////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 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 Jan Steemann
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_AQL_AQL_TRANSACTION_H
#define ARANGOD_AQL_AQL_TRANSACTION_H 1

#include "Aql/Collection.h"
#include "Basics/Common.h"
#include "Basics/Result.h"
#include "Transaction/Methods.h"
#include "Transaction/Options.h"
#include "Transaction/StandaloneContext.h"
#include "VocBase/vocbase.h"

#include <map>

namespace arangodb {
namespace aql {

class AqlTransaction : public transaction::Methods {
 public:
  /// @brief create the transaction and add all collections
  /// from the query context
  static std::shared_ptr<AqlTransaction>
    create(std::shared_ptr<transaction::Context> const& transactionContext,
                                std::map<std::string, aql::Collection*> const* collections,
                                transaction::Options const& options, bool isMainTransaction,
                                std::unordered_set<std::string> inaccessibleCollections =
                                    std::unordered_set<std::string>());

  /// @brief end the transaction
  ~AqlTransaction() {}

  /// @brief add a list of collections to the transaction
  Result addCollections(std::map<std::string, aql::Collection*> const& collections);

  /// @brief documentCollection
  LogicalCollection* documentCollection(TRI_voc_cid_t cid);

  /// @brief lockCollections, this is needed in a corner case in AQL: we need
  /// to lock all shards in a controlled way when we set up a distributed
  /// execution engine. To this end, we prevent the standard mechanism to
  /// lock collections on the DBservers when we instantiate the query. Then,
  /// in a second round, we need to lock the shards in exactly the right
  /// order via an HTTP call. This method is used to implement that HTTP action.
  int lockCollections() override;

  AqlTransaction(std::shared_ptr<transaction::Context> const& transactionContext,
                 transaction::Options const& options);

  /// protected so we can create different subclasses
  AqlTransaction(std::shared_ptr<transaction::Context> const& transactionContext,
                 std::map<std::string, aql::Collection*> const* collections,
                 transaction::Options const& options, bool isMainTransaction);

  /// @brief add a collection to the transaction
  Result processCollection(aql::Collection*);

 protected:
  /// @brief keep a copy of the collections, this is needed for the clone
  /// operation
  std::map<std::string, aql::Collection*> _collections;
};
}  // namespace aql
}  // namespace arangodb

#endif