//  SPDX-License-Identifier: MIT
//
//  EmulationStation Desktop Edition
//  ImageComponent.cpp
//
//  Handles images: loading, resizing, cropping, color shifting etc.
//

#include "components/ImageComponent.h"

#include "Log.h"
#include "Settings.h"
#include "ThemeData.h"
#include "Window.h"
#include "resources/TextureResource.h"
#include "utils/CImgUtil.h"

glm::ivec2 ImageComponent::getTextureSize() const
{
    if (mTexture)
        return mTexture->getSize();
    else
        return glm::ivec2 {};
}

glm::vec2 ImageComponent::getSize() const
{
    return GuiComponent::getSize() * (mBottomRightCrop - mTopLeftCrop);
}

ImageComponent::ImageComponent(bool forceLoad, bool dynamic)
    : mTargetSize {0, 0}
    , mFlipX {false}
    , mFlipY {false}
    , mTargetIsMax {false}
    , mTargetIsMin {false}
    , mColorShift {0xFFFFFFFF}
    , mColorShiftEnd {0xFFFFFFFF}
    , mColorGradientHorizontal {true}
    , mFadeOpacity {0}
    , mFading {false}
    , mForceLoad {forceLoad}
    , mDynamic {dynamic}
    , mRotateByTargetSize {false}
    , mTopLeftCrop {0.0f, 0.0f}
    , mBottomRightCrop {1.0f, 1.0f}
{
    updateColors();
}

void ImageComponent::resize()
{
    if (!mTexture)
        return;

    const glm::vec2 textureSize {mTexture->getSourceImageSize()};
    if (textureSize == glm::vec2 {})
        return;

    if (mTexture->isTiled()) {
        mSize = mTargetSize;
    }
    else {
        // SVG rasterization is determined by height and rasterization is done in terms of pixels.
        // If rounding is off enough in the rasterization step (for images with extreme aspect
        // ratios), it can cause cutoff when the aspect ratio breaks. So we always make sure to
        // round accordingly to avoid such issues.
        if (mTargetIsMax) {
            mSize = textureSize;

            glm::vec2 resizeScale {(mTargetSize.x / mSize.x), (mTargetSize.y / mSize.y)};

            if (resizeScale.x < resizeScale.y) {
                // This will be mTargetSize.x. We can't exceed it, nor be lower than it.
                mSize.x *= resizeScale.x;
                // We need to make sure we're not creating an image larger than max size.
                mSize.y = floorf(std::min(mSize.y * resizeScale.x, mTargetSize.y));
            }
            else {
                // This will be mTargetSize.y(). We can't exceed it.
                mSize.y *= resizeScale.y;
                mSize.x = std::min((mSize.y / textureSize.y) * textureSize.x, mTargetSize.x);
            }
        }
        else if (mTargetIsMin) {
            mSize = textureSize;

            glm::vec2 resizeScale {(mTargetSize.x / mSize.x), (mTargetSize.y / mSize.y)};

            if (resizeScale.x > resizeScale.y) {
                mSize.x *= resizeScale.x;
                mSize.y *= resizeScale.x;

                float cropPercent = (mSize.y - mTargetSize.y) / (mSize.y * 2.0f);
                crop(0.0f, cropPercent, 0.0f, cropPercent);
            }
            else {
                mSize.x *= resizeScale.y;
                mSize.y *= resizeScale.y;

                float cropPercent = (mSize.x - mTargetSize.x) / (mSize.x * 2.0f);
                crop(cropPercent, 0.0f, cropPercent, 0.0f);
            }
            mSize.y = std::max(mSize.y, mTargetSize.y);
            mSize.x = std::max((mSize.y / textureSize.y) * textureSize.x, mTargetSize.x);
        }
        else {
            // If both components are set, we just stretch.
            // If no components are set, we don't resize at all.
            mSize = mTargetSize == glm::vec2 {} ? textureSize : mTargetSize;

            // If only one component is set, we resize in a way that maintains aspect ratio.
            if (!mTargetSize.x && mTargetSize.y) {
                mSize.y = mTargetSize.y;
                mSize.x = (mSize.y / textureSize.y) * textureSize.x;
            }
            else if (mTargetSize.x && !mTargetSize.y) {
                mSize.y = (mTargetSize.x / textureSize.x) * textureSize.y;
                mSize.x = (mSize.y / textureSize.y) * textureSize.x;
            }
        }
    }

    // Make sure sub-pixel values are not rounded to zero.
    if (mSize.x < 1.0f)
        mSize.x = 1.0f;
    if (mSize.y < 1.0f)
        mSize.y = 1.0f;

    mTexture->rasterizeAt(mSize.x, mSize.y);

    onSizeChanged();
}

void ImageComponent::setImage(const std::string& path, bool tile, bool linearMagnify)
{
    // Always load bundled graphic resources statically, unless mForceLoad has been set.
    // This eliminates annoying texture pop-in problems that would otherwise occur.
    if (!mForceLoad && (path[0] == ':') && (path[1] == '/')) {
        mDynamic = false;
    }

    if (path.empty() || !ResourceManager::getInstance().fileExists(path)) {
        if (mDefaultPath.empty() || !ResourceManager::getInstance().fileExists(mDefaultPath))
            mTexture.reset();
        else
            mTexture =
                TextureResource::get(mDefaultPath, tile, mForceLoad, mDynamic, linearMagnify);
    }
    else {
        mTexture = TextureResource::get(path, tile, mForceLoad, mDynamic, linearMagnify);
    }

    resize();
}

void ImageComponent::setImage(const char* data, size_t length, bool tile)
{
    mTexture.reset();

    mTexture = TextureResource::get("", tile);
    mTexture->initFromMemory(data, length);

    resize();
}

void ImageComponent::setImage(const std::shared_ptr<TextureResource>& texture, bool resizeTexture)
{
    mTexture = texture;
    if (resizeTexture)
        resize();
}

void ImageComponent::setResize(float width, float height)
{
    mTargetSize = glm::vec2 {width, height};
    mTargetIsMax = false;
    mTargetIsMin = false;
    resize();
}

void ImageComponent::setMaxSize(const float width, const float height)
{
    mTargetSize = glm::vec2 {width, height};
    mTargetIsMax = true;
    mTargetIsMin = false;
    resize();
}

void ImageComponent::setMinSize(const float width, const float height)
{
    mTargetSize = glm::vec2 {width, height};
    mTargetIsMax = false;
    mTargetIsMin = true;
    resize();
}

void ImageComponent::cropLeft(const float percent)
{
    assert(percent >= 0.0f && percent <= 1.0f);
    mTopLeftCrop.x = percent;
}

void ImageComponent::cropTop(const float percent)
{
    assert(percent >= 0.0f && percent <= 1.0f);
    mTopLeftCrop.y = percent;
}

void ImageComponent::cropRight(const float percent)
{
    assert(percent >= 0.0f && percent <= 1.0f);
    mBottomRightCrop.x = 1.0f - percent;
}

void ImageComponent::cropBot(const float percent)
{
    assert(percent >= 0.0f && percent <= 1.0f);
    mBottomRightCrop.y = 1.0f - percent;
}

void ImageComponent::crop(const float left, const float top, const float right, const float bot)
{
    cropLeft(left);
    cropTop(top);
    cropRight(right);
    cropBot(bot);
}

void ImageComponent::uncrop()
{
    // Remove any applied crop.
    crop(0.0f, 0.0f, 0.0f, 0.0f);
}

void ImageComponent::cropTransparentPadding(const float maxSizeX, const float maxSizeY)
{
    if (mSize == glm::vec2 {})
        return;

    std::vector<unsigned char> imageRGBA = mTexture.get()->getRawRGBAData();

    if (imageRGBA.size() == 0)
        return;

    glm::ivec2 imageSize {mTexture.get()->getSize()};
    cimg_library::CImg<unsigned char> imageCImg(imageSize.x, imageSize.y, 1, 4, 0);

    int paddingCoords[4] {};

    // We need to convert our RGBA data to the CImg internal format as CImg does not interleave
    // the pixels (as in RGBARGBARGBA).
    Utils::CImg::convertRGBAToCImg(imageRGBA, imageCImg);

    // This will give us the coordinates for the fully transparent areas.
    Utils::CImg::getTransparentPaddingCoords(imageCImg, paddingCoords);

    glm::vec2 originalSize {mSize};

    float cropLeft {static_cast<float>(paddingCoords[0]) / static_cast<float>(imageSize.x)};
    float cropTop {static_cast<float>(paddingCoords[1]) / static_cast<float>(imageSize.y)};
    float cropRight {static_cast<float>(paddingCoords[2]) / static_cast<float>(imageSize.x)};
    float cropBottom {static_cast<float>(paddingCoords[3]) / static_cast<float>(imageSize.y)};

    crop(cropLeft, cropTop, cropRight, cropBottom);

    // Cropping the image obviously leads to a reduction in size, so we need to determine
    // how much to scale up after cropping to keep within the max size restrictions that
    // were passed as arguments.
    mSize.x -= mSize.x * (cropLeft + cropRight);
    mSize.y -= mSize.y * (cropTop + cropBottom);

    float scaleFactor = originalSize.y / mSize.y;

    if (scaleFactor * mSize.x < maxSizeX)
        scaleFactor = maxSizeX / mSize.x;

    if (scaleFactor * mSize.y < maxSizeY)
        scaleFactor = maxSizeY / mSize.y;

    if (scaleFactor * mSize.x > maxSizeX)
        scaleFactor = maxSizeX / mSize.x;

    if (scaleFactor * mSize.y > maxSizeY)
        scaleFactor = maxSizeY / mSize.y;

    setResize(mSize.x * scaleFactor, mSize.y * scaleFactor);
    updateVertices();
}

void ImageComponent::setFlipX(bool flip)
{
    mFlipX = flip;
    updateVertices();
}

void ImageComponent::setFlipY(bool flip)
{
    mFlipY = flip;
    updateVertices();
}

void ImageComponent::setColorShift(unsigned int color)
{
    mColorShift = color;
    mColorShiftEnd = color;
    updateColors();
}

void ImageComponent::setColorShiftEnd(unsigned int color)
{
    mColorShiftEnd = color;
    updateColors();
}

void ImageComponent::setColorGradientHorizontal(bool horizontal)
{
    mColorGradientHorizontal = horizontal;
    updateColors();
}

void ImageComponent::setOpacity(unsigned char opacity)
{
    mOpacity = opacity;
    updateColors();
}

void ImageComponent::setSaturation(float saturation)
{
    mSaturation = saturation;
    updateColors();
}

void ImageComponent::updateVertices()
{
    if (!mTexture)
        return;

    // We go through this mess to make sure everything is properly rounded.
    // If we just round vertices at the end, edge cases occur near sizes of 0.5.
    const glm::vec2 topLeft {};
    const glm::vec2 bottomRight {mSize};
    const float px {mTexture->isTiled() ? mSize.x / getTextureSize().x : 1.0f};
    const float py {mTexture->isTiled() ? mSize.y / getTextureSize().y : 1.0f};

    // clang-format off
    mVertices[0] = {{topLeft.x,     topLeft.y    }, {mTopLeftCrop.x,          py   - mTopLeftCrop.y    }, 0};
    mVertices[1] = {{topLeft.x,     bottomRight.y}, {mTopLeftCrop.x,          1.0f - mBottomRightCrop.y}, 0};
    mVertices[2] = {{bottomRight.x, topLeft.y    }, {mBottomRightCrop.x * px, py   - mTopLeftCrop.y    }, 0};
    mVertices[3] = {{bottomRight.x, bottomRight.y}, {mBottomRightCrop.x * px, 1.0f - mBottomRightCrop.y}, 0};
    // clang-format on

    updateColors();

    // Round vertices.
    for (int i = 0; i < 4; ++i)
        mVertices[i].pos = glm::round(mVertices[i].pos);

    if (mFlipX) {
        for (int i = 0; i < 4; ++i)
            mVertices[i].tex[0] = px - mVertices[i].tex[0];
    }

    if (mFlipY) {
        for (int i = 0; i < 4; ++i)
            mVertices[i].tex[1] = py - mVertices[i].tex[1];
    }
}

void ImageComponent::updateColors()
{
    const float opacity = (mOpacity * (mFading ? mFadeOpacity / 255.0f : 1.0f)) / 255.0f;
    const unsigned int color = Renderer::convertRGBAToABGR(
        (mColorShift & 0xFFFFFF00) | static_cast<unsigned char>((mColorShift & 0xFF) * opacity));
    const unsigned int colorEnd =
        Renderer::convertRGBAToABGR((mColorShiftEnd & 0xFFFFFF00) |
                                    static_cast<unsigned char>((mColorShiftEnd & 0xFF) * opacity));

    mVertices[0].col = color;
    mVertices[1].col = mColorGradientHorizontal ? colorEnd : color;
    mVertices[2].col = mColorGradientHorizontal ? color : colorEnd;
    mVertices[3].col = colorEnd;
}

void ImageComponent::render(const glm::mat4& parentTrans)
{
    if (!isVisible() || mTexture == nullptr || mTargetSize == glm::vec2 {0.0f, 0.0f})
        return;

    glm::mat4 trans {parentTrans * getTransform()};
    Renderer::setMatrix(trans);

    if (mTexture && mOpacity > 0) {
        if (Settings::getInstance()->getBool("DebugImage")) {
            glm::vec2 targetSizePos {(mTargetSize - mSize) * mOrigin * glm::vec2 {-1.0f}};
            Renderer::drawRect(targetSizePos.x, targetSizePos.y, mTargetSize.x, mTargetSize.y,
                               0xFF000033, 0xFF000033);
            Renderer::drawRect(0.0f, 0.0f, mSize.x, mSize.y, 0xFF000033, 0xFF000033);
        }
        // An image with zero size would normally indicate a corrupt image file.
        if (mTexture->getSize() != glm::ivec2 {}) {
            // Actually draw the image.
            // The bind() function returns false if the texture is not currently loaded. A blank
            // texture is bound in this case but we want to handle a fade so it doesn't just
            // 'jump' in when it finally loads. The exception is if the cached background is
            // getting invalidated, in which case we want to make sure to not get a partially
            // faded texture rendered onto the new background.
            if (mWindow->isInvalidatingCachedBackground())
                mTexture->bind();
            else
                fadeIn(mTexture->bind());

#if defined(USE_OPENGL_21)
            if (mSaturation < 1.0) {
                mVertices[0].shaders = Renderer::SHADER_DESATURATE;
                mVertices[0].saturation = mSaturation;
            }
#endif
            Renderer::drawTriangleStrips(&mVertices[0], 4, trans);
        }
        else {
            if (!mTexture) {
                LOG(LogError) << "Image texture is not initialized";
            }
            else {
                std::string textureFilePath = mTexture->getTextureFilePath();
                if (textureFilePath != "") {
                    LOG(LogError) << "Image texture for file \"" << textureFilePath
                                  << "\" has zero size";
                }
                else {
                    LOG(LogError) << "Image texture has zero size";
                }
            }
            mTexture.reset();
        }
    }

    GuiComponent::renderChildren(trans);
}

void ImageComponent::fadeIn(bool textureLoaded)
{
    if (!mForceLoad) {
        if (!textureLoaded) {
            // Start the fade if this is the first time we've encountered the unloaded texture.
            if (!mFading) {
                // Start with a zero opacity and flag it as fading.
                mFadeOpacity = 0;
                mFading = true;
                updateColors();
            }
        }
        else if (mFading) {
            // The texture is loaded and we need to fade it in. The fade is based on the frame
            // rate and is 1/4 second if running at 60 frames per second although the actual
            // value is not that important.
            int opacity = mFadeOpacity + 255 / 15;
            // See if we've finished fading.
            if (opacity >= 255) {
                mFadeOpacity = 255;
                mFading = false;
            }
            else {
                mFadeOpacity = static_cast<unsigned char>(opacity);
            }
            updateColors();
        }
    }
}

void ImageComponent::applyTheme(const std::shared_ptr<ThemeData>& theme,
                                const std::string& view,
                                const std::string& element,
                                unsigned int properties)
{
    using namespace ThemeFlags;
    GuiComponent::applyTheme(theme, view, element,
                             (properties ^ ThemeFlags::SIZE) |
                                 ((properties & (ThemeFlags::SIZE | POSITION)) ? ORIGIN : 0));

    const ThemeData::ThemeElement* elem = theme->getElement(view, element, "image");
    if (!elem)
        return;

    glm::vec2 scale {getParent() ? getParent()->getSize() :
                                   glm::vec2(static_cast<float>(Renderer::getScreenWidth()),
                                             static_cast<float>(Renderer::getScreenHeight()))};

    if (properties & ThemeFlags::SIZE) {
        if (elem->has("size"))
            setResize(elem->get<glm::vec2>("size") * scale);
        else if (elem->has("maxSize"))
            setMaxSize(elem->get<glm::vec2>("maxSize") * scale);
        else if (elem->has("minSize"))
            setMinSize(elem->get<glm::vec2>("minSize") * scale);
    }

    if (elem->has("default"))
        setDefaultImage(elem->get<std::string>("default"));

    if (properties & PATH && elem->has("path")) {
        bool tile = (elem->has("tile") && elem->get<bool>("tile"));
        setImage(elem->get<std::string>("path"), tile);
    }

    if (properties & METADATA && elem->has("metadata"))
        setMetadataField(elem->get<std::string>("metadata"));

    if (properties & COLOR) {
        if (elem->has("color"))
            setColorShift(elem->get<unsigned int>("color"));
        if (elem->has("colorEnd"))
            setColorShiftEnd(elem->get<unsigned int>("colorEnd"));
        if (elem->has("gradientType"))
            setColorGradientHorizontal(
                !(elem->get<std::string>("gradientType").compare("horizontal")));
    }
}

std::vector<HelpPrompt> ImageComponent::getHelpPrompts()
{
    std::vector<HelpPrompt> ret;
    ret.push_back(HelpPrompt("a", "select"));
    return ret;
}