/* Copyright 2013-2021 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <QObject>
#include <QVariant>
#include <QAbstractListModel>

#include "BaseVersion.h"
#include "tasks/Task.h"
#include "QObjectPtr.h"

/*!
 * \brief Class that each instance type's version list derives from.
 * Version lists are the lists that keep track of the available game versions
 * for that instance. This list will not be loaded on startup. It will be loaded
 * when the list's load function is called. Before using the version list, you
 * should check to see if it has been loaded yet and if not, load the list.
 *
 * Note that this class also inherits from QAbstractListModel. Methods from that
 * class determine how this version list shows up in a list view. Said methods
 * all have a default implementation, but they can be overridden by plugins to
 * change the behavior of the list.
 */
class BaseVersionList : public QAbstractListModel
{
    Q_OBJECT
public:
    enum ModelRoles
    {
        VersionPointerRole = Qt::UserRole,
        VersionRole,
        VersionIdRole,
        ParentVersionRole,
        RecommendedRole,
        LatestRole,
        TypeRole,
        BranchRole,
        PathRole,
        ArchitectureRole,
        SortRole
    };
    typedef QList<int> RoleList;

    explicit BaseVersionList(QObject *parent = 0);

    /*!
     * \brief Gets a task that will reload the version list.
     * Simply execute the task to load the list.
     * The task returned by this function should reset the model when it's done.
     * \return A pointer to a task that reloads the version list.
     */
    virtual Task::Ptr getLoadTask() = 0;

    //! Checks whether or not the list is loaded. If this returns false, the list should be
    //loaded.
    virtual bool isLoaded() = 0;

    //! Gets the version at the given index.
    virtual const BaseVersionPtr at(int i) const = 0;

    //! Returns the number of versions in the list.
    virtual int count() const = 0;

    //////// List Model Functions ////////
    QVariant data(const QModelIndex &index, int role) const override;
    int rowCount(const QModelIndex &parent) const override;
    int columnCount(const QModelIndex &parent) const override;
    QHash<int, QByteArray> roleNames() const override;

    //! which roles are provided by this version list?
    virtual RoleList providesRoles() const;

    /*!
     * \brief Finds a version by its descriptor.
     * \param descriptor The descriptor of the version to find.
     * \return A const pointer to the version with the given descriptor. NULL if
     * one doesn't exist.
     */
    virtual BaseVersionPtr findVersion(const QString &descriptor);

    /*!
     * \brief Gets the recommended version from this list
     * If the list doesn't support recommended versions, this works exactly as getLatestStable
     */
    virtual BaseVersionPtr getRecommended() const;

    /*!
     * Sorts the version list.
     */
    virtual void sortVersions() = 0;

protected
slots:
    /*!
     * Updates this list with the given list of versions.
     * This is done by copying each version in the given list and inserting it
     * into this one.
     * We need to do this so that we can set the parents of the versions are set to this
     * version list. This can't be done in the load task, because the versions the load
     * task creates are on the load task's thread and Qt won't allow their parents
     * to be set to something created on another thread.
     * To get around that problem, we invoke this method on the GUI thread, which
     * then copies the versions and sets their parents correctly.
     * \param versions List of versions whose parents should be set.
     */
    virtual void updateListData(QList<BaseVersionPtr> versions) = 0;
};
