/*

 * Copyright (c) 2021-2024, Andreas Kling <kling@serenityos.org>

 *

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

 */

#include <AK/IDAllocator.h>

#include <LibWeb/DOM/Document.h>

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

namespace Web::HTML {

JS_DEFINE_ALLOCATOR(Task);

static IDAllocator s_unique_task_source_allocator { static_cast<int>(Task::Source::UniqueTaskSourceStart) };

[[nodiscard]] static TaskID allocate_task_id()

{

    static u64 next_task_id = 1;

    return next_task_id++;

}

JS::NonnullGCPtr<Task> Task::create(JS::VM& vm, Source source, JS::GCPtr<DOM::Document const> document, JS::NonnullGCPtr<JS::HeapFunction<void()>> steps)

{

    return vm.heap().allocate_without_realm<Task>(source, document, move(steps));

}

Task::Task(Source source, JS::GCPtr<DOM::Document const> document, JS::NonnullGCPtr<JS::HeapFunction<void()>> steps)

    : m_id(allocate_task_id())

    , m_source(source)

    , m_steps(steps)

    , m_document(document)

{

}

Task::~Task() = default;

void Task::visit_edges(Visitor& visitor)

{

    Base::visit_edges(visitor);

    visitor.visit(m_steps);

    visitor.visit(m_document);

}

void Task::execute()

{

    m_steps->function()();

}

// https://html.spec.whatwg.org/#concept-task-runnable

bool Task::is_runnable() const

{

    // A task is runnable if its document is either null or fully active.

    return !m_document.ptr() || m_document->is_fully_active();

}

DOM::Document const* Task::document() const

{

    return m_document.ptr();

}

UniqueTaskSource::UniqueTaskSource()

    : source(static_cast<Task::Source>(s_unique_task_source_allocator.allocate()))

{

}

UniqueTaskSource::~UniqueTaskSource()

{

    s_unique_task_source_allocator.deallocate(static_cast<int>(source));

}

}