////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2017 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 "Agency/AgencyComm.h"
#include "Basics/Common.h"
#include "Basics/Exceptions.h"
#include "Basics/FileUtils.h"
#include "Basics/StringUtils.h"
#include "Basics/VelocyPackHelper.h"
#include "Basics/files.h"
#include "Cluster/ClusterFeature.h"
#include "Cluster/ClusterInfo.h"
#include "Cluster/ServerState.h"
#include "ClusterEngine/ClusterEngine.h"
#include "GeneralServer/AuthenticationFeature.h"
#include "Logger/Logger.h"
#include "MMFiles/MMFilesEngine.h"
#include "RocksDBEngine/RocksDBCommon.h"
#include "RocksDBEngine/RocksDBIndex.h"
#include "StorageEngine/EngineSelectorFeature.h"
#include "StorageEngine/PhysicalCollection.h"
#include "Transaction/StandaloneContext.h"
#include "UpgradeTasks.h"
#include "Utils/OperationOptions.h"
#include "Utils/SingleCollectionTransaction.h"
#include "VocBase/LogicalCollection.h"
#include "VocBase/Methods/Collections.h"
#include "VocBase/Methods/Indexes.h"
#include "VocBase/vocbase.h"

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

using namespace arangodb;
using namespace arangodb::methods;
using application_features::ApplicationServer;
using basics::VelocyPackHelper;

// Note: this entire file should run with superuser rights

namespace {

/// create a collection if it does not exists.
void createSystemCollection(TRI_vocbase_t& vocbase, std::string const& name) {
  auto const res = methods::Collections::createSystem(vocbase, name);

  if (res.fail()) {
    THROW_ARANGO_EXCEPTION(res);
  }
}

/// create an index if it does not exist
bool createIndex(
  TRI_vocbase_t& vocbase, // collection vocbase
  std::string const& name, // collection name
  arangodb::Index::IndexType type, // index type
                 std::vector<std::string> const& fields, bool unique, bool sparse) {
  VPackBuilder output;
  Result res1, res2;

  res1 = methods::Collections::lookup(
      vocbase, name, [&](std::shared_ptr<LogicalCollection> const& coll) -> void {
        TRI_ASSERT(coll);
        res2 = methods::Indexes::createIndex(coll.get(), type, fields, unique, sparse);
      });

  if (res1.fail() || res2.fail()) {
    THROW_ARANGO_EXCEPTION(res1.fail() ? res1 : res2);
  }

  return true;
}

arangodb::Result recreateGeoIndex(TRI_vocbase_t& vocbase,
                                  arangodb::LogicalCollection& collection,
                                  arangodb::RocksDBIndex* oldIndex) {
  arangodb::Result res;
  TRI_idx_iid_t iid = oldIndex->id();

  VPackBuilder oldDesc;
  oldIndex->toVelocyPack(oldDesc, Index::makeFlags());
  VPackBuilder overw;

  overw.openObject();
  overw.add(arangodb::StaticStrings::IndexType,
            arangodb::velocypack::Value(
                arangodb::Index::oldtypeName(Index::TRI_IDX_TYPE_GEO_INDEX)));
  overw.close();

  VPackBuilder newDesc = VPackCollection::merge(oldDesc.slice(), overw.slice(), false);
  bool dropped = collection.dropIndex(iid);

  if (!dropped) {
    res.reset(TRI_ERROR_INTERNAL);

    return res;
  }

  bool created = false;
  auto newIndex =
      collection.getPhysical()->createIndex(newDesc.slice(), /*restore*/ true, created);

  if (!created) {
    res.reset(TRI_ERROR_INTERNAL);
  }

  TRI_ASSERT(newIndex->id() == iid);  // will break cluster otherwise
  TRI_ASSERT(newIndex->type() == Index::TRI_IDX_TYPE_GEO_INDEX);

  return res;
}
}  // namespace

bool UpgradeTasks::upgradeGeoIndexes(TRI_vocbase_t& vocbase,
                                     arangodb::velocypack::Slice const& slice) {
  if (EngineSelectorFeature::engineName() != RocksDBEngine::EngineName) {
    LOG_TOPIC("2cb46", DEBUG, Logger::STARTUP) << "No need to upgrade geo indexes!";
    return true;
  }

  auto collections = vocbase.collections(false);

  for (auto collection : collections) {
    auto indexes = collection->getIndexes();
    for (auto index : indexes) {
      RocksDBIndex* rIndex = static_cast<RocksDBIndex*>(index.get());
      if (index->type() == Index::TRI_IDX_TYPE_GEO1_INDEX ||
          index->type() == Index::TRI_IDX_TYPE_GEO2_INDEX) {
        LOG_TOPIC("5e53d", INFO, Logger::STARTUP)
            << "Upgrading legacy geo index '" << rIndex->id() << "'";

        auto res = ::recreateGeoIndex(vocbase, *collection, rIndex);

        if (res.fail()) {
          LOG_TOPIC("5550a", ERR, Logger::STARTUP)
              << "Error upgrading geo indexes " << res.errorMessage();
          return false;
        }
      }
    }
  }

  return true;
}

bool UpgradeTasks::setupGraphs(TRI_vocbase_t& vocbase,
                               arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_graphs"); // throws on error
  return true;
}

bool UpgradeTasks::setupUsers(TRI_vocbase_t& vocbase,
                              arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_users"); // throws on error
  return true;
}

bool UpgradeTasks::createUsersIndex(TRI_vocbase_t& vocbase,
                                    arangodb::velocypack::Slice const& slice) {
  TRI_ASSERT(vocbase.isSystem());

  return ::createIndex(
    vocbase, // collection vocbase
    "_users", // collection name
    arangodb::Index::TRI_IDX_TYPE_HASH_INDEX, // index type
    { "user" }, // index fields
                       /*unique*/ true,
                       /*sparse*/ true);
}

bool UpgradeTasks::addDefaultUserOther(TRI_vocbase_t& vocbase,
                                       arangodb::velocypack::Slice const& params) {
  TRI_ASSERT(!vocbase.isSystem());
  TRI_ASSERT(params.isObject());

  VPackSlice users = params.get("users");

  if (users.isNone()) {
    return true;  // exit, no users were specified
  } else if (!users.isArray()) {
    LOG_TOPIC("44623", ERR, Logger::STARTUP) << "addDefaultUserOther: users is invalid";
    return false;
  }
  auth::UserManager* um = AuthenticationFeature::instance()->userManager();
  if (um == nullptr) {
    return true;  // server does not support users
  }

  for (VPackSlice slice : VPackArrayIterator(users)) {
    std::string user =
        VelocyPackHelper::getStringValue(slice, "username", StaticStrings::Empty);
    if (user.empty()) {
      continue;
    }
    std::string passwd = VelocyPackHelper::getStringValue(slice, "passwd", "");
    bool active = VelocyPackHelper::getBooleanValue(slice, "active", true);
    VPackSlice extra = slice.get("extra");
    Result res = um->storeUser(false, user, passwd, active, VPackSlice::noneSlice());
    if (res.fail() && !res.is(TRI_ERROR_USER_DUPLICATE)) {
      LOG_TOPIC("b5b8a", WARN, Logger::STARTUP) << "could not add database user " << user
                                       << ": " << res.errorMessage();
    } else if (extra.isObject() && !extra.isEmptyObject()) {
      um->updateUser(user, [&](auth::User& user) {
        user.setUserData(VPackBuilder(extra));
        return TRI_ERROR_NO_ERROR;
      });
    }

    res = um->updateUser(user, [&](auth::User& entry) {
      entry.grantDatabase(vocbase.name(), auth::Level::RW);
      entry.grantCollection(vocbase.name(), "*", auth::Level::RW);
      return TRI_ERROR_NO_ERROR;
    });
    if (res.fail()) {
      LOG_TOPIC("60019", WARN, Logger::STARTUP)
          << "could not set permissions for new user " << user << ": "
          << res.errorMessage();
    }
  }
  return true;
}

bool UpgradeTasks::setupAqlFunctions(TRI_vocbase_t& vocbase,
                                     arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_aqlfunctions"); // throws on error
  return true;
}

bool UpgradeTasks::setupQueues(TRI_vocbase_t& vocbase,
                               arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_queues"); // throws on error
  return true;
}

bool UpgradeTasks::setupJobs(TRI_vocbase_t& vocbase, arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_jobs"); // throws on error
  return true;
}

bool UpgradeTasks::createJobsIndex(TRI_vocbase_t& vocbase,
                                   arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_jobs");
  ::createIndex(
    vocbase, // collection vocbase
    "_jobs", // collection name
    arangodb::Index::TRI_IDX_TYPE_SKIPLIST_INDEX, // index type
                {"queue", "status", "delayUntil"},
                /*unique*/ false,
                /*sparse*/ false);
  ::createIndex(
    vocbase, // collection vocbase
    "_jobs", // collection name
    arangodb::Index::TRI_IDX_TYPE_SKIPLIST_INDEX, // index type
                {"status", "queue", "delayUntil"},
                /*unique*/ false,
                /*sparse*/ false);

  return true;
}

bool UpgradeTasks::setupApps(TRI_vocbase_t& vocbase, arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_apps"); // throws on error
  return true;
}

bool UpgradeTasks::createAppsIndex(TRI_vocbase_t& vocbase,
                                   arangodb::velocypack::Slice const& slice) {
  return ::createIndex(
    vocbase, // collection vocbase
    "_apps", // collection name
    arangodb::Index::TRI_IDX_TYPE_HASH_INDEX, // index type
    {"mount"}, // index fields
                       /*unique*/ true,
                       /*sparse*/ true);
}

bool UpgradeTasks::setupAppBundles(TRI_vocbase_t& vocbase,
                                   arangodb::velocypack::Slice const& slice) {
  ::createSystemCollection(vocbase, "_appbundles"); // throws on error
  return true;
}

bool UpgradeTasks::persistLocalDocumentIds(TRI_vocbase_t& vocbase,
                                           arangodb::velocypack::Slice const& slice) {
  if (EngineSelectorFeature::engineName() != MMFilesEngine::EngineName) {
    return true;
  }
  Result res = basics::catchToResult([&vocbase]() -> Result {
    MMFilesEngine* engine = static_cast<MMFilesEngine*>(EngineSelectorFeature::ENGINE);
    return engine->persistLocalDocumentIds(vocbase);
  });
  return res.ok();
}

bool UpgradeTasks::renameReplicationApplierStateFiles(TRI_vocbase_t& vocbase,
                                                      arangodb::velocypack::Slice const& slice) {
  if (EngineSelectorFeature::engineName() == MMFilesEngine::EngineName) {
    return true;
  }

  StorageEngine* engine = EngineSelectorFeature::ENGINE;
  std::string const path = engine->databasePath(&vocbase);

  std::string const source =
      arangodb::basics::FileUtils::buildFilename(path,
                                                 "REPLICATION-APPLIER-STATE");

  if (!basics::FileUtils::isRegularFile(source)) {
    // source file does not exist
    return true;
  }

  bool result = true;

  // copy file REPLICATION-APPLIER-STATE to REPLICATION-APPLIER-STATE-<id>
  Result res = basics::catchToResult([&vocbase, &path, &source, &result]() -> Result {
    std::string const dest = arangodb::basics::FileUtils::buildFilename(
        path, "REPLICATION-APPLIER-STATE-" + std::to_string(vocbase.id()));

    LOG_TOPIC("75337", TRACE, Logger::STARTUP) << "copying replication applier file '"
                                      << source << "' to '" << dest << "'";

    std::string error;
    if (!TRI_CopyFile(source.c_str(), dest.c_str(), error)) {
      LOG_TOPIC("6c90c", WARN, Logger::STARTUP)
          << "could not copy replication applier file '" << source << "' to '"
          << dest << "'";
      result = false;
    }
    return Result();
  });
  if (res.fail()) {
    return false;
  }
  return result;
}