/*

 * Copyright (c) 2024, Sam Atkins <sam@ladybird.org>

 *

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

 */

#pragma once

#include <AK/Checked.h>

#include <AK/FlyString.h>

#include <AK/Optional.h>

namespace Web::CSS {

// "UAs may have implementation-specific limits on the maximum or minimum value of a counter.

// If a counter reset, set, or increment would push the value outside of that range, the value

// must be clamped to that range." - https://drafts.csswg.org/css-lists-3/#auto-numbering

// So, we use a Checked<i32> and saturating addition/subtraction.

using CounterValue = Checked<i32>;

// https://drafts.csswg.org/css-lists-3/#counter

struct Counter {

    FlyString name;

    i32 originating_element_id; // "creator"

    bool reversed { false };

    Optional<CounterValue> value;

};

// https://drafts.csswg.org/css-lists-3/#css-counters-set

class CountersSet {

public:

    CountersSet() = default;

    ~CountersSet() = default;

    Counter& instantiate_a_counter(FlyString name, i32 originating_element_id, bool reversed, Optional<CounterValue>);

    void set_a_counter(FlyString name, i32 originating_element_id, CounterValue value);

    void increment_a_counter(FlyString name, i32 originating_element_id, CounterValue amount);

    void append_copy(Counter const&);

    Optional<Counter&> last_counter_with_name(FlyString const& name);

    Optional<Counter&> counter_with_same_name_and_creator(FlyString const& name, i32 originating_element_id);

    Vector<Counter> const& counters() const { return m_counters; }

    bool is_empty() const { return m_counters.is_empty(); }

private:

    Vector<Counter> m_counters;

};

}