/*
  ==============================================================================

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For the technical preview this file cannot be licensed commercially.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
/**
    Represents a parallelogram that is defined by 3 points.
    @see Rectangle, Point, Line

    @tags{Graphics}
*/
template <typename ValueType>
class Parallelogram
{
public:
    //==============================================================================
    /** Creates a parallelogram with zero size at the origin.
    */
    Parallelogram() = default;

    /** Creates a copy of another parallelogram. */
    Parallelogram (const Parallelogram&) = default;

    /** Creates a parallelogram based on 3 points. */
    Parallelogram (Point<ValueType> topLeftPosition,
                   Point<ValueType> topRightPosition,
                   Point<ValueType> bottomLeftPosition) noexcept
       : topLeft (topLeftPosition), topRight (topRightPosition), bottomLeft (bottomLeftPosition)
    {
    }

    /** Creates a parallelogram from a rectangle. */
    Parallelogram (Rectangle<ValueType> rectangle) noexcept
       : topLeft (rectangle.getTopLeft()),
         topRight (rectangle.getTopRight()),
         bottomLeft (rectangle.getBottomLeft())
    {
    }

    Parallelogram& operator= (const Parallelogram&) = default;

    /** Destructor. */
    ~Parallelogram() = default;

    //==============================================================================
    /** Returns true if the parallelogram has a width or height of more than zero. */
    bool isEmpty() const noexcept                                   { return topLeft != topRight || topLeft != bottomLeft; }

    /** Returns true if the parallelogram's coordinates are all finite numbers, i.e. not NaN or infinity. */
    inline bool isFinite() const noexcept                           { return topLeft.isFinite() && topRight.isFinite() && bottomLeft.isFinite(); }

    /** Returns the width of the parallelogram (i.e. the straight-line distance between the top-left and top-right. */
    inline ValueType getWidth() const noexcept                      { return Line<ValueType> (topLeft, topRight).getLength(); }

    /** Returns the height of the parallelogram (i.e. the straight-line distance between the top-left and bottom-left. */
    inline ValueType getHeight() const noexcept                     { return Line<ValueType> (topLeft, bottomLeft).getLength(); }

    //==============================================================================
    /** Returns the parallelogram's top-left position as a Point. */
    Point<ValueType> getTopLeft() const noexcept                    { return topLeft; }

    /** Returns the parallelogram's top-right position as a Point. */
    Point<ValueType> getTopRight() const noexcept                   { return topRight; }

    /** Returns the parallelogram's bottom-left position as a Point. */
    Point<ValueType> getBottomLeft() const noexcept                 { return bottomLeft; }

    /** Returns the parallelogram's bottom-right position as a Point. */
    Point<ValueType> getBottomRight() const noexcept                { return topRight + (bottomLeft - topLeft); }

    //==============================================================================
    /** Returns true if the two parallelograms are identical. */
    bool operator== (const Parallelogram& other) const noexcept     { return topLeft == other.topLeft && topRight == other.topRight && bottomLeft == other.bottomLeft; }

    /** Returns true if the two parallelograms are not identical. */
    bool operator!= (const Parallelogram& other) const noexcept     { return ! operator== (other); }

    //==============================================================================
    /** Returns a parallelogram which is the same as this one moved by a given amount. */
    Parallelogram operator+ (Point<ValueType> deltaPosition) const noexcept
    {
        auto p = *this;
        p += deltaPosition;
        return p;
    }

    /** Moves this parallelogram by a given amount. */
    Parallelogram& operator+= (Point<ValueType> deltaPosition) noexcept
    {
        topLeft += deltaPosition;
        topRight += deltaPosition;
        bottomLeft += deltaPosition;
        return *this;
    }

    /** Returns a parallelogram which is the same as this one moved by a given amount. */
    Parallelogram operator- (Point<ValueType> deltaPosition) const noexcept
    {
        return operator+ (-deltaPosition);
    }

    /** Moves this parallelogram by a given amount. */
    Parallelogram& operator-= (Point<ValueType> deltaPosition) noexcept
    {
        return operator-= (-deltaPosition);
    }

    /** Returns a parallelogram that has been scaled by the given amount, centred around the origin. */
    template <typename PointOrScalarType>
    Parallelogram operator* (PointOrScalarType scaleFactor) const noexcept
    {
        auto p = *this;
        p *= scaleFactor;
        return p;
    }

    /** Scales this parallelogram by the given amount, centred around the origin. */
    template <typename PointOrScalarType>
    Parallelogram operator*= (PointOrScalarType scaleFactor) noexcept
    {
        topLeft *= scaleFactor;
        topRight *= scaleFactor;
        bottomLeft *= scaleFactor;
        return *this;
    }

    //==============================================================================
    /** Returns a point within this parallelogram, specified as proportional coordinates.
        The relative X and Y values should be between 0 and 1, where 0 is the left or
        top of this parallelogram, and 1 is the right or bottom. (Out-of-bounds values
        will return a point outside the parallelogram).
    */
    Point<ValueType> getRelativePoint (Point<ValueType> relativePosition) const noexcept
    {
        return topLeft
                + (topRight - topLeft) * relativePosition.x
                + (bottomLeft - topLeft) * relativePosition.y;
    }

    /** Returns a transformed version of the parallelogram. */
    Parallelogram transformedBy (const AffineTransform& transform) const noexcept
    {
        auto p = *this;
        transform.transformPoints (p.topLeft.x, p.topLeft.y,
                                   p.topRight.x, p.topRight.y,
                                   p.bottomLeft.x, p.bottomLeft.y);

        return p;
    }

    /** Returns the smallest rectangle that encloses this parallelogram. */
    Rectangle<ValueType> getBoundingBox() const noexcept
    {
        const Point<ValueType> points[] = { topLeft, topRight, bottomLeft, getBottomRight() };
        return Rectangle<ValueType>::findAreaContainingPoints (points, 4);
    }

    Point<ValueType> topLeft, topRight, bottomLeft;
};

} // namespace juce