/*
    SPDX-License-Identifier: GPL-3.0-or-later
*/

#pragma once

#include "effect/effect.h"

#include <QColor>
#include <QMetaObject>
#include <QPointer>
#include <QRectF>

namespace KWin
{

class EffectWindow;
class LogicalOutput;

class WindowGridEffect : public Effect
{
    Q_OBJECT

public:
    WindowGridEffect();
    ~WindowGridEffect() override;

    void reconfigure(ReconfigureFlags flags) override;
    bool isActive() const override;
    bool paintScreen(const RenderTarget &renderTarget, const RenderViewport &viewport, int mask, const Region &deviceRegion, LogicalOutput *screen) override;
    void pointerMotion(PointerMotionEvent *event) override;
    void pointerButton(PointerButtonEvent *event) override;
    void grabbedKeyboardEvent(QKeyEvent *e) override;

private:
    // Native: KWin is doing the normal title bar move. Grid: we own the pointer and
    // show the overlay. Moving: middle button held, window follows the cursor.
    enum class State {
        Idle,
        Native,
        Grid,
        Moving,
    };

    struct Cell
    {
        int col = 0;
        int row = 0;
    };

    void watchWindow(EffectWindow *w);
    void onMoveStarted(EffectWindow *w);
    void onMoveFinished(EffectWindow *w);
    void onMouseChanged(const QPointF &pos, const QPointF &oldpos, Qt::MouseButtons buttons, Qt::MouseButtons oldbuttons);

    void enterGrid(bool viaSpace);
    void finish(bool restoreGeometry);
    void updateArea(const QPointF &pos);
    Cell cellAt(const QPointF &pos) const;
    QRectF cellRect(Cell a, Cell b) const;
    void setSelecting(bool rightButton, bool space, const QPointF &pos);
    void applySelection();
    void moveWithCursor(const QPointF &pos);

    State m_state = State::Idle;
    QPointer<EffectWindow> m_window;
    QMetaObject::Connection m_mouseConnection;
    bool m_keyboardGrabbed = false;

    QRectF m_originalGeometry;
    LogicalOutput *m_screen = nullptr;
    QRectF m_area;
    int m_cols = 1;
    int m_rows = 1;
    Cell m_start;
    Cell m_end;
    bool m_rightHeld = false;
    bool m_spaceHeld = false;
    QPointF m_grabOffset;
    QPointF m_cursor;

    // config, group "Effect-windowgrid" in kwinrc
    int m_cfgColumns = 6;
    int m_cfgRows = 4;
    bool m_useWorkArea = true;
    QColor m_gridColor;
    QColor m_selectionColor;
    qreal m_opacity = 0.35;
};

} // namespace KWin