@link SocksCmdType}
       *
       * @return host that is used as a parameter in {@link SocksCmdType}
       */
      public String host() {
          return addressType == SocksAddressType.DOMAIN ? IDN.toUnicode(host) : host;
      }
 
     /**
      * Returns port that is used as a parameter in {@link SocksCmdType}
      *
      * @return port that is used as a parameter in {@link SocksCmdType}
      */
     public int port() {
         return port;
     }
 
     @Override
     public void encodeAsByteBuf(ByteBuf byteBuf) {
         byteBuf.writeByte(protocolVersion().byteValue());
         byteBuf.writeByte(cmdType.byteValue());
         byteBuf.writeByte(0x00);
         byteBuf.writeByte(addressType.byteValue());
         switch (addressType) {
             case IPv4: {
                 byteBuf.writeBytes(NetUtil.createByteArrayFromIpAddressString(host));
                 ByteBufUtil.writeShortBE(byteBuf, port);
                 break;
             }
 
             case DOMAIN: {
                 byteBuf.writeByte(host.length());
                 byteBuf.writeCharSequence(host, CharsetUtil.US_ASCII);
                 ByteBufUtil.writeShortBE(byteBuf, port);
                 break;
             }
 
             case IPv6: {
                 byteBuf.writeBytes(NetUtil.createByteArrayFromIpAddressString(host));
                 ByteBufUtil.writeShortBE(byteBuf, port);
                 break;
             }
         }
     }
 }