/*
   Copyright (c) 2018-2019 Nokia.

   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.
*/

/*
 * This source code is part of the near-RT RIC (RAN Intelligent Controller)
 * platform project (RICP).
*/

#include "config.h"
#include "private/error.hpp"
#include "private/abort.hpp"
#include "private/asyncstorageimpl.hpp"
#include "private/configurationreader.hpp"
#include "private/asyncdummystorage.hpp"
#include "private/engine.hpp"
#include "private/logger.hpp"
#if HAVE_REDIS
#include "private/redis/asyncredisstorage.hpp"
#endif

#include <boost/optional/optional_io.hpp>
#include <boost/crc.hpp>

using namespace shareddatalayer;
using namespace shareddatalayer::redis;

namespace
{
        std::shared_ptr<AsyncDatabaseDiscovery> asyncDatabaseDiscoveryCreator(std::shared_ptr<Engine> engine,
                                                                              const std::string& ns,
                                                                              const DatabaseConfiguration& databaseConfiguration,
                                                                              const boost::optional<std::size_t>& addressIndex,
                                                                              std::shared_ptr<Logger> logger)
        {
            return AsyncDatabaseDiscovery::create(engine,
                                                  ns,
                                                  databaseConfiguration,
                                                  addressIndex,
                                                  logger);
        }

        std::uint32_t crc32(const std::string& s)
        {
           boost::crc_32_type result;
           result.process_bytes(s.data(), s.size());
           return result.checksum();
        }

        std::uint32_t getClusterHashIndex(const std::string& s, const size_t count)
        {
            return crc32(s)%count;
        }
}

AsyncStorageImpl::AsyncStorageImpl(std::shared_ptr<Engine> engine,
                                   const boost::optional<PublisherId>& pId,
                                   std::shared_ptr<Logger> logger):
    engine(engine),
    databaseConfiguration(std::make_shared<DatabaseConfigurationImpl>()),
    namespaceConfigurations(std::make_shared<NamespaceConfigurationsImpl>()),
    publisherId(pId),
    logger(logger),
    asyncDatabaseDiscoveryCreator(::asyncDatabaseDiscoveryCreator)
{
    ConfigurationReader configurationReader(logger);
    configurationReader.readDatabaseConfiguration(std::ref(*databaseConfiguration));
    configurationReader.readNamespaceConfigurations(std::ref(*namespaceConfigurations));
}

// Meant for UT usage
AsyncStorageImpl::AsyncStorageImpl(std::shared_ptr<Engine> engine,
                                   const boost::optional<PublisherId>& pId,
                                   std::shared_ptr<DatabaseConfiguration> databaseConfiguration,
                                   std::shared_ptr<NamespaceConfigurations> namespaceConfigurations,
                                   std::shared_ptr<Logger> logger,
                                   const AsyncDatabaseDiscoveryCreator& asyncDatabaseDiscoveryCreator):
    engine(engine),
    databaseConfiguration(databaseConfiguration),
    namespaceConfigurations(namespaceConfigurations),
    publisherId(pId),
    logger(logger),
    asyncDatabaseDiscoveryCreator(asyncDatabaseDiscoveryCreator)
{
}

void AsyncStorageImpl::setAsyncRedisStorageHandlersForCluster(const std::string& ns)
{
    static auto serverCount = databaseConfiguration->getServerAddresses().size();
    for (std::size_t addrIndex = 0; addrIndex < serverCount; addrIndex++)
    {
        auto redisHandler = std::make_shared<AsyncRedisStorage>(engine,
                                                                asyncDatabaseDiscoveryCreator(
                                                                        engine,
                                                                        ns,
                                                                        std::ref(*databaseConfiguration),
                                                                        addrIndex,
                                                                        logger),
                                                                publisherId,
                                                                namespaceConfigurations,
                                                                logger);
        asyncStorages.push_back(redisHandler);
    }
}

void AsyncStorageImpl::setAsyncRedisStorageHandlers(const std::string& ns)
{
    if (DatabaseConfiguration::DbType::SDL_STANDALONE_CLUSTER == databaseConfiguration->getDbType() ||
        DatabaseConfiguration::DbType::SDL_SENTINEL_CLUSTER == databaseConfiguration->getDbType())
    {
            setAsyncRedisStorageHandlersForCluster(ns);
            return;
    }
    auto redisHandler = std::make_shared<AsyncRedisStorage>(engine,
                                                            asyncDatabaseDiscoveryCreator(
                                                                    engine,
                                                                    ns,
                                                                    std::ref(*databaseConfiguration),
                                                                    boost::none,
                                                                    logger),
                                                            publisherId,
                                                            namespaceConfigurations,
                                                            logger);
    asyncStorages.push_back(redisHandler);
}

AsyncStorage& AsyncStorageImpl::getAsyncRedisStorageHandler(const std::string& ns)
{
    std::size_t handlerIndex{0};
    if (DatabaseConfiguration::DbType::SDL_STANDALONE_CLUSTER == databaseConfiguration->getDbType() ||
        DatabaseConfiguration::DbType::SDL_SENTINEL_CLUSTER == databaseConfiguration->getDbType())
        handlerIndex = getClusterHashIndex(ns, databaseConfiguration->getServerAddresses().size());
    return *asyncStorages.at(handlerIndex);
}

AsyncStorage& AsyncStorageImpl::getRedisHandler(const std::string& ns)
{
#if HAVE_REDIS
    if (asyncStorages.empty())
            setAsyncRedisStorageHandlers(ns);

    return getAsyncRedisStorageHandler(ns);
#else
    logger->error() << "Redis operations cannot be performed, Redis not enabled";
    SHAREDDATALAYER_ABORT("Invalid configuration.");
#endif
}

AsyncStorage& AsyncStorageImpl::getDummyHandler()
{
    static AsyncDummyStorage dummyHandler{engine};
    return dummyHandler;
}

AsyncStorage& AsyncStorageImpl::getOperationHandler(const std::string& ns)
{
    if (namespaceConfigurations->isDbBackendUseEnabled(ns))
        return getRedisHandler(ns);

    return getDummyHandler();
}

int AsyncStorageImpl::fd() const
{
    return engine->fd();
}

void AsyncStorageImpl::handleEvents()
{
    engine->handleEvents();
}

void AsyncStorageImpl::waitReadyAsync(const Namespace& ns,
                                      const ReadyAck& readyAck)
{
    getOperationHandler(ns).waitReadyAsync(ns, readyAck);
}

void AsyncStorageImpl::setAsync(const Namespace& ns,
                                const DataMap& dataMap,
                                const ModifyAck& modifyAck)
{
    getOperationHandler(ns).setAsync(ns, dataMap, modifyAck);
}

void AsyncStorageImpl::setIfAsync(const Namespace& ns,
                                  const Key& key,
                                  const Data& oldData,
                                  const Data& newData,
                                  const ModifyIfAck& modifyIfAck)
{
    getOperationHandler(ns).setIfAsync(ns, key, oldData, newData, modifyIfAck);
}

void AsyncStorageImpl::removeIfAsync(const Namespace& ns,
                                     const Key& key,
                                     const Data& data,
                                     const ModifyIfAck& modifyIfAck)
{
    getOperationHandler(ns).removeIfAsync(ns, key, data, modifyIfAck);
}

void AsyncStorageImpl::setIfNotExistsAsync(const Namespace& ns,
                                           const Key& key,
                                           const Data& data,
                                           const ModifyIfAck& modifyIfAck)
{
    getOperationHandler(ns).setIfNotExistsAsync(ns, key, data, modifyIfAck);
}

void AsyncStorageImpl::getAsync(const Namespace& ns,
                                const Keys& keys,
                                const GetAck& getAck)
{
    getOperationHandler(ns).getAsync(ns, keys, getAck);
}

void AsyncStorageImpl::removeAsync(const Namespace& ns,
                                   const Keys& keys,
                                   const ModifyAck& modifyAck)
{
    getOperationHandler(ns).removeAsync(ns, keys, modifyAck);
}

void AsyncStorageImpl::findKeysAsync(const Namespace& ns,
                                     const std::string& keyPrefix,
                                     const FindKeysAck& findKeysAck)
{
    getOperationHandler(ns).findKeysAsync(ns, keyPrefix, findKeysAck);
}

void AsyncStorageImpl::listKeys(const Namespace& ns,
                                const std::string& pattern,
                                const FindKeysAck& findKeysAck)
{
    getOperationHandler(ns).listKeys(ns, pattern, findKeysAck);
}

void AsyncStorageImpl::removeAllAsync(const Namespace& ns,
                                       const ModifyAck& modifyAck)
{
    getOperationHandler(ns).removeAllAsync(ns, modifyAck);
}