#include "../include/odhtdb/Database.hpp"
#include "../include/odhtdb/Group.hpp"
#include "../include/odhtdb/Encryption.hpp"
#include "../include/odhtdb/DhtKey.hpp"
#include "../include/odhtdb/bin2hex.hpp"
#include "../include/odhtdb/Log.hpp"
#include <boost/uuid/uuid_generators.hpp>
#include <opendht.h>
#include <sodium/randombytes.h>
#include <thread>
#include <chrono>
#include <sibs/SafeSerializer.hpp>
#include <sibs/SafeDeserializer.hpp>
#include <cassert>
#include <sys/time.h>

using namespace dht;
using namespace std;
using namespace chrono_literals;

static int databaseCount = 0;
// TODO: Verify time_t is always signed
static time_t timeOffset = 0; // Updated by comparing local time with ntp server
static odhtdb::u64 timeOffsetFraction = 0;
static thread *ntpThread = nullptr;
static bool timestampSynced = false;

const int OPENDHT_INFOHASH_LEN = 20;

namespace odhtdb
{
    static boost::uuids::random_generator uuidGen;
    
    const u16 DATABASE_CREATE_PACKET_STRUCTURE_VERSION = 1;
    const u16 DATABASE_ADD_PACKET_STRUCTURE_VERSION = 1;
    const u16 DATABASE_REQUEST_OLD_DATA_STRUCTURE_VERSION = 1;
    const int NODE_PUT_RETRY_TIMES = 3;
    
    static void nodePutWithRetry(dht::DhtRunner *node, const dht::InfoHash &infoHash, shared_ptr<dht::Value> value, int retryCounter = 0)
    {
        node->put(infoHash, value, [node, infoHash, value, retryCounter](bool ok)
        {
            if(!ok)
            {
                if(retryCounter < NODE_PUT_RETRY_TIMES)
                {
                    Log::warn("Failed to execute node.put, retrying (%d/%d)", 1 + retryCounter, NODE_PUT_RETRY_TIMES);
                    nodePutWithRetry(node, infoHash, value, retryCounter + 1);
                }
                else
                    Log::error("Failed to execute node.put with %d retries, stopping...", NODE_PUT_RETRY_TIMES);
            }
        });
    }
    
    class RequestQuarantineException : public runtime_error
    {
    public:
        RequestQuarantineException() : runtime_error("Request quarantine, will be processed later (can be real of fake request)") {}
    };
    
    OwnedByteArray combine(sibs::SafeSerializer &headerSerializer, const Encryption &encryptedData)
    {
        usize allocationSize = headerSerializer.getBuffer().size() + encryptedData.getNonce().size + encryptedData.getCipherText().size;
        u8 *result = new u8[allocationSize];
        memcpy(result, headerSerializer.getBuffer().data(), headerSerializer.getBuffer().size());
        memcpy(result + headerSerializer.getBuffer().size(), encryptedData.getNonce().data, encryptedData.getNonce().size);
        memcpy(result + headerSerializer.getBuffer().size() + encryptedData.getNonce().size, encryptedData.getCipherText().data, encryptedData.getCipherText().size);
        return OwnedByteArray(result, allocationSize);
    }
    
    OwnedByteArray combine(const Signature::PublicKey &publicKey, const string &signedEncryptedData)
    {
        usize allocationSize = publicKey.getSize() + signedEncryptedData.size();
        u8 *result = new u8[allocationSize];
        memcpy(result, publicKey.getData(), publicKey.getSize());
        memcpy(result + publicKey.getSize(), signedEncryptedData.data(), signedEncryptedData.size());
        return OwnedByteArray(result, allocationSize);
    }
    
    DatabaseCreateResponse::DatabaseCreateResponse(std::shared_ptr<Signature::KeyPair> _nodeAdminKeyPair, std::shared_ptr<OwnedByteArray> _nodeAdminGroupId, shared_ptr<OwnedByteArray> _key, shared_ptr<Hash> _hash) : 
        nodeAdminKeyPair(_nodeAdminKeyPair),
        nodeAdminGroupId(_nodeAdminGroupId),
        key(_key),
        hash(_hash)
    {
        
    }
    
    const shared_ptr<Signature::KeyPair> DatabaseCreateResponse::getNodeAdminKeyPair() const
    {
        return nodeAdminKeyPair;
    }
    
    const shared_ptr<OwnedByteArray> DatabaseCreateResponse::getNodeAdminGroupId() const
    {
        return nodeAdminGroupId;
    }
    
    const shared_ptr<OwnedByteArray> DatabaseCreateResponse::getNodeEncryptionKey() const
    {
        return key;
    }
    
    const shared_ptr<Hash> DatabaseCreateResponse::getRequestHash() const
    {
        return hash;
    }
    
    Database::Database(const char *bootstrapNodeAddr, u16 port, const boost::filesystem::path &storageDir, DatabaseCallbackFuncs callbackFuncs) : 
        databaseStorage(this, storageDir),
        onCreateNodeCallbackFunc(callbackFuncs.createNodeCallbackFunc),
        onAddNodeCallbackFunc(callbackFuncs.addNodeCallbackFunc),
        onAddUserCallbackFunc(callbackFuncs.addUserCallbackFunc),
        shuttingDown(false)
    {
        node.run(port , {
            /*.dht_config = */{
                /*.node_config = */{
                    /*.node_id = */{},
                    /*.network = */0,
                    /*.is_bootstrap = */false,
                    /*.maintain_storage*/false
                },
                /*.id = */databaseStorage.getIdentity()
            },
            /*.threaded = */true,
            /*.proxy_server = */"",
            /*.push_node_id = */""
        });
        node.setStorageLimit(1024 * 1024 * 1); // 1 Megabyte
        auto portStr = to_string(port);
        node.bootstrap(bootstrapNodeAddr, portStr.c_str());
        const auto &remoteNodes = databaseStorage.getRemoteNodes();
        if(!remoteNodes.empty())
            node.bootstrap(remoteNodes);
        Log::debug("Connecting to bootstrap node (%s) and %u other known nodes that we have connected to previously with port %d", bootstrapNodeAddr, remoteNodes.size(), port);

        // TODO: Make this work for multiple threads initializing database at same time
        ++databaseCount;
        if(databaseCount == 1)
        {
            if(ntpThread)
                delete ntpThread;
            
            const int ntpFetchTimestampRetries = 5;
            const int ntpFetchFailRetryCooldownSec = 60;

            ntpThread = new thread([ntpFetchFailRetryCooldownSec]()
            {
                ntp::NtpClient ntpClient("pool.ntp.org", 10);
                while(databaseCount > 0)
                {
                    int fetchRetryCounter = 0;
                    while(fetchRetryCounter < ntpFetchTimestampRetries)
                    {
                        try
                        {
                            ntp::NtpTimestamp ntpTimestamp = ntpClient.getTimestamp();
                            struct timeval currentLocalTime;
                            gettimeofday(&currentLocalTime, NULL);
                            timeOffset = currentLocalTime.tv_sec - ntpTimestamp.seconds;
                            timeOffsetFraction = currentLocalTime.tv_usec - ntpTimestamp.fractions;
                            timestampSynced = true;
                            break;
                        }
                        catch(ntp::NtpClientException &e)
                        {
                            Log::warn("Failed to sync clock with ntp server, reason: %s. Try #%d", e.what(), fetchRetryCounter);
                            if(timestampSynced)
                                this_thread::sleep_for(3s);
                        }
                        ++fetchRetryCounter;
                    }
                    
                    if(fetchRetryCounter == ntpFetchTimestampRetries)
                    {
                        if(!timestampSynced)
                        {
                            string errMsg = "Failed to retrieve ntp timestamp after ";
                            errMsg += to_string(ntpFetchTimestampRetries);
                            errMsg += " retries, giving up";
                            throw ntp::NtpClientException(errMsg);
                        }
                        else
                        {
                            Log::warn("Failed to retrieve ntp timestamp after %d retries, retrying in %d seconds", ntpFetchTimestampRetries, ntpFetchFailRetryCooldownSec);
                            this_thread::sleep_for(chrono::seconds(ntpFetchFailRetryCooldownSec));
                        }
                    }
                    
                    this_thread::sleep_for(60s);
                }
            });
            ntpThread->detach();
        }
        
        remoteNodesSaveThread = thread([this]()
        {
            int saveIntervalMs = 5000; // 5 sec
            const int sleepDurationMs = 200;
            while(!shuttingDown)
            {
                for(int i = 0; i < saveIntervalMs / sleepDurationMs; ++i)
                {
                    this_thread::sleep_for(chrono::milliseconds(sleepDurationMs));
                    if(shuttingDown)
                        return;
                }
                databaseStorage.setRemoteNodes(node.exportNodes());
                saveIntervalMs = 30000; // 30 sec
            }
        });
    }

    Database::~Database()
    {
        // TODO: Make this work for multiple threads removing database object at same time
        --databaseCount;
        shuttingDown = true;
        remoteNodesSaveThread.join();
        node.join();
    }
    
    struct ActionGap
    {
        u64 start;
        u64 range;
    };
    
    void Database::sendOldDataToPeer(const DatabaseNode nodeToSeed, const shared_ptr<InfoHash> requestResponseInfoHash, const shared_ptr<Value> value, usize valueOffset)
    {
        Log::debug("Request: Got request to send old data");
        try
        {
            sibs::SafeDeserializer deserializer(value->data.data() + valueOffset, value->data.size() - valueOffset);
            bool userWantsCreateNode = deserializer.extract<u8>() == 1;
            DatabaseFetchOrder fetchOrder = deserializer.extract<DatabaseFetchOrder>();
            
            if(userWantsCreateNode)
            {
                Log::debug("Request: Peer wants CreateNode");
                databaseStorage.fetchNodeRaw(*nodeToSeed.getRequestHash(), [this, requestResponseInfoHash](const DataView rawData)
                {
                    Log::debug("Request: Sent create packet to requesting peer");
                    shared_ptr<Value> value = make_shared<Value>((u8*)rawData.data, rawData.size);
                    nodePutWithRetry(&node, *requestResponseInfoHash, value);
                });
            }
            
            vector<unique_ptr<u8[]>> userPublicKeys;
            
            // TODO(Performance improvement): Sort actions by gap start and do a binary search to check if raw data is the packet the peer wants
            DataViewMap<vector<ActionGap>> actionGaps;
            while(!deserializer.empty())
            {
                unique_ptr<u8[]> userPublicKeyRaw(new u8[PUBLIC_KEY_NUM_BYTES]);
                deserializer.extract(userPublicKeyRaw.get(), PUBLIC_KEY_NUM_BYTES);
                u64 actionGapStart = deserializer.extract<u64>();
                u64 actionGapRange = deserializer.extract<u64>();
                
                DataView userPublicKey(userPublicKeyRaw.get(), PUBLIC_KEY_NUM_BYTES);
                actionGaps[userPublicKey].push_back({ actionGapStart, actionGapRange });
                userPublicKeys.emplace_back(move(userPublicKeyRaw));
            }
            
            if(actionGaps.empty())
                Log::debug("No action gaps received, sending all data");
            
            // TODO(Performance improvement): Instead of sending several packets, combine them into one
            databaseStorage.fetchNodeAddDataRaw(*nodeToSeed.getRequestHash(), [this, requestResponseInfoHash, &actionGaps](const DataView rawData, const DataView creatorPublicKey, u64 actionCounter)
            {
                bool sendData = false;
                auto actionGapsIt = actionGaps.find(creatorPublicKey);
                if(actionGapsIt == actionGaps.end())
                {
                    Log::debug("No action gap received for user %s, sending data", bin2hex((const char*)creatorPublicKey.data, creatorPublicKey.size).c_str());
                    sendData = true;
                }
                else
                {
                    for(const auto &userActionGaps : actionGapsIt->second)
                    {
                        if(actionCounter >= userActionGaps.start && actionCounter <= userActionGaps.start + userActionGaps.range)
                        {
                            Log::debug("Node action counter %llu is requested by peer (%llu - %llu)", actionCounter, userActionGaps.start, userActionGaps.start + userActionGaps.range);
                            sendData = true;
                            break;
                        }
                    }
                }
                
                if(!sendData) return;
                shared_ptr<Value> value = make_shared<Value>((u8*)rawData.data, rawData.size);
                nodePutWithRetry(&node, *requestResponseInfoHash, value);
                this_thread::sleep_for(chrono::milliseconds(50));
            }, fetchOrder);
        }
        catch (std::exception &e)
        {
            Log::warn("Failed while serving peer, error: %s", e.what());
        }
    }

    void Database::seed(const DatabaseNode &nodeToSeed, DatabaseFetchOrder fetchOrder)
    {
        if(seedInfoMap.find(*nodeToSeed.getRequestHash()) != seedInfoMap.end())
        {
            Log::warn("You are already seeding node %s, ignoring...", nodeToSeed.getRequestHash()->toString().c_str());
            return;
        }
        
        DatabaseSeedInfo newSeedInfo;
        
        // TODO: Use cached files and seed those. If none exists, request new files to seed.
        // If nobody requests my cached files in a long time, request new files to seed and remove cached files
        // (only if there are plenty of other seeders for the cached files. This could also cause race issue 
        // where all nodes with a cached file delete it at same time).
        
        databaseStorage.setNodeDecryptionKey(*nodeToSeed.getRequestHash(), DataView(nodeToSeed.getNodeEncryptionKey()->data, nodeToSeed.getNodeEncryptionKey()->size));
        
        Log::debug("Seeding key: %s", nodeToSeed.getRequestHash()->toString().c_str());
        DhtKey dhtKey(*nodeToSeed.getRequestHash());
        
        auto newDataListenerFuture = node.listen(dhtKey.getNewDataListenerKey(), [this, nodeToSeed](const shared_ptr<Value> value)
        {
            Log::debug("Seed: New data listener received data...");
            const Hash requestHash(value->data.data(), value->data.size());
            if(requestHash == *nodeToSeed.getRequestHash())
                return true;
                //return listenCreateData(value, requestHash, encryptionKey);
            else
                return listenAddData(value, requestHash, nodeToSeed.getRequestHash(), nodeToSeed.getNodeEncryptionKey());
        });
        newSeedInfo.newDataListenerFuture = make_shared<future<size_t>>(move(newDataListenerFuture));
        
        u8 responseKey[OPENDHT_INFOHASH_LEN];
        randombytes_buf(responseKey, OPENDHT_INFOHASH_LEN);
        shared_ptr<InfoHash> responseKeyShared = make_shared<InfoHash>(responseKey, OPENDHT_INFOHASH_LEN);;
        newSeedInfo.reponseKeyInfoHash = responseKeyShared;
        
        // TODO: If this response key is spammed, generate a new one.
        auto responseKeyFuture = node.listen(*responseKeyShared, [this, nodeToSeed](const shared_ptr<Value> value)
        {
            if(value->data.size() == OPENDHT_INFOHASH_LEN)
            {
                sibs::SafeDeserializer deserializer(value->data.data(), value->data.size());
                InfoHash pingResponseKey;
                deserializer.extract(pingResponseKey.data(), OPENDHT_INFOHASH_LEN);
                shared_ptr<Value> responseValue = make_shared<Value>();
                nodePutWithRetry(&node, pingResponseKey, responseValue);
                return true;
            }
            
            const Hash requestHash(value->data.data(), value->data.size());
            if(requestHash == *nodeToSeed.getRequestHash())
                return listenCreateData(value, requestHash, nodeToSeed.getNodeEncryptionKey());
            else
                return listenAddData(value, requestHash, nodeToSeed.getRequestHash(), nodeToSeed.getNodeEncryptionKey());
        });
        newSeedInfo.responseKeyFuture = make_shared<future<size_t>>(move(responseKeyFuture));
        
        // TODO:!!! Before listening on this key, we should check how many remote peers are also providing this data.
        // This is to prevent too many peers from responding to a request to get old data.
        auto requestOldDataListenerFuture = node.listen(dhtKey.getRequestOldDataKey(), [this, nodeToSeed, responseKeyShared](const shared_ptr<Value> value)
        {
            try
            {
                static_assert(HASH_LEN == OPENDHT_INFOHASH_LEN, "Wrong hashlen size, did it change with opendht upgrade?");
                sibs::SafeDeserializer deserializer(value->data.data(), value->data.size());
                u16 requestStructureVersion = deserializer.extract<u16>();
                if(requestStructureVersion != DATABASE_REQUEST_OLD_DATA_STRUCTURE_VERSION)
                {
                    Log::warn("Request: structure is version %d but we are at version %d, ignoring request", requestStructureVersion, DATABASE_REQUEST_OLD_DATA_STRUCTURE_VERSION);
                    return true;
                }
                shared_ptr<InfoHash> requestResponseInfoHash = make_shared<InfoHash>();
                deserializer.extract(requestResponseInfoHash->data(), OPENDHT_INFOHASH_LEN);
                if(*responseKeyShared == *requestResponseInfoHash)
                {
                    Log::debug("Request: Ignorning request for old data from ourself");
                    return true;
                }
                else
                    Log::debug("Request: Got request from somebody else");
                
                u8 pingResponseKey[OPENDHT_INFOHASH_LEN];
                randombytes_buf(pingResponseKey, OPENDHT_INFOHASH_LEN);
                InfoHash pingResponseKeyInfoHash(pingResponseKey, OPENDHT_INFOHASH_LEN);
                usize valueOffset = value->data.size() - deserializer.getSize();
                node.listen(pingResponseKeyInfoHash, [this, value, requestResponseInfoHash, nodeToSeed, valueOffset](const shared_ptr<Value> _)
                {
                    sendOldDataToPeer(nodeToSeed, requestResponseInfoHash, value, valueOffset);
                    return false;
                });
                
                shared_ptr<Value> pingRequest = make_shared<Value>(pingResponseKey, OPENDHT_INFOHASH_LEN);
                nodePutWithRetry(&node, *requestResponseInfoHash, pingRequest);
            }
            catch (std::exception &e)
            {
                Log::warn("Failed while serving peer, error: %s", e.what());
            }
            return true;
        });
        newSeedInfo.requestOldDataListenerFuture = make_shared<future<size_t>>(move(requestOldDataListenerFuture));
        seedInfoMap[*nodeToSeed.getRequestHash()] = newSeedInfo;
        
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_REQUEST_OLD_DATA_STRUCTURE_VERSION);
        serializer.add(responseKey, OPENDHT_INFOHASH_LEN);
        bool iHaveCreateNode = databaseStorage.doesNodeExist(*nodeToSeed.getRequestHash());
        serializer.add(iHaveCreateNode ? (u8)0 : (u8)1);
        serializer.add(fetchOrder);
        Signature::MapPublicKey<u64> userLatestActionCounter;
        
        databaseStorage.fetchNodeUserActionGaps(*nodeToSeed.getRequestHash(), [&serializer, &userLatestActionCounter](const DataView userPublicKeyRaw, u64 actionGapStart, u64 actionGapRange)
        {
            serializer.add((const u8*)userPublicKeyRaw.data, PUBLIC_KEY_NUM_BYTES);
            serializer.add(actionGapStart);
            serializer.add(actionGapRange);
            Signature::PublicKey userPublicKey((const char*)userPublicKeyRaw.data, userPublicKeyRaw.size);
            userLatestActionCounter[userPublicKey] = std::max(userLatestActionCounter[userPublicKey], actionGapStart + actionGapRange);
        });
        
        databaseStorage.fetchNodeUserLatestActionCounter(*nodeToSeed.getRequestHash(), [&userLatestActionCounter](const DataView userPublicKeyRaw, u64 latestActionCounter)
        {
            Signature::PublicKey userPublicKey((const char*)userPublicKeyRaw.data, userPublicKeyRaw.size);
            userLatestActionCounter[userPublicKey] = std::max(userLatestActionCounter[userPublicKey], latestActionCounter + 1);
        });
        
        for(auto userLatestActionCounterData : userLatestActionCounter)
        {
            // Public key
            serializer.add((const u8*)userLatestActionCounterData.first.getData(), PUBLIC_KEY_NUM_BYTES);
            // Latest action counter start
            serializer.add(userLatestActionCounterData.second);
            // Latest action counter range (infinite range, meaning we want all packets older than start (latest known packet by user))
            serializer.add(~(u64)0ULL - userLatestActionCounterData.second);
        }
        
        Log::debug("Sending request for old data");
        shared_ptr<Value> requestValue = make_shared<Value>(move(serializer.getBuffer()));
        nodePutWithRetry(&node, dhtKey.getRequestOldDataKey(), requestValue);
    }
    
    void Database::stopSeeding(const Hash &nodeHash)
    {
        auto seedInfoIt = seedInfoMap.find(nodeHash);
        if(seedInfoIt != seedInfoMap.end())
        {
            // TODO: Verify if doing get on listener future stalls program forever... Opendht documentation is not clear on this
            DhtKey dhtKey(nodeHash);
            node.cancelListen(dhtKey.getNewDataListenerKey(), seedInfoIt->second.newDataListenerFuture->get());
            node.cancelListen(dhtKey.getRequestOldDataKey(), seedInfoIt->second.requestOldDataListenerFuture->get());
            node.cancelListen(*seedInfoIt->second.reponseKeyInfoHash, seedInfoIt->second.responseKeyFuture->get());
            seedInfoMap.erase(seedInfoIt);
        }
    }
    
    void Database::loadNode(const Hash &nodeHash, DatabaseLoadOrder loadOrder)
    {
        databaseStorage.loadNode(nodeHash, loadOrder);
    }
    
    unique_ptr<DatabaseCreateResponse> Database::create()
    {
        shared_ptr<Signature::KeyPair> creatorKeyPair = make_shared<Signature::KeyPair>();
        
        auto adminGroupId = uuidGen();
        assert(adminGroupId.size() == GROUP_ID_LENGTH);
        
        // Header
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_CREATE_PACKET_STRUCTURE_VERSION);
        u64 timestampCombined = getSyncedTimestampUtc().getCombined();
        serializer.add(timestampCombined);
        serializer.add((u8*)creatorKeyPair->getPublicKey().getData(), PUBLIC_KEY_NUM_BYTES);
        serializer.add(adminGroupId.data, adminGroupId.size());
        
        try
        {
            unsigned char *encryptionKeyRaw = new unsigned char[ENCRYPTION_KEY_BYTE_SIZE];
            Encryption::generateKey(encryptionKeyRaw);
            shared_ptr<OwnedByteArray> encryptionKey = make_shared<OwnedByteArray>(encryptionKeyRaw, ENCRYPTION_KEY_BYTE_SIZE);
            shared_ptr<Hash> hashRequestKey = make_shared<Hash>(serializer.getBuffer().data(), serializer.getBuffer().size());
            
            databaseStorage.setNodeDecryptionKey(*hashRequestKey, DataView(encryptionKey->data, encryptionKey->size));
            databaseStorage.createStorage(*hashRequestKey, creatorKeyPair->getPublicKey(), DataView(adminGroupId.data, adminGroupId.size()), timestampCombined, (const u8*)serializer.getBuffer().data(), serializer.getBuffer().size());
            
            DhtKey dhtKey(*hashRequestKey);
            shared_ptr<Value> createDataValue = make_shared<Value>(move(serializer.getBuffer()));
            nodePutWithRetry(&node, dhtKey.getNewDataListenerKey(), createDataValue);
            
            shared_ptr<OwnedByteArray> adminGroupIdResponse = make_shared<OwnedByteArray>(new u8[GROUP_ID_LENGTH], GROUP_ID_LENGTH);
            memcpy(adminGroupIdResponse->data, adminGroupId.data, GROUP_ID_LENGTH);
            return make_unique<DatabaseCreateResponse>(creatorKeyPair, adminGroupIdResponse, encryptionKey, hashRequestKey);
        }
        catch (EncryptionException &e)
        {
            throw DatabaseCreateException("Failed to encrypt data for 'create' request");
        }
    }

    void Database::addData(const DatabaseNode &nodeInfo, const Signature::KeyPair &userToPerformActionWith, DataView dataToAdd)
    {
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_ADD_PACKET_STRUCTURE_VERSION);
        u64 timestampCombined = getSyncedTimestampUtc().getCombined();
        serializer.add(timestampCombined);
        serializer.add(DatabaseOperation::ADD_DATA);
        u64 newActionCounter = databaseStorage.getUserActionCounter(*nodeInfo.getRequestHash(), userToPerformActionWith.getPublicKey()) + 1;
        serializer.add(newActionCounter);
        
        DataView encryptionKey(nodeInfo.getNodeEncryptionKey()->data, ENCRYPTION_KEY_BYTE_SIZE);
        Encryption encryptedBody(dataToAdd, encryptionKey);
        OwnedByteArray requestData = combine(serializer, encryptedBody);
        string signedRequestData = userToPerformActionWith.getPrivateKey().sign(requestData.getView());
        OwnedByteArray stagedAddObject = combine(userToPerformActionWith.getPublicKey(), signedRequestData);
        Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
        DataView encryptedDataView((char*)requestData.data + serializer.getBuffer().size(), requestData.size - serializer.getBuffer().size());
        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, DatabaseOperation::ADD_DATA, newActionCounter, userToPerformActionWith.getPublicKey(), timestampCombined, (u8*)stagedAddObject.data, stagedAddObject.size, encryptedDataView);
        
        DhtKey dhtKey(*nodeInfo.getRequestHash());
        shared_ptr<Value> addDataValue = make_shared<Value>((u8*)stagedAddObject.data, stagedAddObject.size);
        nodePutWithRetry(&node, dhtKey.getNewDataListenerKey(), addDataValue);
    }
    
    void Database::addUser(const DatabaseNode &nodeInfo, const Signature::KeyPair &userToPerformActionWith, const Signature::PublicKey &userToAddPublicKey, const DataView &groupToAddUserTo)
    {
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_ADD_PACKET_STRUCTURE_VERSION);
        u64 timestampCombined = getSyncedTimestampUtc().getCombined();
        serializer.add(timestampCombined);
        serializer.add(DatabaseOperation::ADD_USER);
        u64 newActionCounter = databaseStorage.getUserActionCounter(*nodeInfo.getRequestHash(), userToPerformActionWith.getPublicKey()) + 1;
        serializer.add(newActionCounter);
        usize additionalDataOffset = serializer.getBuffer().size();
        serializer.add((u8*)userToAddPublicKey.getData(), PUBLIC_KEY_NUM_BYTES);
        serializer.add((uint8_t*)groupToAddUserTo.data, groupToAddUserTo.size);
        
        auto padding = uuidGen();
        assert(padding.size() == 16);
        serializer.add(padding.data, padding.size());
        
        DataView requestData { serializer.getBuffer().data(), serializer.getBuffer().size() };
        string signedRequestData = userToPerformActionWith.getPrivateKey().sign(requestData);
        OwnedByteArray stagedAddObject = combine(userToPerformActionWith.getPublicKey(), signedRequestData);
        Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
        DataView additionalDataView((void*)(static_cast<const char*>(requestData.data) + additionalDataOffset), requestData.size - additionalDataOffset);
        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, DatabaseOperation::ADD_USER, newActionCounter, userToPerformActionWith.getPublicKey(), timestampCombined, (u8*)stagedAddObject.data, stagedAddObject.size, additionalDataView);
        
        DhtKey dhtKey(*nodeInfo.getRequestHash());
        shared_ptr<Value> addDataValue = make_shared<Value>((u8*)stagedAddObject.data, stagedAddObject.size);
        nodePutWithRetry(&node, dhtKey.getNewDataListenerKey(), addDataValue);
    }

    ntp::NtpTimestamp Database::getSyncedTimestampUtc()
    {
        while(!timestampSynced)
        {
            this_thread::sleep_for(10ms);
        }
        
        struct timeval currentLocalTime;
        gettimeofday(&currentLocalTime, NULL);

        ntp::NtpTimestamp timestamp;
        timestamp.seconds = currentLocalTime.tv_sec - timeOffset;
        timestamp.fractions = currentLocalTime.tv_usec - timeOffsetFraction;
        return timestamp;
    }

    void Database::deserializeCreateRequest(const shared_ptr<dht::Value> &value, const Hash &hash, const shared_ptr<OwnedByteArray> encryptionKey)
    {
        sibs::SafeDeserializer deserializer(value->data.data(), value->data.size());
        u16 packetStructureVersion = deserializer.extract<u16>();
        if(packetStructureVersion != DATABASE_CREATE_PACKET_STRUCTURE_VERSION)
        {
            string errMsg = "Received 'create' request with packet structure version ";
            errMsg += to_string(packetStructureVersion);
            errMsg += ", but our packet structure version is ";
            errMsg += to_string(DATABASE_CREATE_PACKET_STRUCTURE_VERSION);
            throw sibs::DeserializeException(errMsg);
        }
        
        u64 creationDate = deserializer.extract<u64>();
        /* // TODO: This doesn't seem to work right now, fix it
        auto currentTimestamp = getSyncedTimestampUtc();
        if(creationDate > currentTimestamp.getCombined())
        {
            auto creationDateTimestamp = ntp::NtpTimestamp::fromCombined(creationDate);
            string errMsg = "Packet is from the future. Packet creation time: ";
            errMsg += to_string((double)creationDateTimestamp.seconds + creationDateTimestamp.getFractionAsSeconds());
            errMsg += ", current time: ";
            errMsg += to_string((double)currentTimestamp.seconds + currentTimestamp.getFractionAsSeconds());
            throw sibs::DeserializeException(errMsg);
        }
        */
        
        char creatorPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
        deserializer.extract((u8*)creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
        Signature::PublicKey userPublicKey(creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
        
        uint8_t adminGroupId[GROUP_ID_LENGTH];
        deserializer.extract(adminGroupId, GROUP_ID_LENGTH);

        databaseStorage.createStorage(hash, userPublicKey, DataView(adminGroupId, GROUP_ID_LENGTH), creationDate, value->data.data(), value->data.size());
    }

    void Database::deserializeAddRequest(const shared_ptr<dht::Value> &value, const Hash &requestDataHash, const std::shared_ptr<Hash> &nodeHash, const shared_ptr<OwnedByteArray> encryptionKey)
    {
        sibs::SafeDeserializer deserializer(value->data.data(), value->data.size());
        char creatorPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
        deserializer.extract((u8*)creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
        Signature::PublicKey creatorPublicKey(creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
        
        DataView signedData((void*)deserializer.getBuffer(), deserializer.getSize());
        string unsignedData = creatorPublicKey.unsign(signedData);
        sibs::SafeDeserializer deserializerUnsigned((u8*)unsignedData.data(), unsignedData.size());
        
        u16 packetStructureVersion = deserializerUnsigned.extract<u16>();
        if(packetStructureVersion != DATABASE_CREATE_PACKET_STRUCTURE_VERSION)
        {
            string errMsg = "Received 'create' request with packet structure version ";
            errMsg += to_string(packetStructureVersion);
            errMsg += ", but our packet structure version is ";
            errMsg += to_string(DATABASE_CREATE_PACKET_STRUCTURE_VERSION);
            throw sibs::DeserializeException(errMsg);
        }
        
        u64 creationDate = deserializerUnsigned.extract<u64>();
        auto currentTimestamp = getSyncedTimestampUtc();
        /* // TODO: This doesn't seem to work right now, fix it
        if(creationDate > currentTimestamp.getCombined())
        {
            auto creationDateTimestamp = ntp::NtpTimestamp::fromCombined(creationDate);
            string errMsg = "Packet is from the future. Packet creation time: ";
            errMsg += to_string((double)creationDateTimestamp.seconds + creationDateTimestamp.getFractionAsSeconds());
            errMsg += ", current time: ";
            errMsg += to_string((double)currentTimestamp.seconds + currentTimestamp.getFractionAsSeconds());
            throw sibs::DeserializeException(errMsg);
        }
        */
        
        DatabaseOperation operation = deserializerUnsigned.extract<DatabaseOperation>();
        u64 newActionCounter = deserializerUnsigned.extract<u64>();
        
        DataView additionalDataView((void*)deserializerUnsigned.getBuffer(), deserializerUnsigned.getSize());
        databaseStorage.appendStorage(*nodeHash, requestDataHash, operation, newActionCounter, creatorPublicKey, creationDate, value->data.data(), value->data.size(), additionalDataView);
    }

    bool Database::listenCreateData(shared_ptr<dht::Value> value, const Hash &hash, const shared_ptr<OwnedByteArray> encryptionKey)
    {
        Log::debug("Got create data in node %s", hash.toString().c_str());
        try
        {
            // This check is here to reduce processing, it doesn't matter much if the packet bypasses this,
            // the database has constraint to deal with this in multi-threaded way
            if(databaseStorage.doesNodeExist(hash))
                throw DatabaseStorageAlreadyExists("Create request hash is equal to hash already in storage (duplicate data?)");
            deserializeCreateRequest(value, hash, encryptionKey);
        }
        catch (exception &e)
        {
            Log::warn("Failed to deserialize 'create' request: %s", e.what());
        }
        return true;
    }

    bool Database::listenAddData(shared_ptr<dht::Value> value, const Hash &requestDataHash, const std::shared_ptr<Hash> nodeHash, const shared_ptr<OwnedByteArray> encryptionKey)
    {
        Log::debug("Got add data in node %s", nodeHash->toString().c_str());
        try
        {
            // This check is here to reduce processing, it doesn't matter much if the packet bypasses this,
            // the database has constraint to deal with this in multi-threaded way
            if(databaseStorage.doesDataExist(requestDataHash))
                throw DatabaseStorageAlreadyExists("Add data request hash is equal to hash already in storage (duplicate data?)");
            deserializeAddRequest(value, requestDataHash, nodeHash, encryptionKey);
        }
        catch (RequestQuarantineException &e)
        {
            Log::warn("Request was put in quarantine, will be processed later");
        }
        catch (exception &e)
        {
            Log::warn("Failed to deserialize 'add' request: %s", e.what());
        }
        return true;
    }
    
    bool Database::doesStoredUserExist(const string &username) const
    {
        return databaseStorage.doesStoredUserExist(username);
    }
    
    void Database::storeUserWithoutNodes(const string &username, const string &password)
    {
        return databaseStorage.storeUserWithoutNodes(username, password);
    }
    
    void Database::storeNodeInfoForUserEncrypted(const DatabaseNode &nodeInfo, const string &username, const string &password, const Signature::KeyPair &keyPair)
    {
        return databaseStorage.storeNodeInfoForUserEncrypted(nodeInfo, username, password, keyPair);
    }
        
    MapHash<StoredNodeInfo> Database::getStoredNodeUserInfoDecrypted(const string &username, const string &password) const
    {
        return databaseStorage.getStoredNodeUserInfoDecrypted(username, password);
    }
    
    vector<OwnedByteArray> Database::getUserGroups(const Hash &nodeHash, const Signature::PublicKey &userPublicKey) const
    {
        return databaseStorage.getUserGroups(nodeHash, userPublicKey);
    }
    
    std::future<size_t> Database::receiveCustomMessage(const dht::InfoHash &receiveMessageKey, ReceiveCustomMessageCallbackFunc callbackFunc)
    {
        dht::InfoHash responseKey = receiveMessageKey;
        ++responseKey[0];
        
        return node.listen(receiveMessageKey, [callbackFunc, this, responseKey](const shared_ptr<Value> value)
        {
            sibs::SafeSerializer serializer = callbackFunc(value->data.data(), value->data.size());
            if(!serializer.getBuffer().empty())
            {
                shared_ptr<Value> responseValue = make_shared<Value>(move(serializer.getBuffer()));
                nodePutWithRetry(&node, responseKey, responseValue);
            }
            return true;
        });
    }
    
    void Database::sendCustomMessage(const dht::InfoHash &requestKey, vector<u8> &&data)
    {
        shared_ptr<Value> value = make_shared<Value>(move(data));
        nodePutWithRetry(&node, requestKey, value);
    }
    
    std::future<size_t> Database::sendCustomMessage(const dht::InfoHash &requestKey, vector<u8> &&data, SendCustomMessageCallbackFunc callbackFunc)
    {
        dht::InfoHash responseKey = requestKey;
        ++responseKey[0];
        
        auto listener = node.listen(responseKey, [callbackFunc](const shared_ptr<Value> value)
        {
            return callbackFunc(true, value->data.data(), value->data.size());
        });
        
        shared_ptr<Value> value = make_shared<Value>(move(data));
        nodePutWithRetry(&node, requestKey, value);
        return listener;
    }
    
    void Database::cancelNodeListener(const dht::InfoHash &infoHash, std::future<size_t> &nodeListener)
    {
        node.cancelListen(infoHash, nodeListener.get());
    }
    
    int Database::clearCache()
    {
        return databaseStorage.clearCache();
    }
    
    dht::InfoHash Database::getInfoHash(const void *data, usize size)
    {
        return dht::InfoHash::get((const u8*)data, size);
    }
}