// SPDX-FileCopyrightText: Copyright (C) 2013 swift Project Community / Contributors
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-swift-pilot-client-1

// Drag and drop docu:
// http://doc.qt.io/qt-5/model-view-programming.html#using-drag-and-drop-with-item-views

#include "gui/models/listmodelbase.h"

#include <QJsonDocument>
#include <QList>
#include <QMimeData>

#include "gui/guiutility.h"
#include "gui/models/allmodelcontainers.h"
#include "misc/variant.h"
#include "misc/worker.h"

using namespace swift::misc;
using namespace swift::misc::aviation;

namespace swift::gui::models
{
    template <typename T, bool UseCompare>
    CListModelBase<T, UseCompare>::CListModelBase(const QString &translationContext, QObject *parent)
        : CListModelBaseNonTemplate(translationContext, parent)
    {}

    template <typename T, bool UseCompare>
    int CListModelBase<T, UseCompare>::rowCount(const QModelIndex &parentIndex) const
    {
        Q_UNUSED(parentIndex)
        return this->containerOrFilteredContainer().size();
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::canDropMimeData(const QMimeData *data, Qt::DropAction action, int row,
                                                        int column, const QModelIndex &parent) const
    {
        Q_UNUSED(action)
        Q_UNUSED(row)
        Q_UNUSED(column)
        Q_UNUSED(parent)
        if (!this->isDropAllowed()) { return false; }
        if (!this->acceptDrop(data)) { return false; }
        return true;
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::dropMimeData(const QMimeData *mimeData, Qt::DropAction action, int row,
                                                     int column, const QModelIndex &parent)
    {
        Q_UNUSED(row)
        Q_UNUSED(column)

        if (!this->isOrderable() || !this->acceptDrop(mimeData)) { return false; }
        const CVariant valueVariant(this->toCVariant(mimeData));
        if (valueVariant.isValid())
        {
            if (action == Qt::MoveAction)
            {
                const ContainerType container(valueVariant.value<ContainerType>());
                if (container.isEmpty()) { return false; }
                const int position = parent.row();
                this->moveItems(container, position);
            }
        }
        return true;
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::isValidIndex(const QModelIndex &index) const
    {
        if (!index.isValid()) { return false; }
        return (index.row() >= 0 && index.row() < this->rowCount(index) && index.column() >= 0 &&
                index.column() < this->columnCount(index));
    }

    template <typename T, bool UseCompare>
    QVariant CListModelBase<T, UseCompare>::data(const QModelIndex &index, int role) const
    {
        // check / init
        if (!this->isValidIndex(index)) { return QVariant(); }

        if (role == Qt::BackgroundRole) { return CListModelBaseNonTemplate::data(index, role); }

        // Formatter
        const CDefaultFormatter *formatter = m_columns.getFormatter(index);
        Q_ASSERT_X(formatter, Q_FUNC_INFO, "Missing formatter");

        // Upfront checking avoids unnecessary data fetching
        if (!formatter || !formatter->supportsRole(role)) { return CListModelBaseNonTemplate::data(index, role); }

        // index, updront checking
        const int row = index.row();
        const int col = index.column();
        const CPropertyIndex propertyIndex = this->columnToPropertyIndex(col);
        const int propertyIndexFront = propertyIndex.frontCasted<int>();

        // special cases
        switch (propertyIndexFront)
        {
        case CPropertyIndexRef::GlobalIndexLineNumber: return QVariant::fromValue(row + 1);
        case CPropertyIndexRef::GlobalIndexEmpty: return {};
        default: break; // continue here
        }

        // Formatted data
        const ObjectType obj = this->containerOrFilteredContainer()[row];
        return formatter->data(role, obj.propertyByIndex(propertyIndex)).getQVariant();
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::setData(const QModelIndex &index, const QVariant &value, int role)
    {
        Qt::ItemDataRole dataRole = static_cast<Qt::ItemDataRole>(role);
        if (!(dataRole == Qt::UserRole || dataRole == Qt::EditRole)) { return false; }

        // check / init
        if (!this->isValidIndex(index)) { return false; }
        if (!m_columns.isEditable(index)) { return false; }
        const CDefaultFormatter *formatter = m_columns.getFormatter(index);
        Q_ASSERT(formatter);
        if (!formatter) { return false; }

        ObjectType obj = m_container[index.row()];
        const ObjectType currentObject(obj);
        const CPropertyIndex propertyIndex = this->columnToPropertyIndex(index.column());
        obj.setPropertyByIndex(propertyIndex, value);

        if (obj != currentObject)
        {
            const QModelIndex topLeft = index.sibling(index.row(), 0);
            const QModelIndex bottomRight = index.sibling(index.row(), this->columnCount() - 1);
            m_container[index.row()] = obj;
            const CVariant co = CVariant::fromValue(obj);
            emit objectChanged(co, propertyIndex);
            emit this->dataChanged(topLeft, bottomRight);
            this->updateFilteredContainer();
            return true;
        }
        return false;
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::setInContainer(const QModelIndex &index, const ObjectType &obj)
    {
        if (!index.isValid()) { return false; }
        const int row = index.row();
        if (row < 0 || row >= this->container().size()) { return false; }
        m_container[row] = obj;
        return true;
    }

    template <typename T, bool UseCompare>
    int CListModelBase<T, UseCompare>::update(const ContainerType &container, bool sort)
    {
        if (m_modelDestroyed) { return 0; }

        // Keep sorting out of begin/end reset model
        ContainerType sortedContainer;
        ContainerType selection;
        if (m_selectionModel) { selection = m_selectionModel->selectedObjects(); }
        const int oldSize = m_container.size();
        const bool performSort = sort && container.size() > 1 && this->hasValidSortColumn();
        if (performSort)
        {
            const int sortColumn = this->getSortColumn();
            sortedContainer = this->sortContainerByColumn(container, sortColumn, m_sortOrder);
        }

        this->beginResetModel();
        m_container = performSort ? sortedContainer : container;
        this->updateFilteredContainer(); // use sorted container for filtered if applicable
        this->endResetModel();

        // reselect if implemented in specialized view
        if (!selection.isEmpty()) { m_selectionModel->selectObjects(selection); }

        const int newSize = m_container.size();
        Q_UNUSED(oldSize)

        // I have to update even with same size because I cannot tell what/if data are changed
        this->emitModelDataChanged();
        return newSize;
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::update(const QModelIndex &index, const ObjectType &object)
    {
        if (m_modelDestroyed) { return; }
        if (index.row() >= m_container.size()) { return; }
        m_container[index.row()] = object;

        const QModelIndex i1 = index.sibling(index.row(), 0);
        const QModelIndex i2 = index.sibling(index.row(), this->columnCount(index) - 1);
        emit this->dataChanged(i1, i2); // which range has been changed
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::update(int rowIndex, const ObjectType &object)
    {
        this->update(this->index(rowIndex, 0), object);
    }

    template <typename T, bool UseCompare>
    CWorker *CListModelBase<T, UseCompare>::updateAsync(const ContainerType &container, bool sort)
    {
        Q_UNUSED(sort)
        if (m_modelDestroyed) { return nullptr; }
        const auto sortColumn = this->getSortColumn();
        const auto sortOrder = this->getSortOrder();
        CWorker *worker = CWorker::fromTask(this, "ModelSort", [this, container, sortColumn, sortOrder]() {
            return this->sortContainerByColumn(container, sortColumn, sortOrder);
        });
        worker->thenWithResult<ContainerType>(this, [this](const ContainerType &sortedContainer) {
            if (m_modelDestroyed) { return; }
            this->update(sortedContainer, false);
        });
        worker->then(this, &CListModelBase::asyncUpdateFinished);
        return worker;
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::updateContainerMaybeAsync(const ContainerType &container, bool sort)
    {
        if (m_modelDestroyed) { return; }
        if (container.size() > asyncThreshold && sort)
        {
            // larger container with sorting
            this->updateAsync(container, sort);
        }
        else { this->update(container, sort); }
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::hasFilter() const
    {
        const bool f = m_filter && m_filter->isValid();
        return f;
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::removeFilter()
    {
        if (!this->hasFilter()) { return; }
        m_filter.reset(nullptr);
        this->beginResetModel();
        this->updateFilteredContainer();
        this->endResetModel();
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::takeFilterOwnership(std::unique_ptr<IModelFilter<ContainerType>> &filter)
    {
        ContainerType selection;
        if (m_selectionModel) { selection = m_selectionModel->selectedObjects(); }

        if (!filter)
        {
            this->removeFilter(); // clear filter
            return;
        }
        if (filter->isValid())
        {
            m_filter = std::move(filter);
            this->beginResetModel();
            this->updateFilteredContainer();
            this->endResetModel();
            this->emitModelDataChanged();
        }
        else
        {
            // invalid filter, so clear filter
            this->removeFilter();
        }

        // reselect if implemented in specialized views
        if (!selection.isEmpty()) { m_selectionModel->selectObjects(selection); }
    }

    template <typename T, bool UseCompare>
    const typename CListModelBase<T, UseCompare>::ObjectType &
    CListModelBase<T, UseCompare>::at(const QModelIndex &index) const
    {
        if (index.row() < 0 || index.row() >= this->rowCount())
        {
            static const ObjectType def {}; // default object
            return def;
        }
        else { return this->containerOrFilteredContainer()[index.row()]; }
    }

    template <typename T, bool UseCompare>
    const typename CListModelBase<T, UseCompare>::ContainerType &CListModelBase<T, UseCompare>::container() const
    {
        return m_container;
    }

    template <typename T, bool UseCompare>
    const typename CListModelBase<T, UseCompare>::ContainerType &
    CListModelBase<T, UseCompare>::containerFiltered() const
    {
        return m_containerFiltered;
    }

    template <typename T, bool UseCompare>
    const typename CListModelBase<T, UseCompare>::ContainerType &
    CListModelBase<T, UseCompare>::containerOrFilteredContainer(bool *filtered) const
    {
        if (this->hasFilter())
        {
            if (filtered) { *filtered = true; }
            return m_containerFiltered;
        }
        else
        {
            if (filtered) { *filtered = false; }
            return m_container;
        }
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::push_back(const ObjectType &object)
    {
        beginInsertRows(QModelIndex(), m_container.size(), m_container.size());
        m_container.push_back(object);
        endInsertRows();

        if (this->hasFilter())
        {
            // this will change the whole used model as we cannot predict the filter
            this->beginResetModel();
            this->updateFilteredContainer();
            this->endResetModel();
        }
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::push_back(const ContainerType &container)
    {
        beginInsertRows(QModelIndex(), m_container.size(), m_container.size());
        m_container.push_back(container);
        endInsertRows();

        if (this->hasFilter())
        {
            // this will change the whole used model as we cannot predict the filter
            this->beginResetModel();
            this->updateFilteredContainer();
            this->endResetModel();
        }
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::insert(const ObjectType &object)
    {
        beginInsertRows(QModelIndex(), 0, 0);
        m_container.insert(m_container.begin(), object);
        endInsertRows();

        if (this->hasFilter())
        {
            // this will change the whole used model as we cannot predict the filter
            this->beginResetModel();
            this->updateFilteredContainer();
            this->endResetModel();
        }
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::insert(const ContainerType &container)
    {
        if (container.isEmpty()) { return; }
        beginInsertRows(QModelIndex(), 0, 0);
        m_container.push_back(container);
        endInsertRows();

        if (this->hasFilter())
        {
            // this will change the whole used model as we cannot predict the filter
            this->beginResetModel();
            this->updateFilteredContainer();
            this->endResetModel();
        }
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::remove(const ObjectType &object)
    {
        const int oldSize = m_container.size();
        beginRemoveRows(QModelIndex(), 0, 0);
        m_container.remove(object);
        endRemoveRows();
        const int newSize = m_container.size();
        if (oldSize != newSize)
        {
            this->emitModelDataChanged();
            if (this->hasFilter())
            {
                this->beginResetModel();
                this->updateFilteredContainer();
                this->endResetModel();
            }
        }
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::clear()
    {
        beginResetModel();
        m_container.clear();
        m_containerFiltered.clear();
        endResetModel();
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::isEmpty() const
    {
        return m_container.isEmpty();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::updateFilteredContainer()
    {
        if (this->hasFilter()) { m_containerFiltered = m_filter->filter(m_container); }
        else { m_containerFiltered.clear(); }
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::emitModelDataChanged()
    {
        const int n = this->containerOrFilteredContainer().size();
        emit this->modelDataChanged(n, this->hasFilter());
        emit this->changed();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::onDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight,
                                                      const QVector<int> &roles)
    {
        // underlying base class changed
        Q_UNUSED(topLeft)
        Q_UNUSED(bottomRight)
        Q_UNUSED(roles)
        this->emitModelDataChanged();
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::onChangedDigest()
    {
        const int n = this->containerOrFilteredContainer().size();
        emit this->changedDigest();
        emit this->modelDataChangedDigest(n, this->hasFilter());
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::moveItems(const ContainerType &items, int position)
    {
        // overridden in specialized class
        Q_UNUSED(items)
        Q_UNUSED(position)
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::sort()
    {
        this->sort(this->getSortColumn(), this->getSortOrder());
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::resort()
    {
        // sort the values
        this->updateContainerMaybeAsync(m_container, true);
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::sort(int column, Qt::SortOrder order)
    {
        if (column == m_sortColumn && order == m_sortOrder) { return; }

        // new order
        m_sortColumn = column;
        m_sortOrder = order;
        if (m_container.size() < 2)
        {
            return; // nothing to do
        }

        // sort the values
        this->updateContainerMaybeAsync(m_container, true);
    }

    template <typename T, bool UseCompare>
    void CListModelBase<T, UseCompare>::truncate(int maxNumber, bool forceSort)
    {
        if (this->rowCount() <= maxNumber) { return; }
        if (forceSort)
        {
            this->sort(); // make sure container is sorted
        }
        ContainerType container(this->container());
        container.truncate(maxNumber);
        this->updateContainerMaybeAsync(container, false);
    }

    template <typename T, bool UseCompare>
    typename CListModelBase<T, UseCompare>::ContainerType
    CListModelBase<T, UseCompare>::sortContainerByColumn(const ContainerType &container, int column,
                                                         Qt::SortOrder order) const
    {
        if (m_modelDestroyed) { return container; }
        if (container.size() < 2 || !m_columns.isSortable(column))
        {
            return container; // nothing to do
        }

        // this is the only part not really thread safe, but columns do not change so far
        const CPropertyIndex propertyIndex = m_columns.columnToSortPropertyIndex(column);
        Q_ASSERT(!propertyIndex.isEmpty());
        if (propertyIndex.isEmpty())
        {
            return container; // at release build do nothing
        }

        // sort the values
        const auto tieBreakersCopy =
            m_sortTieBreakers; //! \todo workaround T579 still not thread-safe, but less likely to crash
        const std::integral_constant<bool, UseCompare> marker {};
        const auto p = [=](const ObjectType &a, const ObjectType &b) -> bool {
            return Private::compareForModelSort<ObjectType>(a, b, order, propertyIndex, tieBreakersCopy, marker);
        };

        return container.sorted(p);
    }

    template <typename T, bool UseCompare>
    QMimeData *CListModelBase<T, UseCompare>::mimeData(const QModelIndexList &indexes) const
    {
        QMimeData *mimeData = new QMimeData();
        if (indexes.isEmpty()) { return mimeData; }

        ContainerType container;
        QList<int> rows; // avoid redundant objects

        // Indexes are per row and column
        for (const QModelIndex &index : indexes)
        {
            if (!index.isValid()) { continue; }
            const int r = index.row();
            if (rows.contains(r)) { continue; }
            container.push_back(this->at(index));
            rows.append(r);
        }

        // to JSON via CVariant
        const QJsonDocument containerJson(CVariant::fromValue(container).toJson());
        const QString jsonString(containerJson.toJson(QJsonDocument::Compact));

        mimeData->setData(CGuiUtility::swiftJsonDragAndDropMimeType(), jsonString.toUtf8());
        return mimeData;
    }

    template <typename T, bool UseCompare>
    QJsonObject CListModelBase<T, UseCompare>::toJson(bool selectedOnly) const
    {
        const CVariant variant =
            CVariant::fromValue(selectedOnly && m_selectionModel ? m_selectionModel->selectedObjects() : container());
        return variant.toJson();
    }

    template <typename T, bool UseCompare>
    QString CListModelBase<T, UseCompare>::toJsonString(QJsonDocument::JsonFormat format, bool selectedOnly) const
    {
        const CVariant variant =
            CVariant::fromValue(selectedOnly && m_selectionModel ? m_selectionModel->selectedObjects() : container());
        return variant.toJsonString(format);
    }

    template <typename T, bool UseCompare>
    bool CListModelBase<T, UseCompare>::isOrderable() const
    {
        return false;
    }

} // namespace swift::gui::models