#include "card_database_model.h"

#include <QMap>
#include <libcockatrice/card/database/card_database.h>

#define CARDDBMODEL_COLUMNS 6

CardDatabaseModel::CardDatabaseModel(CardDatabase *_db, bool _showOnlyCardsFromEnabledSets, QObject *parent)
    : QAbstractListModel(parent), db(_db), showOnlyCardsFromEnabledSets(_showOnlyCardsFromEnabledSets)
{
    connect(db, &CardDatabase::cardAdded, this, &CardDatabaseModel::cardAdded);
    connect(db, &CardDatabase::cardRemoved, this, &CardDatabaseModel::cardRemoved);
    connect(db, &CardDatabase::cardDatabaseEnabledSetsChanged, this,
            &CardDatabaseModel::cardDatabaseEnabledSetsChanged);
    connect(db, &CardDatabase::cardDatabaseReset, this, &CardDatabaseModel::resetCardList);

    cardDatabaseEnabledSetsChanged();
}

CardDatabaseModel::~CardDatabaseModel() = default;

int CardDatabaseModel::rowCount(const QModelIndex & /*parent*/) const
{
    return cardList.size();
}

int CardDatabaseModel::columnCount(const QModelIndex & /*parent*/) const
{
    return CARDDBMODEL_COLUMNS;
}

QVariant CardDatabaseModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid() || index.row() >= cardList.size() || index.column() >= CARDDBMODEL_COLUMNS ||
        (role != Qt::DisplayRole && role != SortRole)) {
        return QVariant();
    }

    CardInfoPtr card = cardList.at(index.row());
    switch (index.column()) {
        case NameColumn:
            return card->getName();
        case SetListColumn:
            return card->getSetsNames();
        case ManaCostColumn:
            return role == SortRole ? QString("%1%2").arg(card->getCmc(), 4, QChar('0')).arg(card->getManaCost())
                                    : card->getManaCost();
        case CardTypeColumn:
            return card->getCardType();
        case PTColumn:
            return card->getPowTough();
        case ColorColumn:
            return card->getColors();
        default:
            return QVariant();
    }
}

QVariant CardDatabaseModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    if (role != Qt::DisplayRole) {
        return QVariant();
    }
    if (orientation != Qt::Horizontal) {
        return QVariant();
    }
    switch (section) {
        case NameColumn:
            return QString(tr("Name"));
        case SetListColumn:
            return QString(tr("Sets"));
        case ManaCostColumn:
            return QString(tr("Mana cost"));
        case CardTypeColumn:
            return QString(tr("Card type"));
        case PTColumn:
            return QString(tr("P/T"));
        case ColorColumn:
            return QString(tr("Color(s)"));
        default:
            return QVariant();
    }
}

void CardDatabaseModel::cardInfoChanged(const CardInfoPtr &card)
{
    const int row = cardList.indexOf(card);
    if (row == -1) {
        return;
    }

    emit dataChanged(index(row, 0), index(row, CARDDBMODEL_COLUMNS - 1));
}

bool CardDatabaseModel::checkCardHasAtLeastOneEnabledSet(const CardInfoPtr &card) const
{
    if (!showOnlyCardsFromEnabledSets) {
        return true;
    }

    for (const auto &printings : card->getSets()) {
        for (const auto &printing : printings) {
            if (printing.getSet()->getEnabled()) {
                return true;
            }
        }
    }

    return false;
}

void CardDatabaseModel::cardDatabaseEnabledSetsChanged()
{
    // Build the new card list in a single pass.
    QList<CardInfoPtr> newCardList;
    newCardList.reserve(cardList.size());
    for (const CardInfoPtr &card : cardList) {
        if (checkCardHasAtLeastOneEnabledSet(card)) {
            newCardList.append(card);
        }
    }
    for (const CardInfoPtr &card : db->getCardList()) {
        if (!cardListSet.contains(card) && checkCardHasAtLeastOneEnabledSet(card)) {
            newCardList.append(card);
        }
    }

    if (newCardList == cardList) {
        return;
    }

    // Rebuild the whole list inside a single model reset instead of emitting
    // per-card insert/remove notifications. With tens of thousands of cards the
    // per-card path is the dominant cost of constructing a CardDatabaseModel.
    QSet<CardInfoPtr> oldCardListSet = cardListSet;
    QSet<CardInfoPtr> newCardListSet(newCardList.begin(), newCardList.end());

    beginResetModel();

    // Disconnect cards that are no longer shown.
    for (const CardInfoPtr &card : cardList) {
        if (!newCardListSet.contains(card)) {
            disconnect(card.data(), nullptr, this, nullptr);
        }
    }

    cardList = newCardList;
    cardListSet = newCardListSet;

    // Connect cards that are now shown for the first time.
    for (const CardInfoPtr &card : cardList) {
        if (!oldCardListSet.contains(card)) {
            connect(card.data(), &CardInfo::cardInfoChanged, this, &CardDatabaseModel::cardInfoChanged);
        }
    }

    endResetModel();
}

void CardDatabaseModel::cardAdded(const CardInfoPtr &card)
{
    if (checkCardHasAtLeastOneEnabledSet(card)) {
        // add the card if it's present in at least one enabled set
        beginInsertRows(QModelIndex(), cardList.size(), cardList.size());
        cardList.append(card);
        cardListSet.insert(card);
        connect(card.data(), &CardInfo::cardInfoChanged, this, &CardDatabaseModel::cardInfoChanged);
        endInsertRows();
    }
}

void CardDatabaseModel::cardRemoved(CardInfoPtr card)
{
    const int row = cardList.indexOf(card);
    if (row == -1) {
        return;
    }

    beginRemoveRows(QModelIndex(), row, row);
    disconnect(card.data(), nullptr, this, nullptr);
    cardListSet.remove(card);
    card.clear();
    cardList.removeAt(row);
    endRemoveRows();
}

void CardDatabaseModel::resetCardList()
{
    beginResetModel();
    cardList.clear();
    cardListSet.clear();
    for (const CardInfoPtr &card : db->getCardList()) {
        if (checkCardHasAtLeastOneEnabledSet(card)) {
            cardList.append(card);
            cardListSet.insert(card);
            connect(card.data(), &CardInfo::cardInfoChanged, this, &CardDatabaseModel::cardInfoChanged);
        }
    }
    endResetModel();
}