/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 * Copyright (C) 2012-2019 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "AffineTransform.h"
#include "FloatSize.h"
#include <wtf/EnumTraits.h>

// X11 headers define a bunch of macros with common terms, interfering with WebCore and WTF enum values.
// As a workaround, we explicitly undef them here.
#if defined(None)
#undef None
#endif

namespace WebCore {

struct ImageOrientation {
    enum class Orientation : int {
        FromImage         = 0, // Orientation from the image should be respected.

        // This range intentionally matches the orientation values from the EXIF spec.
        // See JEITA CP-3451, page 18. http://www.exif.org/Exif2-2.PDF
        OriginTopLeft     = 1, // default
        OriginTopRight    = 2, // mirror along y-axis
        OriginBottomRight = 3, // 180 degree rotation
        OriginBottomLeft  = 4, // mirror along the x-axis
        OriginLeftTop     = 5, // mirror along x-axis + 270 degree CW rotation
        OriginRightTop    = 6, // 90 degree CW rotation
        OriginRightBottom = 7, // mirror along x-axis + 90 degree CW rotation
        OriginLeftBottom  = 8, // 270 degree CW rotation

        None              = OriginTopLeft
    };

    constexpr ImageOrientation() = default;

    constexpr ImageOrientation(Orientation orientation)
        : m_orientation(orientation)
    {
    }
    
    ImageOrientation(int orientation)
    {
        RELEASE_ASSERT(isValidOrientation(orientation));
        m_orientation = static_cast<Orientation>(orientation);
    }

    static constexpr Orientation fromEXIFValue(int exifValue)
    {
        return isValidEXIFOrientation(exifValue) ? static_cast<Orientation>(exifValue) : Orientation::None;
    }

    constexpr operator int() const { return static_cast<int>(m_orientation); }
    friend constexpr bool operator==(const ImageOrientation&, const ImageOrientation&) = default;

    constexpr Orientation orientation() const { return m_orientation; }
    
    constexpr bool usesWidthAsHeight() const
    {
        ASSERT(m_orientation != Orientation::FromImage);
        // Values 5 through 8 all flip the width/height.
        switch (m_orientation) {
        case Orientation::OriginLeftTop:
        case Orientation::OriginRightTop:
        case Orientation::OriginRightBottom:
        case Orientation::OriginLeftBottom:
            return true;
        default:
            return false;
        }
    }

    constexpr AffineTransform transformFromDefault(const FloatSize& drawnSize) const
    {
        float w = drawnSize.width();
        float h = drawnSize.height();

        switch (m_orientation) {
        case Orientation::FromImage:
            ASSERT_NOT_REACHED();
            return AffineTransform();
        case Orientation::OriginTopLeft:
            return AffineTransform();
        case Orientation::OriginTopRight:
            return AffineTransform(-1,  0,  0,  1,  w, 0);
        case Orientation::OriginBottomRight:
            return AffineTransform(-1,  0,  0, -1,  w, h);
        case Orientation::OriginBottomLeft:
            return AffineTransform( 1,  0,  0, -1,  0, h);
        case Orientation::OriginLeftTop:
            return AffineTransform( 0,  1,  1,  0,  0, 0);
        case Orientation::OriginRightTop:
            return AffineTransform( 0,  1, -1,  0,  w, 0);
        case Orientation::OriginRightBottom:
            return AffineTransform( 0, -1, -1,  0,  w, h);
        case Orientation::OriginLeftBottom:
            return AffineTransform( 0, -1,  1,  0,  0, h);
        }

        ASSERT_NOT_REACHED();
        return AffineTransform();
    }

    constexpr ImageOrientation withFlippedY() const
    {
        ASSERT(m_orientation != Orientation::FromImage);

        switch (m_orientation) {
        case Orientation::FromImage:
            ASSERT_NOT_REACHED();
            return Orientation::None;
        case Orientation::OriginTopLeft:
            return Orientation::OriginBottomLeft;
        case Orientation::OriginTopRight:
            return Orientation::OriginBottomRight;
        case Orientation::OriginBottomRight:
            return Orientation::OriginTopRight;
        case Orientation::OriginBottomLeft:
            return Orientation::OriginTopLeft;
        case Orientation::OriginLeftTop:
            return Orientation::OriginLeftBottom;
        case Orientation::OriginRightTop:
            return Orientation::OriginRightBottom;
        case Orientation::OriginRightBottom:
            return Orientation::OriginRightTop;
        case Orientation::OriginLeftBottom:
            return Orientation::OriginLeftTop;
        }

        ASSERT_NOT_REACHED();
        return Orientation::None;
    }

private:
    static constexpr auto EXIFFirst = Orientation::OriginTopLeft;
    static constexpr auto EXIFLast = Orientation::OriginLeftBottom;
    static constexpr auto First = Orientation::FromImage;
    static constexpr auto Last = EXIFLast;

    static constexpr bool isValidOrientation(int orientation)
    {
        return orientation >= static_cast<int>(First) && orientation <= static_cast<int>(Last);
    }

    static constexpr bool isValidEXIFOrientation(int orientation)
    {
        return orientation >= static_cast<int>(EXIFFirst) && orientation <= static_cast<int>(EXIFLast);
    }

    Orientation m_orientation { Orientation::None };
};

} // namespace WebCore
