////////////////////////////////////////////////////////////////////////////////
/// 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
////////////////////////////////////////////////////////////////////////////////

#include "ClusterIndexFactory.h"
#include "Basics/StaticStrings.h"
#include "Basics/StringUtils.h"
#include "Basics/VelocyPackHelper.h"
#include "Cluster/ServerState.h"
#include "ClusterEngine/ClusterEngine.h"
#include "ClusterEngine/ClusterIndex.h"
#include "Indexes/Index.h"
#include "StorageEngine/EngineSelectorFeature.h"
#include "VocBase/LogicalCollection.h"
#include "VocBase/ticks.h"
#include "VocBase/voc-types.h"

#include <velocypack/Builder.h>
#include <velocypack/Iterator.h>
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>

namespace arangodb {

ClusterIndexFactory::ClusterIndexFactory() {
  emplaceFactory("edge",
                 [](LogicalCollection& collection, velocypack::Slice const& definition,
                    TRI_idx_iid_t id, bool isClusterConstructor) -> std::shared_ptr<Index> {
                   if (!isClusterConstructor) {
                     // this indexes cannot be created directly
                     THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL,
                                                    "cannot create edge index");
                   }

                   auto* ce = static_cast<ClusterEngine*>(EngineSelectorFeature::ENGINE);
                   auto ct = ce->engineType();

                   return std::make_shared<ClusterIndex>(id, collection, ct,
                                                         Index::TRI_IDX_TYPE_EDGE_INDEX,
                                                         definition);
                 });

  emplaceFactory(
      "primary",
      [](LogicalCollection& collection, velocypack::Slice const& definition,
         TRI_idx_iid_t id, bool isClusterConstructor) -> std::shared_ptr<Index> {
        if (!isClusterConstructor) {
          // this indexes cannot be created directly
          THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL,
                                         "cannot create primary index");
        }

        auto* ce = static_cast<ClusterEngine*>(EngineSelectorFeature::ENGINE);
        auto ct = ce->engineType();

        return std::make_shared<ClusterIndex>(0, collection, ct,
                                              Index::TRI_IDX_TYPE_PRIMARY_INDEX, definition);
      });

  // both engines support all types right now
  static const std::vector<std::string> supported = {"fulltext", "geo",
                                                     "geo1",     "geo2",
                                                     "hash",     "persistent",
                                                     "skiplist"};

  for (auto& typeStr : supported) {
    auto type = Index::type(typeStr);

    emplaceFactory(typeStr,
                   [type](LogicalCollection& collection,
                          velocypack::Slice const& definition, TRI_idx_iid_t id,
                          bool isClusterConstructor) -> std::shared_ptr<Index> {
                     auto* ce = static_cast<ClusterEngine*>(EngineSelectorFeature::ENGINE);
                     auto ct = ce->engineType();

                     return std::make_shared<ClusterIndex>(id, collection, ct, type, definition);
                   });
  }
}

Result ClusterIndexFactory::enhanceIndexDefinition(VPackSlice const definition,
                                                   VPackBuilder& normalized, bool isCreation,
                                                   bool isCoordinator) const {
  auto* ce = static_cast<ClusterEngine*>(EngineSelectorFeature::ENGINE);

  if (!ce) {
    return TRI_ERROR_INTERNAL;
  }
  auto* ae = ce->actualEngine();
  if (!ae) {
    return TRI_ERROR_INTERNAL;
  }
  return ae->indexFactory().enhanceIndexDefinition(definition, normalized,
                                                   isCreation, isCoordinator);
}

void ClusterIndexFactory::fillSystemIndexes(arangodb::LogicalCollection& col,
                                            std::vector<std::shared_ptr<arangodb::Index>>& systemIndexes) const {
  // create primary index
  VPackBuilder input;
  input.openObject();
  input.add(StaticStrings::IndexType, VPackValue("primary"));
  input.add(StaticStrings::IndexId, VPackValue("0"));
  input.add(StaticStrings::IndexFields, VPackValue(VPackValueType::Array));
  input.add(VPackValue(StaticStrings::KeyString));
  input.close();
  input.add(StaticStrings::IndexUnique, VPackValue(true));
  input.add(StaticStrings::IndexSparse, VPackValue(false));
  input.close();

  // get the storage engine type
  ClusterEngine* ce = static_cast<ClusterEngine*>(EngineSelectorFeature::ENGINE);
  ClusterEngineType ct = ce->engineType();

  systemIndexes.emplace_back(
      std::make_shared<arangodb::ClusterIndex>(0, col, ct, Index::TRI_IDX_TYPE_PRIMARY_INDEX,
                                               input.slice()));

  // create edges indexes
  if (col.type() == TRI_COL_TYPE_EDGE) {
    // first edge index
    input.clear();
    input.openObject();
    input.add(StaticStrings::IndexType,
              VPackValue(Index::oldtypeName(Index::TRI_IDX_TYPE_EDGE_INDEX)));
    input.add(StaticStrings::IndexId, VPackValue("1"));
    input.add(StaticStrings::IndexFields, VPackValue(VPackValueType::Array));
    input.add(VPackValue(StaticStrings::FromString));

    if (ct == ClusterEngineType::MMFilesEngine) {
      input.add(VPackValue(StaticStrings::ToString));
    }

    input.close();
    input.add(StaticStrings::IndexUnique, VPackValue(false));
    input.add(StaticStrings::IndexSparse, VPackValue(false));
    input.close();
    systemIndexes.emplace_back(
        std::make_shared<arangodb::ClusterIndex>(1, col, ct, Index::TRI_IDX_TYPE_EDGE_INDEX,
                                                 input.slice()));

    // second edge index
    if (ct == ClusterEngineType::RocksDBEngine) {
      input.clear();
      input.openObject();
      input.add(StaticStrings::IndexType,
                VPackValue(Index::oldtypeName(Index::TRI_IDX_TYPE_EDGE_INDEX)));
      input.add(StaticStrings::IndexId, VPackValue("2"));
      input.add(StaticStrings::IndexFields, VPackValue(VPackValueType::Array));
      input.add(VPackValue(StaticStrings::ToString));
      input.close();
      input.add(StaticStrings::IndexUnique, VPackValue(false));
      input.add(StaticStrings::IndexSparse, VPackValue(false));
      input.close();
      systemIndexes.emplace_back(std::make_shared<arangodb::ClusterIndex>(
          2, col, ct, Index::TRI_IDX_TYPE_EDGE_INDEX, input.slice()));
    }
  }
}

void ClusterIndexFactory::prepareIndexes(
    LogicalCollection& col, arangodb::velocypack::Slice const& indexesSlice,
    std::vector<std::shared_ptr<arangodb::Index>>& indexes) const {
  TRI_ASSERT(indexesSlice.isArray());

  for (auto const& v : VPackArrayIterator(indexesSlice)) {
    if (basics::VelocyPackHelper::getBooleanValue(v, "error", false)) {
      // We have an error here. Do not add.
      continue;
    }

    if (basics::VelocyPackHelper::getBooleanValue(v, "isBuilding", false)) {
      // This index is still being built. Do not add.
      continue;
    }

    auto idx = prepareIndexFromSlice(v, false, col, true);

    if (!idx) {
      LOG_TOPIC(ERR, arangodb::Logger::ENGINES)
          << "error creating index from definition '" << v.toString() << "'";

      continue;
    }

    indexes.emplace_back(std::move(idx));
  }
}

}  // namespace arangodb

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