#include "DataModel.h"
#include <easylogging++.h>

#include <fstream>
#include <filesystem>
#include "SystemConfig.h"
#include <charconv>
#include <mutex>

#include "PublisherPowercenter.h"
#include "PublisherBenderRcm.h"

std::chrono::milliseconds timeoutMS = std::chrono::milliseconds(10'000);

long DataModel::permanentParamHistory = 0;
int DataModel::narrowBlock = 0;

//Initialization of static member
std::unique_ptr<DataModel> DataModel::instance = nullptr;

//Read file locker
std::timed_mutex accessFilesMTX;


constexpr unsigned long long DataModel::timepoint_to_sec_long(const std::chrono::system_clock::time_point& t) {
    return duration_to_sec_long(t.time_since_epoch());
}

const ts_map<ModbusRegister, SavedData> &DataModel::getPublisherData() const
{
    return temporaryStorage;
}

CappedStorage* DataModel::getPermanentData(ModbusRegister reg){
    auto it = permanentStorage.find(reg);
    if(it != permanentStorage.end()){
        return &(it->second);
    }
    else
        return nullptr;
}

constexpr unsigned long long DataModel::duration_to_sec_long(const std::chrono::system_clock::duration& t) {
    return std::chrono::duration_cast<std::chrono::seconds>(t).count();
}

inline void DataModel::Create() {
    instance = std::make_unique<DataModel>();

    permanentParamHistory = SystemConfig::getIntConfigParameter("permanent_param_history");
    narrowBlock = SystemConfig::getIntConfigParameter("narrow_block");
}

DataModel::~DataModel()
{
    LOG(INFO) << "Save locally stored permanent data to permanent storage...";
    //Save permanent data to storage
    long long time = std::chrono::system_clock::now().time_since_epoch().count();
    std::fstream file;
    std::stringstream ss;
    ss << dataDir << "data_" << time;
    std::string filename = ss.str();
    file.open(filename, std::ios::out);

    if (file.is_open()) {
        for(auto &storage : permanentStorage){
            if(storage.second.size() == 0)
                continue;
            file << (int)storage.first << ":" << std::endl;
            file << storage.second << std::endl;
        }
        file.close();
    }
    else
        LOG(ERROR) << "Could not access file to store permanent data...";

}



std::unique_ptr<DataModel>& DataModel::Instance() {
    if (!instance)
        Create();
    return instance;
}

void DataModel::Destroy() {
    if (instance)
        instance.reset();

}


void DataModel::makePermanent(ModbusRegister reg, bool biased)
{
    permanentStorage.emplace(reg, CappedStorage(biased));
}



void DataModel::saveModbusParameter(ParameterSpecification param)
{
    if(param.cat == Category::Alert){
        short bitmask = 0;
        std::memcpy(&bitmask, param.readedBytes.data(), param.length);
        //Found an alert here
        if(bitmask != 0)
            LOG(WARNING) << "Received an alert from Modbus " << param.connection->getConnectionType() << ", ID " << param.connection->getID();
            alerts.push(param);
        return;
    }

    //Temporary storage of last value
    temporaryStorage.emplaceOrOverwrite(param.description, SavedData(param.cat, param.readedBytes));

    //If parameter is listet to be stored permanently
    auto res = permanentStorage.find(param.description);
    if(res != permanentStorage.end()){
        checkForFlushData();
        res->second.store(param.readedBytes);
    }
}

void DataModel::checkForFlushData() {

    while(1){
        auto permStorageIter = permanentStorage.begin();
        auto storageIter = permanentStorage.find(permStorageIter->first);
        auto& X = storageIter->second.getX();
        auto& y = storageIter->second.getY();
        //Rescale Matrix if data exceeds time limit
        storageIter->second.lock();
        if(X.size() > 1 && (X(0,1) <= (X(X.rows()-1, 1) - DataModel::permanentParamHistory))){
            if(X.size() <= narrowBlock)
                return;
            LOG(INFO) << "Shrink permanent storage of parameter " << std::dec << (int)permStorageIter->first;
            std::stringstream ss;
            ss << (int)storageIter->first << "(X);";
            Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic> temp(X.rows()-narrowBlock, X.cols());
            temp = X.block(narrowBlock, 0, X.rows() - narrowBlock, X.cols());
            //backup capped data to flush to file
            for(int i = 0; i < narrowBlock-1; i++){
                ss << std::fixed << std::setprecision(0) << X(i, X.cols()-1) << ";";
            }

            X.resize(X.rows() - narrowBlock, X.cols());
            X = std::move(temp);

            ss << std::fixed << std::setprecision(0) << std::endl << (int)storageIter->first << "(y);";

            temp.resize(y.rows()-narrowBlock, 1);
            temp = y.block(narrowBlock, 0, y.rows() - narrowBlock, 1);
            //backup capped data to flush to file
            for(int i = 0; i < narrowBlock-1; i++){
                ss << std::fixed << std::setprecision(5) << y(i) << ";";
            }
            ss << std::endl;
            y.resize(y.rows() - narrowBlock, 1);
            y = std::move(temp);

            flush(ss);
        }
        storageIter->second.unlock();
        if((++permStorageIter) == permanentStorage.end())
            break;
    }
}


bool DataModel::flush(std::stringstream& ss)
{
    //Data file lock condition
    if (!accessFilesMTX.try_lock_for(timeoutMS)) {
        LOG(ERROR) << "Timeout after waiting " << (long long)timeoutMS.count() << " for reading data files";
        return false;
    }

    LOG(INFO) << "Flush data to local file";
    std::fstream file;
    auto now = std::chrono::system_clock::now();
    std::stringstream filename;
    filename << dataDir << "data_" << now.time_since_epoch().count();
    file.open(filename.str(), std::ios_base::out);
    if (file.is_open()) {
        file << ss.str();
        file.close();
    }
    else
        LOG(ERROR) << "Could not open file for writing";
    accessFilesMTX.unlock();
    return true;
}

//reads in the log file to the supplied stringstream
//define fromTime to get only logs older than fromTime (seconds after epoch)
uintmax_t DataModel::readLogFile(std::stringstream& ss, long long fromTime) {
    el::Loggers::flushAll();

    uintmax_t sizeRead = 0;

    std::filesystem::path p{ logDir };
    std::ifstream file;
    std::string lineBuffer;
    std::filesystem::directory_iterator iterator(p);
    for (auto& currentFile : std::filesystem::directory_iterator(p))
        if (currentFile.is_regular_file()) {
            if (logFileName.compare(currentFile.path().filename().string()) == 0) {
                file.open(currentFile.path());
                if (file.is_open()) {
                    sizeRead += currentFile.file_size();
                    bool foundTimePoint = false;
                    while (std::getline(file, lineBuffer)) {
                        if (lineBuffer.size() == 0)
                            continue;
                        if (fromTime != 0 && foundTimePoint == false) {
                            std::stringstream temp;
                            temp << lineBuffer;
                            std::tm tm{};
                            temp >> std::get_time(&tm, dateFormatLogger.c_str());
                            auto timePoint = std::chrono::system_clock::from_time_t(std::mktime(&tm));
                            if (timePoint.time_since_epoch().count() >= fromTime) {
                                foundTimePoint = true;
                            }
                        }
                        else
                            ss << lineBuffer << std::endl;
                    }
                    file.close();
                    LOG(INFO) << "Readed log file";
                }
                else
                    LOG(WARNING) << "Couldn't open LOG file for writing";
                break;
            }
        }
    //If size read is 0, no tile at specified index found or file was empty
    return sizeRead;
}


uintmax_t DataModel::readAllDataFiles(std::stringstream& ss) {
    uintmax_t sizeRead = 0;

    if (!accessFilesMTX.try_lock_for(timeoutMS)) {
        LOG(ERROR) << "Timeout after waiting " << (long long)timeoutMS.count() << " for reading data files - blocked by another thread";
        return 0;
    }
    std::filesystem::path p{ dataDir };
    std::ifstream file;
    std::string lineBuffer;
    std::filesystem::directory_iterator iterator(p);
    for (auto& currentFile : std::filesystem::directory_iterator(p)){
        if (currentFile.is_regular_file() && std::regex_match(currentFile.path().filename().string(), regexPatternFile)) {
            //look for a valid file with the specified index
            file.open(currentFile.path());
            if (file.is_open()) {
                sizeRead += currentFile.file_size();
                while (std::getline(file, lineBuffer)) {
                    ss << lineBuffer << std::endl;
                }
                file.close();
                std::filesystem::remove(currentFile.path());
            }
        }
    }
    accessFilesMTX.unlock();
    //If size read is 0, no tile at specified index found or file was empty
    return sizeRead;
}

std::stringstream& DataModel::readPermanentData(std::stringstream& buffer, bool retain){
    for(auto &e: permanentStorage){
        buffer << (int)e.first << ":" << std::endl;
        buffer << e.second;
    }
    if(!retain)
        permanentStorage.clear();
    return buffer;
}

ts_queue<ParameterSpecification>& DataModel::getAlerts()
{
    return alerts;
}

std::stringstream& DataModel::readTemporaryData(std::stringstream& buffer){
    for(auto &e: temporaryStorage){
        buffer << (int)e.first << ":";
        buffer << e.second;
    }
    return buffer;
}

//olderThan: files which are older than this specified time are deleted
unsigned long DataModel::removeStoredData(seconds olderThan) {
    using namespace std::filesystem;
    auto timeNow = duration_cast<seconds>(system_clock::now().time_since_epoch());
    u_int filesDeleted = 0;
    for (auto& file : directory_iterator(path("data/"))) {
        if (file.is_regular_file()) {
            if (std::regex_match(file.path().stem().string(), regexPatternFile)) {
                std::string str = file.path().stem().string();
                str = str.substr(str.find_first_of("0123456789", 0));
                //time of file in seconds after 01/01/1970
                long long timeOfFile = 0;
                //if (auto [p, ec] = std::from_chars(str.data(), str.data() + str.length(), timeOfFile); ec == std::errc())
                timeOfFile = std::stoll(str, 0);
                if ((timeOfFile + olderThan.count()) < timeNow.count())
                    if(remove(file))
                        filesDeleted++;
            }
        }
    }
    LOG(INFO) << "Deleted data files (" << filesDeleted << ") that were older than " << (long long)olderThan.count() <<"seconds on local storage";
    return filesDeleted;
}

//remove every file that are stored locally
unsigned long DataModel::removeStoredData() {
    using namespace std::filesystem;
    create_directory("data/");
    unsigned long filesDeleted = 0;
    try{

        for (auto& file : directory_iterator(path("data/"))) {
            if (file.is_regular_file()) {
                if (std::regex_match(file.path().stem().string(), regexPatternFile)) {
                    std::string str = file.path().stem().string();
                    str = str.substr(str.find_first_of("0123456789", 0));
                    filesDeleted++;
                }
            }
        }
    }
    catch(std::exception& e){
        LOG(ERROR) << "Can't access data directory";
    }
    LOG(INFO) << "Deleted all data files (" << filesDeleted << ") on local storage";
    return filesDeleted;
}



std::ostream& operator<<(std::ostream& os, const PublisherType type) {
    switch (type) {
    case PublisherType::RCMS_BENDER:
        os << "Bender RCMS";
        break;
    case PublisherType::POWERCENTER:
        os << "Siemens Powercenter";
        break;
    default:
        os << "<Unknown Publisher Type>";
        break;
    }
    return os;
}

std::ostream& operator<<(std::ostream& os, const SavedData& savedData){
    float value = 0;
    std::memcpy(&value, savedData.data.data(), 4);
    os << value << std::endl;
    return os;
}