/*

 * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>

 *

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

 */

#include <LibJS/Runtime/Array.h>

#include <LibJS/Runtime/Iterator.h>

#include <LibWeb/Bindings/HeadersIteratorPrototype.h>

#include <LibWeb/Bindings/Intrinsics.h>

#include <LibWeb/Fetch/HeadersIterator.h>

namespace Web::Bindings {

template<>

void Intrinsics::create_web_prototype_and_constructor<HeadersIteratorPrototype>(JS::Realm& realm)

{

    auto prototype = heap().allocate<HeadersIteratorPrototype>(realm, realm);

    m_prototypes.set("HeadersIterator"_fly_string, prototype);

}

}

namespace Web::Fetch {

JS_DEFINE_ALLOCATOR(HeadersIterator);

JS::NonnullGCPtr<HeadersIterator> HeadersIterator::create(Headers const& headers, JS::Object::PropertyKind iteration_kind)

{

    return headers.heap().allocate<HeadersIterator>(headers.realm(), headers, iteration_kind);

}

HeadersIterator::HeadersIterator(Headers const& headers, JS::Object::PropertyKind iteration_kind)

    : PlatformObject(headers.realm())

    , m_headers(headers)

    , m_iteration_kind(iteration_kind)

{

}

HeadersIterator::~HeadersIterator() = default;

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

{

    Base::initialize(realm);

    WEB_SET_PROTOTYPE_FOR_INTERFACE(HeadersIterator);

}

void HeadersIterator::visit_edges(JS::Cell::Visitor& visitor)

{

    Base::visit_edges(visitor);

    visitor.visit(m_headers);

}

// https://webidl.spec.whatwg.org/#es-iterable, Step 2

JS::NonnullGCPtr<JS::Object> HeadersIterator::next()

{

    // The value pairs to iterate over are the return value of running sort and combine with this’s header list.

    auto value_pairs_to_iterate_over = [&]() {

        return m_headers->m_header_list->sort_and_combine();

    };

    auto pairs = value_pairs_to_iterate_over();

    if (m_index >= pairs.size())

        return create_iterator_result_object(vm(), JS::js_undefined(), true);

    auto const& pair = pairs[m_index++];

    StringView pair_name { pair.name };

    StringView pair_value { pair.value };

    switch (m_iteration_kind) {

    case JS::Object::PropertyKind::Key:

        return create_iterator_result_object(vm(), JS::PrimitiveString::create(vm(), pair_name), false);

    case JS::Object::PropertyKind::Value:

        return create_iterator_result_object(vm(), JS::PrimitiveString::create(vm(), pair_value), false);

    case JS::Object::PropertyKind::KeyAndValue: {

        auto array = JS::Array::create_from(realm(), { JS::PrimitiveString::create(vm(), pair_name), JS::PrimitiveString::create(vm(), pair_value) });

        return create_iterator_result_object(vm(), array, false);

    }

    default:

        VERIFY_NOT_REACHED();

    }

}

}