/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  package org.waarp.openr66.protocol.networkhandler.packet;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufAllocator;
  import org.waarp.common.utility.WaarpNettyUtil;
  import org.waarp.common.utility.WaarpStringUtils;
  import org.waarp.openr66.protocol.exception.OpenR66ProtocolPacketException;
  import org.waarp.openr66.protocol.localhandler.LocalChannelReference;
  import org.waarp.openr66.protocol.localhandler.packet.AbstractLocalPacket;
  import org.waarp.openr66.protocol.localhandler.packet.LocalPacketFactory;
  
  /**
   * Network Packet A Packet is composed of one global length field, two Id (4
   * bytes x 2) and a buffer. The
   * first Id is the localId on receive operation and the remoteId on send
   * operation. The second Id is the
   * reverse.
   */
  public class NetworkPacket {
    public static final int NETWORK_HEADER_SIZE = 4 * 3 + 1;
    private ByteBuf buffer;
  
    private final int remoteId;
  
    private final int localId;
  
    private final byte code;
  
    private boolean uniqueBuffer;
  
    /**
     * @param localId
     * @param remoteId
     * @param code
     * @param buffer
     */
    public NetworkPacket(final int localId, final int remoteId, final byte code,
                         final ByteBuf buffer) {
      this.remoteId = remoteId;
      this.localId = localId;
      this.code = code;
      this.buffer = buffer;
      this.uniqueBuffer = false;
    }
  
    /**
     * @param localId
     * @param remoteId
     * @param packet
     * @param lcr the LocalChannelReference in use
     *
     * @throws OpenR66ProtocolPacketException
     */
    public NetworkPacket(final int localId, final int remoteId,
                         final AbstractLocalPacket packet,
                         final LocalChannelReference lcr)
        throws OpenR66ProtocolPacketException {
      this.remoteId = remoteId;
      this.localId = localId;
      code = packet.getType();
      uniqueBuffer = true;
      buffer = packet.getLocalPacketForNetworkPacket(lcr, this);
    }
  
    /**
     * @return the buffer
     */
    public final ByteBuf getBuffer() {
      return buffer;
    }
  
    /**
     * @return the remoteId
     */
    public final int getRemoteId() {
      return remoteId;
    }
  
    /**
     * @return the localId
    */
   public final int getLocalId() {
     return localId;
   }
 
   /**
    * @return the code
    */
   public final byte getCode() {
     return code;
   }
 
   public final void writeNetworkHeader(final ByteBuf buf, final int capacity) {
     buf.writerIndex(0);
     buf.writeInt(capacity + NETWORK_HEADER_SIZE - 4);
     buf.writeInt(remoteId);
     buf.writeInt(localId);
     buf.writeByte(code);
   }
 
   /**
    * @return The corresponding ByteBuf
    */
   public ByteBuf getNetworkPacket() {
     if (uniqueBuffer) {
       writeNetworkHeader(buffer, buffer.capacity() - NETWORK_HEADER_SIZE);
       buffer.writerIndex(buffer.capacity());
       return buffer;
     }
     final ByteBuf buf = ByteBufAllocator.DEFAULT.ioBuffer(NETWORK_HEADER_SIZE,
                                                           NETWORK_HEADER_SIZE);
     writeNetworkHeader(buf, buffer.capacity());
     buffer = ByteBufAllocator.DEFAULT.compositeDirectBuffer(2)
                                      .addComponents(buf, buffer);
     uniqueBuffer = true;
     return buffer;
   }
 
   @Override
   public String toString() {
     return "RId: " + remoteId + " LId: " + localId + " Code: " + code +
            " Length: " + (buffer != null? (buffer.readableBytes() + (code ==
                                                                      LocalPacketFactory.REQUESTPACKET?
         buffer.toString(buffer.readerIndex(), buffer.readableBytes(),
                         WaarpStringUtils.UTF8) : "")) : "no buffer");
   }
 
   public final void clear() {
     if (WaarpNettyUtil.release(buffer)) {
       buffer = null;
     }
   }
 }