/*
    SPDX-FileCopyrightText: 2016 Eike Hein <hein@kde.org>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/

#pragma once

#include <QAbstractProxyModel>

#include <memory>

#include "abstracttasksmodeliface.h"
#include "tasksmodel.h"

#include "taskmanager_export.h"

namespace TaskManager
{
/**
 * @short A proxy tasks model for grouping tasks, forming a tree.
 *
 * This proxy model groups tasks in its source tasks model, forming a tree
 * of tasks. Gouping behavior is influenced by various properties set on
 * the proxy model instance.
 *
 * @author Eike Hein <hein@kde.org>
 **/

class TASKMANAGER_EXPORT TaskGroupingProxyModel : public QAbstractProxyModel, public AbstractTasksModelIface
{
    Q_OBJECT

    Q_PROPERTY(TasksModel::GroupMode groupMode READ groupMode WRITE setGroupMode NOTIFY groupModeChanged)
    Q_PROPERTY(bool groupDemandingAttention READ groupDemandingAttention WRITE setGroupDemandingAttention NOTIFY groupDemandingAttentionChanged)
    Q_PROPERTY(int windowTasksThreshold READ windowTasksThreshold WRITE setWindowTasksThreshold NOTIFY windowTasksThresholdChanged)
    Q_PROPERTY(QStringList blacklistedAppIds READ blacklistedAppIds WRITE setBlacklistedAppIds NOTIFY blacklistedAppIdsChanged)
    Q_PROPERTY(QStringList blacklistedLauncherUrls READ blacklistedLauncherUrls WRITE setBlacklistedLauncherUrls NOTIFY blacklistedLauncherUrlsChanged)

public:
    explicit TaskGroupingProxyModel(QObject *parent = nullptr);
    ~TaskGroupingProxyModel() override;

    QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
    QModelIndex parent(const QModelIndex &child) const override;

    QModelIndex mapFromSource(const QModelIndex &sourceIndex) const override;
    QModelIndex mapToSource(const QModelIndex &proxyIndex) const override;

    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
    bool hasChildren(const QModelIndex &parent = QModelIndex()) const override;
    int columnCount(const QModelIndex &parent = QModelIndex()) const override;

    QVariant data(const QModelIndex &proxyIndex, int role) const override;

    void setSourceModel(QAbstractItemModel *sourceModel) override;

    /**
     * Returns the current group mode, i.e. the criteria by which tasks should
     * be grouped.
     *
     * Defaults to TasksModel::GroupApplication, which groups tasks backed by
     * the same application.
     *
     * If the group mode is TasksModel::GroupDisabled, no grouping is done.
     *
     * @see TasksModel
     * @see setGroupMode
     * @returns the active group mode.
     **/
    TasksModel::GroupMode groupMode() const;

    /**
     * Sets the group mode, i.e. the criteria by which tasks should be grouped.
     *
     * The group mode can be set to TasksModel::GroupDisabled to disable grouping
     * entirely, breaking apart any existing groups.
     *
     * @see TasksModel
     * @see groupMode
     * @param mode A TasksModel group mode.
     **/
    void setGroupMode(TasksModel::GroupMode mode);

    /**
     * Whether new tasks which demand attention
     * (AbstractTasksModel::IsDemandingAttention) should be grouped immediately,
     * or only once they have stopped demanding attention. Defaults to @c false.
     *
     * @see setGroupDemandingAttention
     * @returns whether tasks which demand attention are grouped immediately.
     **/
    bool groupDemandingAttention() const;

    /**
     * Sets whether new tasks which demand attention
     * (AbstractTasksModel::IsDemandingAttention) should be grouped immediately,
     * or only once they have stopped demanding attention.
     *
     * @see groupDemandingAttention
     * @param group Whether tasks with demand attention should be grouped immediately.
     **/
    void setGroupDemandingAttention(bool group);

    /**
     * As window tasks (AbstractTasksModel::IsWindow) come and go in the source
     * model, groups will be formed when this threshold value is exceeded, and
     * broken apart when it matches or falls below.
     *
     * Defaults to @c -1, which means grouping is done regardless of the number
     * of window tasks in the source model.
     *
     * @see setWindowTasksThreshold
     * @return the threshold number of source window tasks used in grouping
     * decisions.
     **/
    int windowTasksThreshold() const;

    /**
     * Sets the number of source model window tasks (AbstractTasksModel::IsWindow)
     * above which groups will be formed, and at or below which groups will be broken
     * apart.
     *
     * If set to -1, grouping will be done regardless of the number of window tasks
     * in the source model.
     *
     * @see windowTasksThreshold
     * @param threshold A threshold number of source window tasks used in grouping
     * decisions.
     **/
    void setWindowTasksThreshold(int threshold);

    /**
     * A blacklist of app ids (AbstractTasksModel::AppId) that is consulted before
     * grouping a task. If a task's app id is found on the blacklist, it is not
     * grouped.
     *
     * The default app id blacklist is empty.
     *
     * @see setBlacklistedAppIds
     * @returns the blacklist of app ids consulted before grouping a task.
     **/
    QStringList blacklistedAppIds() const;

    /**
     * Sets the blacklist of app ids (AbstractTasksModel::AppId) that is consulted
     * before grouping a task. If a task's app id is found on the blacklist, it is
     * not grouped.
     *
     * When set, groups will be formed and broken apart as necessary.
     *
     * @see blacklistedAppIds
     * @param list a blacklist of app ids to be consulted before grouping a task.
     **/
    void setBlacklistedAppIds(const QStringList &list);

    /**
     * A blacklist of launcher URLs (AbstractTasksModel::LauncherUrl) that is
     * consulted before grouping a task. If a task's launcher URL is found on the
     * blacklist, it is not grouped.
     *
     * The default launcher URL blacklist is empty.
     *
     * @see setBlacklistedLauncherUrls
     * @returns the blacklist of launcher URLs consulted before grouping a task.
     **/
    QStringList blacklistedLauncherUrls() const;

    /**
     * Sets the blacklist of launcher URLs (AbstractTasksModel::LauncherUrl) that
     * is consulted before grouping a task. If a task's launcher URL is found on
     * the blacklist, it is not grouped.
     *
     * When set, groups will be formed and broken apart as necessary.
     *
     * @see blacklistedLauncherUrls
     * @param list a blacklist of launcher URLs to be consulted before grouping a task.
     **/
    void setBlacklistedLauncherUrls(const QStringList &list);

    /**
     * Request activation of the task at the given index. Derived classes are
     * free to interpret the meaning of "activate" themselves depending on
     * the nature and state of the task, e.g. launch or raise a window task.
     *
     * @param index An index in this tasks model.
     **/
    void requestActivate(const QModelIndex &index) override;

    /**
     * Request an additional instance of the application backing the task
     * at the given index.
     *
     * @param index An index in this tasks model.
     **/
    void requestNewInstance(const QModelIndex &index) override;

    /**
     * Requests to open the given URLs with the application backing the task
     * at the given index.
     *
     * @param index An index in this tasks model.
     * @param urls The URLs to be passed to the application.
     **/
    void requestOpenUrls(const QModelIndex &index, const QList<QUrl> &urls) override;

    /**
     * Request the task at the given index be closed.
     *
     * @param index An index in this tasks model.
     **/
    void requestClose(const QModelIndex &index) override;

    /**
     * Request starting an interactive move for the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * This base implementation does nothing.
     *
     * @param index An index in this tasks model.
     **/
    void requestMove(const QModelIndex &index) override;

    /**
     * Request starting an interactive resize for the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be a
     * no-op when there is no window.
     *
     * @param index An index in this tasks model.
     **/
    void requestResize(const QModelIndex &index) override;

    /**
     * Request toggling the minimized state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * This base implementation does nothing.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleMinimized(const QModelIndex &index) override;

    /**
     * Request toggling the maximized state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleMaximized(const QModelIndex &index) override;

    /**
     * Request toggling the keep-above state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleKeepAbove(const QModelIndex &index) override;

    /**
     * Request toggling the keep-below state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleKeepBelow(const QModelIndex &index) override;

    /**
     * Request toggling the fullscreen state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * This base implementation does nothing.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleFullScreen(const QModelIndex &index) override;

    /**
     * Request toggling the shaded state of the task at the given index.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleShaded(const QModelIndex &index) override;

    /**
     * Request entering the window at the given index on the specified virtual desktops,
     * leaving any other desktops.
     *
     * On Wayland, virtual desktop ids are QStrings. On X11, they are uint >0.
     *
     * An empty list has a special meaning: The window is entered on all virtual desktops
     * in the session.
     *
     * On X11, a window can only be on one or all virtual desktops. Therefore, only the
     * first list entry is actually used.
     *
     * On X11, the id 0 has a special meaning: The window is entered on all virtual
     * desktops in the session.
     *
     * @param index An index in this window tasks model.
     * @param desktops A list of virtual desktop ids.
     **/
    void requestVirtualDesktops(const QModelIndex &index, const QVariantList &desktops) override;

    /**
     * Request entering the window at the given index on a new virtual desktop,
     * which is created in response to this request.
     *
     * @param index An index in this window tasks model.
     **/
    void requestNewVirtualDesktop(const QModelIndex &index) override;

    /**
     * Request moving the task at the given index to the specified activities.
     *
     * This is meant for tasks that have an associated window, and may be
     * a no-op when there is no window.
     *
     * This base implementation does nothing.
     *
     * @param index An index in this tasks model.
     * @param activities The new list of activities.
     **/
    void requestActivities(const QModelIndex &index, const QStringList &activities) override;

    /**
     * Request informing the window manager of new geometry for a visual
     * delegate for the task at the given index. The geometry should be in
     * screen coordinates.
     *
     * If the task at the given index is a group parent, the geometry is
     * set for all of its children. If the task at the given index is a
     * group member, the geometry is set for all of its siblings.
     *
     * @param index An index in this tasks model.
     * @param geometry Visual delegate geometry in screen coordinates.
     * @param delegate The delegate. Implementations are on their own with
     * regard to extracting information from this, and should take care to
     * reject invalid objects.
     **/
    void requestPublishDelegateGeometry(const QModelIndex &index, const QRect &geometry, QObject *delegate = nullptr) override;

    /**
     * Request toggling whether the task at the given index, along with any
     * tasks matching its kind, should be grouped or not. Task groups will be
     * formed or broken apart as needed, along with affecting future grouping
     * decisions as new tasks appear in the source model.
     *
     * As grouping is toggled for a task, updates are made to the blacklisted*
     * properties of the model instance.
     *
     * @see blacklistedAppIds
     * @see blacklistedLauncherUrls
     *
     * @param index An index in this tasks model.
     **/
    void requestToggleGrouping(const QModelIndex &index);

Q_SIGNALS:
    void groupModeChanged() const;
    void groupDemandingAttentionChanged() const;
    void windowTasksThresholdChanged() const;
    void blacklistedAppIdsChanged() const;
    void blacklistedLauncherUrlsChanged() const;

private:
    class Private;
    std::unique_ptr<Private> d;

    Q_PRIVATE_SLOT(d, void sourceRowsAboutToBeInserted(const QModelIndex &parent, int first, int last))
    Q_PRIVATE_SLOT(d, void sourceRowsInserted(const QModelIndex &parent, int start, int end))
    Q_PRIVATE_SLOT(d, void sourceRowsAboutToBeRemoved(const QModelIndex &parent, int first, int last))
    Q_PRIVATE_SLOT(d, void sourceRowsRemoved(const QModelIndex &parent, int start, int end))
    Q_PRIVATE_SLOT(d, void sourceModelAboutToBeReset())
    Q_PRIVATE_SLOT(d, void sourceModelReset())
    Q_PRIVATE_SLOT(d, void sourceDataChanged(QModelIndex, QModelIndex, QList<int>))
};

}
