/* Copyright (C) 2013
 * swift project Community / Contributors
 *
 * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
 * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
 * including this file, may be copied, modified, propagated, or distributed except according to the terms
 * contained in the LICENSE file.
 */

#include "blackmisc/aviation/selcal.h"
#include "blackmisc/pq/frequency.h"
#include "blackmisc/pq/units.h"

#include <QStringList>
#include <Qt>
#include <QtGlobal>

using namespace BlackMisc::PhysicalQuantities;

namespace BlackMisc
{
    namespace Aviation
    {
        QString CSelcal::convertToQString(bool /** i18n **/) const
        {
            return m_code;
        }

        QString CSelcal::unifyCode(const QString &selcalCandidate)
        {
            QString s;
            for (QChar c : selcalCandidate)
            {
                if (CSelcal::isValidCharacter(c)) { s += c;}
            }
            return CSelcal::isValidCode(s) ? s : QString("");
        }

        bool CSelcal::equalsString(const QString &code) const
        {
            if (code.isEmpty()) return false;
            return (m_code.compare(code, Qt::CaseInsensitive) == 0);
        }

        QList<CFrequency> CSelcal::getFrequencies() const
        {
            QList<CFrequency> f;
            if (!CSelcal::isValidCode(m_code)) return f;
            f.reserve(m_code.length());
            for (int pos = 0; pos < m_code.length(); pos++)
            {
                f.append(CSelcal::audioFrequencyEquivalent(m_code.at(pos)));
            }
            return f;
        }

        const QString &CSelcal::validCharacters()
        {
            static const QString valid = "ABCDEFGHJKLMPQRS";
            return valid;
        }

        bool CSelcal::isValidCharacter(QChar c)
        {
            return CSelcal::validCharacters().contains(c.toUpper());
        }

        bool CSelcal::isValidCode(const QString &code)
        {
            if (code.length() != 4) return false;
            int p1, p2, p3, p4;
            QString codeUpper = code.toUpper();
            if ((p1 = CSelcal::validCharacters().indexOf(codeUpper.at(0))) < 0) return false;
            if ((p2 = CSelcal::validCharacters().indexOf(codeUpper.at(1))) < 0) return false;
            if ((p3 = CSelcal::validCharacters().indexOf(codeUpper.at(2))) < 0) return false;
            if ((p4 = CSelcal::validCharacters().indexOf(codeUpper.at(3))) < 0) return false;
            if (p1 >= p2 || p3 >= p4) return false; // pair in alphabetical order
            if (p1 == p3 || p2 == p3 || p2 == p4 || p3 == p4) return false; // given letter can be used only once in a SELCAL code
            return true;
        }

        const PhysicalQuantities::CFrequency &CSelcal::audioFrequencyEquivalent(QChar c)
        {
            int pos = CSelcal::validCharacters().indexOf(c);
            Q_ASSERT(pos >= 0);
            Q_ASSERT(CSelcal::audioFrequencyEquivalents().size() > pos);
            return CSelcal::audioFrequencyEquivalents()[pos];
        }

        const QList<CFrequency> &CSelcal::audioFrequencyEquivalents()
        {
            static const QList<CFrequency> frequencies(
            {
                CFrequency(312.7, CFrequencyUnit::Hz()),
                CFrequency(346.7, CFrequencyUnit::Hz()),
                CFrequency(384.6, CFrequencyUnit::Hz()),
                CFrequency(426.6, CFrequencyUnit::Hz()),
                CFrequency(473.2, CFrequencyUnit::Hz()),
                CFrequency(524.8, CFrequencyUnit::Hz()),
                CFrequency(582.1, CFrequencyUnit::Hz()),
                CFrequency(645.7, CFrequencyUnit::Hz()),
                CFrequency(716.1, CFrequencyUnit::Hz()),
                CFrequency(794.3, CFrequencyUnit::Hz()),
                CFrequency(881.0, CFrequencyUnit::Hz()),
                CFrequency(977.2, CFrequencyUnit::Hz()),
                CFrequency(1083.9, CFrequencyUnit::Hz()),
                CFrequency(1202.3, CFrequencyUnit::Hz()),
                CFrequency(1333.5, CFrequencyUnit::Hz()),
                CFrequency(1479.1, CFrequencyUnit::Hz())
            });
            return frequencies;
        }

        namespace Private
        {
            QStringList selcalCodePairs()
            {
                QStringList pairs;
                for (int p1 = 0; p1 < (CSelcal::validCharacters().length() - 1); p1++)
                {
                    for (int p2 = p1 + 1; p2 < CSelcal::validCharacters().length(); p2++)
                    {
                        QString pair;
                        pair.append(CSelcal::validCharacters().at(p1)).append(CSelcal::validCharacters().at(p2));
                        pairs.append(pair);
                    }
                }
                return pairs;
            }
        }

        const QStringList &CSelcal::codePairs()
        {
            static const QStringList allCodePairs = Private::selcalCodePairs();
            return allCodePairs;
        }
    } // namespace
} // namespace