#include "calculator_functions.h"
#include "payment_option.h"
#include "utilities.h"
#include "tariff_log.h"
#include "tariff_time_range.h"
#include "ticket.h"
#include "tariff_global_defines.h"

#include <sstream>
#include <algorithm>
#include <QDateTime>
#include <QScopedArrayPointer>
#include <QDebug>

double total_duration_min = 0.0f;
double total_cost = 0.0f;
bool overtime = false;

#ifdef _WIN32
inline struct tm* localtime_r(const time_t *clock, struct tm* result){
    if(!clock || !result) return NULL;
    memcpy(result,localtime(clock),sizeof(*result));
    return result;
}
#endif

QDateTime Calculator::GetDailyTicketDuration(Configuration* cfg, const QDateTime start_datetime, uint8_t payment_option, bool carry_over)
{
    if(!start_datetime.isValid()) {
        return QDateTime();
    }

    double day_price = 0.0f;
    int current_special_day_id = -1;
    bool is_special_day = Utilities::CheckSpecialDay(cfg, start_datetime.toString(Qt::ISODate).toStdString().c_str(), &current_special_day_id, &day_price);

    QDateTime inputDateTime = start_datetime;
    QTime worktime_from;
    QTime worktime_to;

    int daily_card_price = cfg->PaymentOption.find(payment_option)->second.pop_daily_card_price;
    if(daily_card_price <= 0) {
        qCritical() << "Calculator::GetDailyTicketDuration(): Daily ticket price zero or less";
        return QDateTime();
    }

    if(is_special_day)
    {
        worktime_from = QTime::fromString(cfg->SpecialDaysWorktime.find(current_special_day_id)->second.pedwt_time_from.c_str(), Qt::ISODate);
        worktime_to = QTime::fromString(cfg->SpecialDaysWorktime.find(current_special_day_id)->second.pedwt_time_to.c_str(),Qt::ISODate);

        if(inputDateTime.time() < worktime_from) inputDateTime.setTime(worktime_from);
        if(carry_over) inputDateTime.setTime(worktime_from);

        if(inputDateTime.time() >= worktime_to)
        {
            // Go to next day if outside worktime
            inputDateTime = inputDateTime.addSecs(86400);
            return GetDailyTicketDuration(cfg,inputDateTime, payment_option,true);
        }

        if(day_price <=0)
        {
            // Go to next day if special day price is 0
            inputDateTime = inputDateTime.addSecs(86400);
            return GetDailyTicketDuration(cfg,inputDateTime, payment_option,true);
        }

        int diff = abs(inputDateTime.time().secsTo(worktime_to));
        inputDateTime = inputDateTime.addSecs(diff);

        //qDebug() << "Ticket is valid until: " << inputDateTime.toString(Qt::ISODate) << "price = " << daily_card_price << ", duration = " << diff / 60;
        return inputDateTime;
    }
    else
    {
        // Get day of week
        int const weekdayId = inputDateTime.date().dayOfWeek();

        // If no working day found, skip it (recursively call method again)
        size_t found = cfg->WeekDaysWorktime.count(weekdayId);

        // When no workday found, go to next available day
        if(found <=0)
        {
            inputDateTime = inputDateTime.addSecs(86400);
            return GetDailyTicketDuration(cfg,inputDateTime, payment_option,true);
        }
        else
        {
            worktime_from = QTime::fromString(cfg->WeekDaysWorktime.find(weekdayId)->second.pwd_time_from.c_str(),Qt::ISODate);
            worktime_to = QTime::fromString(cfg->WeekDaysWorktime.find(weekdayId)->second.pwd_time_to.c_str(),Qt::ISODate);
            if(inputDateTime.time() < worktime_from)
                inputDateTime.setTime(worktime_from);

            if(carry_over)
                inputDateTime.setTime(worktime_from);

            if(inputDateTime.time() >= worktime_to)
            {
                // Go to next day if outside worktime
                inputDateTime = inputDateTime.addSecs(86400);
                return GetDailyTicketDuration(cfg,inputDateTime, payment_option,true);
            }

            int diff = abs(inputDateTime.time().secsTo(worktime_to));
            inputDateTime = inputDateTime.addSecs(diff);

            //qDebug() << "Ticket is valid until: " << inputDateTime.toString(Qt::ISODate) << "price = " << daily_card_price << ", duration = " << diff / 60;            
            return inputDateTime;
        }
    }

    return QDateTime();
}
/// <inheritdoc/>
std::string Calculator::GetDurationFromCost(Configuration* cfg,
                                            uint8_t payment_option,
                                            char const *startDatetimePassed, // given in local time
                                            double cost,
                                            bool nextDay,
                                            bool prepaid)
{
    Q_UNUSED(payment_option);
    Q_UNUSED(nextDay);

    // Get input date
    QDateTime inputDate = QDateTime::fromString(startDatetimePassed,Qt::ISODate);

    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        if (tariffIs24_7(cfg)) {
            // use tariff with structure as for instance Schoenau, Koenigsee:
            // without given YearPeriod, SpecialDays and SpecialDaysWorktime
            inputDate = inputDate.addSecs(GetDurationForPrice(cfg, cost) * 60);
            return inputDate.toString(Qt::ISODate).toStdString();
        } else {
            if (Utilities::IsYearPeriodActive(cfg, inputDate)) {
                if (!prepaid) {
                    CalcState cs = isParkingAllowed(cfg, inputDate);
                    if (cs) {
                        inputDate.setTime(cs.getAllowedTimeRange().getTimeUntil());
                        return inputDate.toString(Qt::ISODate).toStdString();
                    }
                }

                // TODO: man braucht den richtigen Index
                int paymentOptionIndex = 0;
                int const pop_id = cfg->getPaymentOptions(paymentOptionIndex).pop_id;
                int const pop_max_price = cfg->getPaymentOptions(paymentOptionIndex).pop_max_price;
                int const pop_min_price = cfg->getPaymentOptions(paymentOptionIndex).pop_min_price;

                if (cost > pop_max_price) {
                    qCritical() << DBG_HEADER << "MAX-PARKING-PRICE" << pop_max_price << ", COST" << cost;
                    return CalcState::OVERPAID.toStdString();
                }

                if (cost < pop_min_price) {
                    qCritical() << DBG_HEADER << "MIN-PARKING-PRICE" << pop_min_price << ", COST" << cost;
                    return CalcState::BELOW_MIN_PARKING_PRICE.toStdString();
                }

                // int const pop_pre_paid = 1;

                if (prepaid) {
                    // no limits on pre-pay-option, i.e. pre-pay-ranges are exactly
                    // the complements of operational-ranges

                    // find out if we are in a pre-pay-range.
                    // in this case, adapt inputDate accordingly.

                    qCritical() << DBG_HEADER << "PRE-PAID-OPTION: ADAPT-INPUT-DATE" << inputDate.toString(Qt::ISODate);

                    QTime currentTime = inputDate.time();
                    int pwd_period_day_in_week_id = inputDate.date().dayOfWeek();

                    bool useWeekDaysWorkTimeOfOtherDay = true;

                    for (auto[iter, rEnd] = cfg->WeekDaysWorktime.equal_range(pwd_period_day_in_week_id); iter != rEnd; ++iter) {
                        QTime pwd_time_from = QTime::fromString(QString::fromStdString(iter->second.pwd_time_from), Qt::ISODate);
                        QTime pwd_time_to = QTime::fromString(QString::fromStdString(iter->second.pwd_time_to), Qt::ISODate);

                        if (inputDate.time() < pwd_time_from) {
                            inputDate.setTime(pwd_time_from);
                            useWeekDaysWorkTimeOfOtherDay = false;
                            break;
                        }
                        if (currentTime <= pwd_time_to) {
                            useWeekDaysWorkTimeOfOtherDay = false;
                            break;
                        }
                    }

                    if (useWeekDaysWorkTimeOfOtherDay) {// for the current day, we are above
                                                        // the latest worktime-range -> find the next valid range

                        QTime pwd_time_from_next_valid_range(0, 0, 0);
                        int pwd_period_next_day_in_week_id = pwd_period_day_in_week_id;
                        for (int days = 1; days < 8; ++days) {
                            pwd_period_next_day_in_week_id += 1;
                            if (pwd_period_next_day_in_week_id > (int)Qt::Sunday) {
                                pwd_period_next_day_in_week_id = Qt::Monday;
                            }

                            if (cfg->WeekDaysWorktime.count(pwd_period_next_day_in_week_id) > 0) {
                                for (auto[iter, rEnd] = cfg->WeekDaysWorktime.equal_range(pwd_period_next_day_in_week_id); iter != rEnd; ++iter) {
                                    QTime pwd_time_from = QTime::fromString(QString::fromStdString(iter->second.pwd_time_from), Qt::ISODate);
                                    if (pwd_time_from_next_valid_range < pwd_time_from) {
                                        pwd_time_from_next_valid_range = pwd_time_from;
                                        break;
                                    }
                                }
                                inputDate = inputDate.addDays(days);
                                inputDate.setTime(pwd_time_from_next_valid_range);
                                break;
                            }
                        }
                    }
                }

                qCritical() << DBG_HEADER << "(ADAPTED) INPUT-DATE" << inputDate.toString(Qt::ISODate);

                // inputDate is now located in a valid operational-working-range
                // find this working-time-range
                int pwd_period_day_in_week_id = inputDate.date().dayOfWeek();
                if (cfg->WeekDaysWorktime.count(pwd_period_day_in_week_id) == 0) {
                    qCritical() << DBG_HEADER
                                << "ERROR" << inputDate.toString(Qt::ISODate)
                                << "NOT IN VALID WORKING TIME-RANGE";
                    return "";
                }

                QTime current_working_time_from;
                QTime current_working_time_to;

                for (auto[iter, rEnd] = cfg->WeekDaysWorktime.equal_range(pwd_period_day_in_week_id); iter != rEnd; ++iter) {
                    QTime pwd_time_from = QTime::fromString(QString::fromStdString(iter->second.pwd_time_from), Qt::ISODate);
                    QTime pwd_time_to = QTime::fromString(QString::fromStdString(iter->second.pwd_time_to), Qt::ISODate);
                    if (pwd_time_from <= inputDate.time() && inputDate.time() <= pwd_time_to) {
                        current_working_time_from = pwd_time_from;
                        current_working_time_to = pwd_time_to;
                    }
                }

                if (current_working_time_from.isNull() || current_working_time_to.isNull()) {
                    // can never happen
                    qCritical() << DBG_HEADER
                                << "ERROR" << inputDate.toString(Qt::ISODate)
                                << "NOT IN VALID WORKING TIME-RANGE";
                    return "";
                }

                qCritical() << DBG_HEADER << "CURRENT WORKING-TIME-FROM" << current_working_time_from.toString(Qt::ISODate);
                qCritical() << DBG_HEADER << "  CURRENT WORKING-TIME-TO" << current_working_time_to.toString(Qt::ISODate);

                for (auto[itr, rangeEnd] = cfg->PaymentRate.equal_range(pop_id); itr != rangeEnd; ++itr) {
                    int const pra_price = itr->second.pra_price;
                    if ((double)pra_price == cost) {
                        int const durationId = itr->second.pra_payment_unit_id;
                        auto search = cfg->Duration.find(durationId);
                        if (search != cfg->Duration.end()) {
                            // found now the duration in minutes
                            // check if we are still inside the working-time-range
                            ATBDuration duration = search->second;

                            int durationInSecs = duration.pun_duration * 60;

                            QDateTime current_working_date_time_to = inputDate;
                            current_working_date_time_to.setTime(current_working_time_to);

                            qCritical() << DBG_HEADER << "DURATION IN MINUTES" << duration.pun_duration;
                            qCritical() << DBG_HEADER << "DURATION IN SECONDS" << duration.pun_duration * 60;
                            qCritical() << DBG_HEADER << "CURRENT-WORKING-DATE-TIME-TO"
                                                      << current_working_date_time_to.toString(Qt::ISODate);
                            qCritical() << DBG_HEADER << "NEW INPUT DATE" << inputDate.addSecs(durationInSecs).toString(Qt::ISODate);

                            if (inputDate.addSecs(durationInSecs) > current_working_date_time_to) {

                                qCritical() << DBG_HEADER;

                                QTime next_working_time_from;
                                if (cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over != 0) {
                                    qCritical() << DBG_HEADER << "CARRY-OVER SET";
                                    // check for next working-time-range on same day
                                    int day_in_week_id = inputDate.date().dayOfWeek();
                                    for (auto[iter, rEnd] = cfg->WeekDaysWorktime.equal_range(day_in_week_id); iter != rEnd; ++iter) {
                                        QTime pwd_time_from = QTime::fromString(QString::fromStdString(iter->second.pwd_time_from), Qt::ISODate);
                                        if (pwd_time_from > current_working_time_to) {
                                            next_working_time_from = pwd_time_from;
                                            qCritical() << DBG_HEADER << "NEXT-WORKING-TIME-FROM"
                                                        << next_working_time_from.toString(Qt::ISODate);
                                            break;
                                        }
                                    }
                                    // check for next working-time-range on following day(s)
                                    if (next_working_time_from.isNull()) {
                                        next_working_time_from = QTime(0, 0, 0);
                                        for (int days = 1; days < 8; ++days) {
                                            day_in_week_id += 1;
                                            if (day_in_week_id > (int)Qt::Sunday) {
                                                day_in_week_id = Qt::Monday;
                                            }
                                            if (cfg->WeekDaysWorktime.count(day_in_week_id) > 0) {
                                                for (auto[iter, rEnd] = cfg->WeekDaysWorktime.equal_range(day_in_week_id); iter != rEnd; ++iter) {
                                                    QTime pwd_time_from = QTime::fromString(QString::fromStdString(iter->second.pwd_time_from), Qt::ISODate);
                                                    if (next_working_time_from < pwd_time_from) {
                                                        next_working_time_from = pwd_time_from;
                                                        break;
                                                    }
                                                }

                                            }
                                            QDateTime upper = inputDate.addDays(days);
                                            upper.setTime(next_working_time_from);

                                            QDateTime lower = inputDate;
                                            lower.setTime(current_working_time_to);

                                            inputDate = inputDate.addSecs(lower.secsTo(upper) + durationInSecs);
                                            qCritical() << DBG_HEADER << "TICKET-END" << inputDate.toString(Qt::ISODate);
                                        }
                                    } else { // next working-time is on same day
                                        QDateTime upper = inputDate;
                                        upper.setTime(next_working_time_from);

                                        QDateTime lower = inputDate;
                                        lower.setTime(current_working_time_to);

                                        inputDate = inputDate.addSecs(lower.secsTo(upper) + durationInSecs);
                                        qCritical() << DBG_HEADER << "TICKET-END" << inputDate.toString(Qt::ISODate);
                                    }
                                }
                            } else {
                                inputDate = inputDate.addSecs(duration.pun_duration * 60);
                                qCritical() << DBG_HEADER << "INPUT-DATE" << inputDate.toString(Qt::ISODate);
                            }

                            QString const &s = inputDate.toString(Qt::ISODate);
                            qCritical() << DBG_HEADER << "TICKET-END" << s;
                            return s.toStdString();
                        }
                    }
                }

                return "";
            }
        }
    } else
    if (paymentMethodId == PaymentMethod::Progressive) {
        // started with Neuhauser, Kirchdorf: merge into main algo. later
        // for now try out some ideas

        // started with Neuhauser, Kirchdorf: merge into main algo. later
        // for now try out some ideas

        static const bool carryOverNotSet = Utilities::isCarryOverNotSet(cfg, paymentMethodId);
        static const uint minParkingPrice = Utilities::getMinimalParkingPrice(cfg, paymentMethodId);
        static const uint maxParkingPrice = Utilities::getMaximalParkingPrice(cfg, paymentMethodId);

        if (cost < minParkingPrice) {
            qCritical() << QString("ERROR: COST < MIN_PARKING_PRICE (%1 < %2)").arg(cost).arg(minParkingPrice);
            return QDateTime().toString(Qt::ISODate).toStdString();
        }

        if (cost > maxParkingPrice) {
            qCritical() << QString("WARN: COST > MAX_PARKING_PRICE (%1 > %2)").arg(cost).arg(maxParkingPrice);
            cost = maxParkingPrice;
        }

        Q_ASSERT_X(carryOverNotSet, __func__, "CARRYOVER SET (FOR KIRCHDORF)");
        Q_ASSERT_X(prepaid, __func__, "PREPAID NOT SET (FOR KIRCHDORF)");

        QDateTime start_datetime = QDateTime::fromString(QString(startDatetimePassed), Qt::ISODate);
        QDateTime start = start_datetime;
        QDateTime end_datetime = QDateTime();

        int weekdayId = -1;
        int weekdayIdLast = -1;
        int durationMinutes = Utilities::getMaximalParkingTime(cfg, paymentMethodId);
        int durationMinutesBrutto = 0;

#ifdef _DEBUG_
#undef _DEBUG_
#endif

//#define _DEBUG_ 1
#define _DEBUG_ 0

        QDateTime current = start;

        int days = 7;
        while (--days > 0) {
            weekdayId = current.date().dayOfWeek();
            weekdayIdLast = weekdayId; // TODO: some end condition in json-file

            while (cfg->WeekDaysWorktime.count(weekdayId) == 0) {
                current = current.addDays(1);
                weekdayId = current.date().dayOfWeek();
                if (weekdayId == weekdayIdLast) {
                    qCritical() << "ERROR: NO VALID WORKDAY-TIMES DEFINED";
                    return QDateTime().toString(Qt::ISODate).toStdString();
                }
            }

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            QTime to = QTime(0, 0, 0);
            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                QTime const &t = Utilities::WeekDaysWorkTimeUntil(itr);

                if (to < t) {
                    to = t;
                }
            }

            if (current.time() >= to) {
                if (carryOverNotSet) {
                    return end_datetime.toString(Qt::ISODate).toStdString();
                } else {
                    QDateTime const dt = start;
                    start = start.addDays(1);
                    start.setTime(QTime(0, 0, 0));

                    durationMinutesBrutto += dt.secsTo(start) / 60;
                    current = start;
                }
            } else {
                break;
            }
        }

        int durationMinutesNetto = 0;
        uint price = 0;

        if (carryOverNotSet) {
            int minsToCarryOver = 0; // from one work-time to the other on the same day
            int minsUsed = 0;
            QDateTime lastCurrent = QDateTime();

            QVector<ATBWeekDaysWorktime> weekDayWorkTimeRanges;

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                weekDayWorkTimeRanges.append(itr->second); // working with vector is easier
            }

            int weekDayWorkTimeIndex = 0;
            bool moveToNextTimeRange = false;

            // time ranges for Neuhauser-Kirchdorf (743): 30, 5, 5, ... 5
            auto timeRangeIt = cfg->TimeRange.cbegin();
            while (timeRangeIt != cfg->TimeRange.cend()) { // ; ++timeRangeIt) {

                if (weekDayWorkTimeIndex >= weekDayWorkTimeRanges.size()) {

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "weekDayWorkTimeRanges.size()" << weekDayWorkTimeRanges.size()
                                << "price" << price;
#endif
                    end_datetime = current;
                    return end_datetime.toString(Qt::ISODate).toStdString();
                }

                QTime const &from = QTime::fromString(weekDayWorkTimeRanges[weekDayWorkTimeIndex].pwd_time_from.c_str(), Qt::ISODate);
                QTime const &to = QTime::fromString(weekDayWorkTimeRanges[weekDayWorkTimeIndex].pwd_time_to.c_str(), Qt::ISODate);

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "current" << current.toString(Qt::ISODate)
                            << "from" << from.toString(Qt::ISODate)
                            << "to" << to.toString(Qt::ISODate);
#endif

                Q_ASSERT_X(from < to, __func__, "MISCONFIGURED WORK-TIMES");

                if (current.time() >= to) {
                    ++weekDayWorkTimeIndex;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "try to use next available work-time with"
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "price" << price;
#endif
                    // time range is not affected
                    continue;
                } else
                if (current.time() <= from) {
                    if (prepaid) {
                        lastCurrent = current;
                        current.setTime(from); // move current forward (range==1),
                                               // as prepaid is set
                        uint const minutesMoved = lastCurrent.secsTo(current) / 60;
                        durationMinutesBrutto += minutesMoved;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                    << "current" << current.toString(Qt::ISODate)
                                    << "minutesMoved" << minutesMoved
                                    << "durationMinutesBrutto" << durationMinutesBrutto;
#endif

                        if (weekDayWorkTimeIndex == 0) {
                            start_datetime = current;
                        }
                    }
                }

                ATBTimeRange timeRange = timeRangeIt->second;

                timeRange.computeQTimes(current.time());

                int duration = timeRange.time_range_to_in_minutes_from_start -
                               timeRange.time_range_from_in_minutes_from_start;

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "current" << current.toString(Qt::ISODate)
                            << "duration" << duration
                            << "minsUsed" << minsUsed
                            << "minsToCarryOver" << minsToCarryOver
                            << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                            << "price" << price;
#endif

                if (minsToCarryOver > 0) {  // the price for this time range
                                            // has been is paid already
                    Q_ASSERT_X(weekDayWorkTimeIndex > 0, __func__, "WRONG-WORK-TIME");

                    current = current.addSecs(minsToCarryOver*60);

                    durationMinutes -= minsToCarryOver;
                    durationMinutesNetto += minsToCarryOver;
                    durationMinutesBrutto += minsToCarryOver;

                    minsToCarryOver = 0;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "durationMinutes" << durationMinutes
                                << "durationMinutesNetto" << durationMinutesNetto
                                << "durationMinutesBrutto" << durationMinutesBrutto
                                << "price" << price;
#endif
                    if (price >= cost) {
                        end_datetime = current;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif
                        return end_datetime.toString(Qt::ISODate).toStdString();
                    }
                }

                if (current.addSecs(duration * 60).time() <= to) {

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "current.addSecs(" << duration * 60 << ")" << current.addSecs(duration*60).time().toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes;
#endif

                    moveToNextTimeRange = false;
                    for(const auto &x: cfg->PaymentRate) {
                        ATBPaymentRate const rate = x.second;
                        if (rate.pra_payment_unit_id == timeRange.time_range_payment_type_id) {
                            price += (uint)rate.pra_price;

                            if (price >= maxParkingPrice) {
                                price = maxParkingPrice;
                            }

                            durationMinutes -= duration;
                            durationMinutesNetto += duration;
                            durationMinutesBrutto += duration;

                            current = current.addSecs(duration * 60);

                            if (price >= cost) {
                                end_datetime = current;
#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif
                                return end_datetime.toString(Qt::ISODate).toStdString();
                            }

                            // price has been updated; use next time range
                            moveToNextTimeRange = true;
                            break;
                        }
                    }

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "price" << price
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes
                                << "durationMinutesNetto" << durationMinutesNetto
                                << "durationMinutesBrutto" << durationMinutesBrutto;
#endif

                    if (price >= cost) {
                        end_datetime = current;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif

                        return end_datetime.toString(Qt::ISODate).toStdString();
                    }

                    if (moveToNextTimeRange) {
                        if (++timeRangeIt != cfg->TimeRange.cend()) {
                            continue;
                        }
                    }

                    // havin a new time range means that we always have a new
                    // work-time-range
                    // ++timeRangeIt;

                } else { // current.addSecs(duration * 60).time() > to

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "current.addSecs(" << duration * 60 << ")" << current.addSecs(duration*60).time().toString(Qt::ISODate)
                                << "duration" << duration
                                << ", to:" << to.toString(Qt::ISODate);
#endif

                    lastCurrent = current;
                    current.setTime(to);
                    minsUsed = lastCurrent.secsTo(current) / 60;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes;
#endif

                    // mod duration: possibly discard some minutes in
                    // the next time-range
                    if (duration >= minsUsed) {
                        minsToCarryOver = duration - minsUsed;
                    }

                    durationMinutes -= minsUsed;
                    durationMinutesNetto += minsUsed;
                    durationMinutesBrutto += minsUsed;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes
                                << "price" << price;
#endif

                    moveToNextTimeRange = false;

                    if (minsUsed > 0) {
                        for(const auto &x: cfg->PaymentRate) {
                            ATBPaymentRate const rate = x.second;
                            if (rate.pra_payment_unit_id == timeRange.time_range_payment_type_id) {
                                price += (uint)rate.pra_price;

                                if (price >= maxParkingPrice) {
                                    price = maxParkingPrice;
                                }

                                if (price >= cost) {
                                    end_datetime = current;

#if _DEBUG_==1
                                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                                << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                                << "price" << price;
#endif

                                    // return end_datetime.toString(Qt::ISODate).toStdString();
                                }

                                // price has been updated; use next time range
                                moveToNextTimeRange = true;
                                break;
                            }
                        }
                    }

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "minsUsed" << minsUsed
                                << "durationMinutes" << durationMinutes
                                << "moveToNextTimeRange" << moveToNextTimeRange
                                << "price" << price;
#endif

                    if (moveToNextTimeRange) {
                        if (++timeRangeIt != cfg->TimeRange.cend()) {
                            continue;
                        }

                        // no valid time range left
                        end_datetime = current;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif

                        return end_datetime.toString(Qt::ISODate).toStdString();
                    }
                }

                end_datetime = start.addSecs(durationMinutesBrutto * 60);

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "start" << start.toString(Qt::ISODate)
                            << "end_datetime" << end_datetime.toString(Qt::ISODate)
                            << "final price" << std::max(price, minParkingPrice);
#endif

                return end_datetime.toString(Qt::ISODate).toStdString();
            } // while (timeRangeIt != cfg->TimeRange.cend()) {
        }

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "INVALID END TIME";
#endif
        end_datetime = QDateTime();
        return end_datetime.toString(Qt::ISODate).toStdString();
    }

    Ticket t = private_GetDurationFromCost(cfg, inputDate, cost, prepaid);

    // qCritical().noquote() << t;

    // TODO: im fehlerfall
    return t.getValidUntil().toString(Qt::ISODate).toStdString();
}
#undef _DEBUG_

///////////////////////////////////////

/// <inheritdoc/>
///

uint32_t Calculator::GetCostFromDuration(Configuration *cfg,
                                         QDateTime const &start,
                                         quint64 timeStepInMinutes,
                                         int paymentOptionIndex) const {
    // for instance, a tariff as used in Schoenau, Koenigssee: only steps, no
    // special days, nonstop.
    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        QDateTime const end = start.addSecs(timeStepInMinutes*60);
        return GetCostFromDuration(cfg, start, end, paymentOptionIndex);
    }
    return 0;
}

uint32_t Calculator::GetCostFromDuration(Configuration * cfg,
                                         QDateTime const &start,
                                         QDateTime const &end,
                                         int paymentOptionIndex) const {
    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        int const timeStepInMinutes = start.secsTo(end) / 60;
        return GetPriceForTimeStep(cfg, timeStepInMinutes, paymentOptionIndex);
    }
    return 0;
}

CalcState Calculator::isParkingAllowedForWeekDay(Configuration const *cfg,
                                                 QDateTime const &start,
                                                 int netto_parking_time,
                                                 int paymentOptionIndex) {

    qCritical() << DBG_HEADER << "start" << start.toString(Qt::ISODate)
                << "paymentOptionIndex" << paymentOptionIndex;

    QString errorStr = "UNKNOWN ERROR";

    PaymentMethod const paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        uint64_t const businessHours = cfg->getPaymentOptions(paymentOptionIndex).pop_business_hours;

        if (cfg->isDayIncluded(businessHours, start)) {
            if (businessHours == BusinessHours::NO_RESTRICTION_24_7) {
                return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED",
                         QTime(0, 0, 0), QTime(23, 59, 59));
            }

            int const weekdayId = start.date().dayOfWeek();

            // qCritical() << DBG_HEADER
            //             << "weekdayId" << weekdayId
            //             << "count" << cfg->WeekDaysWorktime.count(weekdayId);

            if (cfg->WeekDaysWorktime.count(weekdayId) > 0) {
                using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
                std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

                for (WTIterator itr = p.first; itr != p.second; ++itr) {
                    QTime const &from = Utilities::WeekDaysWorkTimeFrom(itr);
                    QTime const &until = Utilities::WeekDaysWorkTimeUntil(itr);

                    qCritical() << DBG_HEADER
                                << "CHECK IF PARKING IS ALLOWED IN TIME-RANGE ("
                                << from.toString(Qt::ISODate) << "->" << until.toString(Qt::ISODate) << ") ...";

                    QTime const &startTime = start.time();

                    if (startTime >= from && startTime <= until) {
                        QDateTime const end = start.addSecs(netto_parking_time*60);
                        QTime const endTime = end.time();
                        if (endTime <= until && start.date().dayOfWeek() == end.date().dayOfWeek()) {
                            qCritical() << DBG_HEADER;
                            return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED", from, until);
                        } else {
                            errorStr = QString("%1 startTime not in range (%2 not in [%3, %4))")
                                                .arg(__LINE__)
                                                .arg(startTime.toString(Qt::ISODate))
                                                .arg(from.toString(Qt::ISODate))
                                                .arg(endTime.toString(Qt::ISODate));
                        }
                    } else {
                        errorStr = QString("%1 startTime not in range (%2 not in [%3, %4))")
                                            .arg(__LINE__)
                                            .arg(startTime.toString(Qt::ISODate))
                                            .arg(from.toString(Qt::ISODate))
                                            .arg(until.toString(Qt::ISODate));
                    }

                    int const pop_carry_over = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over;

                    // qCritical() << DBG_HEADER
                    //             << "paymentOptionIndex" << paymentOptionIndex
                    //             << "pop_carry_over" << pop_carry_over;

                    if (pop_carry_over == 1) {
                        // qCritical() << DBG_HEADER
                        //             << "NO. CHECK IF PARKING IS ALLOWED WITH CARRY-OVER ...";

                        int const pop_carry_over_start_time_range = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over_start_time_range;
                        int const pop_carry_over_end_time_range = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over_end_time_range;

                        // qCritical() << DBG_HEADER
                        //             << "pop_carry_over_start_time_range" << pop_carry_over_start_time_range
                        //             << "pop_carry_over_end_time_range" << pop_carry_over_end_time_range;

                        if ((int)cfg->TimeRange.count(pop_carry_over_start_time_range) <= 0 &&
                            (int)cfg->TimeRange.count(pop_carry_over_end_time_range) <= 0) {

                            qCritical() << DBG_HEADER << "PARKING_ALLOWED. startTime" << startTime.toString(Qt::ISODate);
                            return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED", startTime);

                        } else
                        // search entry in time-range-field of tariff-file
                        if (cfg->TimeRange.count(pop_carry_over_start_time_range) == 1 &&
                            cfg->TimeRange.count(pop_carry_over_end_time_range) == 1) {

                            ATBTimeRange s = cfg->TimeRange.find(pop_carry_over_start_time_range)->second;
                            ATBTimeRange e = cfg->TimeRange.find(pop_carry_over_end_time_range)->second;

                            // qCritical() << DBG_HEADER
                            //             << "startTime" << startTime.toString(Qt::ISODate);

                            if (startTime >= s.getTimeFrom() && startTime <= s.getTimeUntil()) {

                                QDateTime sd = start;
                                sd.setTime(s.getTimeUntil());

                                // qCritical() << DBG_HEADER << "jumpFrom" << sd.toString(Qt::ISODate);

                                QDateTime ed = start.addDays(1);
                                ed.setTime(e.getTimeFrom());

                                // qCritical() << DBG_HEADER << "to" << ed.toString(Qt::ISODate);

                                int const jumpSecs = sd.secsTo(ed);

                                // qCritical() << DBG_HEADER << "jumpSecs" << jumpSecs;

                                QDateTime const end = start.addSecs(netto_parking_time*60 + jumpSecs);

                                // qCritical() << DBG_HEADER << "new end" << end.toString(Qt::ISODate);

                                if (end.time() <= e.getTimeUntil()) {

                                    qCritical() << DBG_HEADER
                                                << "PARKING IS ALLOWED WITH CARRY-OVER ("
                                                << start.toString(Qt::ISODate) << "->" << ed.toString(Qt::ISODate) << ")";

                                    return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED",
                                                     startTime, end.time());
                                } else {
                                    errorStr = QString("endTime %1 outside [%2, %3))")
                                                  .arg(end.toString(Qt::ISODate))
                                                  .arg(sd.toString(Qt::ISODate))
                                                  .arg(ed.toString(Qt::ISODate));
                                }
                            } else {
                                errorStr = QString("startTime %1 outside [%2, %3))")
                                              .arg(startTime.toString(Qt::ISODate))
                                              .arg(s.getTimeFrom().toString(Qt::ISODate))
                                              .arg(s.getTimeUntil().toString(Qt::ISODate));
                            }
                        } else {
                           errorStr = "no carry-over limits configured";
                        }
                    } else {
                        errorStr = "no carry-over configured";
                    }
                }
            } else {
                errorStr = QString("no weekday configured for day-id %1").arg(weekdayId);
            }

        } else {
            errorStr = QString("start %1 not contained in business hours %2")
                            .arg(start.toString(Qt::ISODate))
                            .arg(businessHours);
        }
    }

    qCritical() << DBG_HEADER << "errorStr" << errorStr;

    return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME, errorStr,
                     QTime(), QTime());
}


CalcState Calculator::isParkingAllowedForSpecialDay(Configuration const *cfg,
                                                    QDateTime const &start,
                                                    int netto_parking_time,
                                                    int paymentOptionIndex) {
    QString errorStr = "UNKNOWN ERROR";

    qCritical() << DBG_HEADER << "start" << start.toString(Qt::ISODate)
                << "paymentOptionIndex" << paymentOptionIndex;

    PaymentMethod const paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        //uint64_t const businessHours = cfg->getPaymentOptions(paymentOptionIndex).pop_business_hours;
        int const specialDayId = cfg->specialDayId(start);
        if ((specialDayId > 0) && (cfg->SpecialDaysWorktime.count(specialDayId) > 0)) {
            using SDIterator = Configuration::SpecialDaysWorktimeType::const_iterator;
            std::pair<SDIterator, SDIterator> p = cfg->SpecialDaysWorktime.equal_range(specialDayId);

            for (SDIterator it = p.first; it != p.second; ++it) {
                QTime const &from = Utilities::SpecialDaysWorkTimeFrom(it);
                QTime const &until = Utilities::SpecialDaysWorkTimeUntil(it);

                qCritical() << DBG_HEADER
                            << "CHECK IF PARKING IS ALLOWED IN TIME-RANGE ("
                            << from.toString(Qt::ISODate) << "->" << until.toString(Qt::ISODate) << ") ...";

                QTime const &startTime = start.time();

                if (startTime >= from && startTime <= until) {
                    QTime const endTime = start.addSecs(netto_parking_time*60).time();
                    if (endTime <= until) {
                        return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED", from, until);
                    } else {
                        errorStr = QString("%1 startTime not in range (%2 not in [%3, %4))")
                                            .arg(__LINE__)
                                            .arg(startTime.toString(Qt::ISODate))
                                            .arg(from.toString(Qt::ISODate))
                                            .arg(endTime.toString(Qt::ISODate));
                    }
                } else {
                    errorStr = QString("%1 startTime not in range (%2 not in [%3, %4))")
                                        .arg(__LINE__)
                                        .arg(startTime.toString(Qt::ISODate))
                                        .arg(from.toString(Qt::ISODate))
                                        .arg(until.toString(Qt::ISODate));
                }

                int const pop_carry_over = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over;
                if (pop_carry_over == 1) {
                    qCritical() << DBG_HEADER << "NO. CHECK IF PARKING IS ALLOWED WITH CARRY-OVER ...";

                    int const pop_carry_over_start_time_range = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over_start_time_range;
                    int const pop_carry_over_end_time_range = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over_end_time_range;

                    if (cfg->TimeRange.count(pop_carry_over_start_time_range) == 1 &&
                        cfg->TimeRange.count(pop_carry_over_end_time_range) == 1) {

                        ATBTimeRange s = cfg->TimeRange.find(pop_carry_over_start_time_range)->second;
                        ATBTimeRange e = cfg->TimeRange.find(pop_carry_over_end_time_range)->second;

                        if (startTime >= s.getTimeFrom() && startTime <= s.getTimeUntil()) {
                            QDateTime sd = start;
                            sd.setTime(s.getTimeUntil());

                            QDateTime ed = start.addDays(1);
                            ed.setTime(e.getTimeFrom());

                            int const jumpSecs = sd.secsTo(ed);
                            QDateTime const end = start.addSecs(netto_parking_time*60 + jumpSecs);
                            if (end.time() <= e.getTimeUntil()) {

                                ed.setTime(e.getTimeUntil()); // for printing

                                qCritical() << DBG_HEADER
                                            << "PARKING IS ALLOWED WITH CARRY-OVER ("
                                            << start.toString(Qt::ISODate) << "->" << ed.toString(Qt::ISODate) << ")";

                                return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED",
                                                 startTime, end.time());
                            } else {
                                ed.setTime(e.getTimeUntil()); // for printing

                                errorStr = QString("endTime %1 exceeds [%2, %3))")
                                              .arg(end.toString(Qt::ISODate))
                                              .arg(sd.toString(Qt::ISODate))
                                              .arg(ed.toString(Qt::ISODate));
                            }
                        } else {
                            errorStr = QString("startTime %1 exceeds [%2, %3))")
                                          .arg(startTime.toString(Qt::ISODate))
                                          .arg(s.getTimeFrom().toString(Qt::ISODate))
                                          .arg(s.getTimeUntil().toString(Qt::ISODate));
                        }
                    } else {
                       errorStr = "no carry-over limits configured";
                    }
                } else {
                    errorStr = "no carry-over configured";
                }
            }
        }
    }

    return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME, errorStr,
                     QTime(), QTime());
}


CalcState Calculator::isParkingAllowed(Configuration const *cfg,
                                       QDateTime const &start,
                                       int netto_parking_time,
                                       int paymentOptionIndex) {

    qCritical() << DBG_HEADER << "CHECK IF PARKING IS ALLOWED AT"
                << start.toString(Qt::ISODate) << "...";

    CalcState cs;

    if ((cs = isParkingAllowedForWeekDay(cfg, start, netto_parking_time, paymentOptionIndex))) {
        return cs;
    }

    qCritical() << DBG_HEADER << QString(cs);

    if ((cs = isParkingAllowedForSpecialDay(cfg, start, netto_parking_time, paymentOptionIndex))) {
        return cs;
    }

    qCritical() << DBG_HEADER << QString(cs);

    return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME, "UNKNOWN ERROR",
                     QTime(), QTime());
}

CalcState Calculator::isParkingAllowed(Configuration const *cfg,
                                       QDateTime const &start) {
    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);

    if (paymentMethodId == PaymentMethod::Steps) {
        int const weekdayId = start.date().dayOfWeek();
        BusinessHours businessHours = Utilities::getBusinessHours(cfg, paymentMethodId);
        if (businessHours == BusinessHours::NoRestriction_24_7) {
            return CalcState(CalcState::State::SUCCESS, "PARKING_ALLOWED",
                             QTime(0, 0, 0), QTime(23, 59, 59));
        } else
        if (businessHours == BusinessHours::OnlyWeekDays) {
            if (weekdayId != (int)Qt::Saturday && weekdayId != (int)Qt::Sunday) { // e.g. Neuhauser, Linsinger Maschinenbau (741)
                if (cfg->WeekDaysWorktime.count(weekdayId) > 0) {
                    using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
                    std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

                    for (WTIterator itr = p.first; itr != p.second; ++itr) {
                        QTime const &from = Utilities::WeekDaysWorkTimeFrom(itr);
                        QTime const &until = Utilities::WeekDaysWorkTimeUntil(itr);
                        QTime const &startTime = start.time();
                        if (from > startTime) {
                            return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME,
                                QString("%1 < %2").arg(from.toString(Qt::ISODate))
                                                  .arg(startTime.toString(Qt::ISODate)), from, until);
                        } else
                        if (startTime >= until) {
                            return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME,
                                QString("%1 >= %2").arg(startTime.toString(Qt::ISODate))
                                                   .arg(until.toString(Qt::ISODate)), from, until);
                        }
                        return CalcState(CalcState::State::SUCCESS,
                                         "PARKING ALLOWED", from, until);
                    }
                }
            }
        } else
        if (businessHours == BusinessHours::AllDaysWithRestrictedHours) { // e.g. for Neuhauser, NAZ (744)
            if (cfg->WeekDaysWorktime.count(weekdayId) > 0) {
                using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
                std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

                for (WTIterator itr = p.first; itr != p.second; ++itr) {
                    QTime const &from = Utilities::WeekDaysWorkTimeFrom(itr);
                    QTime const &until = Utilities::WeekDaysWorkTimeUntil(itr);
                    QTime const &startTime = start.time();
                    if (from > startTime) {
                        return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME,
                            QString("%1 < %2").arg(from.toString(Qt::ISODate))
                                              .arg(startTime.toString(Qt::ISODate)), from, until);
                    } else
                    if (startTime >= until) {
                        return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME,
                            QString("%1 >= %2").arg(startTime.toString(Qt::ISODate))
                                               .arg(until.toString(Qt::ISODate)), from, until);
                    }
                    return CalcState(CalcState::State::SUCCESS,
                                     "PARKING ALLOWED", from, until);
                }
            }
        }
    }

    return CalcState(CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME, "UNKNOWN ERROR",
                     QTime(), QTime());
}


///////////////////////////////////////

/// <inheritdoc/>
double Calculator::GetCostFromDuration(Configuration* cfg,
                                       uint8_t payment_option,
                                       QDateTime &start_datetime,
                                       QDateTime &end_datetime,
                                       int durationMinutes,
                                       bool nextDay,
                                       bool prepaid) {
    Q_UNUSED(payment_option);
    Q_UNUSED(nextDay);

    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    if (paymentMethodId == PaymentMethod::Steps) {
        if (tariffIs24_7(cfg)) {
            end_datetime = start_datetime.addSecs(durationMinutes*60);
            return GetCostFromDuration(cfg, start_datetime, end_datetime);
        } else {
            if (Utilities::IsYearPeriodActive(cfg, start_datetime)) {
                if (!prepaid) {
                    CalcState cs = isParkingAllowed(cfg, start_datetime);
                    if (cs) {
                        end_datetime = start_datetime.addSecs(durationMinutes*60);
                        double cost = GetCostFromDuration(cfg, start_datetime, end_datetime);
                        end_datetime = start_datetime;
                        end_datetime.setTime(cs.getAllowedTimeRange().getTimeUntil());
                        return cost;
                    }
                } else {
                    // it might be that in such a case even prepaid ("vorkauf")
                    // is not allowed at any moment
                }
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")" << "NOT YET IMPLEMENTED";
                end_datetime = QDateTime();
                return 0;
            }
        }
    } else
    if (paymentMethodId == PaymentMethod::Progressive) {
        // started with Neuhauser, Kirchdorf: merge into main algo. later
        // for now try out some ideas

        static const bool carryOverNotSet = Utilities::isCarryOverNotSet(cfg, paymentMethodId);
        static const uint minParkingPrice = Utilities::getMinimalParkingPrice(cfg, paymentMethodId);

        Q_ASSERT_X(carryOverNotSet, __func__, "CARRYOVER SET (FOR KIRCHDORF)");
        Q_ASSERT_X(prepaid, __func__, "PREPAID NOT SET (FOR KIRCHDORF)");

        QDateTime start = start_datetime;

        int weekdayId = -1;
        int weekdayIdLast = -1;
        int durationMinutesBrutto = 0;

#ifdef _DEBUG_
#undef _DEBUG_
#endif

//#define _DEBUG_ 1
#define _DEBUG_ 0

        QDateTime current = start;

        int days = 7;
        while (--days > 0) {
            weekdayId = current.date().dayOfWeek();
            weekdayIdLast = weekdayId; // TODO: some end condition in json-file

            while (cfg->WeekDaysWorktime.count(weekdayId) == 0) {
                current = current.addDays(1);
                weekdayId = current.date().dayOfWeek();
                if (weekdayId == weekdayIdLast) {
                    qCritical() << "ERROR: NO VALID WORKDAY-TIMES DEFINED";
                    return 0;
                }
            }

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            QTime to = QTime(0, 0, 0);
            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                QTime const &t = Utilities::WeekDaysWorkTimeUntil(itr);

                if (to < t) {
                    to = t;
                }
            }

            if (current.time() >= to) {
                if (carryOverNotSet) {
                    end_datetime = start;
                    return 0;
                } else {
                    QDateTime const dt = start;
                    start = start.addDays(1);
                    start.setTime(QTime(0, 0, 0));

                    durationMinutesBrutto += dt.secsTo(start) / 60;
                    current = start;
                }
            } else {
                break;
            }
        }

        int durationMinutesNetto = 0;
        uint price = 0;

        if (carryOverNotSet) {
            int minsToCarryOver = 0; // from one work-time to the other on the same day
            int minsUsed = 0;
            QDateTime lastCurrent = QDateTime();

            QVector<ATBWeekDaysWorktime> weekDayWorkTimeRanges;

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                weekDayWorkTimeRanges.append(itr->second); // working with vector is easier
            }

            int weekDayWorkTimeIndex = 0;
            bool moveToNextTimeRange = false;

            // time ranges for Neuhauser-Kirchdorf (743): 30, 5, 5, ... 5
            auto timeRangeIt = cfg->TimeRange.cbegin();
            while (timeRangeIt != cfg->TimeRange.cend()) { // ; ++timeRangeIt) {

                if (weekDayWorkTimeIndex >= weekDayWorkTimeRanges.size()) {

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "weekDayWorkTimeRanges.size()" << weekDayWorkTimeRanges.size();
#endif
                    end_datetime = current;
                    return price;
                }

                QTime const &from = QTime::fromString(weekDayWorkTimeRanges[weekDayWorkTimeIndex].pwd_time_from.c_str(), Qt::ISODate);
                QTime const &to = QTime::fromString(weekDayWorkTimeRanges[weekDayWorkTimeIndex].pwd_time_to.c_str(), Qt::ISODate);

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "current" << current.toString(Qt::ISODate)
                            << "from" << from.toString(Qt::ISODate)
                            << "to" << to.toString(Qt::ISODate);
#endif

                Q_ASSERT_X(from < to, __func__, "MISCONFIGURED WORK-TIMES");

                if (current.time() >= to) {
                    ++weekDayWorkTimeIndex;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "try to use next available work-time with"
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "price" << price;
#endif
                    // time range is not affected
                    continue;
                } else
                if (current.time() <= from) {
                    if (prepaid) {
                        lastCurrent = current;
                        current.setTime(from); // move current forward (range==1),
                                               // as prepaid is set
                        uint const minutesMoved = lastCurrent.secsTo(current) / 60;
                        durationMinutesBrutto += minutesMoved;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                    << "current" << current.toString(Qt::ISODate)
                                    << "minutesMoved" << minutesMoved
                                    << "durationMinutesBrutto" << durationMinutesBrutto;
#endif

                        if (weekDayWorkTimeIndex == 0) {
                            start_datetime = current;
                        }
                    }
                }

                ATBTimeRange timeRange = timeRangeIt->second;

                timeRange.computeQTimes(current.time());

                int duration = timeRange.time_range_to_in_minutes_from_start -
                               timeRange.time_range_from_in_minutes_from_start;

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "current" << current.toString(Qt::ISODate)
                            << "duration" << duration
                            << "minsUsed" << minsUsed
                            << "minsToCarryOver" << minsToCarryOver
                            << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                            << "price" << price;
#endif

                if (minsToCarryOver > 0) {  // the price for this time range
                                            // has been is paid already
                    Q_ASSERT_X(weekDayWorkTimeIndex > 0, __func__, "WRONG-WORK-TIME");

                    current = current.addSecs(minsToCarryOver*60);

                    durationMinutes -= minsToCarryOver;
                    durationMinutesNetto += minsToCarryOver;
                    durationMinutesBrutto += minsToCarryOver;

                    minsToCarryOver = 0;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "durationMinutes" << durationMinutes
                                << "durationMinutesNetto" << durationMinutesNetto
                                << "durationMinutesBrutto" << durationMinutesBrutto;
#endif
                    if (durationMinutes <= 0) {
                        end_datetime = current;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif

                        return price;
                    }
                }

                if (current.addSecs(duration * 60).time() <= to) {

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "current.addSecs(" << duration * 60 << ")" << current.addSecs(duration*60).time().toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes;
#endif

                    moveToNextTimeRange = false;
                    for(const auto &x: cfg->PaymentRate) {
                        ATBPaymentRate const rate = x.second;
                        if (rate.pra_payment_unit_id == timeRange.time_range_payment_type_id) {
                            price += (uint)rate.pra_price;

                            durationMinutes -= duration;
                            durationMinutesNetto += duration;
                            durationMinutesBrutto += duration;

                            current = current.addSecs(duration * 60);

                            // price has been updated; use next time range
                            moveToNextTimeRange = true;
                            break;
                        }
                    }

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "price" << price
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes
                                << "durationMinutesNetto" << durationMinutesNetto
                                << "durationMinutesBrutto" << durationMinutesBrutto;
#endif

                    if (durationMinutes <= 0) {
                        end_datetime = current;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                << "price" << price;
#endif

                        return price;
                    }

                    if (moveToNextTimeRange) {
                        if (++timeRangeIt != cfg->TimeRange.cend()) {
                            continue;
                        }
                    }

                    // havin a new time range means that we always have a new
                    // work-time-range
                    // ++timeRangeIt;

                } else { // current.addSecs(duration * 60).time() > to

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "current.addSecs(" << duration * 60 << ")" << current.addSecs(duration*60).time().toString(Qt::ISODate)
                                << "duration" << duration
                                << ", to:" << to.toString(Qt::ISODate);
#endif

                    lastCurrent = current;
                    current.setTime(to);
                    minsUsed = lastCurrent.secsTo(current) / 60;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes;
#endif

                    // mod duration: possibly discard some minutes in
                    // the next time-range
                    if (duration >= minsUsed) {
                        minsToCarryOver = duration - minsUsed;
                    }

                    durationMinutes -= minsUsed;
                    durationMinutesNetto += minsUsed;
                    durationMinutesBrutto += minsUsed;

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "lastCurrent" << lastCurrent.toString(Qt::ISODate)
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "to" << to.toString(Qt::ISODate)
                                << "minsUsed" << minsUsed
                                << "minsToCarryOver" << minsToCarryOver
                                << "weekDayWorkTimeIndex" << weekDayWorkTimeIndex
                                << "durationMinutes" << durationMinutes
                                << "price" << price;
#endif

                    moveToNextTimeRange = false;

                    if (minsUsed > 0) {
                        for(const auto &x: cfg->PaymentRate) {
                            ATBPaymentRate const rate = x.second;
                            if (rate.pra_payment_unit_id == timeRange.time_range_payment_type_id) {
                                price += (uint)rate.pra_price;

                                // price has been updated; use next time range
                                moveToNextTimeRange = true;
                                break;
                            }
                        }
                    }

#if _DEBUG_==1
                    qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                << "current" << current.toString(Qt::ISODate)
                                << "duration" << duration
                                << "minsUsed" << minsUsed
                                << "durationMinutes" << durationMinutes
                                << "moveToNextTimeRange" << moveToNextTimeRange
                                << "price" << price;
#endif

                    if (moveToNextTimeRange) {
                        if (++timeRangeIt != cfg->TimeRange.cend()) {
                            continue;
                        }

                        // no valid time range left
                        end_datetime = current;

#if _DEBUG_==1
                        qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                                    << "end_datetime" << end_datetime.toString(Qt::ISODate)
                                    << "price" << price;
#endif

                        return price;
                    }
                }

                end_datetime = start.addSecs(durationMinutesBrutto * 60);

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "start" << start.toString(Qt::ISODate)
                            << "end_datetime" << end_datetime.toString(Qt::ISODate)
                            << "final price" << std::max(price, minParkingPrice);
#endif

                return std::max(price, minParkingPrice);
            } // while (timeRangeIt != cfg->TimeRange.cend()) {
        }

#if _DEBUG_==1
                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
                            << "INVALID END TIME";
#endif
        end_datetime = QDateTime();
        return 0;
    }

    QDateTime start = start_datetime;

    Ticket t = private_GetCostFromDuration(cfg, start,
                                           durationMinutes,
                                           prepaid);
    if (t) {
        // qCritical().noquote() << t;
    }

    end_datetime = t.getValidUntil();

    return t.getPrice();
}

bool Calculator::checkDurationMinutes(int minParkingTime,
                                      int maxParkingTime,
                                      int durationMinutes) {
    if (durationMinutes > maxParkingTime) {
        qWarning() << QString("Total duration >= max_min (%1 >= %2)").arg(durationMinutes).arg(maxParkingTime);
        return false;
    }
    if (durationMinutes < minParkingTime) {
        qWarning() << QString("Total duration <= minMin (%1 <= %2)").arg(durationMinutes).arg(minParkingTime);
        return false;
    }

    return true;
}

int Calculator::findWorkTimeRange(QDateTime const &dt,
                                  QScopedArrayPointer<TariffTimeRange> const &worktime,
                                  size_t size) {
    for (size_t w = 0; w < size; ++w) {
        QTime const &worktime_from = worktime[w].getTimeFrom();
        QTime const &worktime_to = worktime[w].getTimeUntil();

        if ((dt.time() >= worktime_from) && (dt.time() < worktime_to)) {
            return w;
        }
    }
    return -1;
}

int Calculator::findNextWorkTimeRange(QDateTime const &dt,
                                      QScopedArrayPointer<TariffTimeRange> const &worktime,
                                      size_t size) {
    int nextWorkTimeRange = -1;
    for (size_t w = 0; w < size; ++w) {
        QTime const &worktime_from = worktime[w].getTimeFrom();

        if (dt.time() < worktime_from) {
            nextWorkTimeRange = w;
            break;
        }
    }
    return nextWorkTimeRange;
}

using namespace Utilities;

Ticket Calculator::private_GetCostFromDuration(Configuration const* cfg,
                                               QDateTime const &start,
                                               int durationMinutes, // Netto
                                               bool prepaid) {

    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    static const bool carryOverNotSet = isCarryOverNotSet(cfg, paymentMethodId);
    static const int minParkingTimeMinutes = Utilities::getMinimalParkingTime(cfg, paymentMethodId);
    static const int maxParkingTimeMinutes = Utilities::getMaximalParkingTime(cfg, paymentMethodId);
    static const bool checkMinMaxMinutes = (minParkingTimeMinutes < maxParkingTimeMinutes);
    static const int durationMinutesNetto = durationMinutes;
    static const uint32_t weekDaysPrice = Utilities::computeWeekDaysPrice(cfg, paymentMethodId);
    static const double weekDaysDurationUnit = Utilities::computeWeekDaysDurationUnit(cfg, paymentMethodId);
    static const double specialDaysDurationUnit = 60.0;

    if (!checkMinMaxMinutes) {
        qCritical() << QString(
            "ERROR: CONDITION minMin < maxMin (%1 < %2) IS NOT VALID")
                .arg(minParkingTimeMinutes).arg(maxParkingTimeMinutes);
        return Ticket();
    }

    if (!checkDurationMinutes(minParkingTimeMinutes,
                              maxParkingTimeMinutes, durationMinutes)) {
        return Ticket();
    }

    uint32_t price = 0;
    uint32_t costFromDuration = 0;
    double durationUnit = 0.0;
    int specialDayId = -1;
    bool isSpecialDay = false;
    Ticket ticket;
    QDateTime end = start;
    QDateTime current;
    int totalTimeRanges = 0;

    for (current = start; durationMinutes > 0; current = current.addDays(1)) {
        int const weekdayId = current.date().dayOfWeek();

        specialDayId = -1;

        // find worktime ranges for the current day
        int const timeRanges = std::max((int)cfg->WeekDaysWorktime.count(weekdayId), 1);
        QScopedArrayPointer<TariffTimeRange> worktime(new TariffTimeRange[timeRanges]);
        int ranges = 0;

        if((isSpecialDay = Utilities::CheckSpecialDay(cfg, current, &specialDayId, &price))) {
            // Set special day price:
            durationUnit = specialDaysDurationUnit;
            worktime[ranges].setTimeRange(SpecialDaysWorkTimeFrom(cfg, specialDayId),
                                          SpecialDaysWorkTimeUntil(cfg, specialDayId));
            ranges = 1;
        } else {
            // Set new price for the normal day: do not use a floating-point type
            // for the price, rather compute with integers. Only at the very end of
            // the computation the price is divided by durationUnit.
            price = weekDaysPrice;
            durationUnit = weekDaysDurationUnit;

            // If no working day found, skip it (epsecially Sundays!)
            if (cfg->WeekDaysWorktime.count(weekdayId) <= 0) {
                qDebug() << "No workday found, trying to find next available day";
                end = current;
                current.setTime(QTime()); // start at midnight on the next day
                continue;
            }

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                worktime[ranges].setTimeRange(WeekDaysWorkTimeFrom(itr),
                                              WeekDaysWorkTimeUntil(itr));
                ranges += 1;
            }
        }

        QTime const &lastWorktimeTo = worktime[ranges-1].getTimeUntil();

        // qCritical() << "start" << start.toString(Qt::ISODate)
        //             << "current" << current.toString(Qt::ISODate) << lastWorktimeTo;

        // find worktime range to start with
        int currentRange = 0;
        if (!isSpecialDay) {
            if (start != current) { // on next day
                current.setTime(worktime[currentRange].getTimeFrom());
            } else {
                // check if inputDate is located inside a valid worktime-range...
                if ((currentRange = findWorkTimeRange(current, worktime, ranges)) == -1) {
                    if (!prepaid && carryOverNotSet) {       // parking is not allowed
                        return Ticket(start, QDateTime(), durationMinutesNetto, 0,
                                      0, Ticket::s[INVALID_FROM_DATETIME]);
                    }
                    // find the next worktime-range (on the same day), and start from there
                    if ((currentRange = findNextWorkTimeRange(current, worktime, ranges)) == -1) {
                        end = current;
                        continue;
                    }
                    current.setTime(worktime[currentRange].getTimeFrom());
                }
            }
        }

        // qCritical() << "current" << current.toString(Qt::ISODate);

        for (int w = currentRange; w < ranges; ++w, ++totalTimeRanges) {
            if (durationMinutes > 0) {
                QTime const &worktime_from = worktime[w].getTimeFrom();
                QTime const &worktime_to = worktime[w].getTimeUntil();

                if (totalTimeRanges) {
                    // durationMinutes are always meant as netto time and
                    // the time between worktime-ranges are free.
                    current.setTime(worktime_from);
                }

                if (price == 0) {
                    end = current;
                    current.setTime(QTime());
                    continue;
                }

                if (current.time() == worktime_to) {
                    end = current;
                    current.setTime(QTime());
                    continue;
                }

                // Check prepaid
                if (!prepaid) {
                    if ((current.time() < worktime_from) || (current.time() > worktime_to)) {
                        qDebug() << "[STOP] * Ticket is not valid * ";
                        return Ticket();
                    }
                } else {
                    //qDebug() << "* PREPAID MODE ACTIVE *";
                    //qCritical() << "current" << current.toString(Qt::ISODate) << worktime_from << lastWorktimeTo;
                    if (current.time() < worktime_from) {
                        current.setTime(worktime_from);
                        end = current;
                    } else if(current.time() > lastWorktimeTo) {
                        //qDebug() << " *** PREPAID *** Current time is past the time range end, searching for next available day";
                        end = current;
                        current.setTime(QTime());
                        continue;
                    }
                }

                while(durationMinutes > 0) {
                    // Check for active year period
                    if (!IsYearPeriodActive(cfg, current)) {
                        return Ticket();
                    }
                    if(current.time() >= lastWorktimeTo) {
                        // Go to next day if minutes not spent
                        if (carryOverNotSet) {
                            // no carry_over, so stop computation
                            break;
                        }
                        current.setTime(QTime());
                        break; // stop while, and continue in outer loop
                    } else {
                        //qCritical() << "current" << current.toString(Qt::ISODate) << worktime_to;
                        if(current.time() < worktime_to) {
                            // Increment input date minutes for each monetary unit
                            current = current.addSecs(60);
                            end = current;
                            durationMinutes -= 1;
                            //costFromDuration += price_per_unit;
                            costFromDuration += price;
                            //qCritical() << "current" << current.toString(Qt::ISODate);
                        } else break;
                    }
                } // while(durationMinutes > 0) {
            } // if (durationMinutes > 0) {
        } // for (int w = currentRange; w < ranges; ++w, ++totalTimeRanges) {
    } // for (current = start; durationMinutes > 0; current = current.addDays(1)) {

    int durationMinutesBrutto =  start.secsTo(end) / 60;

    return
        Ticket(start, end, durationMinutesNetto, durationMinutesBrutto,
               ceil(Utilities::CalculatePricePerUnit(costFromDuration, durationUnit)),
               Ticket::s[VALID]);
}


Ticket Calculator::private_GetDurationFromCost(Configuration *cfg,
                                               QDateTime const &start,
                                               uint32_t cost,
                                               bool prepaid) {
    // Get input date
    QDateTime current = start;

    static const PaymentMethod paymentMethodId = Utilities::getPaymentMethodId(cfg);
    static const bool carryOverNotSet = isCarryOverNotSet(cfg, paymentMethodId);
    static const uint32_t minParkingTimeMinutes = std::max(Utilities::getMinimalParkingTime(cfg, paymentMethodId), 0);
    static const uint32_t maxParkingTimeMinutes = std::max(Utilities::getMaximalParkingTime(cfg, paymentMethodId), 0);
    static const uint32_t minParkingPrice = getMinimalParkingPrice(cfg, paymentMethodId);
    // static const bool checkMinMaxMinutes = (minParkingTimeMinutes < maxParkingTimeMinutes);
    static const uint32_t weekDaysPrice = Utilities::computeWeekDaysPrice(cfg, paymentMethodId);
    static const uint32_t weekDaysDurationUnit = Utilities::computeWeekDaysDurationUnit(cfg, paymentMethodId);
    static const uint32_t specialDaysDurationUnit = 60;

    if(cost < minParkingPrice) {
        uint64_t const durationMinutes = GetDurationForPrice(cfg, cost);
        return Ticket(start, current, durationMinutes, durationMinutes,
                   cost, Ticket::s[INVALID_PRICE]);
    }
    if (minParkingTimeMinutes >= maxParkingTimeMinutes) {
        // TODO
        return Ticket();
    }
    if (maxParkingTimeMinutes <= minParkingTimeMinutes) {
        // TODO
        return Ticket();
    }

    uint32_t durationMinutesNetto = 0;
    double moneyLeft = cost;
    double durationUnit = 1;
    int specialDayId = -1;
    bool isSpecialDay = false;
    QDateTime end = start;
    int totalTimeRanges = 0;
    double price = 0;

    for (current = start; moneyLeft > 0 && moneyLeft >= price; current = current.addDays(1)) {
        int const weekdayId = current.date().dayOfWeek();

        specialDayId = -1;

        // find worktime ranges for the current day
        int const timeRanges = std::max((int)cfg->WeekDaysWorktime.count(weekdayId), 1);
        QScopedArrayPointer<TariffTimeRange> worktime(new TariffTimeRange[timeRanges]);
        int ranges = 0;

        uint32_t p = 0;
        if((isSpecialDay = Utilities::CheckSpecialDay(cfg, current, &specialDayId, &p))) {
            // Set special day price:
            durationUnit = specialDaysDurationUnit;
            price = p / durationUnit;
            price = std::round(price * 1000.0) / 1000.0;
            worktime[ranges].setTimeRange(SpecialDaysWorkTimeFrom(cfg, specialDayId),
                                          SpecialDaysWorkTimeUntil(cfg, specialDayId));
            ranges = 1;
        } else {
            // Set new price for the normal day: do not use a floating-point type
            // for the price, rather compute with integers. Only at the very end of
            // the computation the price is divided by durationUnit.
            price = weekDaysPrice;
            durationUnit = weekDaysDurationUnit;
            price /= durationUnit;
            price = std::round(price * 1000.0) / 1000.0; // round to 3 decimals

            // If no working day found, skip it (epsecially Sundays!)
            if (cfg->WeekDaysWorktime.count(weekdayId) <= 0) {
         //     qDebug() << "No workday found, trying to find next available day";
                end = current;
                current.setTime(QTime()); // start at midnight on the next day
                continue;
            }

            using WTIterator = std::multimap<int, ATBWeekDaysWorktime>::const_iterator;
            std::pair<WTIterator, WTIterator> p = cfg->WeekDaysWorktime.equal_range(weekdayId);

            for (WTIterator itr = p.first; itr != p.second; ++itr) {
                worktime[ranges].setTimeRange(WeekDaysWorkTimeFrom(itr),
                                              WeekDaysWorkTimeUntil(itr));
                ranges += 1;
            }
        }

        QTime const &lastWorktimeTo = worktime[ranges-1].getTimeUntil();

        // find worktime range to start with
        int currentRange = 0;
        if (!isSpecialDay) {
            if (start != current) { // on next day
                current.setTime(worktime[currentRange].getTimeFrom());
            } else {
                // check if inputDate is located inside a valid worktime-range...
                if ((currentRange = findWorkTimeRange(current, worktime, ranges)) == -1) {
                    if (!prepaid && carryOverNotSet) {       // parking is not allowed
                        return Ticket(start, QDateTime(), durationMinutesNetto, 0,
                                      0, Ticket::s[INVALID_FROM_DATETIME]);
                    }
                    // find the next worktime-range (on the same day), and start from there
                    if ((currentRange = findNextWorkTimeRange(current, worktime, ranges)) == -1) {
                        end = current;
                        continue;
                    }
                    current.setTime(worktime[currentRange].getTimeFrom());
                }
            }
        }

        for (int w = currentRange; w < ranges; ++w, ++totalTimeRanges) {
            if (moneyLeft > 0) {
                QTime const &worktime_from = worktime[w].getTimeFrom();
                QTime const &worktime_to = worktime[w].getTimeUntil();

                if (totalTimeRanges) {
                    // durationMinutes are always meant as netto time and
                    // the time between worktime-ranges are free.
                    current.setTime(worktime_from);
                }

                if (price == 0) {
                    // inputDate = inputDate.addDays(1);
                    // inputDate.setTime(worktime_from);
                    end = current;
                    current.setTime(QTime());
                    continue;
                }

                if (current.time() == worktime_to) {
                    end = current;
                    current.setTime(QTime());
                    continue;
                }

                // Check prepaid
                if (!prepaid) {
                    if (current.time() < worktime_from) {
                        qDebug() << "[STOP] TICKET IS NOT VALID: "
                                 << QString("%1 (current) < %2 (start)")
                                        .arg(current.toString(Qt::ISODate)
                                        .arg(worktime_from.toString(Qt::ISODate)));
                        return Ticket();
                    } else
                    if (current.time() > worktime_to) {
                        qDebug() << "[STOP] TICKET IS NOT VALID: "
                                 << QString("%1 (current) > %2 (end)")
                                        .arg(current.toString(Qt::ISODate)
                                        .arg(worktime_to.toString(Qt::ISODate)));
                        return Ticket();
                    }
                } else {
                    if (current.time() < worktime_from) {
                        qDebug() << "*** PREPAID *** Current time is before time range start, fast-forward to start"
                                 << worktime_from.toString(Qt::ISODate);
                        current.setTime(worktime_from);
                        end = current;
                    } else if(current.time() > lastWorktimeTo) {
                        qDebug() << " *** PREPAID *** Current time is past the time range end, searching for next available day";
                        end = current;
                        current.setTime(QTime());
                        continue;
                    }
                }

                while(moneyLeft >= price) {
                    // Check for active year period
                    if (!IsYearPeriodActive(cfg, current)) {
                        return Ticket();
                    }
                    // if(durationMinutesNetto >= maxParkingTimeMinutes) {
                    //  might be useful for overpayment
                    //    durationMinutesNetto = maxParkingTimeMinutes;
                    //    int durationMinutesBrutto = start.secsTo(end) / 60;
                    //
                    //    return
                    //        Ticket(start, end, durationMinutesNetto,
                    //               durationMinutesBrutto, cost, Ticket::s[INVALID_PRICE]);
                    //
                    // }
                    if(current.time() >= lastWorktimeTo) {
                        // Go to next day if minutes not spent
                        if (carryOverNotSet) {
                            // no carry_over, so stop computation
                            break;
                        }
                        current.setTime(QTime());
                        break; // stop while, and continue in outer loop
                    } else {
                        if(current.time() < worktime_to) {
                            // Increment input date minutes for each monetary unit
                            durationMinutesNetto += 1;
                            moneyLeft -= price;
                            moneyLeft = std::round(moneyLeft * 1000.0) / 1000.0;
                            current = current.addSecs(60);

                            //qCritical() << "moneyLeft" << moneyLeft
                            //            << "durationMinutesNetto" << durationMinutesNetto
                            //            << "current" << current.toString(Qt::ISODate);

                            if(durationMinutesNetto <= maxParkingTimeMinutes) {
                                // stop updating of end-date if parking time is
                                // overshot
                                end = current;
                            }
                        } else break;
                    }
                } // while(durationMinutes > 0) {
            } // if (durationMinutes > 0) {
        } // for (int w = currentRange; w < ranges; ++w, ++totalTimeRanges) {
    } // for (current = start; durationMinutes > 0; current = current.addDays(1)) {

    int durationMinutesBrutto = start.secsTo(end) / 60;

    //qCritical() << "start" << start.toString(Qt::ISODate) << "end"
    //            << end.toString(Qt::ISODate) << durationMinutesBrutto;

    return
        Ticket(start, end, durationMinutesNetto, durationMinutesBrutto,
               cost, Ticket::s[VALID]);
}

QList<int> Calculator::GetPriceSteps(Configuration * /*cfg*/) const {
    return QList<int>();
}

QList<int> Calculator::GetTimeSteps(Configuration *cfg, int paymentOptionIndex) const {
    qCritical() << "(" << __func__ << ":" << __LINE__ << ")" << "paymentOptionIndex:" << paymentOptionIndex;

    if (m_timeSteps.size() > paymentOptionIndex) {
        //qCritical() << __PRETTY_FUNCTION__ << "timeSteps:" << m_timeSteps;
        return m_timeSteps[paymentOptionIndex];
    } else {
        m_timeSteps.push_back(QList<int>());
    }

    QDateTime start = QDateTime::currentDateTime();
    start.setTime(QTime(start.time().hour(), start.time().minute(), 0));

    int const pop_id = cfg->getPaymentOptions(paymentOptionIndex).pop_id;
    int const pop_carry_over = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over;
    int const pop_time_step_config = cfg->getPaymentOptions(paymentOptionIndex).pop_time_step_config;

    static PaymentMethod const paymentMethodId = Utilities::getPaymentMethodId(cfg);

    qCritical() << "(" << __func__ << ":" << __LINE__ << ")        start parking time:" << start.toString(Qt::ISODate);
    qCritical() << "(" << __func__ << ":" << __LINE__ << ")         payment option id:" << pop_id;
    qCritical() << "(" << __func__ << ":" << __LINE__ << ") payment option carry over:" << pop_carry_over;

    if (pop_time_step_config == (int)ATBTimeStepConfig::TimeStepConfig::DYNAMIC) {
        //qCritical() << __PRETTY_FUNCTION__ << "payment option time step config:" << "TimeStepConfig::DYNAMIC";

        if (paymentMethodId == PaymentMethod::Progressive) { // e.g. neuhauser kirchdorf (743)
            std::size_t const s = cfg->TimeRange.size();
            for (std::size_t id = 1; id <= s; ++id) {
                int const step = Utilities::getTimeRangeStep(cfg, id, paymentMethodId);
                m_timeSteps[paymentOptionIndex].append(step);
            }
        } else {
            uint16_t timeStepCompensation = 0;

            if (pop_carry_over) {
                int const pop_carry_over_time_range_id = cfg->getPaymentOptions(paymentOptionIndex).pop_carry_over_time_range_id;
                QTime const carryOverTimeRangeFrom = cfg->TimeRange.find(pop_carry_over_time_range_id)->second.time_range_from;
                QTime const carryOverTimeRangeTo = cfg->TimeRange.find(pop_carry_over_time_range_id)->second.time_range_to;

                if (carryOverTimeRangeFrom.secsTo(carryOverTimeRangeTo) <= 60) { // carry over time point, usually 00:00:00
                    if (carryOverTimeRangeFrom == QTime(0, 0, 0)) {
                        for (auto[itr, rangeEnd] = cfg->PaymentRate.equal_range(pop_id); itr != rangeEnd; ++itr) {
                            int const durationId = itr->second.pra_payment_unit_id;
                            auto search = cfg->Duration.find(durationId);
                            if (search != cfg->Duration.end()) {
                                ATBDuration duration = search->second;
                                if (durationId == 1) {
                                    QDateTime carryOver = start;
                                    carryOver = carryOver.addDays(1);
                                    carryOver.setTime(QTime(0, 0, 0));

                                    int const timeStep = std::ceil(start.secsTo(carryOver) / 60.0);
                                    if (timeStep < duration.pun_duration_min || timeStep > duration.pun_duration_max) {
                                        qCritical()
                                            << QString("ERROR timeStep (%1) < durationMin (%2) || timeStep (%3)) > durationMax (%4)")
                                                .arg(timeStep).arg(duration.pun_duration_min)
                                                .arg(timeStep).arg(duration.pun_duration_max);
                                        break;
                                    }
                                    qCritical() << "(" << __func__ << ":" << __LINE__ << ") configured minimal parking time:" << cfg->getPaymentOptions(paymentOptionIndex).pop_min_time;

                                    // set dynamic minimal parking time
                                    cfg->getPaymentOptions(paymentOptionIndex).pop_min_time = timeStep;

                                    qCritical() << "(" << __func__ << ":" << __LINE__ << ") computed minimal parking time:" << cfg->getPaymentOptions(paymentOptionIndex).pop_min_time;

                                    duration.pun_duration = timeStep;
                                    timeStepCompensation = duration.pun_duration_max - duration.pun_duration;
                                    m_timeSteps[paymentOptionIndex] << duration.pun_duration;
                                } else {
                                    duration.pun_duration = duration.pun_duration_max - timeStepCompensation;
                                    m_timeSteps[paymentOptionIndex] << duration.pun_duration;;
                                }

                                cfg->Duration.erase(search);
                                cfg->Duration.insert(pair<int, ATBDuration>(duration.pun_id, duration));

                            } else { // if (search != cfg->Duration.end()) {
                               // TODO
                            }
                        }
                    } else { // if (carryOverTimeRangeFrom == QTime(0, 0, 0)) {
                        // TODO
                    }
                } else { // if (carryOverTimeRangeFrom == carryOverTimeRangeTo) {
                    // TODO
                }
            } else { // if (pop_carry_over) {
                // TODO
            }
        }
    } else {
        qCritical() << "(" << __func__ << ":" << __LINE__ << ") payment option time step config:" << "TimeStepConfig::STATIC";

        for (auto[itr, rangeEnd] = cfg->PaymentRate.equal_range(pop_id); itr != rangeEnd; ++itr)
        {
            int const durationId = itr->second.pra_payment_unit_id;
            int const durationUnit = cfg->Duration.find(durationId)->second.pun_duration;
            int size = m_timeSteps.size();

            while (size <= paymentOptionIndex) {
                m_timeSteps.push_back(QList<int>());
                size = m_timeSteps.size();
            }

            m_timeSteps[paymentOptionIndex] << durationUnit;
        }
    }

    qCritical() << "(" << __func__ << ":" << __LINE__ << ")" << "NEW timeSteps:" << m_timeSteps;

    return m_timeSteps[paymentOptionIndex];
}

uint32_t Calculator::GetPriceForTimeStep(Configuration *cfg, int timeStep, int paymentOptionIndex) const {

    int const pop_id = cfg->getPaymentOptions(paymentOptionIndex).pop_id;

    for (auto[itr, rangeEnd] = cfg->PaymentRate.equal_range(pop_id); itr != rangeEnd; ++itr)
    {
        int const payment_unit_id = itr->second.pra_payment_unit_id;
        int const pun_id = cfg->Duration.find(payment_unit_id)->second.pun_id;

        Q_ASSERT(pun_id == payment_unit_id);

        int const pun_duration = cfg->Duration.find(payment_unit_id)->second.pun_duration;
        if (timeStep == pun_duration) {
            return (uint32_t)(itr->second.pra_price);
        }
    }

    return 0;
}

uint32_t Calculator::GetDurationForPrice(Configuration *cfg, int price) const {
    int const pop_id = cfg->getPaymentOptions().pop_id;

    uint32_t duration = 0;

    for (auto[itr, rangeEnd] = cfg->PaymentRate.equal_range(pop_id); itr != rangeEnd; ++itr)
    {
        int const durationId = itr->second.pra_payment_unit_id;
        int const pra_price = itr->second.pra_price;

        uint32_t const durationUnit = cfg->Duration.find(durationId)->second.pun_duration;

        if (pra_price == price) {
            return durationUnit;
        }

        if (pra_price < price) {
            duration = durationUnit;
        }
    }

    return duration;
}

std::optional<struct price_t>
Calculator::GetDailyTicketPrice(Configuration* cfg,
                                QDateTime const &startDatetime,
                                QDateTime &endTime,
                                PERMIT_TYPE permitType) {
    struct price_t price;
    std::optional<struct price_t> value;

    std::optional<ATBWeekDaysWorktime> workTime =
        cfg->getWeekDayWorkTime(startDatetime.time(),
                                (Qt::DayOfWeek)startDatetime.date().dayOfWeek());
    if (workTime) {
        ATBWeekDaysWorktime const &wt = workTime.value();
        endTime = startDatetime;
        endTime.setTime(QTime::fromString(wt.pwd_time_to.c_str(), Qt::ISODate));
        std::optional<QVector<ATBDailyTicket>> dailyTickets = cfg->getDailyTicketsForAllKeys();
        if (dailyTickets) {
            QVector<ATBDailyTicket> const tickets = dailyTickets.value();
            switch (permitType) {
                case PERMIT_TYPE::TWENTY_FOUR_HOURS_TICKET: {
                    // TODO
                } break;
                case PERMIT_TYPE::FOOD_STAMP: {
                    // TODO
                } break;
                case PERMIT_TYPE::DAY_TICKET_ADULT: {
                    std::optional<ATBCustomer> c = cfg->getCustomerForType(ATBCustomer::CustomerType::ADULT);
                    if (c) {
                        for (QVector<ATBDailyTicket>::size_type i=0; i<tickets.size(); ++i) {
                            if (tickets[i].daily_ticket_clearance_customer_ids.contains(c.value().cust_id)) {
                                int priceId = tickets[i].daily_ticket_price_id;
                                QVector<ATBPaymentOption> const &paymentOptions = cfg->getAllPaymentOptions();
                                for (QVector<ATBPaymentOption>::size_type j=0; j < paymentOptions.size(); ++j) {
                                    int const pop_id = paymentOptions.at(j).pop_id;
                                    std::optional<QVector<ATBPaymentRate>> const &paymentRates = cfg->getPaymentRateForKey(pop_id);
                                    if (paymentRates) {
                                        QVector<ATBPaymentRate> const &pr = paymentRates.value();
                                        for (QVector<ATBPaymentRate>::size_type k=0; k < pr.size(); ++k) {
                                            if (pr.at(k).pra_payment_option_id == pop_id) {
                                                if (priceId == pr.at(k).pra_payment_unit_id) {
                                                    price.netto = pr.at(k).pra_price;
                                                    value = value.value_or(price);
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                } break;
                case PERMIT_TYPE::DAY_TICKET_TEEN: {
                    std::optional<ATBCustomer> c = cfg->getCustomerForType(ATBCustomer::CustomerType::TEEN);
                    if (c) {
                        for (QVector<ATBDailyTicket>::size_type i=0; i<tickets.size(); ++i) {
                            if (tickets[i].daily_ticket_clearance_customer_ids.contains(c.value().cust_id)) {
                                int priceId = tickets[i].daily_ticket_price_id;
                                QVector<ATBPaymentOption> const &paymentOptions = cfg->getAllPaymentOptions();
                                for (QVector<ATBPaymentOption>::size_type j=0; j < paymentOptions.size(); ++j) {
                                    int const pop_id = paymentOptions.at(j).pop_id;
                                    std::optional<QVector<ATBPaymentRate>> const &paymentRates = cfg->getPaymentRateForKey(pop_id);
                                    if (paymentRates) {
                                        QVector<ATBPaymentRate> const &pr = paymentRates.value();
                                        for (QVector<ATBPaymentRate>::size_type k=0; k < pr.size(); ++k) {
                                            if (pr.at(k).pra_payment_option_id == pop_id) {
                                                if (priceId == pr.at(k).pra_payment_unit_id) {
                                                    price.netto = pr.at(k).pra_price;
                                                    value = value.value_or(price);
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                } break;
                case PERMIT_TYPE::DAY_TICKET_CHILD: {
                    std::optional<ATBCustomer> c = cfg->getCustomerForType(ATBCustomer::CustomerType::CHILD);
                    if (c) {
                        for (QVector<ATBDailyTicket>::size_type i=0; i<tickets.size(); ++i) {
                            if (tickets[i].daily_ticket_clearance_customer_ids.contains(c.value().cust_id)) {
                                int priceId = tickets[i].daily_ticket_price_id;
                                QVector<ATBPaymentOption> const &paymentOptions = cfg->getAllPaymentOptions();
                                for (QVector<ATBPaymentOption>::size_type j=0; j < paymentOptions.size(); ++j) {
                                    int const pop_id = paymentOptions.at(j).pop_id;
                                    std::optional<QVector<ATBPaymentRate>> const &paymentRates = cfg->getPaymentRateForKey(pop_id);
                                    if (paymentRates) {
                                        QVector<ATBPaymentRate> const &pr = paymentRates.value();
                                        for (QVector<ATBPaymentRate>::size_type k=0; k < pr.size(); ++k) {
                                            if (pr.at(k).pra_payment_option_id == pop_id) {
                                                if (priceId == pr.at(k).pra_payment_unit_id) {
                                                    price.netto = pr.at(k).pra_price;
                                                    value = value.value_or(price);
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
                // [[fallthrough]];
                case PERMIT_TYPE::SHORT_TERM_PARKING: {
                }
                // [[fallthrough]];
                case PERMIT_TYPE::DAY_TICKET: {
                }
                // [[fallthrough]];
                case PERMIT_TYPE::SZEGED_START:
                    // [[fallthrough]];
                case PERMIT_TYPE::SZEGED_STOP:
                    // [[fallthrough]];
                case PERMIT_TYPE::INVALID:
                    break;
            }
        } else {
            // for projects which have not defined a daily ticket in their
            // tariff-files (e.g. szeged)
            price.netto = cfg->getPaymentOptions().pop_daily_card_price;

            qCritical() << "( GetDailyTicketPrice():" << __LINE__ << ")";
            qCritical() << "                  start:" << startDatetime.toString(Qt::ISODate);
            qCritical() << "          workTime from:" << QTime::fromString(QString(wt.pwd_time_from.c_str()), Qt::ISODate);
            qCritical() << "            workTime to:" << QTime::fromString(QString(wt.pwd_time_to.c_str()), Qt::ISODate);
            qCritical() << "daily_ticket_card_price:" << price.netto;

            value = value.value_or(price);
        }
    }

    return value;
}