/******************************************************************************
 * QSkinny - Copyright (C) 2016 Uwe Rathmann
 * This file may be used under the terms of the QSkinny License, Version 1.0
 *****************************************************************************/

#ifndef QSK_GRDIENT_DIRECTION_H
#define QSK_GRDIENT_DIRECTION_H

#include "QskGlobal.h"

#include <qmetatype.h>
#include <qpoint.h>
#include <qline.h>

class QLineF;

class QSK_EXPORT QskLinearDirection
{
    Q_GADGET

    Q_PROPERTY( qreal x1 READ x1 WRITE setX1 )
    Q_PROPERTY( qreal y1 READ y1 WRITE setY1 )
    Q_PROPERTY( qreal x2 READ x2 WRITE setX2 )
    Q_PROPERTY( qreal y2 READ y2 WRITE setY2 )

  public:
    constexpr QskLinearDirection() noexcept = default;

    constexpr QskLinearDirection( Qt::Orientation ) noexcept;

    constexpr QskLinearDirection( const QLineF& ) noexcept;
    constexpr QskLinearDirection( const QPointF&, const QPointF& ) noexcept;
    constexpr QskLinearDirection( qreal x1, qreal y1, qreal x2, qreal y2 ) noexcept;

    void setVector( const QLineF& ) noexcept;
    void setVector( const QPointF&, const QPointF& ) noexcept;
    void setVector( qreal x1, qreal y1, qreal x2, qreal y2 ) noexcept;

    constexpr QLineF vector() const noexcept;

    void setStart( const QPointF& ) noexcept;
    void setStart( qreal x, qreal y ) noexcept;

    void setStop(const QPointF& ) noexcept;
    void setStop( qreal x, qreal y ) noexcept;

    void setInterval( Qt::Orientation, qreal, qreal );

    void setOrientation( Qt::Orientation ) noexcept;
    constexpr bool isOriented( Qt::Orientation ) const noexcept;

    constexpr bool isHorizontal() const noexcept;
    constexpr bool isVertical() const noexcept;
    constexpr bool isTilted() const noexcept;

    constexpr QPointF start() const noexcept;
    constexpr QPointF stop() const noexcept;

    constexpr qreal x1() const noexcept;
    void setX1( qreal ) noexcept;

    constexpr qreal y1() const noexcept;
    void setY1( qreal ) noexcept;

    constexpr qreal x2() const noexcept;
    void setX2( qreal ) noexcept;

    constexpr qreal y2() const noexcept;
    void setY2( qreal ) noexcept;

    /*
        In direction of the gradient vector, where 0.0 corresponds to
        points on the perpendicular at the start and 1.0 to points on
        the perpendicular of the end point. 

        Also corresponds to the positions of the color stops and can be
        used to calculate the color at a specific position.
     */
    qreal valueAt( const QPointF& ) const;
    qreal valueAt( qreal x, qreal y ) const;

    bool contains( const QRectF& ) const;

  private:
    qreal m_x1 = 0.0;
    qreal m_y1 = 0.0;
    qreal m_x2 = 0.0;
    qreal m_y2 = 1.0;
};

class QSK_EXPORT QskConicDirection
{
    Q_GADGET

    Q_PROPERTY( qreal x READ x WRITE setX )
    Q_PROPERTY( qreal y READ y WRITE setY )
    Q_PROPERTY( qreal startAngle READ startAngle WRITE setStartAngle )
    Q_PROPERTY( qreal spanAngle READ spanAngle WRITE setSpanAngle )

  public:
    // counter-clockwise
    constexpr QskConicDirection() noexcept = default;

    constexpr QskConicDirection( qreal x, qreal y, qreal startAngle = 0.0 ) noexcept;
    constexpr QskConicDirection( qreal x, qreal y, qreal startAngle, qreal spanAngle ) noexcept;

    constexpr QskConicDirection( const QPointF&, qreal startAngle = 0.0 ) noexcept;
    constexpr QskConicDirection( const QPointF&, qreal startAngle, qreal spanAngle ) noexcept;

    constexpr QPointF center() const noexcept;
    void setCenter(const QPointF& center) noexcept;
    void setCenter(qreal x, qreal y) noexcept;

    void setX( qreal ) noexcept;
    constexpr qreal x() const noexcept;

    void setY( qreal ) noexcept;
    constexpr qreal y() const noexcept;

    constexpr qreal startAngle() const noexcept;
    void setStartAngle( qreal ) noexcept;

    constexpr qreal spanAngle() const noexcept;
    void setSpanAngle( qreal ) noexcept;

  private:
    qreal m_x = 0.5;
    qreal m_y = 0.5;
    qreal m_startAngle = 0.0;
    qreal m_spanAngle = 360.0;
};

class QSK_EXPORT QskRadialDirection
{
    Q_GADGET

    Q_PROPERTY( qreal x READ x WRITE setX )
    Q_PROPERTY( qreal y READ y WRITE setY )
    Q_PROPERTY( qreal radiusX READ radiusX WRITE setRadiusX )
    Q_PROPERTY( qreal radiusY READ radiusY WRITE setRadiusY )

  public:
    constexpr QskRadialDirection() noexcept = default;

    constexpr QskRadialDirection( const QPointF& center, qreal radius ) noexcept;
    constexpr QskRadialDirection( qreal cx, qreal cy, qreal radius ) noexcept;
    constexpr QskRadialDirection( qreal cx, qreal cy, qreal radiusX, qreal radiusY ) noexcept;

    constexpr QPointF center() const noexcept;
    void setCenter(const QPointF& ) noexcept;
    void setCenter(qreal x, qreal y) noexcept;

    void setX( qreal ) noexcept;
    constexpr qreal x() const noexcept;

    void setY( qreal ) noexcept;
    constexpr qreal y() const noexcept;

    constexpr qreal radiusX() const noexcept;
    void setRadiusX( qreal ) noexcept;

    constexpr qreal radiusY() const noexcept;
    void setRadiusY( qreal ) noexcept;

    void setRadius( qreal ) noexcept;
    void setRadius( qreal, qreal ) noexcept;

  private:
    qreal m_x = 0.5;
    qreal m_y = 0.5;
    qreal m_radiusX = 0.5;
    qreal m_radiusY = 0.5;
};

inline constexpr QskLinearDirection::QskLinearDirection(
        Qt::Orientation orientation ) noexcept
    : m_x2( ( orientation == Qt::Vertical ) ? 0.0 : 1.0 )
    , m_y2( ( orientation == Qt::Vertical ) ? 1.0 : 0.0 )
{
}

inline constexpr QskLinearDirection::QskLinearDirection( const QLineF& vector ) noexcept
    : QskLinearDirection( vector.x1(), vector.y1(), vector.x2(), vector.y2() )
{
}

inline constexpr QskLinearDirection::QskLinearDirection(
        const QPointF& start, const QPointF& stop ) noexcept
    : QskLinearDirection( start.x(), start.y(), stop.x(), stop.y() )
{
}

inline constexpr QskLinearDirection::QskLinearDirection(
        qreal x1, qreal y1, qreal x2, qreal y2 ) noexcept
    : m_x1( x1 )
    , m_y1( y1 )
    , m_x2( x2 )
    , m_y2( y2 )
{
}

inline constexpr qreal QskLinearDirection::x1() const noexcept
{
    return m_x1;
}

inline constexpr qreal QskLinearDirection::y1() const noexcept
{
    return m_y1;
}

inline constexpr qreal QskLinearDirection::x2() const noexcept
{
    return m_x2;
}

inline constexpr qreal QskLinearDirection::y2() const noexcept
{
    return m_y2;
}

inline constexpr QLineF QskLinearDirection::vector() const noexcept
{
    return QLineF( m_x1, m_y1, m_x2, m_y2 );
}

inline constexpr QPointF QskLinearDirection::start() const noexcept
{
    return QPointF( m_x1, m_y1 );
}

inline constexpr QPointF QskLinearDirection::stop() const noexcept
{
    return QPointF( m_x2, m_y2 );
}

inline constexpr bool QskLinearDirection::isOriented(
    Qt::Orientation orientation ) const noexcept
{
    return ( orientation == Qt::Horizontal ) ? isHorizontal() : isVertical();
}

inline constexpr bool QskLinearDirection::isHorizontal() const noexcept
{
    return !isVertical() && ( m_y1 == m_y2 );
}

inline constexpr bool QskLinearDirection::isVertical() const noexcept
{
    return m_x1 == m_x2;
}

inline constexpr bool QskLinearDirection::isTilted() const noexcept
{
    return ( m_x1 != m_x2 ) && ( m_y1 != m_y2 );
}

inline qreal QskLinearDirection::valueAt( const QPointF& pos ) const
{
    return valueAt( pos.x(), pos.y() );
}

inline qreal QskLinearDirection::valueAt( qreal x, qreal y ) const
{
    // we could cache these values TODO ..
    const qreal dx = m_x2 - m_x1;
    const qreal dy = m_y2 - m_y1;
    const qreal dot = dx * dx + dy * dy;

    return ( ( x - m_x1 ) * dx + ( y - m_y1 ) * dy ) / dot;
}

inline constexpr QskConicDirection::QskConicDirection(
        qreal x, qreal y, qreal startAngle ) noexcept
    : QskConicDirection( x, y, startAngle, 360.0 )
{
}

inline constexpr QskConicDirection::QskConicDirection(
        qreal x, qreal y, qreal startAngle, qreal spanAngle ) noexcept
    : m_x( x )
    , m_y( y )
    , m_startAngle( startAngle )
    , m_spanAngle( spanAngle )
{
}

inline constexpr QskConicDirection::QskConicDirection(
        const QPointF& pos, qreal startAngle ) noexcept
    : QskConicDirection( pos.x(), pos.y(), startAngle )
{
}

inline constexpr QskConicDirection::QskConicDirection(
        const QPointF& pos, qreal startAngle, qreal spanAngle ) noexcept
    : QskConicDirection( pos.x(), pos.y(), startAngle, spanAngle )
{
}

inline constexpr QPointF QskConicDirection::center() const noexcept
{
    return QPointF( m_x, m_y );
}

inline constexpr qreal QskConicDirection::startAngle() const noexcept
{
    return m_startAngle;
}

inline constexpr qreal QskConicDirection::spanAngle() const noexcept
{
    return m_spanAngle;
}

inline constexpr qreal QskConicDirection::x() const noexcept
{
    return m_x;
}

inline constexpr qreal QskConicDirection::y() const noexcept
{
    return m_y;
}

inline constexpr QskRadialDirection::QskRadialDirection(
        qreal x, qreal y, qreal radius ) noexcept
    : m_x( x )
    , m_y( y )
    , m_radiusX( radius )
    , m_radiusY( radius )
{
}

inline constexpr QskRadialDirection::QskRadialDirection(
        qreal x, qreal y, qreal radiusX, qreal radiusY ) noexcept
    : m_x( x )
    , m_y( y )
    , m_radiusX( radiusX )
    , m_radiusY( radiusY )
{
}

inline constexpr QskRadialDirection::QskRadialDirection(
        const QPointF& center, qreal radius ) noexcept
    : QskRadialDirection( center.x(), center.y(), radius )
{
}

inline constexpr QPointF QskRadialDirection::center() const noexcept
{
    return QPointF( m_x, m_y );
}

inline constexpr qreal QskRadialDirection::x() const noexcept
{
    return m_x;
}

inline constexpr qreal QskRadialDirection::y() const noexcept
{
    return m_y;
}

inline constexpr qreal QskRadialDirection::radiusX() const noexcept
{
    return m_radiusX;
}

inline constexpr qreal QskRadialDirection::radiusY() const noexcept
{
    return m_radiusY;
}

#endif