// Copyright (c) 2012-2015, The CryptoNote developers, The Bytecoin developers
//
// This file is part of Bytecoin.
//
// Bytecoin is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Bytecoin 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with Bytecoin.  If not, see <http://www.gnu.org/licenses/>.

#include "BlockIndex.h"

#include <boost/utility/value_init.hpp>

#include "CryptoNoteSerialization.h"
#include "Serialization/SerializationOverloads.h"

namespace CryptoNote {
  Crypto::Hash BlockIndex::getBlockId(uint32_t height) const {
    assert(height < m_container.size());

    return m_container[static_cast<size_t>(height)];
  }

  std::vector<Crypto::Hash> BlockIndex::getBlockIds(uint32_t startBlockIndex, uint32_t maxCount) const {
    std::vector<Crypto::Hash> result;
    if (startBlockIndex >= m_container.size()) {
      return result;
    }

    size_t count = std::min(static_cast<size_t>(maxCount), m_container.size() - static_cast<size_t>(startBlockIndex));
    result.reserve(count);
    for (size_t i = 0; i < count; ++i) {
      result.push_back(m_container[startBlockIndex + i]);
    }

    return result;
  }

  bool BlockIndex::findSupplement(const std::vector<Crypto::Hash>& ids, uint32_t& offset) const {
    for (const auto& id : ids) {
      if (getBlockHeight(id, offset)) {
        return true;
      }
    }

    return false;
  }

  std::vector<Crypto::Hash> BlockIndex::buildSparseChain(const Crypto::Hash& startBlockId) const {
    assert(m_index.count(startBlockId) > 0);

    uint32_t startBlockHeight;
    getBlockHeight(startBlockId, startBlockHeight);

    std::vector<Crypto::Hash> result;
    size_t sparseChainEnd = static_cast<size_t>(startBlockHeight + 1);
    for (size_t i = 1; i <= sparseChainEnd; i *= 2) {
      result.emplace_back(m_container[sparseChainEnd - i]);
    }

    if (result.back() != m_container[0]) {
      result.emplace_back(m_container[0]);
    }

    return result;
  }

  Crypto::Hash BlockIndex::getTailId() const {
    assert(!m_container.empty());
    return m_container.back();
  }

  void BlockIndex::serialize(ISerializer& s) {
    if (s.type() == ISerializer::INPUT) {
      readSequence<Crypto::Hash>(std::back_inserter(m_container), "index", s);
    } else {
      writeSequence<Crypto::Hash>(m_container.begin(), m_container.end(), "index", s);
    }
  }
}