#include "calculate_price.h"
#include "configuration.h"
#include "calculator_functions.h"
#include "payment_option.h"

#include <QFile>
#include <QFileInfo>
#include <QDateTime>
#include <QDebug>

static Calculator calculator;

int CALCULATE_LIBRARY_API get_zone_nr() {
    QFile zone("/etc/zone_nr");
    if (zone.exists()) {
        QFileInfo finfo(zone);
        if (finfo.size() <= 4) { // decimal 000\n
            if (zone.open(QIODevice::ReadOnly | QIODevice::Text)) {
                QTextStream in(&zone);
                return in.readLine(100).toInt();
            }
        }
    }
    return -1;
}

CalcState CALCULATE_LIBRARY_API init_tariff(parking_tariff_t **tariff, char const *config_file) {
    *tariff = new Configuration();

    CalcState calcState;
    int const zone = get_zone_nr();

    // DEBUG
    qCritical() << "init_tariff:";
    qCritical() << "      ... zone = " << zone;

    if (zone <= 0) {
        delete *tariff;
        *tariff = nullptr;
        return calcState.set(CalcState::State::ERROR_PARSING_ZONE_NR);
    }

    QString confFile(config_file);
    if (!confFile.endsWith(QChar('/'))) {
        confFile += "/";
    }

    char buffer[32];
    memset(buffer, 0x00, sizeof(buffer));
    snprintf(buffer, sizeof(buffer)-1, "tariff%02d.json", zone);
    confFile += buffer;

    // DEBUG
    qCritical() << "      ... confFile = " << confFile;

    QFile fname(confFile);
    if (fname.exists() &&
        fname.open(QIODevice::ReadOnly | QIODevice::Text)) {
        // DEBUG
        qCritical() << "      ... confFile is open";

        QString json = fname.readAll();
        if (! (*tariff)->ParseJson(*tariff, json.toStdString().c_str())) {
            delete *tariff;
            *tariff = nullptr;
            return calcState.set(CalcState::State::ERROR_PARSING_TARIFF);
        }
    } else {
        delete *tariff;
        *tariff = nullptr;
        return calcState.set(CalcState::State::ERROR_LOADING_TARIFF);
    }

    qCritical() << "init_tariff: Parsing tariff config (" << confFile << ")";

    return calcState;
}

void CALCULATE_LIBRARY_API free_tariff(parking_tariff_t *tariff) {
    if (tariff != nullptr) {
        delete tariff;
    }
}

CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
                                    parking_tariff_t *tariff,
                                    time_t start_parking_time, // in minutes
                                    time_t end_parking_time,   // in minutes
                                    struct price_t *price) {
    CalcState calcState;
    double minMin = tariff->PaymentOption.find(PaymentOption::Option1)->second.pop_min_time;
    double maxMin = tariff->PaymentOption.find(PaymentOption::Option1)->second.pop_max_time;

    if (minMin < 0 || maxMin < 0 || maxMin < minMin) {
        calcState.setDesc(QString("minMin=%1, maxMin=%2").arg(minMin, maxMin));
        return calcState.set(CalcState::State::WRONG_PARAM_VALUES);
    }

    int const duration = end_parking_time - start_parking_time;
    if (duration < 0) {
        calcState.setDesc(QString("end=%1, start=%2")
                            .arg(end_parking_time, start_parking_time));
        return calcState.set(CalcState::State::NEGATIVE_PARING_TIME);
    }
    if (duration > maxMin) {
        calcState.setDesc(QString("duration=%1, maxMin=%2").arg(duration, maxMin));
        return calcState.set(CalcState::State::ABOVE_MAX_PARKING_TIME);
    }
    if (duration < minMin) {
        calcState.setDesc(QString("duration=%1, minMin=%2").arg(duration, minMin));
        return calcState.set(CalcState::State::BELOW_MIN_PARKING_TIME);
    }
    if (duration == 0) {
        memset(price, 0x00, sizeof(*price));
        return calcState.set(CalcState::State::SUCCESS);
    }

    QDate const d(1970, 1, 1);
    QTime const t(0, 0, 0);
    QDateTime start(d, t, Qt::UTC);
    start = start.toLocalTime().addSecs(start_parking_time * 60);
    if (start.isValid()) {
        QString cs = start.toString(Qt::ISODate);
        double cost = calculator.GetCostFromDuration(
                        tariff, PaymentOption::Option1,
                        cs.toLocal8Bit().constData(),
                        duration, false, true);
        double minCost = tariff->PaymentOption.find(PaymentOption::Option1)->second.pop_min_price;
        if (cost < minCost) {
            calcState.setDesc(QString("minCost=%1, cost=%2").arg(minCost, cost));
            return calcState.set(CalcState::State::BELOW_MIN_PARKING_PRICE);
        }
        price->units = cost;
        price->netto = cost;
    } else {
        return calcState.set(CalcState::State::INVALID_START_DATE);
    }

    return calcState.set(CalcState::State::SUCCESS);
}

CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
                                            parking_tariff_t *tariff,
                                            time_t start_parking_time,
                                            double price,
                                            QString &duration) {
    CalcState calcState;
    QDate const d(1970, 1, 1);
    QTime const t(0, 0, 0);
    QDateTime start(d, t, Qt::UTC);
    start = start.toLocalTime().addSecs(start_parking_time * 60);
    if (start.isValid()) {
        QString cs = start.toString(Qt::ISODate);
        duration = calculator.GetDurationFromCost(tariff, PaymentOption::Option1,
                                                  cs.toLocal8Bit().constData(),
                                                  price, false, true).c_str();
    } else {
        return calcState.set(CalcState::State::INVALID_START_DATE);
    }

    return calcState.set(CalcState::State::SUCCESS);
}