text: #pragma once
  //------------------------------------------------------------------------------
  //
  //   Copyright 2018-2020 Fetch.AI Limited
  //
  //   Licensed 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
  //
  //       http://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.
  //
  //------------------------------------------------------------------------------
  
  #include "chain/constants.hpp"
  #include "ledger/chain/block.hpp"
  
  namespace fetch {
  namespace ledger {
  
  /**
   * The class represents block structure in permanent chain storage file.
   */
  struct BlockDbRecord
  {
    Block block;
    // empty next hash is used as undefined value
    Block::Hash next_hash;
  
    Block::Hash hash() const
    {
      return block.hash;
    }
  };
  
  }  // namespace ledger
  
  namespace serializers {
  
  template <typename V, typename D>
  struct MapSerializer;
  
  template <typename D>
  struct MapSerializer<ledger::BlockDbRecord, D>
  {
  public:
    using Type       = ledger::BlockDbRecord;
    using DriverType = D;
  
    static uint8_t const BLOCK     = 1;
    static uint8_t const NEXT_HASH = 2;
  
    template <typename Constructor>
    static void Serialize(Constructor &map_constructor, Type const &dbRecord)
    {
      auto map = map_constructor(2);
      map.Append(BLOCK, dbRecord.block);
      map.Append(NEXT_HASH, dbRecord.next_hash);
    }
  
    template <typename MapDeserializer>
    static void Deserialize(MapDeserializer &map, Type &dbRecord)
    {
      map.ExpectKeyGetValue(BLOCK, dbRecord.block);
      map.ExpectKeyGetValue(NEXT_HASH, dbRecord.next_hash);
    }
  };
  
  }  // namespace serializers
  }  // namespace fetch
  