ladybird/Libraries/LibWeb/CSS/GridTrackSize.h

/*
 * Copyright (c) 2022, Martin Falisse <mfalisse@outlook.com>
 * Copyright (c) 2025, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
 * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/FlyString.h>
#include <AK/HashMap.h>
#include <AK/Vector.h>
#include <LibWeb/CSS/PercentageOr.h>
#include <LibWeb/CSS/Size.h>
#include <LibWeb/Layout/AvailableSpace.h>

namespace Web::CSS {

class GridSize {
public:
    GridSize(NonnullRefPtr<StyleValue const>);
    ~GridSize();

    static GridSize make_auto();

    bool is_auto(Layout::AvailableSize const&) const;
    bool is_fixed(Layout::AvailableSize const&) const;
    bool is_flexible_length() const;
    bool is_fit_content() const;
    bool is_max_content() const;
    bool is_min_content() const;

    Size css_size() const { return Size::from_style_value(m_value); }
    double flex_factor() const { return Flex::from_style_value(m_value).to_fr(); }

    NonnullRefPtr<StyleValue const> style_value() const { return m_value; }

    // https://www.w3.org/TR/css-grid-2/#layout-algorithm
    // An intrinsic sizing function (min-content, max-content, auto, fit-content()).
    bool is_intrinsic(Layout::AvailableSize const&) const;

    bool is_definite() const;

    void serialize(StringBuilder&, SerializationMode) const;
    String to_string(SerializationMode) const;
    GridSize absolutized(ComputationContext const&) const;
    bool operator==(GridSize const& other) const = default;

    bool is_computationally_independent() const { return m_value->is_computationally_independent(); }

private:
    ValueComparingNonnullRefPtr<StyleValue const> m_value;
};

class GridMinMax {
public:
    GridMinMax(CSS::GridSize min_grid_size, CSS::GridSize max_grid_size);

    GridSize const& min_grid_size() const& { return m_min_grid_size; }
    GridSize const& max_grid_size() const& { return m_max_grid_size; }

    void serialize(StringBuilder&, SerializationMode) const;
    String to_string(SerializationMode) const;
    GridMinMax absolutized(ComputationContext const&) const;
    bool operator==(GridMinMax const& other) const = default;

    bool is_computationally_independent() const
    {
        return m_min_grid_size.is_computationally_independent() && m_max_grid_size.is_computationally_independent();
    }

private:
    GridSize m_min_grid_size;
    GridSize m_max_grid_size;
};

struct GridLineName {
    FlyString name;
    bool implicit { false };
    bool adopted_from_parent_grid { false };

    bool operator==(GridLineName const& other) const = default;
};

struct GridArea {
    size_t row_start { 0 };
    size_t row_end { 1 };
    size_t column_start { 0 };
    size_t column_end { 1 };

    bool operator==(GridArea const& other) const = default;
};

struct GridTemplateAreas {
    HashMap<String, GridArea> areas;
    size_t row_count { 0 };
    size_t column_count { 0 };

    bool is_empty() const { return row_count == 0; }
    bool operator==(GridTemplateAreas const& other) const = default;
};

class GridLineNames {
public:
    void append(FlyString const& name) { m_names.append({ name }); }
    bool is_empty() const { return m_names.is_empty(); }
    auto const& names() const& { return m_names; }

    void serialize(StringBuilder&) const;
    String to_string() const;

    bool operator==(GridLineNames const& other) const = default;

private:
    Vector<GridLineName> m_names;
};

class GridTrackSizeList {
public:
    static GridTrackSizeList make_none();
    static GridTrackSizeList make_line_name_list();
    static GridTrackSizeList make_subgrid();

    Vector<CSS::ExplicitGridTrack> track_list() const;
    auto const& list() const { return m_list; }
    bool is_subgrid() const { return m_is_subgrid; }

    void serialize(StringBuilder&, SerializationMode) const;
    String to_string(SerializationMode) const;
    bool operator==(GridTrackSizeList const& other) const;

    bool is_empty() const { return !m_is_subgrid && m_list.is_empty(); }

    void append(GridLineNames&&);
    void append(ExplicitGridTrack&&);

    GridTrackSizeList absolutized(ComputationContext const&) const;

    bool is_computationally_independent() const;

private:
    bool m_is_subgrid { false };
    bool m_preserve_line_name_sets { false };
    Vector<Variant<ExplicitGridTrack, GridLineNames>> m_list;
};

enum class GridRepeatType {
    AutoFit,
    AutoFill,
    Fixed,
};

struct GridRepeatParams {
    GridRepeatType type;
    RefPtr<StyleValue const> count { nullptr };
};

class GridRepeat {
public:
    GridRepeat(GridRepeatType, GridTrackSizeList&&, RefPtr<StyleValue const> repeat_count);
    GridRepeat(GridTrackSizeList&&, GridRepeatParams const&);

    bool is_auto_fill() const { return m_type == GridRepeatType::AutoFill; }
    bool is_auto_fit() const { return m_type == GridRepeatType::AutoFit; }
    bool is_fixed() const { return m_type == GridRepeatType::Fixed; }
    size_t repeat_count() const
    {
        VERIFY(is_fixed());
        return int_from_style_value(*m_repeat_count);
    }
    GridTrackSizeList const& grid_track_size_list() const& { return m_grid_track_size_list; }
    GridRepeatType type() const& { return m_type; }

    void serialize(StringBuilder&, SerializationMode) const;
    String to_string(SerializationMode) const;
    GridRepeat absolutized(ComputationContext const&) const;
    bool operator==(GridRepeat const& other) const = default;

    bool is_computationally_independent() const { return m_grid_track_size_list.is_computationally_independent() && (!m_repeat_count || m_repeat_count->is_computationally_independent()); }

private:
    GridRepeatType m_type;
    GridTrackSizeList m_grid_track_size_list;
    ValueComparingRefPtr<StyleValue const> m_repeat_count;
};

class ExplicitGridTrack {
public:
    ExplicitGridTrack(Variant<GridRepeat, GridMinMax, GridSize>&& value);

    bool is_repeat() const { return m_value.has<GridRepeat>(); }
    GridRepeat const& repeat() const { return m_value.get<GridRepeat>(); }

    bool is_minmax() const { return m_value.has<GridMinMax>(); }
    GridMinMax const& minmax() const { return m_value.get<GridMinMax>(); }

    bool is_default() const { return m_value.has<GridSize>(); }
    GridSize const& grid_size() const { return m_value.get<GridSize>(); }

    void serialize(StringBuilder&, SerializationMode) const;
    String to_string(SerializationMode) const;
    ExplicitGridTrack absolutized(ComputationContext const&) const;
    bool operator==(ExplicitGridTrack const& other) const = default;

    bool is_computationally_independent() const
    {
        return m_value.visit([](auto const& value) { return value.is_computationally_independent(); });
    }

private:
    Variant<GridRepeat, GridMinMax, GridSize> m_value;
};

}