/**
 * @file StationList.cpp
 * @brief Implementation of StationList class
 */

#include "StationList.h"
#include "DriftingDateTime.h"
#include "FrequencyList.h"
#include "JS8_Include/pimpl_impl.h"
#include "JS8_Main/Bands.h"
#include "Radio.h"

#include <QAbstractTableModel>
#include <QByteArray>
#include <QDataStream>
#include <QDebug>
#include <QDebugStateSaver>
#include <QMetaType>
#include <QMimeData>
#include <QObject>
#include <QString>
#include <QStringList>
#include <QTimeZone>
#include <QVector>

#include <algorithm>
#include <cmath>
#include <utility>

#if !defined(QT_NO_DEBUG_STREAM)
QDebug operator<<(QDebug debug, StationList::Station const &station) {
    QDebugStateSaver saver{debug};
    debug.nospace() << "Station(" << station.band_name_ << ", "
                    << station.frequency_ << ", " << station.switch_at_ << ", "
                    << station.switch_until_ << ", " << station.description_
                    << ')';
    return debug;
}
#endif

QDataStream &operator<<(QDataStream &os, StationList::Station const &station) {
    return os << station.band_name_ << station.frequency_ << station.switch_at_
              << station.switch_until_ << station.description_;
}

QDataStream &operator>>(QDataStream &is, StationList::Station &station) {
    is >> station.band_name_ >> station.frequency_ >> station.switch_at_ >>
        station.switch_until_ >> station.description_;

    // Set the timezones to UTC. Will be local time when read from the saved
    // configuration
    station.switch_at_.setTimeZone(QTimeZone::utc());
    station.switch_until_.setTimeZone(QTimeZone::utc());

    // Convert to UTC. This is necessary because the TimeSpec needs to be
    // Qt::UTC
    station.switch_at_ = station.switch_at_.toUTC();
    station.switch_until_ = station.switch_until_.toUTC();

    return is;
}

class StationList::impl final : public QAbstractTableModel {
  public:
    impl(Bands const *bands, Stations stations, QObject *parent)
        : QAbstractTableModel{parent}, bands_{bands}, stations_{stations} {}

    Stations station_list(Stations);
    QModelIndex add(Station);
    FrequencyDelta offset(Frequency) const;

    // Implement the QAbstractTableModel interface.
    int rowCount(QModelIndex const &parent = QModelIndex{}) const override;
    int columnCount(QModelIndex const &parent = QModelIndex{}) const override;
    Qt::ItemFlags flags(QModelIndex const & = QModelIndex{}) const override;
    QVariant data(QModelIndex const &, int role) const override;
    QVariant headerData(int section, Qt::Orientation,
                        int = Qt::DisplayRole) const override;
    bool setData(QModelIndex const &, QVariant const &value,
                 int role = Qt::EditRole) override;
    bool removeRows(int row, int count,
                    QModelIndex const &parent = QModelIndex{}) override;
    bool insertRows(int row, int count,
                    QModelIndex const &parent = QModelIndex{}) override;
    Qt::DropActions supportedDropActions() const override;
    QStringList mimeTypes() const override;
    QMimeData *mimeData(QModelIndexList const &) const override;
    bool dropMimeData(QMimeData const *, Qt::DropAction, int row, int column,
                      QModelIndex const &parent) override;

    // Helper method for band validation.
    QModelIndex first_matching_band(QString const &band_name) const {
        // find first exact match in bands
        auto matches = bands_->match(bands_->index(0, 0), Qt::DisplayRole,
                                     band_name, 1, Qt::MatchExactly);
        return matches.isEmpty() ? QModelIndex{} : matches.first();
    }

    static int constexpr num_columns{5};
    static auto constexpr mime_type = "application/wsjt.antenna-descriptions";

    Bands const *bands_;
    Stations stations_;
};

StationList::StationList(Bands const *bands, QObject *parent)
    : StationList{bands, {}, parent} {}

StationList::StationList(Bands const *bands, Stations stations, QObject *parent)
    : QSortFilterProxyModel{parent}, m_{bands, stations, parent} {
    setSourceModel(&*m_);
    setSortRole(SortRole);
}

StationList::~StationList() {}

auto StationList::station_list(Stations stations) -> Stations {
    return m_->station_list(stations);
}

auto StationList::station_list() const -> Stations const & {
    return m_->stations_;
}

QModelIndex StationList::add(Station s) { return mapFromSource(m_->add(s)); }

bool StationList::remove(Station s) {
    auto row = m_->stations_.indexOf(s);
    if (0 > row) {
        return false;
    }
    return removeRow(row);
}

namespace {
bool row_is_higher(QModelIndex const &lhs, QModelIndex const &rhs) {
    return lhs.row() > rhs.row();
}
} // namespace

bool StationList::removeDisjointRows(QModelIndexList rows) {
    bool result{true};

    // We must work with source model indexes because we don't want row
    // removes to invalidate model indexes we haven't yet processed. We
    // achieve that by processing them in decending row order.
    for (int r = 0; r < rows.size(); ++r) {
        rows[r] = mapToSource(rows[r]);
    }

    // reverse sort by row
    std::sort(rows.begin(), rows.end(), row_is_higher);
    for (auto index : std::as_const(rows)) {
        if (result && !m_->removeRow(index.row())) {
            result = false;
        }
    }

    return result;
}

auto StationList::impl::station_list(Stations stations) -> Stations {
    beginResetModel();
    std::swap(stations_, stations);
    endResetModel();
    return stations;
}

QModelIndex StationList::impl::add(Station s) {
    // Any band that isn't in the list may be added
    if (!stations_.contains(s)) {
        auto row = stations_.size();

        beginInsertRows(QModelIndex{}, row, row);
        stations_.append(s);
        endInsertRows();

        return index(row, 0);
    }

    return QModelIndex{};
}

#if 0
auto StationList::impl::offset (Frequency f) const -> FrequencyDelta
{
  // Lookup band for frequency
  auto const& band = bands_->find (f);
  if (!band.isEmpty ())
    {
      // Lookup station for band
      for (int i = 0; i < stations_.size (); ++i)
        {
          if (stations_[i].band_name_ == band)
            {
              return stations_[i].frequency_;
            }
        }
    }
  return 0;                     // no offset
}
#endif

int StationList::impl::rowCount(QModelIndex const &parent) const {
    return parent.isValid() ? 0 : stations_.size();
}

int StationList::impl::columnCount(QModelIndex const &parent) const {
    return parent.isValid() ? 0 : num_columns;
}

Qt::ItemFlags StationList::impl::flags(QModelIndex const &index) const {
    auto result = QAbstractTableModel::flags(index);

    auto row = index.row();
    auto column = index.column();

    if (index.isValid() && row < stations_.size() && column < num_columns) {
        if (band_column == column) {
            result |= Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled;

        } else if (description_column == column) {
            result |= Qt::ItemIsEditable | Qt::ItemIsDragEnabled |
                      Qt::ItemIsDropEnabled;
        } else {
            result |= Qt::ItemIsEditable | Qt::ItemIsDropEnabled;
        }
    } else {
        result |= Qt::ItemIsDropEnabled;
    }

    return result;
}

QVariant StationList::impl::data(QModelIndex const &index, int role) const {
    QVariant item;

    auto row = index.row();
    auto column = index.column();

    if (index.isValid() && row < stations_.size()) {
        switch (column) {
        case band_column:
            switch (role) {
            case SortRole: {
                // Lookup band.
                auto band_index =
                    first_matching_band(stations_.at(row).band_name_);
                // Use the sort role value of the band.
                item = band_index.data(Bands::SortRole);
            } break;

            case Qt::DisplayRole:
            case Qt::EditRole:
            case Qt::AccessibleTextRole:
                item = stations_.at(row).band_name_;
                break;

            case Qt::ToolTipRole:
            case Qt::AccessibleDescriptionRole:
                item = tr("Band name");
                break;

            case Qt::TextAlignmentRole:
                item = Qt::AlignCenter;
                break;
            }
            break;

        case frequency_column: {
            auto frequency_offset = stations_.at(row).frequency_;
            switch (role) {
            case SortRole:
            case Qt::EditRole:
            case Qt::AccessibleTextRole:
                item = frequency_offset;
                break;

            case Qt::DisplayRole:
                item = Radio::pretty_frequency_MHz_string(frequency_offset) +
                       " MHz";
                break;

            case Qt::ToolTipRole:
            case Qt::AccessibleDescriptionRole:
                item = tr("Frequency");
                break;

            case Qt::TextAlignmentRole:
                item = static_cast<Qt::Alignment::Int>(Qt::AlignRight |
                                                       Qt::AlignVCenter);
                break;
            }
        } break;

        case switch_at_column:
            switch (role) {
            case SortRole:
            case Qt::EditRole:
            case Qt::DisplayRole:
            case Qt::AccessibleTextRole:
                item = stations_.at(row).switch_at_.time().toString("hh:mm");
                break;

            case Qt::ToolTipRole:
            case Qt::AccessibleDescriptionRole:
                item = tr("Switch at this time");
                break;

            case Qt::TextAlignmentRole:
                item = Qt::AlignCenter;
                break;
            }
            break;

        case switch_until_column:
            switch (role) {
            case SortRole:
            case Qt::EditRole:
            case Qt::DisplayRole:
            case Qt::AccessibleTextRole:
                item = stations_.at(row).switch_until_.time().toString("hh:mm");
                break;

            case Qt::ToolTipRole:
            case Qt::AccessibleDescriptionRole:
                item = tr("Switch until this time\nFrequency will not return "
                          "at end time.\nEnter a new line to return to "
                          "original or other frequency.");
                break;

            case Qt::TextAlignmentRole:
                item = Qt::AlignCenter;
                break;
            }
            break;

        case description_column:
            switch (role) {
            case SortRole:
            case Qt::EditRole:
            case Qt::DisplayRole:
            case Qt::AccessibleTextRole:
                item = stations_.at(row).description_;
                break;

            case Qt::ToolTipRole:
            case Qt::AccessibleDescriptionRole:
                item = tr("Antenna description");
                break;

            case Qt::TextAlignmentRole:
                item = static_cast<Qt::Alignment::Int>(Qt::AlignLeft |
                                                       Qt::AlignVCenter);
                break;
            }
            break;
        }
    }

    return item;
}

QVariant StationList::impl::headerData(int section, Qt::Orientation orientation,
                                       int role) const {
    QVariant header;

    if (Qt::DisplayRole == role && Qt::Horizontal == orientation) {
        switch (section) {
        case band_column:
            header = tr("Band");
            break;
        case frequency_column:
            header = tr("Freq. (MHz)");
            break;
        case switch_at_column:
            header = tr("Switch at (UTC)");
            break;
        case switch_until_column:
            header = tr("Until (UTC)");
            break;
        case description_column:
            header = tr("Description");
            break;
        }
    } else {
        header = QAbstractTableModel::headerData(section, orientation, role);
    }

    return header;
}

bool StationList::impl::setData(QModelIndex const &model_index,
                                QVariant const &value, int role) {
    bool changed{false};

    auto row = model_index.row();
    auto size = stations_.size();
    if (model_index.isValid() && Qt::EditRole == role && row < size) {
        QVector<int> roles;
        roles << role;

        switch (model_index.column()) {
        case band_column: {
            // Check if band name is valid.
            auto band_index = first_matching_band(value.toString());
            if (band_index.isValid()) {
                stations_[row].band_name_ = band_index.data().toString();
                Q_EMIT dataChanged(model_index, model_index, roles);
                changed = true;
            }
        } break;

        case frequency_column: {
            if (value.canConvert<Frequency>()) {
                Frequency offset{qvariant_cast<Radio::Frequency>(value)};

                if (offset == 0) {
                    Frequency l;
                    Frequency h;
                    if (bands_->findFreq(stations_[row].band_name_, &l, &h)) {
                        offset = l;
                    }
                }

                if (offset != stations_[row].frequency_) {
                    stations_[row].frequency_ = offset;
                    Q_EMIT dataChanged(model_index, model_index, roles);

                    auto band = bands_->find(offset);
                    if (band != stations_[row].band_name_) {
                        stations_[row].band_name_ = band;
                        auto band_index = model_index.model()->index(
                            row, band_column, model_index);
                        Q_EMIT dataChanged(band_index, band_index, roles);
                    }
                    changed = true;
                }
            }
        } break;
        case switch_at_column: {
            QString s = value.toString();
            if (s.length() < 5) {
                s = QString("0").repeated(5 - s.length()) + s;
            }
            auto t = QTime::fromString(s);
            auto at = QDateTime(QDate(2000, 1, 1), t, QTimeZone::utc());
            auto until = stations_[row].switch_until_;
            stations_[row].switch_at_ = at;
            stations_[row].switch_until_ = until;

            Q_EMIT dataChanged(model_index, model_index, roles);

            auto switch_until_index = model_index.model()->index(
                row, switch_until_column, model_index);
            Q_EMIT dataChanged(switch_until_index, switch_until_index, roles);

            changed = true;
            break;
        }
        case switch_until_column: {
            QString s = value.toString();
            if (s.length() < 5) {
                s = QString("0").repeated(5 - s.length()) + s;
            }
            auto t = QTime::fromString(s);
            auto until = QDateTime(QDate(2000, 1, 1), t, QTimeZone::utc());
            auto at = stations_[row].switch_at_;
            stations_[row].switch_at_ = at;
            stations_[row].switch_until_ = until;

            Q_EMIT dataChanged(model_index, model_index, roles);

            auto switch_at_index =
                model_index.model()->index(row, switch_at_column, model_index);
            Q_EMIT dataChanged(switch_at_index, switch_at_index, roles);

            changed = true;
            break;
        }
        case description_column:
            stations_[row].description_ = value.toString();
            Q_EMIT dataChanged(model_index, model_index, roles);
            changed = true;
            break;
        }
    }

    return changed;
}

bool StationList::impl::removeRows(int row, int count,
                                   QModelIndex const &parent) {
    if (0 < count && (row + count) <= rowCount(parent)) {
        beginRemoveRows(parent, row, row + count - 1);
        for (auto r = 0; r < count; ++r) {
            stations_.removeAt(row);
        }
        endRemoveRows();
        return true;
    }

    return false;
}

bool StationList::impl::insertRows(int row, int count,
                                   QModelIndex const &parent) {
    if (0 < count) {
        beginInsertRows(parent, row, row + count - 1);
        for (auto r = 0; r < count; ++r) {
            stations_.insert(row, Station());
        }
        endInsertRows();
        return true;
    }

    return false;
}

Qt::DropActions StationList::impl::supportedDropActions() const {
    return Qt::CopyAction | Qt::MoveAction;
}

QStringList StationList::impl::mimeTypes() const {
    QStringList types;
    types << mime_type;
    types << "application/wsjt.Frequencies";
    return types;
}

QMimeData *StationList::impl::mimeData(QModelIndexList const &items) const {
    QMimeData *mime_data = new QMimeData{};
    QByteArray encoded_data;
    QDataStream stream{&encoded_data, QIODevice::WriteOnly};

    for (auto const &item : std::as_const(items)) {
        if (item.isValid()) {
            stream << QString{data(item, Qt::DisplayRole).toString()};
        }
    }

    mime_data->setData(mime_type, encoded_data);
    return mime_data;
}

bool StationList::impl::dropMimeData(QMimeData const *data,
                                     Qt::DropAction action, int /* row */,
                                     int /* column */,
                                     QModelIndex const &parent) {
    if (Qt::IgnoreAction == action) {
        return true;
    }
    if (parent.isValid() && description_column == parent.column() &&
        data->hasFormat(mime_type)) {
        QByteArray encoded_data{data->data(mime_type)};
        QDataStream stream{&encoded_data, QIODevice::ReadOnly};
        auto dest_index = parent;
        while (!stream.atEnd()) {
            QString text;
            stream >> text;
            setData(dest_index, text);
            dest_index =
                index(dest_index.row() + 1, dest_index.column(), QModelIndex{});
        }
        return true;
    } else if (data->hasFormat("application/wsjt.Frequencies")) {
        QByteArray encoded_data{data->data("application/wsjt.Frequencies")};
        QDataStream stream{&encoded_data, QIODevice::ReadOnly};
        while (!stream.atEnd()) {
            FrequencyList_v3::Item item;
            stream >> item;
            auto const &band = bands_->find(item.frequency_);
            if (stations_.cend() ==
                std::find_if(stations_.cbegin(), stations_.cend(),
                             [&band](Station const &s) {
                                 return s.band_name_ == band;
                             })) {
                // not found so add it
                add(Station{band, 0, DriftingDateTime::currentDateTimeUtc(),
                            DriftingDateTime::currentDateTimeUtc(), QString{}});
            }
        }
        return true;
    }
    return false;
}