////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2018 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 Kaveh Vahedipour
/// @author Matthew Von-Maszewski
////////////////////////////////////////////////////////////////////////////////

#include "UpdateCollection.h"

#include "ApplicationFeatures/ApplicationServer.h"
#include "Basics/VelocyPackHelper.h"
#include "Cluster/ClusterComm.h"
#include "Cluster/ClusterFeature.h"
#include "Cluster/FollowerInfo.h"
#include "Cluster/MaintenanceFeature.h"
#include "Utils/DatabaseGuard.h"
#include "VocBase/LogicalCollection.h"
#include "VocBase/Methods/Collections.h"
#include "VocBase/Methods/Databases.h"

using namespace arangodb;
using namespace arangodb::application_features;
using namespace arangodb::maintenance;
using namespace arangodb::methods;

UpdateCollection::UpdateCollection(MaintenanceFeature& feature, ActionDescription const& desc)
    : ActionBase(feature, desc) {
  std::stringstream error;

  _labels.emplace(FAST_TRACK);

  if (!desc.has(COLLECTION)) {
    error << "collection must be specified. ";
  }
  TRI_ASSERT(desc.has(COLLECTION));

  if (!desc.has(SHARD)) {
    error << "shard must be specified. ";
  }
  TRI_ASSERT(desc.has(SHARD));

  if (!desc.has(DATABASE)) {
    error << "database must be specified. ";
  }
  TRI_ASSERT(desc.has(DATABASE));

  if (!desc.has(FOLLOWERS_TO_DROP)) {
    error << "followersToDrop must be specified. ";
  }
  TRI_ASSERT(desc.has(FOLLOWERS_TO_DROP));

  if (!error.str().empty()) {
    LOG_TOPIC(ERR, Logger::MAINTENANCE) << "UpdateCollection: " << error.str();
    _result.reset(TRI_ERROR_INTERNAL, error.str());
    setState(FAILED);
  }
}

UpdateCollection::~UpdateCollection(){};

bool UpdateCollection::first() {
  auto const& database = _description.get(DATABASE);
  auto const& collection = _description.get(COLLECTION);
  auto const& shard = _description.get(SHARD);
  auto const& followersToDrop = _description.get(FOLLOWERS_TO_DROP);
  auto const& props = properties();

  try {
    DatabaseGuard guard(database);
    auto vocbase = &guard.database();

    Result found = methods::Collections::lookup(
        vocbase, shard, [&](std::shared_ptr<LogicalCollection> const& coll) -> void {
          TRI_ASSERT(coll);
          LOG_TOPIC(DEBUG, Logger::MAINTENANCE)
              << "Updating local collection " + shard;

          // If someone (the Supervision most likely) has thrown
          // out a follower from the plan, then the leader
          // will not notice until it fails to replicate an operation
          // to the old follower. This here is to drop such a follower
          // from the local list of followers. Will be reported
          // to Current in due course.
          if (!followersToDrop.empty()) {
            auto& followers = coll->followers();
            std::vector<std::string> ftd =
                arangodb::basics::StringUtils::split(followersToDrop, ',');
            for (auto const& s : ftd) {
              followers->remove(s);
            }
          }
          _result = Collections::updateProperties(*coll, props, false);  // always a full-update

          if (!_result.ok()) {
            LOG_TOPIC(ERR, Logger::MAINTENANCE)
                << "failed to update properties"
                   " of collection "
                << shard << ": " << _result.errorMessage();
          }
        });

    if (found.fail()) {
      std::stringstream error;
      error << "failed to lookup local collection " << shard << "in database " + database;
      LOG_TOPIC(ERR, Logger::MAINTENANCE) << error.str();
      _result = actionError(TRI_ERROR_ARANGO_DATA_SOURCE_NOT_FOUND, error.str());
    }
  } catch (std::exception const& e) {
    std::stringstream error;

    error << "action " << _description << " failed with exception " << e.what();
    LOG_TOPIC(WARN, Logger::MAINTENANCE) << "UpdateCollection: " << error.str();
    _result.reset(TRI_ERROR_INTERNAL, error.str());
  }

  if (_result.fail()) {
    _feature.storeShardError(database, collection, shard,
                             _description.get(SERVER_ID), _result);
  }

  notify();

  return false;
}