/*
    * Copyright 2024 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.channel.uring;
  
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.channel.ChannelException;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.DefaultChannelConfig;
  import io.netty.channel.MessageSizeEstimator;
  import io.netty.channel.RecvByteBufAllocator;
  import io.netty.channel.ServerChannelRecvByteBufAllocator;
  import io.netty.channel.WriteBufferWaterMark;
  import io.netty.channel.socket.ServerSocketChannelConfig;
  import io.netty.util.NetUtil;
  
  import java.io.IOException;
  import java.util.Map;
  
  import static io.netty.channel.ChannelOption.TCP_FASTOPEN;
  import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
  
  final class IoUringServerSocketChannelConfig extends DefaultChannelConfig implements ServerSocketChannelConfig {
      private volatile int backlog = NetUtil.SOMAXCONN;
      private volatile int pendingFastOpenRequestsThreshold;
  
      IoUringServerSocketChannelConfig(AbstractIoUringServerChannel channel) {
          super(channel, new ServerChannelRecvByteBufAllocator());
          setReuseAddress(true);
      }
  
      @Override
      public Map<ChannelOption<?>, Object> getOptions() {
          return getOptions(super.getOptions(), ChannelOption.SO_RCVBUF, ChannelOption.SO_REUSEADDR,
                  ChannelOption.SO_BACKLOG, IoUringChannelOption.SO_REUSEPORT, IoUringChannelOption.IP_FREEBIND,
                  IoUringChannelOption.IP_TRANSPARENT, IoUringChannelOption.TCP_DEFER_ACCEPT, ChannelOption.TCP_FASTOPEN);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public <T> T getOption(ChannelOption<T> option) {
          if (option == ChannelOption.SO_RCVBUF) {
              return (T) Integer.valueOf(getReceiveBufferSize());
          }
          if (option == ChannelOption.SO_REUSEADDR) {
              return (T) Boolean.valueOf(isReuseAddress());
          }
          if (option == ChannelOption.SO_BACKLOG) {
              return (T) Integer.valueOf(getBacklog());
          }
          if (option == IoUringChannelOption.SO_REUSEPORT) {
              return (T) Boolean.valueOf(isReusePort());
          }
          if (option == IoUringChannelOption.IP_FREEBIND) {
              return (T) Boolean.valueOf(isFreeBind());
          }
          if (option == IoUringChannelOption.IP_TRANSPARENT) {
              return (T) Boolean.valueOf(isIpTransparent());
          }
          if (option == IoUringChannelOption.TCP_DEFER_ACCEPT) {
              return (T) Integer.valueOf(getTcpDeferAccept());
          }
          if (option == TCP_FASTOPEN) {
              return (T) Integer.valueOf(getTcpFastopen());
          }
          return super.getOption(option);
      }
  
      @Override
      public <T> boolean setOption(ChannelOption<T> option, T value) {
          validate(option, value);
          if (option == ChannelOption.SO_RCVBUF) {
              setReceiveBufferSize((Integer) value);
          } else if (option == ChannelOption.SO_REUSEADDR) {
              setReuseAddress((Boolean) value);
          } else if (option == ChannelOption.SO_BACKLOG) {
              setBacklog((Integer) value);
          } else if (option == IoUringChannelOption.SO_REUSEPORT) {
              setReusePort((Boolean) value);
          } else if (option == IoUringChannelOption.IP_FREEBIND) {
              setFreeBind((Boolean) value);
          } else if (option == IoUringChannelOption.IP_TRANSPARENT) {
              setIpTransparent((Boolean) value);
          } else if (option == IoUringChannelOption.TCP_DEFER_ACCEPT) {
              setTcpDeferAccept((Integer) value);
          } else if (option == TCP_FASTOPEN) {
              setTcpFastopen((Integer) value);
         } else {
             return super.setOption(option, value);
         }
 
         return true;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setPerformancePreferences(int connectionTime, int latency, int bandwidth) {
         return this;
     }
 
     @Override
     public boolean isReuseAddress() {
         try {
             return ((AbstractIoUringChannel) channel).socket.isReuseAddress();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     @Override
     public IoUringServerSocketChannelConfig setReuseAddress(boolean reuseAddress) {
         try {
             ((AbstractIoUringChannel) channel).socket.setReuseAddress(reuseAddress);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     @Override
     public int getReceiveBufferSize() {
         try {
             return ((AbstractIoUringChannel) channel).socket.getReceiveBufferSize();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     @Override
     public IoUringServerSocketChannelConfig setReceiveBufferSize(int receiveBufferSize) {
         try {
             ((AbstractIoUringChannel) channel).socket.setReceiveBufferSize(receiveBufferSize);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     @Override
     public int getBacklog() {
         return backlog;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setBacklog(int backlog) {
         checkPositiveOrZero(backlog, "backlog");
         this.backlog = backlog;
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setConnectTimeoutMillis(int connectTimeoutMillis) {
         super.setConnectTimeoutMillis(connectTimeoutMillis);
         return this;
     }
 
     @Override
     @Deprecated
     public IoUringServerSocketChannelConfig setMaxMessagesPerRead(int maxMessagesPerRead) {
         super.setMaxMessagesPerRead(maxMessagesPerRead);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setWriteSpinCount(int writeSpinCount) {
         super.setWriteSpinCount(writeSpinCount);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setAllocator(ByteBufAllocator allocator) {
         super.setAllocator(allocator);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setRecvByteBufAllocator(RecvByteBufAllocator allocator) {
         super.setRecvByteBufAllocator(allocator);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setAutoRead(boolean autoRead) {
         super.setAutoRead(autoRead);
         return this;
     }
 
     @Override
     @Deprecated
     public IoUringServerSocketChannelConfig setWriteBufferHighWaterMark(int writeBufferHighWaterMark) {
         super.setWriteBufferHighWaterMark(writeBufferHighWaterMark);
         return this;
     }
 
     @Override
     @Deprecated
     public IoUringServerSocketChannelConfig setWriteBufferLowWaterMark(int writeBufferLowWaterMark) {
         super.setWriteBufferLowWaterMark(writeBufferLowWaterMark);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setWriteBufferWaterMark(WriteBufferWaterMark writeBufferWaterMark) {
         super.setWriteBufferWaterMark(writeBufferWaterMark);
         return this;
     }
 
     @Override
     public IoUringServerSocketChannelConfig setMessageSizeEstimator(MessageSizeEstimator estimator) {
         super.setMessageSizeEstimator(estimator);
         return this;
     }
 
     /**
      * Returns {@code true} if the SO_REUSEPORT option is set.
      */
     public boolean isReusePort() {
         try {
             return ((IoUringServerSocketChannel) channel).socket.isReusePort();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Set the SO_REUSEPORT option on the underlying Channel. This will allow to bind multiple
      * {@link io.netty.channel.socket.ServerSocketChannel}s to the same port and so accept connections with multiple
      * threads.
      *
      * Be aware this method needs be called before
      * {@link io.netty.channel.socket.ServerSocketChannel#bind(java.net.SocketAddress)} to have any affect.
      */
     public IoUringServerSocketChannelConfig setReusePort(boolean reusePort) {
         try {
             ((IoUringServerSocketChannel) channel).socket.setReusePort(reusePort);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Returns {@code true} if <a href="https://man7.org/linux/man-pages/man7/ip.7.html">IP_FREEBIND</a> is enabled,
      * {@code false} otherwise.
      */
     public boolean isFreeBind() {
         try {
             return ((IoUringServerSocketChannel) channel).socket.isIpFreeBind();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * If {@code true} is used <a href="https://man7.org/linux/man-pages/man7/ip.7.html">IP_FREEBIND</a> is enabled,
      * {@code false} for disable it. Default is disabled.
      */
     public IoUringServerSocketChannelConfig setFreeBind(boolean freeBind) {
         try {
             ((IoUringServerSocketChannel) channel).socket.setIpFreeBind(freeBind);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Returns {@code true} if <a href="https://man7.org/linux/man-pages/man7/ip.7.html">IP_TRANSPARENT</a> is enabled,
      * {@code false} otherwise.
      */
     public boolean isIpTransparent() {
         try {
             return ((IoUringServerSocketChannel) channel).socket.isIpTransparent();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * If {@code true} is used <a href="https://man7.org/linux/man-pages/man7/ip.7.html">IP_TRANSPARENT</a> is enabled,
      * {@code false} for disable it. Default is disabled.
      */
     public IoUringServerSocketChannelConfig setIpTransparent(boolean transparent) {
         try {
             ((IoUringServerSocketChannel) channel).socket.setIpTransparent(transparent);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Set the {@code TCP_DEFER_ACCEPT} option on the socket. See {@code man 7 tcp} for more details.
      */
     public IoUringServerSocketChannelConfig setTcpDeferAccept(int deferAccept) {
         try {
             ((IoUringServerSocketChannel) channel).socket.setTcpDeferAccept(deferAccept);
             return this;
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Returns a positive value if <a href="https://linux.die.net/man/7/tcp">TCP_DEFER_ACCEPT</a> is enabled.
      */
     public int getTcpDeferAccept() {
         try {
             return ((IoUringServerSocketChannel) channel).socket.getTcpDeferAccept();
         } catch (IOException e) {
             throw new ChannelException(e);
         }
     }
 
     /**
      * Returns threshold value of number of pending for fast open connect.
      *
      * @see <a href="https://tools.ietf.org/html/rfc7413#appendix-A.2">RFC 7413 Passive Open</a>
      */
     public int getTcpFastopen() {
         return pendingFastOpenRequestsThreshold;
     }
 
     /**
      * Enables tcpFastOpen on the server channel. If the underlying os doesn't support TCP_FASTOPEN setting this has no
      * effect. This has to be set before doing listen on the socket otherwise this takes no effect.
      *
      * @param pendingFastOpenRequestsThreshold number of requests to be pending for fastopen at a given point in time
      * for security.
      *
      * @see <a href="https://tools.ietf.org/html/rfc7413#appendix-A.2">RFC 7413 Passive Open</a>
      */
     public IoUringServerSocketChannelConfig setTcpFastopen(int pendingFastOpenRequestsThreshold) {
         this.pendingFastOpenRequestsThreshold = checkPositiveOrZero(pendingFastOpenRequestsThreshold,
                 "pendingFastOpenRequestsThreshold");
         return this;
     }
 }