/*
 * libpapyros - A QML module and collection of classes used throughout Papyros
 * Copyright (C) 2016 Michael Spencer <sonrisesoftware@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 2.1 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef QOBJECTLISTMODEL_H
#define QOBJECTLISTMODEL_H

#include <QAbstractListModel>
#include <QtQml>
#include <QSet>
#include <QBasicTimer>
#include <functional>

#include <papyros/papyros_export.h>

class PAPYROS_EXPORT QObjectListModel : public QAbstractListModel
{
    Q_OBJECT
    Q_DISABLE_COPY(QObjectListModel)

    //! Whether changes to underlying objects are exposed via `dataChanged` signals
    Q_PROPERTY(bool elementChangeTracking READ elementChangeTracking WRITE setElementChangeTracking
                       NOTIFY elementChangeTrackingChanged)

public:
    //! default constructor
    QObjectListModel(QObject *parent = NULL);

    //! A model that creates instances via a given metaobject
    QObjectListModel(const QMetaObject *mo, QObject *parent = NULL);
    //! A model that creates instances using a factory function
    QObjectListModel(const std::function<QObject *()> &factory, QObject *parent = NULL);

    //! A factory to get a model of QList<T*>
    template <class T> static QObjectListModel *create(QList<T *> list, QObject *parent = NULL)
    {
        QObjectListModel *newModel = new QObjectListModel(&T::staticMetaObject, parent);

        newModel->clear();
        newModel->insert(list);

        return newModel;
    }

    ~QObjectListModel();

    bool elementChangeTracking() const;
    void setElementChangeTracking(bool tracking);
    Q_SIGNAL void elementChangeTrackingChanged(bool);
    int rowCount(const QModelIndex &) const Q_DECL_OVERRIDE;
    QVariant data(const QModelIndex &index, int role) const Q_DECL_OVERRIDE;
    bool setData(const QModelIndex &index, const QVariant &value, int role) Q_DECL_OVERRIDE;
    bool replace(QObject *const &item, int row);
    bool insert(QObject *const &item, int row = -1);
    template <class T> bool insert(QList<T *> const &items, int row = -1)
    {
        if (row == -1)
            row = m_data.count();

        if (!items.empty()) {
            beginInsertRows(QModelIndex(), row, row + items.count() - 1);
            for (int i = 0; i < items.count(); i++) {
                Q_ASSERT(items[i]);
                m_data.insert(i + row, items[i]);
                updateTracking(items[i]);
                QQmlEngine::setObjectOwnership(items[i], QQmlEngine::CppOwnership);
            }
            endInsertRows();
        }

        return true;
    }
    bool moveRows(int sourceRow, int count, int destinationChild);
    bool moveRows(const QModelIndex &sourceParent, int sourceRow, int count,
                  const QModelIndex &destinationParent, int destinationChild) Q_DECL_OVERRIDE;
    bool clear();
    bool removeAll(QObject *const &item);
    bool removeOne(QObject *const &item);
    bool removeAt(int row);
    bool removeFirst();
    bool removeLast();
    bool insertRows(int row, int count, const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;
    bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;

    // We're intentionally overloading the sort method
    using QAbstractListModel::sort;

    template <typename T, typename LessThan> void sort(T *t, LessThan lessThan)
    {
        Q_UNUSED(t);

        QList<T *> listtosort;

        foreach (QObject *object, m_data) {
            listtosort << dynamic_cast<T *>(object);
        }

        qSort(listtosort.begin(), listtosort.end(), lessThan);

        int oldpos = 0;

        for (int i = 0; i < listtosort.length(); i++) {
            oldpos = m_data.lastIndexOf((QObject *)listtosort[i]);
            if (oldpos > i) {
                beginMoveRows(QModelIndex(), oldpos, oldpos, QModelIndex(), i);
                m_data.move(oldpos, i);
                endMoveRows();
            }
        }
    }

    Q_INVOKABLE QVariant get(int index) const;

protected:
    //! Emits the notifications of changes done on the underlying QObject properties
    void timerEvent(QTimerEvent *ev);

private:
    //! Updates the property tracking connections on given object.
    void updateTracking(QObject *obj);
    //! Receives property notification changes
    Q_SLOT void propertyNotification();

    QObjectList m_data;
    std::function<QObject *()> m_factory;
    bool m_tracking;
    QBasicTimer m_notifyTimer;
    QMap<int, char> m_notifyIndexes;
};

#endif // QOBJECTMODEL_H
