#include "../include/odhtdb/Database.hpp"
#include "../include/odhtdb/Group.hpp"
#include "../include/odhtdb/LocalUser.hpp"
#include "../include/odhtdb/RemoteUser.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 <fmt/format.h>
#include <sodium/randombytes.h>
#include <thread>
#include <chrono>
#include <sibs/SafeSerializer.hpp>
#include <sibs/SafeDeserializer.hpp>
#include <cassert>

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 thread *ntpThread = nullptr;
static bool timestampSynced = false;
static InfoHash CREATE_DATA_HASH = InfoHash::get("__odhtdb__.create_data");
static InfoHash ADD_DATA_HASH = InfoHash::get("__odhtdb__.add_data");

const int OPENDHT_INFOHASH_LEN = 20;

namespace odhtdb
{
    const u16 DATABASE_CREATE_PACKET_STRUCTURE_VERSION = 1;
    const u16 DATABASE_ADD_PACKET_STRUCTURE_VERSION = 1;
    
    class RequestQuarantineException : public runtime_error
    {
    public:
        RequestQuarantineException() : runtime_error("Request quarantine, will be processed later (can be real of fake request)") {}
    };
    
    DataView combine(sibs::SafeSerializer &headerSerializer, const Encryption &encryptedData)
    {
        usize allocationSize = headerSerializer.getBuffer().size() + encryptedData.getNonce().size + encryptedData.getCipherText().size;
        char *result = new char[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 DataView(result, allocationSize);
    }
    
    DataView combine(const Signature::PublicKey &publicKey, const string &signedEncryptedData)
    {
        usize allocationSize = publicKey.getSize() + signedEncryptedData.size();
        char *result = new char[allocationSize];
        memcpy(result, publicKey.getData(), publicKey.getSize());
        memcpy(result + publicKey.getSize(), signedEncryptedData.data(), signedEncryptedData.size());
        return DataView(result, allocationSize);
    }
    
    DatabaseCreateResponse::DatabaseCreateResponse(LocalUser *_nodeAdminUser, const shared_ptr<OwnedMemory> &_key, const shared_ptr<Hash> &_hash) : 
        nodeAdminUser(_nodeAdminUser),
        key(_key),
        hash(_hash)
    {
        
    }
    
    const LocalUser* DatabaseCreateResponse::getNodeAdminUser() const
    {
        return nodeAdminUser;
    }
        
    const shared_ptr<OwnedMemory> 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) : 
        onCreateNodeCallbackFunc(nullptr),
        onAddNodeCallbackFunc(nullptr),
        onAddUserCallbackFunc(nullptr),
        databaseStorage(storageDir)
    {
        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 = */""
        });
        fmt::MemoryWriter portStr;
        portStr << port;
        node.bootstrap(bootstrapNodeAddr, portStr.c_str());

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

            ntpThread = new thread([]()
            {
                ntp::NtpClient ntpClient("pool.ntp.org");
                while(databaseCount > 0)
                {
                    ntp::NtpTimestamp ntpTimestamp = ntpClient.getTimestamp();
                    timeOffset = time(nullptr) - ntpTimestamp.seconds;
                    timestampSynced = true;
                    // TODO: Also use timestamp fraction (milliseconds)
                    this_thread::sleep_for(60s);
                }
                timestampSynced = false;
            });

            // TODO: Catch std::system_error instead of this if-statement
            if(ntpThread->joinable())
                ntpThread->detach();
        }
    }

    Database::~Database()
    {
        // TODO: Make this work for multiple threads removing database object at same time
        --databaseCount;
        node.join();
    }

    void Database::seed(const DatabaseNode &nodeToSeed)
    {
        // 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)
        
        Log::debug("Seeding key: %s", nodeToSeed.getRequestHash()->toString().c_str());
        DhtKey dhtKey(*nodeToSeed.getRequestHash());
        
        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());
        });
        
        u8 responseKey[OPENDHT_INFOHASH_LEN];
        randombytes_buf(responseKey, OPENDHT_INFOHASH_LEN);
        
        // TODO: If this response key is spammed, generate a new one.
        node.listen(InfoHash(responseKey, OPENDHT_INFOHASH_LEN), [this, nodeToSeed](const shared_ptr<Value> &value)
        {
            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());
        });
        
        // 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.
        node.listen(dhtKey.getRequestOldDataKey(), [this, nodeToSeed](const shared_ptr<Value> &value)
        {
            Log::debug("Request: Got request to send old data");
            try
            {
                sibs::SafeDeserializer deserializer(value->data.data(), value->data.size());
                u64 dataStartTimestamp = deserializer.extract<u64>();
                u8 requestResponseKey[OPENDHT_INFOHASH_LEN];
                deserializer.extract(requestResponseKey, OPENDHT_INFOHASH_LEN);
                
                auto requestedData = databaseStorage.getStorage(*nodeToSeed.getRequestHash());
                if(!requestedData)
                {
                    Log::warn("No data found for hash %s, unable to serve peer", nodeToSeed.getRequestHash()->toString().c_str());
                    return true;
                }
                
                InfoHash requestResponseInfoHash(requestResponseKey, OPENDHT_INFOHASH_LEN);
                
                if(dataStartTimestamp == 0)
                {
                    Log::debug("Request: Sent create packet to requesting peer");
                    node.put(requestResponseInfoHash, Value((u8*)requestedData->data.data, requestedData->data.size), [](bool ok)
                    {
                        if(!ok)
                            Log::warn("Failed to put response for old data for 'create' data");
                    });
                }
                
                for(auto requestedObject : requestedData->objects)
                {
                    node.put(requestResponseInfoHash, Value((u8*)requestedObject->data.data, requestedObject->data.size), [](bool ok)
                    {
                        if(!ok)
                            Log::warn("Failed to put response for old data for 'add' data");
                    });
                }
            }
            catch (sibs::DeserializeException &e)
            {
                Log::warn("Failed to deserialize 'get old data' request: %s", e.what());
            }
            return true;
        });
        
        sibs::SafeSerializer serializer;
        serializer.add((u64)0); // Timestamp in microseconds, fetch data newer than this. // TODO: Get timestamp from database storage
        serializer.add(responseKey, OPENDHT_INFOHASH_LEN);
        node.put(dhtKey.getRequestOldDataKey(), Value(serializer.getBuffer().data(), serializer.getBuffer().size()), [](bool ok)
        {
            if(!ok)
                Log::warn("Failed to put request to get old data");
        });

        //node.listen(CREATE_DATA_HASH, bind(&Database::listenCreateData, this, _1));
        //node.listen(ADD_DATA_HASH, bind(&Database::listenAddData, this, _1));
    }

    unique_ptr<DatabaseCreateResponse> Database::create(const string &ownerName, const std::string &ownerPlainPassword, const string &nodeName)
    {
        // TODO: Should this be declared static? is there any difference in behavior/performance?
        boost::uuids::random_generator uuidGen;
        auto adminGroupId = uuidGen();
        auto adminGroup = new Group("administrator", adminGroupId.data, ADMIN_PERMISSION);
        LocalUser *nodeAdminUser = LocalUser::create(Signature::KeyPair(), ownerName, adminGroup, ownerPlainPassword);
        
        // Header
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_CREATE_PACKET_STRUCTURE_VERSION); // Packet structure version
        // TODO: Append fractions to get real microseconds time
        u64 timestampMicroseconds = ((u64)getSyncedTimestampUtc().seconds) * 1000000ull;
        serializer.add(timestampMicroseconds);
        serializer.add((u8*)nodeAdminUser->getPublicKey().getData(), PUBLIC_KEY_NUM_BYTES);
        serializer.add(adminGroupId.data, adminGroupId.size());
        
        // Encrypted body
        sibs::SafeSerializer encryptedSerializer;
        assert(nodeAdminUser->getName().size() <= 255);
        encryptedSerializer.add((u8)nodeAdminUser->getName().size());
        encryptedSerializer.add((u8*)nodeAdminUser->getName().data(), nodeAdminUser->getName().size());
        assert(nodeName.size() <= 255);
        encryptedSerializer.add((u8)nodeName.size());
        encryptedSerializer.add((u8*)nodeName.data(), nodeName.size());
        
        try
        {
            Encryption encryptedBody(DataView(encryptedSerializer.getBuffer().data(), encryptedSerializer.getBuffer().size()));
            DataView requestData = combine(serializer, encryptedBody);
            shared_ptr<Hash> hashRequestKey = make_shared<Hash>(requestData.data, requestData.size);
            databaseStorage.createStorage(*hashRequestKey, adminGroup, timestampMicroseconds, (const u8*)requestData.data, requestData.size);

            string nodeNameCopy(nodeName);
            DatabaseCreateNodeRequest createNodeRequest(hashRequestKey.get(), timestampMicroseconds, nodeAdminUser, move(nodeNameCopy));
            if(onCreateNodeCallbackFunc)
                onCreateNodeCallbackFunc(createNodeRequest);

            stagedCreateObjects.emplace_back(make_unique<StagedObject>(requestData, hashRequestKey));
            
            assert(encryptedBody.getKey().size == ENCRYPTION_KEY_BYTE_SIZE);
            auto key = make_shared<OwnedMemory>(new char[encryptedBody.getKey().size], encryptedBody.getKey().size);
            memcpy(key->data, encryptedBody.getKey().data, encryptedBody.getKey().size);
            return make_unique<DatabaseCreateResponse>(nodeAdminUser, move(key), hashRequestKey);
        }
        catch (EncryptionException &e)
        {
            throw DatabaseCreateException("Failed to encrypt data for 'create' request");
        }
    }

    void Database::addData(const DatabaseNode &nodeInfo, LocalUser *userToPerformActionWith, DataView dataToAdd)
    {
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_ADD_PACKET_STRUCTURE_VERSION);
        // TODO: Append fractions to get real microseconds time
        u64 timestampMicroseconds = ((u64)getSyncedTimestampUtc().seconds) * 1000000ull;
        serializer.add(timestampMicroseconds);
        serializer.add(DatabaseOperation::ADD_DATA);
        
        DataView encryptionKey(nodeInfo.getNodeEncryptionKey()->data, ENCRYPTION_KEY_BYTE_SIZE);
        Encryption encryptedBody(dataToAdd, DataView(), encryptionKey);
        DataView requestData = combine(serializer, encryptedBody);
        string signedRequestData = userToPerformActionWith->getPrivateKey().sign(requestData);
        free(requestData.data);
        DataView stagedAddObject = combine(userToPerformActionWith->getPublicKey(), signedRequestData);
        Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size);

        DatabaseAddNodeRequest addNodeRequest(&*nodeInfo.getRequestHash(), &requestDataHash, timestampMicroseconds, userToPerformActionWith, dataToAdd);
        if(onAddNodeCallbackFunc)
            onAddNodeCallbackFunc(addNodeRequest);

        stagedAddObjects.emplace_back(make_unique<StagedObject>(stagedAddObject, nodeInfo.getRequestHash()));
    }
    
    Group* getGroupWithRightsToAddUserToGroup(const vector<Group*> &groups, Group *groupToAddUserTo)
    {
        for(auto group : groups)
        {
            const auto &groupPermission = group->getPermission();
            if(groupPermission.getFlag(PermissionType::ADD_USER_LOWER_LEVEL) && groupPermission.getPermissionLevel() < groupToAddUserTo->getPermission().getPermissionLevel())
            {
                return group;
            }
            else if(groupPermission.getFlag(PermissionType::ADD_USER_SAME_LEVEL) && groupPermission.getPermissionLevel() == groupToAddUserTo->getPermission().getPermissionLevel())
            {
                return group;
            }
        }
        return nullptr;
    }
    
    void Database::addUser(const DatabaseNode &nodeInfo, LocalUser *userToPerformActionWith, const string &userToAddName, const Signature::PublicKey &userToAddPublicKey, Group *groupToAddUserTo)
    {
        auto groupWithAddUserRights = getGroupWithRightsToAddUserToGroup(userToPerformActionWith->getGroups(), groupToAddUserTo);
        if(!groupWithAddUserRights)
        {
            string errMsg = "The user ";
            errMsg += userToPerformActionWith->getName();
            errMsg += " does not belong to any group that is allowed to add an user to the group ";
            errMsg += groupToAddUserTo->getName();
            throw PermissionDeniedException(errMsg);
        }
        
        sibs::SafeSerializer serializer;
        serializer.add(DATABASE_ADD_PACKET_STRUCTURE_VERSION);
        // TODO: Append fractions to get real microseconds time
        u64 timestampMicroseconds = ((u64)getSyncedTimestampUtc().seconds) * 1000000ull;
        serializer.add(timestampMicroseconds);
        serializer.add(DatabaseOperation::ADD_USER);
        
        assert(userToAddName.size() <= 255);
        serializer.add((u8)userToAddName.size());
        serializer.add((u8*)userToAddName.data(), userToAddName.size());
        serializer.add((u8*)userToAddPublicKey.getData(), PUBLIC_KEY_NUM_BYTES);
        serializer.add((uint8_t*)groupToAddUserTo->getId().data, groupToAddUserTo->getId().size);
        
        DataView requestData { serializer.getBuffer().data(), serializer.getBuffer().size() };
        string signedRequestData = userToPerformActionWith->getPrivateKey().sign(requestData);
        DataView stagedAddObject = combine(userToPerformActionWith->getPublicKey(), signedRequestData);
        Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size);
        auto userToAdd = RemoteUser::create(userToAddPublicKey, userToAddName, groupToAddUserTo);
        databaseStorage.addUser(*nodeInfo.getRequestHash(), userToAdd);

        DatabaseAddUserRequest addUserRequest(&*nodeInfo.getRequestHash(), &requestDataHash, timestampMicroseconds, userToPerformActionWith, userToAdd, groupToAddUserTo);
        if(onAddUserCallbackFunc)
            onAddUserCallbackFunc(addUserRequest);

        stagedAddObjects.emplace_back(make_unique<StagedObject>(stagedAddObject, nodeInfo.getRequestHash()));
    }

    void Database::commit()
    {
        // TODO: Combine staged objects into one object for efficiency.

        try
        {
            Log::debug("Num objects to create: %zu", stagedCreateObjects.size());
            for(const auto &stagedObject : stagedCreateObjects)
            {
                commitStagedCreateObject(stagedObject);
            }
            
            Log::debug("Num objects to add: %zu", stagedAddObjects.size());
            for(const auto &stagedObject : stagedAddObjects)
            {
                commitStagedAddObject(stagedObject);
            }
        }
        catch (exception &e)
        {
            // TODO: Add rollback
            Log::error("Failed to commit, reason: %s", e.what());
        }
        
        for(const auto &stagedObject : stagedCreateObjects)
        {
            free(stagedObject->data.data);
        }
        stagedCreateObjects.clear();
        
        for(const auto &stagedObject : stagedAddObjects)
        {
            free(stagedObject->data.data);
        }
        stagedAddObjects.clear();
        
        // TODO: Add node.listen here to get notified when remote peers got the commit, then we can say we can return
    }

    void Database::commitStagedCreateObject(const unique_ptr<StagedObject> &stagedObject)
    {
        DhtKey dhtKey(*stagedObject->requestKey);
        Value createDataValue((u8*)stagedObject->data.data, stagedObject->data.size);
        node.put(dhtKey.getNewDataListenerKey(), move(createDataValue), [](bool ok)
        {
            // TODO: Handle failure to put data
            if(!ok)
                Log::warn("Failed to put: %s, what to do?", "commitStagedCreateObject");
        }/* TODO: How to make this work?, time_point(), false*/);
    }

    void Database::commitStagedAddObject(const unique_ptr<StagedObject> &stagedObject)
    {
        DhtKey dhtKey(*stagedObject->requestKey);
        Value createDataValue((u8*)stagedObject->data.data, stagedObject->data.size);
        node.put(dhtKey.getNewDataListenerKey(), move(createDataValue), [](bool ok)
        {
            // TODO: Handle failure to put data
            if(!ok)
                Log::warn("Failed to put: %s, what to do?", "commitStagedAddObject");
        }/* TODO: How to make this work?, time_point(), false*/);
    }

    ntp::NtpTimestamp Database::getSyncedTimestampUtc() const
    {
        while(!timestampSynced)
        {
            this_thread::sleep_for(10ms);
        }
        ntp::NtpTimestamp timestamp;
        timestamp.seconds = time(nullptr) - timeOffset;
        timestamp.fractions = 0; // TODO: Set this
        return timestamp;
    }

    void Database::deserializeCreateRequest(const shared_ptr<dht::Value> &value, const Hash &hash, const shared_ptr<OwnedMemory> 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: Append fractions to get real microseconds time
        u64 timestampMicroseconds = ((u64)getSyncedTimestampUtc().seconds) * 1000000ull;
        if(creationDate > timestampMicroseconds)
            throw sibs::DeserializeException("Packet is from the future");
        
        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[16];
        deserializer.extract(adminGroupId, 16);
        
        if(deserializer.getSize() < ENCRYPTION_NONCE_BYTE_SIZE)
            throw sibs::DeserializeException("Unsigned encrypted body is too small (unable to extract nonce)");
        
        auto adminGroup = new Group("administrator", adminGroupId, ADMIN_PERMISSION);
        // TODO: Username is encrypted, we dont know it... unless we have encryption key, in which case we should modify the user name and set it
        auto creatorUser = RemoteUser::create(userPublicKey, "ENCRYPTED USER NAME", adminGroup);
        databaseStorage.createStorage(hash, adminGroup, creationDate, value->data.data(), value->data.size());
        
        u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
        deserializer.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
        
        DataView dataToDecrypt((void*)deserializer.getBuffer(), deserializer.getSize());
        Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(encryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
        sibs::SafeDeserializer bodyDeserializer((const u8*)decryptedBody.getDecryptedText().data, decryptedBody.getDecryptedText().size);
        
        u8 creatorNameLength = bodyDeserializer.extract<u8>();
        string creatorName; // TODO: Add this user name to storage added above
        creatorName.resize(creatorNameLength);
        bodyDeserializer.extract((u8*)&creatorName[0], creatorNameLength);
        
        u8 nameLength = bodyDeserializer.extract<u8>();
        string name;
        name.resize(nameLength);
        bodyDeserializer.extract((u8*)&name[0], nameLength);
        
        Log::debug("Got create object, name: %s", name.c_str());
        DatabaseCreateNodeRequest createNodeRequest(&hash, creationDate, creatorUser, move(name));
        if(onCreateNodeCallbackFunc)
            onCreateNodeCallbackFunc(createNodeRequest);
    }
    
    bool isUserAllowedToAddData(const User *user)
    {
        for(Group *group : user->getGroups())
        {
            if(group->getPermission().getFlag(PermissionType::ADD_DATA))
                return true;
        }
        return false;
    }

    void Database::deserializeAddRequest(const shared_ptr<dht::Value> &value, const Hash &requestDataHash, const std::shared_ptr<Hash> &nodeHash, const shared_ptr<OwnedMemory> 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>();
        // TODO: Append fractions to get real microseconds time
        u64 timestampMicroseconds = ((u64)getSyncedTimestampUtc().seconds) * 1000000ull;
        if(creationDate > timestampMicroseconds)
            throw sibs::DeserializeException("Packet is from the future");
        
        DatabaseOperation operation = deserializerUnsigned.extract<DatabaseOperation>();
#if 0
        const Hash *node = databaseStorage.getNodeByUserPublicKey(creatorPublicKey);
        if(!node)
        {
            // The user (public key) could belong to a node but we might not have retrieved the node info yet since data may
            // not be retrieved in order.
            // Data in quarantine is processed when 'create' packet is received or removed after 60 seconds
            databaseStorage.addToQuarantine(requestDataHash, creatorPublicKey, creationDate, value->data.data(), value->data.size());
            throw RequestQuarantineException();
        }
#endif
        auto creatorUser = databaseStorage.getUserByPublicKey(*nodeHash, creatorPublicKey);
        // TODO: Verify there isn't already data with same timestamp for this node. Same for quarantine.
        // TODO: We might receive 'add' data packet before 'create'. If that happens, we should put it in quarantine and process it later.
        databaseStorage.appendStorage(*nodeHash, requestDataHash, creatorUser, creationDate, value->data.data(), value->data.size());
        
        if(operation == DatabaseOperation::ADD_DATA)
        {
            if(deserializerUnsigned.getSize() < ENCRYPTION_NONCE_BYTE_SIZE)
                throw sibs::DeserializeException("Unsigned encrypted body is too small (unable to extract nonce)");
            
            u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
            deserializerUnsigned.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
            DataView dataToDecrypt((void*)deserializerUnsigned.getBuffer(), deserializerUnsigned.getSize());
            Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(encryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
            
            if(!isUserAllowedToAddData(creatorUser))
            {
                // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
                // or we haven't received the packet that modifies group with the permission to perform the operation.
                // This also means that an user can be in a group that has permission to perform the operation and then later be removed from it,
                // and remote peers would accept our request to perform operation if they haven't received the operation that removes the user from the group.
                // How to handle this?
                string errMsg = "User ";
                errMsg += creatorUser->getName();
                errMsg += " is not allowed to perform the operation: ";
                errMsg += to_string((u8)operation);
                throw PermissionDeniedException(errMsg);
            }
            
            Log::debug("Got add object, timestamp: %zu, data: %.*s", creationDate, decryptedBody.getDecryptedText().size, decryptedBody.getDecryptedText().data);
            const DatabaseAddNodeRequest addNodeRequest(&*nodeHash, &requestDataHash, creationDate, creatorUser, decryptedBody.getDecryptedText());
            if(onAddNodeCallbackFunc)
                onAddNodeCallbackFunc(addNodeRequest);
        }
        else if(operation == DatabaseOperation::ADD_USER)
        { 
            u8 nameLength = deserializerUnsigned.extract<u8>();
            string name;
            name.resize(nameLength);
            deserializerUnsigned.extract((u8*)&name[0], nameLength);
            
            char userToAddPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
            deserializerUnsigned.extract((u8*)userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
            Signature::PublicKey userToAddPublicKey(userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
            
            uint8_t groupId[16];
            deserializerUnsigned.extract(groupId, 16);
            
            auto group = databaseStorage.getGroupById(*nodeHash, groupId);
            if(group)
            {
                auto user = RemoteUser::create(userToAddPublicKey, name, group);
                // TODO: What if we receive packets in wrong order? (maliciously or non-maliciously). You would be able to register a user to a group with given name
                // and further registration would be dropped (even if that is the correct one)
                if(!databaseStorage.addUser(*nodeHash, user)) return;
                
                auto creatorUserGroupWithRights = getGroupWithRightsToAddUserToGroup(creatorUser->getGroups(), group);
                if(!creatorUserGroupWithRights)
                {
                    // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
                    // or we haven't received the packet that modifies group with the permission to perform the operation.
                    // This also means that an user can be in a group that has permission to perform the operation and then later be removed from it,
                    // and remote peers would accept our request to perform operation if they haven't received the operation that removes the user from the group.
                    // How to handle this?
                    string errMsg = "User ";
                    errMsg += creatorUser->getName();
                    errMsg += " is not allowed to perform the operation: ";
                    errMsg += to_string((u8)operation);
                    throw PermissionDeniedException(errMsg);
                }
                
                Log::debug("Got add user object, timestamp: %zu, user added: %.*s", creationDate, nameLength, name.c_str());
                DatabaseAddUserRequest addUserRequest(&*nodeHash, &requestDataHash, creationDate, creatorUser, user, group);
                if(onAddUserCallbackFunc)
                    onAddUserCallbackFunc(addUserRequest);
            }
            else
            {
                throw sibs::DeserializeException("TODO: Add to quarantine? You can receive ADD_USER packet before you receive ADD_GROUP");
            }
        }
        else
        {
            string errMsg = "Got unexpected operation: ";
            errMsg += to_string((u8)operation);
            throw sibs::DeserializeException(errMsg);
        }  
    }

    bool Database::listenCreateData(shared_ptr<dht::Value> value, const Hash &hash, const shared_ptr<OwnedMemory> encryptionKey)
    {
        Log::debug("Got create data");
        try
        {
            if(databaseStorage.getStorage(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<OwnedMemory> encryptionKey)
    {
        Log::debug("Got add data");
        try
        {
            deserializeAddRequest(value, requestDataHash, nodeHash, encryptionKey);
            //Log::debug("Got add object, timestamp: %zu", addObject.timestamp);
        }
        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;
    }

    void Database::setOnCreateNodeCallback(function<void(const DatabaseCreateNodeRequest&)> callbackFunc)
    {
        onCreateNodeCallbackFunc = callbackFunc;
    }

    void Database::setOnAddNodeCallback(function<void(const DatabaseAddNodeRequest&)> callbackFunc)
    {
        onAddNodeCallbackFunc = callbackFunc;
    }

    void Database::setOnAddUserCallback(function<void(const DatabaseAddUserRequest&)> callbackFunc)
    {
        onAddUserCallbackFunc = callbackFunc;
    }
    
    DatabaseStorage& Database::getStorage()
    {
        return databaseStorage;
    }
}