/*

 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>

 * Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>

 * Copyright (c) 2022-2023, MacDue <macdue@dueutil.tech>

 *

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

 */

#pragma once

#include <AK/Vector.h>

#include <LibWeb/CSS/Angle.h>

#include <LibWeb/CSS/Percentage.h>

#include <LibWeb/CSS/StyleValues/AbstractImageStyleValue.h>

#include <LibWeb/Painting/GradientPainting.h>

namespace Web::CSS {

// Note: The sides must be before the corners in this enum (as this order is used in parsing).

enum class SideOrCorner {

    Top,

    Bottom,

    Left,

    Right,

    TopLeft,

    TopRight,

    BottomLeft,

    BottomRight

};

class LinearGradientStyleValue final : public AbstractImageStyleValue {

public:

    using GradientDirection = Variant<Angle, SideOrCorner>;

    enum class GradientType {

        Standard,

        WebKit

    };

    static ValueComparingNonnullRefPtr<LinearGradientStyleValue> create(GradientDirection direction, Vector<LinearColorStopListElement> color_stop_list, GradientType type, GradientRepeating repeating)

    {

        VERIFY(color_stop_list.size() >= 2);

        return adopt_ref(*new (nothrow) LinearGradientStyleValue(direction, move(color_stop_list), type, repeating));

    }

    virtual String to_string() const override;

    virtual ~LinearGradientStyleValue() override = default;

    virtual bool equals(CSSStyleValue const& other) const override;

    Vector<LinearColorStopListElement> const& color_stop_list() const

    {

        return m_properties.color_stop_list;

    }

    bool is_repeating() const { return m_properties.repeating == GradientRepeating::Yes; }

    float angle_degrees(CSSPixelSize gradient_size) const;

    void resolve_for_size(Layout::NodeWithStyleAndBoxModelMetrics const&, CSSPixelSize) const override;

    bool is_paintable() const override { return true; }

    void paint(PaintContext& context, DevicePixelRect const& dest_rect, CSS::ImageRendering image_rendering, Vector<Gfx::Path> const& clip_paths = {}) const override;

private:

    LinearGradientStyleValue(GradientDirection direction, Vector<LinearColorStopListElement> color_stop_list, GradientType type, GradientRepeating repeating)

        : AbstractImageStyleValue(Type::LinearGradient)

        , m_properties { .direction = direction, .color_stop_list = move(color_stop_list), .gradient_type = type, .repeating = repeating }

    {

    }

    struct Properties {

        GradientDirection direction;

        Vector<LinearColorStopListElement> color_stop_list;

        GradientType gradient_type;

        GradientRepeating repeating;

        bool operator==(Properties const&) const = default;

    } m_properties;

    struct ResolvedData {

        Painting::LinearGradientData data;

        CSSPixelSize size;

    };

    mutable Optional<ResolvedData> m_resolved;

};

}