/*
 * Copyright (c) 2015, Cryptonomex, Inc.
 * All rights reserved.
 *
 * This source code is provided for evaluation in private test networks only, until September 8, 2015. After this date, this license expires and
 * the code may not be used, modified or distributed for any purpose. Redistribution and use in source and binary forms, with or without modification,
 * are permitted until September 8, 2015, provided that the following conditions are met:
 *
 * 1. The code and/or derivative works are used only for private test networks consisting of no more than 10 P2P nodes.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#pragma once
#include <fc/array.hpp>
#include <fc/io/varint.hpp>
#include <fc/network/ip.hpp>
#include <fc/io/raw.hpp>
#include <fc/crypto/ripemd160.hpp>
#include <fc/reflect/variant.hpp>

namespace graphene { namespace net {

  /**
   *  Defines an 8 byte header that is always present because the minimum encrypted packet
   *  size is 8 bytes (blowfish).  The maximum message size is defined in config.hpp. The channel,
   *  and message type is also included because almost every channel will have a message type
   *  field and we might as well include it in the 8 byte header to save space.
   */
  struct message_header
  {
     uint32_t  size;   // number of bytes in message, capped at MAX_MESSAGE_SIZE
     uint32_t  msg_type;  // every channel gets a 16 bit message type specifier
  };

  typedef fc::uint160_t message_hash_type;

  /**
   *  Abstracts the process of packing/unpacking a message for a 
   *  particular channel.
   */
  struct message : public message_header
  {
     std::vector<char> data;

     message(){}

     message( message&& m )
     :message_header(m),data( std::move(m.data) ){}

     message( const message& m )
     :message_header(m),data( m.data ){}

     /**
      *  Assumes that T::type specifies the message type
      */
     template<typename T>
     message( const T& m ) 
     {
        msg_type = T::type;
        data     = fc::raw::pack(m);
        size     = (uint32_t)data.size();
     }

     fc::uint160_t id()const
     {
        return fc::ripemd160::hash( data.data(), (uint32_t)data.size() );
     }

     /**
      *  Automatically checks the type and deserializes T in the
      *  opposite process from the constructor.
      */
     template<typename T>
     T as()const 
     {
         try {
          FC_ASSERT( msg_type == T::type );
          T tmp;
          if( data.size() )
          {
             fc::datastream<const char*> ds( data.data(), data.size() );
             fc::raw::unpack( ds, tmp );
          }
          else
          {
             // just to make sure that tmp shouldn't have any data
             fc::datastream<const char*> ds( nullptr, 0 );
             fc::raw::unpack( ds, tmp );
          }
          return tmp;
         } FC_RETHROW_EXCEPTIONS( warn, 
              "error unpacking network message as a '${type}'  ${x} !=? ${msg_type}", 
              ("type", fc::get_typename<T>::name() )
              ("x", T::type)
              ("msg_type", msg_type)
              );
     }
  };




} } // graphene::net

FC_REFLECT( graphene::net::message_header, (size)(msg_type) )
FC_REFLECT_DERIVED( graphene::net::message, (graphene::net::message_header), (data) )