/*
 * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/HashMap.h>
#include <AK/NonnullRefPtr.h>
#include <AK/String.h>
#include <AK/Variant.h>
#include <AK/Vector.h>
#include <LibWeb/Bindings/Wrappable.h>
#include <LibWeb/DOM/ExceptionOr.h>
#include <LibWeb/Fetch/Infrastructure/HTTP/Headers.h>

namespace Web::Fetch {

using HeadersInit = Variant<Vector<Vector<String>>, OrderedHashMap<String, String>>;

// https://fetch.spec.whatwg.org/#headers-class
class Headers
    : public Bindings::Wrappable
    , public RefCounted<Headers> {
public:
    using WrapperType = Bindings::HeadersWrapper;

    enum class Guard {
        Immutable,
        Request,
        RequestNoCORS,
        Response,
        None,
    };

    static DOM::ExceptionOr<NonnullRefPtr<Headers>> create(Optional<HeadersInit> const&);

    static DOM::ExceptionOr<NonnullRefPtr<Headers>> create_with_global_object(Bindings::WindowObject&, Optional<HeadersInit> const& init)
    {
        return create(init);
    }

    DOM::ExceptionOr<void> append(Infrastructure::Header);
    DOM::ExceptionOr<void> append(String const& name, String const& value);
    DOM::ExceptionOr<void> delete_(String const& name);
    DOM::ExceptionOr<String> get(String const& name);
    DOM::ExceptionOr<bool> has(String const& name);
    DOM::ExceptionOr<void> set(String const& name, String const& value);

    using ForEachCallback = Function<JS::ThrowCompletionOr<void>(String const&, String const&)>;
    JS::ThrowCompletionOr<void> for_each(ForEachCallback);

private:
    friend class HeadersIterator;

    Headers() = default;

    DOM::ExceptionOr<void> fill(HeadersInit const&);
    void remove_privileged_no_cors_headers();

    // https://fetch.spec.whatwg.org/#concept-headers-header-list
    // A Headers object has an associated header list (a header list), which is initially empty.
    Infrastructure::HeaderList m_header_list;

    // https://fetch.spec.whatwg.org/#concept-headers-guard
    // A Headers object also has an associated guard, which is a headers guard. A headers guard is "immutable", "request", "request-no-cors", "response" or "none".
    Guard m_guard { Guard::None };
};

}

namespace Web::Bindings {

HeadersWrapper* wrap(JS::GlobalObject&, Fetch::Headers&);

}