////////////////////////////////////////////////////////////////////////////////
/// 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 Max Neunhoeffer
////////////////////////////////////////////////////////////////////////////////

#include "Aql/CollectOptions.h"
#include "Basics/Exceptions.h"

#include <velocypack/velocypack-aliases.h>

using namespace arangodb::aql;
using Json = arangodb::basics::Json;
using JsonHelper = arangodb::basics::JsonHelper;

////////////////////////////////////////////////////////////////////////////////
/// @brief constructor, using JSON
////////////////////////////////////////////////////////////////////////////////

CollectOptions::CollectOptions(Json const& json) {
  Json obj = json.get("collectOptions");

  method =
      methodFromString(JsonHelper::getStringValue(obj.json(), "method", ""));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not the hash method can be used
////////////////////////////////////////////////////////////////////////////////

bool CollectOptions::canUseHashMethod() const {
  if (method == CollectMethod::COLLECT_METHOD_SORTED) {
    return false;
  }

  return true;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief convert the options to JSON
////////////////////////////////////////////////////////////////////////////////

void CollectOptions::toJson(arangodb::basics::Json& json,
                            TRI_memory_zone_t* zone) const {
  Json options = Json(Json::Object, 1)("method", Json(methodToString(method)));
  json("collectOptions", options);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief convert the options to VelocyPack
////////////////////////////////////////////////////////////////////////////////

void CollectOptions::toVelocyPack(VPackBuilder& builder) const {
  VPackObjectBuilder guard(&builder);
  builder.add("method", VPackValue(methodToString(method)));
}

////////////////////////////////////////////////////////////////////////////////
/// @brief get the aggregation method from a string
////////////////////////////////////////////////////////////////////////////////

CollectOptions::CollectMethod CollectOptions::methodFromString(
    std::string const& method) {
  if (method == "hash") {
    return CollectMethod::COLLECT_METHOD_HASH;
  }
  if (method == "sorted") {
    return CollectMethod::COLLECT_METHOD_SORTED;
  }

  return CollectMethod::COLLECT_METHOD_UNDEFINED;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief stringify the aggregation method
////////////////////////////////////////////////////////////////////////////////

std::string CollectOptions::methodToString(
    CollectOptions::CollectMethod method) {
  if (method == CollectMethod::COLLECT_METHOD_HASH) {
    return std::string("hash");
  }
  if (method == CollectMethod::COLLECT_METHOD_SORTED) {
    return std::string("sorted");
  }

  THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL,
                                 "cannot stringify unknown aggregation method");
}