#include "../include/dchat/Room.hpp"
#include "../include/dchat/Cache.hpp"
#include "../include/dchat/RoomDataType.hpp"
#include <odhtdb/Database.hpp>
#include <odhtdb/Log.hpp>
#include <sibs/SafeSerializer.hpp>
#include <thread>

// TODO: Remove error checks when odhtdb has been improved to take care of such errors
namespace dchat
{
    Room::Room(Rooms *_rooms, std::shared_ptr<odhtdb::Hash> _id) : 
        rooms(_rooms),
        id(_id),
        userdata(nullptr)
    {

    }

    std::shared_ptr<User> Room::addUser(const odhtdb::Signature::PublicKey &userPublicKey, const odhtdb::DataView groupId)
    {
        auto it = userByPublicKey.find(userPublicKey);
        if(it != userByPublicKey.end())
        {
            odhtdb::Log::error("The user %s already exists in the room %s", userPublicKey.toString().c_str(), id->toString().c_str());
            assert(false);
            return nullptr;
        }

        auto user = std::make_shared<User>(userPublicKey);
        userByPublicKey[userPublicKey] = user;
        return user;
    }

    std::shared_ptr<User> Room::getUserByPublicKey(const odhtdb::Signature::PublicKey &userPublicKey)
    {
        auto userIt = userByPublicKey.find(userPublicKey);
        if(userIt != userByPublicKey.end())
            return userIt->second;
        return nullptr;
    }

    void Room::publishMessage(const std::string &msg)
    {
        assert(localUser);
        assert(publicKeyToKeyPairMap.find(localUser->publicKey) != publicKeyToKeyPairMap.end());
        assert(encryptionKey);
        sibs::SafeSerializer serializer;
        serializer.add(RoomDataType::ADD_MESSAGE);
        serializer.add((const u8*)msg.data(), msg.size());
        auto &keyPair = publicKeyToKeyPairMap[localUser->publicKey];
        odhtdb::DatabaseNode roomNode(encryptionKey, id);
        rooms->database->addData(roomNode, *keyPair, { serializer.getBuffer().data(), serializer.getSize() });
    }

    Rooms::Rooms(const char *address, u16 port, RoomCallbackFuncs _callbackFuncs) :
        callbackFuncs(_callbackFuncs),
        loggedIn(false)
    {
        odhtdb::DatabaseCallbackFuncs databaseCallbackFuncs;
        databaseCallbackFuncs.createNodeCallbackFunc = std::bind(&Rooms::createNodeCallbackFunc, this, std::placeholders::_1);
        databaseCallbackFuncs.addNodeCallbackFunc = std::bind(&Rooms::addNodeCallbackFunc, this, std::placeholders::_1);
        databaseCallbackFuncs.addUserCallbackFunc = std::bind(&Rooms::addUserCallbackFunc, this, std::placeholders::_1);
        database = odhtdb::Database::connect(address, port, Cache::getDchatDir(), databaseCallbackFuncs).get();
    }

    void Rooms::createNodeCallbackFunc(const odhtdb::DatabaseCreateNodeRequest &request)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        auto roomIt = roomById.find(*request.nodeHash);
        if(roomIt != roomById.end())
        {
            odhtdb::Log::error("Room %s has already been created once", request.nodeHash->toString().c_str());
            assert(false);
            return;
        }

        auto roomId = std::make_shared<odhtdb::Hash>(*request.nodeHash);
        auto room = std::make_shared<Room>(this, roomId);
        auto encryptionKeyIt = roomEncryptionKey.find(*request.nodeHash);
        if(encryptionKeyIt != roomEncryptionKey.end())
            room->encryptionKey = encryptionKeyIt->second;
        roomById[*request.nodeHash] = room;
        if(callbackFuncs.createRoomCallbackFunc)
            callbackFuncs.createRoomCallbackFunc(room);
        
        auto user = room->addUser(*request.creatorPublicKey, request.groupId);
        auto localUserIt = roomLocalUser.find(*request.nodeHash);
        if(localUserIt != roomLocalUser.end())
        {
            room->localUser = user;
            room->publicKeyToKeyPairMap[user->publicKey] = localUserIt->second;
        }
        if(callbackFuncs.addUserCallbackFunc)
            callbackFuncs.addUserCallbackFunc(room, user);
    }

    void Rooms::addNodeCallbackFunc(const odhtdb::DatabaseAddNodeRequest &request)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        auto roomIt = roomById.find(*request.nodeHash);
        if(roomIt == roomById.end())
        {
            odhtdb::Log::error("Attempting to add data to node %s but the node has not been created", request.nodeHash->toString().c_str());
            assert(false);
            return;
        }
        auto room = roomIt->second;

        auto user = room->getUserByPublicKey(*request.creatorPublicKey);
        if(!user)
        {
            odhtdb::Log::error("Attempting to add data to node %s but the the user %s doesn't exist in the node %s", request.creatorPublicKey->toString().c_str(), request.nodeHash->toString().c_str());
            assert(false);
            return;
        }

        if(request.decryptedData.size == 0)
            return;

        uint32_t timestampSeconds = ntp::NtpTimestamp::fromCombined(request.timestamp).seconds;

        RoomDataType roomDataType = (RoomDataType)static_cast<const char*>(request.decryptedData.data)[0];
        try
        {
            switch(roomDataType)
            {
                case RoomDataType::ADD_MESSAGE:
                {
                    RoomMessage message;
                    message.id = *request.requestHash;
                    message.creator = user;
                    message.timestampSeconds = timestampSeconds;
                    message.text = std::string((const char*)request.decryptedData.data + 1, request.decryptedData.size - 1);

                    RoomAddMessageRequest roomRequest;
                    roomRequest.room = room;
                    roomRequest.loadedFromCache = request.loadedFromCache;
                    roomRequest.message = std::move(message);
                    if(callbackFuncs.addMessageCallbackFunc)
                        callbackFuncs.addMessageCallbackFunc(roomRequest);

                    room->messages.push_back(std::move(roomRequest.message));
                    break;
                }
                case RoomDataType::NICKNAME_CHANGE:
                {
                    sibs::SafeDeserializer deserializer((const u8*)request.decryptedData.data + 1, request.decryptedData.size - 1);
                    u8 nameLength = deserializer.extract<u8>();
                    if(nameLength > 0)
                    {
                        std::string nickname;
                        nickname.resize(nameLength);
                        deserializer.extract((u8*)&nickname[0], nameLength);

                        UserChangeNicknameRequest roomRequest;
                        roomRequest.room = room;
                        roomRequest.user = user;
                        roomRequest.timestampSeconds = timestampSeconds;
                        roomRequest.loadedFromCache = request.loadedFromCache;
                        roomRequest.newNickname = nickname;
                        if(callbackFuncs.userChangeNicknameCallbackFunc)
                            callbackFuncs.userChangeNicknameCallbackFunc(roomRequest);
                        user->nickname = std::move(nickname);
                    }
                    break;
                }
                case RoomDataType::CHANGE_ROOM_NAME:
                {
                    int userPermissionLevel = database->getUserLowestPermissionLevel(*room->id, user->publicKey);
                    if(userPermissionLevel != odhtdb::PERMISSION_LEVEL_ADMIN)
                    {    
                        odhtdb::Log::debug("Room change name: attempted by user %s who is not an admin (permission level: %d)\n", user->publicKey.toString().c_str(), userPermissionLevel);
                        return;
                    }    
                    
                    sibs::SafeDeserializer deserializer((const u8*)request.decryptedData.data + 1, request.decryptedData.size - 1);
                    u16 channelNameLength = deserializer.extract<u16>();
                    if(channelNameLength > 0 && channelNameLength <= 32)
                    {
                        RoomChangeNameRequest roomRequest;
                        roomRequest.room = room;
                        roomRequest.user = user;
                        roomRequest.timestampSeconds = timestampSeconds;
                        roomRequest.loadedFromCache = request.loadedFromCache;
                        roomRequest.newName.resize(channelNameLength);
                        deserializer.extract((u8*)&roomRequest.newName[0], channelNameLength);
                        if(callbackFuncs.changeRoomNameCallbackFunc)
                            callbackFuncs.changeRoomNameCallbackFunc(roomRequest);
                        room->name = std::move(roomRequest.newName);
                    } 
                    break;
                }
                default:
                    break;
            }
        }
        catch(std::exception &e)
        {
            odhtdb::Log::warn("Failed to process add node request, reason: %s\n", e.what());
        }
    }

    void Rooms::addUserCallbackFunc(const odhtdb::DatabaseAddUserRequest &request)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        auto roomIt = roomById.find(*request.nodeHash);
        if(roomIt == roomById.end())
        {
            odhtdb::Log::error("User %s was added to node %s but the node has not been created", request.userToAddPublicKey->toString().c_str(), request.nodeHash->toString().c_str());
            assert(false);
            return;
        }

        auto user = roomIt->second->addUser(*request.userToAddPublicKey, request.groupToAddUserTo);
        auto localUserIt = roomLocalUser.find(*request.nodeHash);
        if(localUserIt != roomLocalUser.end())
        {
            roomIt->second->localUser = user;
            roomIt->second->publicKeyToKeyPairMap[user->publicKey] = localUserIt->second;
        }
        if(callbackFuncs.addUserCallbackFunc)
            callbackFuncs.addUserCallbackFunc(roomIt->second, user);
    }

    void Rooms::connect(const char *address, u16 port, RoomCallbackFuncs callbackFuncs)
    {
        assert(callbackFuncs.connectCallbackFunc);
        std::thread([](const char *address, u16 port, RoomCallbackFuncs callbackFuncs)
        {
            try
            {
                callbackFuncs.connectCallbackFunc(std::shared_ptr<Rooms>(new Rooms(address, port, callbackFuncs)), nullptr);
            }
            catch(std::exception &e)
            {
                callbackFuncs.connectCallbackFunc(nullptr, e.what());
            }
        }, address, port, callbackFuncs).detach();
    }

    void Rooms::loginUser(const std::string &username, const std::string &password)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        if(loggedIn)
            throw std::runtime_error(std::string("You are already logged in as ") + username);

        auto storedNodes = database->getStoredNodeUserInfoDecrypted(username, password);
        loggedIn = true;
        currentUsername = username;
        currentUserPassword = password;
        for(auto &nodeInfo : storedNodes)
        {
            roomLocalUser[nodeInfo.first] = nodeInfo.second.userKeyPair;
            roomEncryptionKey[nodeInfo.first] = nodeInfo.second.nodeEncryptionKey;

            auto roomId = std::make_shared<odhtdb::Hash>(nodeInfo.first);
            odhtdb::DatabaseNode roomNode(nodeInfo.second.nodeEncryptionKey, roomId);
            database->seed(roomNode);
            database->loadNode(nodeInfo.first);
        }
    }

    void Rooms::registerUser(const std::string &username, const std::string &password)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        if(loggedIn)
            throw std::runtime_error(std::string("You are already logged in as ") + username);

        database->storeUserWithoutNodes(username, password);
        loggedIn = true;
        currentUsername = username;
        currentUserPassword = password;
    }

    void Rooms::createRoom(const std::string &name)
    {
        std::lock_guard<std::recursive_mutex> lock(roomModifyMutex);
        if(!loggedIn)
            throw std::runtime_error("You need to be logged in to create a room ");

        auto newNode = database->create();
        roomLocalUser[*newNode->getRequestHash()] = newNode->getNodeAdminKeyPair();
        roomEncryptionKey[*newNode->getRequestHash()] = newNode->getNodeEncryptionKey();
        auto roomIt = roomById.find(*newNode->getRequestHash());
        if(roomIt != roomById.end())
        {
            roomIt->second->encryptionKey = newNode->getNodeEncryptionKey();
            auto user = roomIt->second->getUserByPublicKey(newNode->getNodeAdminKeyPair()->getPublicKey());
            if(user)
            {
                roomIt->second->localUser = user;
                roomIt->second->publicKeyToKeyPairMap[user->publicKey] = newNode->getNodeAdminKeyPair();
            }
        }

        odhtdb::DatabaseNode nodeInfo(newNode->getNodeEncryptionKey(), newNode->getRequestHash());
        database->storeNodeInfoForUserEncrypted(nodeInfo, currentUsername, currentUserPassword, *newNode->getNodeAdminKeyPair());
        sibs::SafeSerializer serializer;
        serializer.add(RoomDataType::CHANGE_ROOM_NAME);
        serializer.add((u16)name.size());
        serializer.add(name.data(), name.size());
        database->addData(nodeInfo, *newNode->getNodeAdminKeyPair(), { serializer.getBuffer().data(), serializer.getSize() });
    }
}