#pragma once

#include <kernel/FS/Socket.h>
#include <kernel/Networking/NetworkInterface.h>

namespace Kernel
{

	struct PseudoHeader
	{
		BAN::IPv4Address src_ipv4				{ 0 };
		BAN::IPv4Address dst_ipv4				{ 0 };
		BAN::NetworkEndian<uint16_t> protocol	{ 0 };
		BAN::NetworkEndian<uint16_t> length		{ 0 };
	};
	static_assert(sizeof(PseudoHeader) == 12);

	class NetworkSocket;

	class NetworkLayer
	{
	public:
		virtual ~NetworkLayer() {}

		virtual void unbind_socket(uint16_t port) = 0;
		virtual BAN::ErrorOr<void> bind_socket_with_target(BAN::RefPtr<NetworkSocket>, const sockaddr* target_address, socklen_t target_address_len) = 0;
		virtual BAN::ErrorOr<void> bind_socket_to_address(BAN::RefPtr<NetworkSocket>, const sockaddr* address, socklen_t address_len) = 0;
		virtual BAN::ErrorOr<void> get_socket_address(BAN::RefPtr<NetworkSocket>, sockaddr* address, socklen_t* address_len) = 0;

		virtual BAN::ErrorOr<size_t> sendto(NetworkSocket&, BAN::ConstByteSpan, const sockaddr*, socklen_t) = 0;

		virtual Socket::Domain domain() const = 0;
		virtual size_t header_size() const = 0;

	protected:
		NetworkLayer() = default;
	};

	uint16_t calculate_internet_checksum(BAN::ConstByteSpan buffer);
	uint16_t calculate_internet_checksum(BAN::Span<const BAN::ConstByteSpan> buffers);

}