/*

 * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2023, MacDue <macdue@dueutil.tech>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <AK/QuickSort.h>

#include <LibWeb/Bindings/CanvasGradientPrototype.h>

#include <LibWeb/Bindings/Intrinsics.h>

#include <LibWeb/HTML/CanvasGradient.h>

#include <LibWeb/WebIDL/ExceptionOr.h>

namespace Web::HTML {

JS_DEFINE_ALLOCATOR(CanvasGradient);

// https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createradialgradient

WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_radial(JS::Realm& realm, double x0, double y0, double r0, double x1, double y1, double r1)

{

    // If either of r0 or r1 are negative, then an "IndexSizeError" DOMException must be thrown.

    if (r0 < 0)

        return WebIDL::IndexSizeError::create(realm, "The r0 passed is less than 0"_string);

    if (r1 < 0)

        return WebIDL::IndexSizeError::create(realm, "The r1 passed is less than 0"_string);

    auto radial_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasRadialGradientPaintStyle::create(Gfx::FloatPoint { x0, y0 }, r0, Gfx::FloatPoint { x1, y1 }, r1));

    return realm.heap().allocate<CanvasGradient>(realm, realm, *radial_gradient);

}

// https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createlineargradient

WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_linear(JS::Realm& realm, double x0, double y0, double x1, double y1)

{

    auto linear_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasLinearGradientPaintStyle::create(Gfx::FloatPoint { x0, y0 }, Gfx::FloatPoint { x1, y1 }));

    return realm.heap().allocate<CanvasGradient>(realm, realm, *linear_gradient);

}

// https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createconicgradient

WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_conic(JS::Realm& realm, double start_angle, double x, double y)

{

    auto conic_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasConicGradientPaintStyle::create(Gfx::FloatPoint { x, y }, start_angle));

    return realm.heap().allocate<CanvasGradient>(realm, realm, *conic_gradient);

}

CanvasGradient::CanvasGradient(JS::Realm& realm, Gfx::GradientPaintStyle& gradient)

    : PlatformObject(realm)

    , m_gradient(gradient)

{

}

CanvasGradient::~CanvasGradient() = default;

void CanvasGradient::initialize(JS::Realm& realm)

{

    Base::initialize(realm);

    WEB_SET_PROTOTYPE_FOR_INTERFACE(CanvasGradient);

}

// https://html.spec.whatwg.org/multipage/canvas.html#dom-canvasgradient-addcolorstop

WebIDL::ExceptionOr<void> CanvasGradient::add_color_stop(double offset, StringView color)

{

    // 1. If the offset is less than 0 or greater than 1, then throw an "IndexSizeError" DOMException.

    if (offset < 0 || offset > 1)

        return WebIDL::IndexSizeError::create(realm(), "CanvasGradient color stop offset out of bounds"_string);

    // 2. Let parsed color be the result of parsing color.

    auto parsed_color = Color::from_string(color);

    // 3. If parsed color is failure, throw a "SyntaxError" DOMException.

    if (!parsed_color.has_value())

        return WebIDL::SyntaxError::create(realm(), "Could not parse color for CanvasGradient"_string);

    // 4. Place a new stop on the gradient, at offset offset relative to the whole gradient, and with the color parsed color.

    TRY_OR_THROW_OOM(realm().vm(), m_gradient->add_color_stop(offset, parsed_color.value()));

    // FIXME: If multiple stops are added at the same offset on a gradient, then they must be placed in the order added,

    //        with the first one closest to the start of the gradient, and each subsequent one infinitesimally further along

    //        towards the end point (in effect causing all but the first and last stop added at each point to be ignored).

    return {};

}

}