#include "eetv4adapter.h"

#include <QRegularExpression>

namespace
{
void setError(QString *error, const QString &message)
{
    if (error != nullptr)
    {
        *error = message;
    }
}

QDateTime withExplicitOffset(const QDateTime &dateTime)
{
    if (!dateTime.isValid())
    {
        return {};
    }

    return dateTime.timeSpec() == Qt::LocalTime
        ? dateTime.toOffsetFromUtc(dateTime.offsetFromUtc())
        : dateTime;
}
}

bool EetV4ShopConfig::validate(QString *error) const
{
    if (!endpoint.isValid() || endpoint.scheme().compare(QStringLiteral("https"),
                                                         Qt::CaseInsensitive) != 0)
    {
        setError(error, QStringLiteral("EET v4 endpoint must be a valid HTTPS URL."));
        return false;
    }
    if (taxpayerEic.isEmpty())
    {
        setError(error, QStringLiteral("EET v4 taxpayer EIC must not be empty."));
        return false;
    }
    if (unitId < 1)
    {
        setError(error, QStringLiteral("EET v4 unit ID must be positive."));
        return false;
    }
    if (cashRegisterId.isEmpty())
    {
        setError(error, QStringLiteral("EET v4 cash-register ID must not be empty."));
        return false;
    }
    if (timeoutMilliseconds < 1)
    {
        setError(error, QStringLiteral("EET v4 timeout must be positive."));
        return false;
    }
    return true;
}

bool EetV4ShopAdapter::amountText(const QDecDouble &amount,
                                  QString *text,
                                  QString *error)
{
    QString value = QString::fromLatin1(amount.toString());
    if (value.contains(QRegularExpression(QStringLiteral("[eE]"))))
    {
        setError(error, QStringLiteral("Voucher amount must not use exponential notation."));
        return false;
    }

    if (!value.contains(QLatin1Char('.')))
    {
        value += QStringLiteral(".00");
    }
    else
    {
        const int decimals = value.size() - value.indexOf(QLatin1Char('.')) - 1;
        if (decimals > 2)
        {
            setError(error, QStringLiteral("Voucher amount has more than two decimal places."));
            return false;
        }
        value = value.leftJustified(value.size() + (2 - decimals), QLatin1Char('0'));
    }

    EetV4Amount parsed;
    if (!EetV4Amount::fromString(value, &parsed, error))
    {
        return false;
    }

    if (text != nullptr)
    {
        *text = parsed.toString();
    }
    return true;
}

bool EetV4ShopAdapter::createRequest(const Voucher &voucher,
                                     const EetV4ShopConfig &config,
                                     EetV4SaleRequest *request,
                                     QString *error)
{
    if (request == nullptr)
    {
        setError(error, QStringLiteral("EET v4 request output must not be null."));
        return false;
    }
    if (!config.validate(error))
    {
        return false;
    }

    const QDateTime saleAt = withExplicitOffset(voucher.payDateTime());
    if (!saleAt.isValid())
    {
        setError(error, QStringLiteral("Voucher payment date must be valid."));
        return false;
    }

    QString totalText;
    if (!amountText(voucher.totalPrice(), &totalText, error))
    {
        return false;
    }

    EetV4Amount total;
    if (!EetV4Amount::fromString(totalText, &total, error))
    {
        return false;
    }

    EetV4SaleRequest result;
    result.sentAt = withExplicitOffset(QDateTime::currentDateTime());
    result.saleAt = saleAt;
    result.firstSubmission = voucher.eetStatus() == Voucher::EET_FOR_SEND;
    result.verificationMode = config.verificationMode;
    result.taxpayerEic = config.taxpayerEic;
    result.unitId = config.unitId;
    result.cashRegisterId = config.cashRegisterId;
    result.receiptNumber = voucher.numSer();
    result.totalSale = total;

    QStringList validationErrors;
    if (!result.validate(&validationErrors))
    {
        setError(error, validationErrors.join(QStringLiteral("; ")));
        return false;
    }

    *request = result;
    return true;
}