// Copyright (c) 2011-2021 The Limenka developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef LIMENKA_QT_LIMENKAUNITS_H
#define LIMENKA_QT_LIMENKAUNITS_H

#include <consensus/amount.h>

#include <QAbstractListModel>
#include <QDataStream>
#include <QFont>
#include <QString>

// U+2009 THIN SPACE = UTF-8 E2 80 89
#define REAL_THIN_SP_CP 0x2009
#define REAL_THIN_SP_UTF8 "\xE2\x80\x89"

// QMessageBox seems to have a bug whereby it doesn't display thin/hair spaces
// correctly.  Workaround is to display a space in a small font.  If you
// change this, please test that it doesn't cause the parent span to start
// wrapping.
#define HTML_HACK_SP "<span style='white-space: nowrap; font-size: 6pt'> </span>"

// Define THIN_SP_* variables to be our preferred type of thin space
#define THIN_SP_CP   REAL_THIN_SP_CP
#define THIN_SP_UTF8 REAL_THIN_SP_UTF8
#define THIN_SP_HTML HTML_HACK_SP

/** Limenka ticker and symbol constants. */
static constexpr const char* TICKER = "LMKA";
static constexpr const char* SYMBOL_WHOLE = "\xce\xbb";  // λ (lambda)
static constexpr const char* SYMBOL_ATTO = "\xce\x9b";   // Λ (capital lambda)

/** Limenka unit definitions. Encapsulates parsing and formatting
   and serves as list model for drop-down selection boxes.
*/
class LimenkaUnits: public QAbstractListModel
{
    Q_OBJECT

public:
    explicit LimenkaUnits(QObject *parent);

    /** Limenka units.
      @note Source: https://en.limenka.it/wiki/Units . Please add only sensible ones
     */
    enum class Unit {
        BTC,      // λ whole units (1.23456789 λ)
        mBTC,     // millisats (legacy, deprecated)
        uBTC,     // microsats (legacy, deprecated)
        SAT,      // satoshis (integer)
        ATTO,     // attosats (Λ) - only available post-activation
        bTBC,     // legacy
        sTBC,     // legacy
        TBC,      // legacy
    };
    Q_ENUM(Unit)

    /** Check if unit requires fork activation. */
    static bool requiresActivation(Unit unit) { return unit == Unit::ATTO; }

    enum class SeparatorStyle
    {
        NEVER,
        STANDARD,
        ALWAYS
    };

    //! @name Static API
    //! Unit conversion and formatting
    ///@{

    //! Get list of units, for drop-down box
    static QList<Unit> availableUnits();
    //! String for setting(s)
    static std::variant<qint8, QString> ToSetting(Unit unit);
    //! Convert setting(s) string to unit
    static Unit FromSetting(const QString&, Unit def);
    //! Long name
    static QString longName(Unit unit);
    //! Short name
    static QString shortName(Unit unit);
    //! Longer description
    static QString description(Unit unit);
    //! Number of Satoshis (1e-8) per unit
    static qint64 factor(Unit unit);
    //! Number of fractional places
    static int decimals(Unit unit);
    //! Radix
    static int radix(Unit unit);
    //! Number system
    static Unit numsys(Unit unit);
    //! Number of digits total in maximum value
    static qint64 max_digits(Unit unit);
    //! "Single step" amount, in satoshis
    static qint64 singlestep(Unit unit);
    //! Format as string
    static QString format(Unit unit, const CAmount& amount, bool plussign = false, SeparatorStyle separators = SeparatorStyle::STANDARD, bool justify = false);
    //! Format as string (with unit)
    static QString formatWithUnit(Unit unit, const CAmount& amount, bool plussign = false, SeparatorStyle separators = SeparatorStyle::STANDARD);
    //! Format as HTML string (with unit)
    static QString formatHtmlWithUnit(const QFont& font, Unit unit, const CAmount& amount, bool plussign = false, SeparatorStyle separators = SeparatorStyle::STANDARD);
    /** Format amount with sub-satoshi precision (dimmed trailing digits). */
    static QString formatWithSubSatoshi(const QFont& font, Unit unit, const CAmount& amount, uint64_t subSatoshi = 0, bool plussign = false, SeparatorStyle separators = SeparatorStyle::STANDARD);
    //! Format as string (with unit) of fixed length to preserve privacy, if it is set.
    static QString formatWithPrivacy(Unit unit, const CAmount& amount, SeparatorStyle separators, bool privacy);
    //! Parse string to coin amount
    static bool parse(Unit unit, const QString& value, CAmount* val_out);
    //! Gets title for amount column including current display unit if optionsModel reference available */
    static QString getAmountColumnTitle(Unit unit);
    ///@}

    //! @name AbstractListModel implementation
    //! List model for unit drop-down selection box.
    ///@{
    enum RoleIndex {
        /** Unit identifier */
        UnitRole = Qt::UserRole
    };
    int rowCount(const QModelIndex &parent) const override;
    QVariant data(const QModelIndex &index, int role) const override;
    ///@}

    static QString removeSpaces(QString text)
    {
        text.remove(' ');
        text.remove(QChar(THIN_SP_CP));
        return text;
    }

    //! Return maximum number of base units (Satoshis)
    static CAmount maxMoney();

private:
    QList<Unit> unitlist;
};
typedef LimenkaUnits::Unit LimenkaUnit;

QDataStream& operator<<(QDataStream& out, const LimenkaUnit& unit);
QDataStream& operator>>(QDataStream& in, LimenkaUnit& unit);

#endif // LIMENKA_QT_LIMENKAUNITS_H