////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2017 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Daniel H. Larkin
/// @author Jan Steemann
/// @author Jan Christoph Uhde
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGO_ROCKSDB_ROCKSDB_COMMON_H
#define ARANGO_ROCKSDB_ROCKSDB_COMMON_H 1

#include "Basics/Common.h"
#include "Basics/Endian.h"
#include "Basics/Result.h"
#include "Basics/RocksDBUtils.h"
#include "RocksDBEngine/RocksDBComparator.h"
#include "RocksDBEngine/RocksDBEngine.h"
#include "RocksDBEngine/RocksDBKey.h"
#include "RocksDBEngine/RocksDBKeyBounds.h"
#include "RocksDBEngine/RocksDBTypes.h"
#include "RocksDBEngine/RocksDBValue.h"

#include <rocksdb/iterator.h>
#include <rocksdb/options.h>
#include <rocksdb/status.h>
#include <rocksdb/utilities/transaction_db.h>

namespace rocksdb {
class TransactionDB;
class DB;
struct ReadOptions;
class Comparator;
class ColumnFamilyHandle;
}  // namespace rocksdb

namespace arangodb {

class RocksDBMethods;
class RocksDBKeyBounds;
class RocksDBEngine;

namespace rocksutils {

rocksdb::TransactionDB* globalRocksDB();
rocksdb::ColumnFamilyHandle* defaultCF();
RocksDBEngine* globalRocksEngine();
arangodb::Result globalRocksDBPut(rocksdb::ColumnFamilyHandle* cf,
                                  rocksdb::Slice const& key, rocksdb::Slice const& value,
                                  rocksdb::WriteOptions const& = rocksdb::WriteOptions{});

arangodb::Result globalRocksDBRemove(rocksdb::ColumnFamilyHandle* cf,
                                     rocksdb::Slice const& key,
                                     rocksdb::WriteOptions const& = rocksdb::WriteOptions{});

uint64_t latestSequenceNumber();

std::pair<TRI_voc_tick_t, TRI_voc_cid_t> mapObjectToCollection(uint64_t);
std::tuple<TRI_voc_tick_t, TRI_voc_cid_t, TRI_idx_iid_t> mapObjectToIndex(uint64_t);

/// @brief count all keys in the given column family
std::size_t countKeys(rocksdb::DB*, rocksdb::ColumnFamilyHandle* cf);

/// @brief iterate over all keys in range and count them
std::size_t countKeyRange(rocksdb::DB*, RocksDBKeyBounds const&, bool prefix_same_as_start);

/// @brief helper method to remove large ranges of data
/// Should mainly be used to implement the drop() call
Result removeLargeRange(rocksdb::DB* db, RocksDBKeyBounds const& bounds,
                        bool prefixSameAsStart, bool useRangeDelete);

// optional switch to std::function to reduce amount of includes and
// to avoid template
// this helper is not meant for transactional usage!
template <typename T>  // T is a invokeable that takes a rocksdb::Iterator*
void iterateBounds(RocksDBKeyBounds const& bounds, T callback,
                   rocksdb::ReadOptions options = rocksdb::ReadOptions()) {
  rocksdb::Slice const end = bounds.end();
  options.iterate_upper_bound = &end;  // save to use on rocksb::DB directly
  options.prefix_same_as_start = true;
  options.verify_checksums = false;
  options.fill_cache = false;
  std::unique_ptr<rocksdb::Iterator> it(
      globalRocksDB()->NewIterator(options, bounds.columnFamily()));
  for (it->Seek(bounds.start()); it->Valid(); it->Next()) {
    callback(it.get());
  }
}

}  // namespace rocksutils
}  // namespace arangodb

#endif