/*

 * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2022, the SerenityOS developers.

 *

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

 */

#include <LibWeb/Bindings/IdleDeadlinePrototype.h>

#include <LibWeb/HTML/EventLoop/EventLoop.h>

#include <LibWeb/HTML/Window.h>

#include <LibWeb/HighResolutionTime/TimeOrigin.h>

#include <LibWeb/RequestIdleCallback/IdleDeadline.h>

namespace Web::RequestIdleCallback {

JS_DEFINE_ALLOCATOR(IdleDeadline);

JS::NonnullGCPtr<IdleDeadline> IdleDeadline::create(JS::Realm& realm, bool did_timeout)

{

    return realm.heap().allocate<IdleDeadline>(realm, realm, did_timeout);

}

IdleDeadline::IdleDeadline(JS::Realm& realm, bool did_timeout)

    : PlatformObject(realm)

    , m_did_timeout(did_timeout)

{

}

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

{

    Base::initialize(realm);

    WEB_SET_PROTOTYPE_FOR_INTERFACE(IdleDeadline);

}

IdleDeadline::~IdleDeadline() = default;

// https://w3c.github.io/requestidlecallback/#dom-idledeadline-timeremaining

double IdleDeadline::time_remaining() const

{

    auto const& event_loop = HTML::main_thread_event_loop();

    // 1. Let now be a DOMHighResTimeStamp representing current high resolution time in milliseconds.

    auto now = HighResolutionTime::current_high_resolution_time(HTML::relevant_global_object(*this));

    // 2. Let deadline be the result of calling IdleDeadline's get deadline time algorithm.

    auto deadline = event_loop.compute_deadline();

    // 3. Let timeRemaining be deadline - now.

    auto time_remaining = deadline - now;

    // 4. If timeRemaining is negative, set it to 0.

    if (time_remaining < 0)

        time_remaining = 0;

    // 5. Return timeRemaining.

    // NOTE: coarsening to milliseconds

    return ceil(time_remaining);

}

}