////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2018 ArangoDB 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 Simon Grätzer
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_CLUSTER_ENGINE_CLUSTER_COLLECTION_H
#define ARANGOD_CLUSTER_ENGINE_CLUSTER_COLLECTION_H 1

#include "Basics/Common.h"
#include "Basics/ReadWriteLock.h"
#include "ClusterEngine/ClusterSelectivityEstimates.h"
#include "ClusterEngine/Common.h"
#include "StorageEngine/PhysicalCollection.h"
#include "VocBase/LogicalCollection.h"

#include <velocypack/StringRef.h>

namespace rocksdb {
class Transaction;
}

namespace arangodb {
namespace cache {
class Cache;
}

class LogicalCollection;
class ManagedDocumentResult;
class Result;
class RocksDBPrimaryIndex;
class RocksDBVPackIndex;
class LocalDocumentId;

class ClusterCollection final : public PhysicalCollection {
  constexpr static double defaultLockTimeout = 10.0 * 60.0;

 public:
  explicit ClusterCollection(LogicalCollection& collection, ClusterEngineType sengineType,
                             arangodb::velocypack::Slice const& info);
  ClusterCollection(LogicalCollection& collection,
                    PhysicalCollection const*);  // use in cluster only!!!!!

  ~ClusterCollection();

  /// @brief fetches current index selectivity estimates
  /// if allowUpdate is true, will potentially make a cluster-internal roundtrip
  /// to fetch current values!
  IndexEstMap clusterIndexEstimates(bool allowUpdating, TRI_voc_tick_t tid) override;

  /// @brief sets the current index selectivity estimates
  void setClusterIndexEstimates(IndexEstMap&& estimates) override;

  /// @brief flushes the current index selectivity estimates
  void flushClusterIndexEstimates() override;

  std::string const& path() const override;
  void setPath(std::string const& path) override;

  arangodb::Result updateProperties(velocypack::Slice const& slice, bool doSync) override;
  virtual arangodb::Result persistProperties() override;

  virtual PhysicalCollection* clone(LogicalCollection& collection) const override;

  /// @brief export properties
  void getPropertiesVPack(velocypack::Builder&) const override;

  /// @brief return the figures for a collection
  std::shared_ptr<velocypack::Builder> figures() override;

  /// @brief closes an open collection
  int close() override;
  void load() override;
  void unload() override;

  TRI_voc_rid_t revision(arangodb::transaction::Methods* trx) const override;
  uint64_t numberDocuments(transaction::Methods* trx) const override;

  /// @brief report extra memory used by indexes etc.
  size_t memory() const override;
  void open(bool ignoreErrors) override;

  ////////////////////////////////////
  // -- SECTION Indexes --
  ///////////////////////////////////

  void prepareIndexes(arangodb::velocypack::Slice indexesSlice) override;

  std::shared_ptr<Index> createIndex(arangodb::velocypack::Slice const& info,
                                     bool restore, bool& created) override;

  /// @brief Drop an index with the given iid.
  bool dropIndex(TRI_idx_iid_t iid) override;
  std::unique_ptr<IndexIterator> getAllIterator(transaction::Methods* trx) const override;
  std::unique_ptr<IndexIterator> getAnyIterator(transaction::Methods* trx) const override;

  std::unique_ptr<IndexIterator> getSortedAllIterator(transaction::Methods* trx) const;

  void invokeOnAllElements(transaction::Methods* trx,
                           std::function<bool(LocalDocumentId const&)> callback) override;

  ////////////////////////////////////
  // -- SECTION DML Operations --
  ///////////////////////////////////

  Result truncate(transaction::Methods& trx, OperationOptions& options) override;
  
  /// @brief compact-data operation
  Result compact() override;

  void deferDropCollection(std::function<bool(LogicalCollection&)> const& callback) override;

  LocalDocumentId lookupKey(transaction::Methods* trx, velocypack::Slice const& key) const override;

  Result read(transaction::Methods*, arangodb::velocypack::StringRef const& key,
              ManagedDocumentResult& result, bool) override;

  Result read(transaction::Methods* trx, arangodb::velocypack::Slice const& key,
              ManagedDocumentResult& result, bool locked) override {
    return this->read(trx, arangodb::velocypack::StringRef(key), result, locked);
  }

  bool readDocument(transaction::Methods* trx, LocalDocumentId const& token,
                    ManagedDocumentResult& result) const override;

  bool readDocumentWithCallback(transaction::Methods* trx, LocalDocumentId const& token,
                                IndexIterator::DocumentCallback const& cb) const override;

  Result insert(arangodb::transaction::Methods* trx, arangodb::velocypack::Slice newSlice,
                arangodb::ManagedDocumentResult& result, OperationOptions& options,
                bool lock, KeyLockInfo* /*keyLockInfo*/,
                std::function<void()> const& callbackDuringLock) override;

  Result update(arangodb::transaction::Methods* trx, arangodb::velocypack::Slice const newSlice,
                ManagedDocumentResult& result, OperationOptions& options,
                bool lock, ManagedDocumentResult& previous) override;

  Result replace(transaction::Methods* trx, arangodb::velocypack::Slice const newSlice,
                 ManagedDocumentResult& result, OperationOptions& options,
                 bool lock, ManagedDocumentResult& previous) override;

  Result remove(transaction::Methods& trx, velocypack::Slice slice,
                ManagedDocumentResult& previous, OperationOptions& options,
                bool lock, KeyLockInfo* keyLockInfo,
                std::function<void()> const& callbackDuringLock) override;

 protected:
  /// @brief Inject figures that are specific to StorageEngine
  void figuresSpecific(std::shared_ptr<arangodb::velocypack::Builder>&) override;

 private:
  void addIndex(std::shared_ptr<arangodb::Index> idx);

  // keep locks just to adhere to behavior in other collections
  mutable basics::ReadWriteLock _exclusiveLock;
  ClusterEngineType _engineType;
  velocypack::Builder _info;
  ClusterSelectivityEstimates _selectivityEstimates;
};

}  // namespace arangodb

#endif