/*
	This file is part of Fennix Kernel.

	Fennix Kernel is free software: you can redistribute it and/or
	modify it under the terms of the GNU General Public License as
	published by the Free Software Foundation, either version 3 of
	the License, or (at your option) any later version.

	Fennix Kernel is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#ifndef __FENNIX_KERNEL_IPv4_H__
#define __FENNIX_KERNEL_IPv4_H__

#include <net/ipv4.hpp>
#include <net/arp.hpp>
#include <net/nc.hpp>
#include <types.h>

namespace NetworkIPv4
{
	struct IPv4Header
	{
		uint8_t IHL : 4;
		uint8_t Version : 4;
		uint8_t TypeOfService;
		uint16_t TotalLength;
		uint16_t Identification;
		uint8_t Flags;
		uint8_t FragmentOffset;
		uint8_t TimeToLive;
		uint8_t Protocol;
		uint16_t HeaderChecksum;
		uint32_t SourceIP;
		uint32_t DestinationIP;

		/* On wikipedia page we have this: https://en.wikipedia.org/wiki/File:IPv4_Packet-en.svg
		   but only the code above works... */
		// uint8_t Version : 4;
		// uint8_t IHL : 4;
		// uint16_t TypeOfService : 8;
		// uint16_t TotalLength : 12;
		// uint16_t Identification : 16;
		// uint16_t Flags : 3;
		// uint16_t FragmentOffset : 13;
		// uint8_t TimeToLive : 8;
		// uint8_t Protocol : 8;
		// uint16_t HeaderChecksum;
		// uint32_t SourceIP;
		// uint32_t DestinationIP;
	};

	struct IPv4Packet
	{
		IPv4Header Header;
		uint8_t Data[];
	};

	enum IPv4Protocols
	{
		PROTOCOL_ICMP = 1,
		PROTOCOL_IGMP = 2,
		PROTOCOL_TCP = 6,
		PROTOCOL_UDP = 17,
		PROTOCOL_IPV6 = 41,
		PROTOCOL_ROUTING = 43,
		PROTOCOL_FRAGMENT = 44,
		PROTOCOL_ESP = 50,
		PROTOCOL_AH = 51,
		PROTOCOL_ICMPV6 = 58,
		PROTOCOL_NONE = 59,
		PROTOCOL_DSTOPTS = 60,
		PROTOCOL_ND = 77,
		PROTOCOL_ICLFXBM = 78,
		PROTOCOL_PIM = 103,
		PROTOCOL_COMP = 108,
		PROTOCOL_SCTP = 132,
		PROTOCOL_UDPLITE = 136,
		PROTOCOL_RAW = 255
	};

	class IPv4 : public NetworkEthernet::EthernetEvents
	{
	private:
		NetworkARP::ARP *ARP;
		NetworkEthernet::Ethernet *Ethernet;

		virtual bool OnEthernetPacketReceived(uint8_t *Data, size_t Length);

	public:
		InternetProtocol GatewayIP;
		InternetProtocol SubNetworkMaskIP;
		IPv4(NetworkARP::ARP *ARP, NetworkEthernet::Ethernet *Ethernet);
		~IPv4();

		/**
		 * @brief Send an IPv4 packet.
		 *
		 * @param Data The data to send.
		 * @param Length The length of the data.
		 * @param Protocol The protocol of the packet.
		 * @param DestinationIP The IP address of the destination. (Big-endian)
		 */
		void Send(uint8_t *Data, size_t Length, uint8_t Protocol, InternetProtocol DestinationIP);
	};

	class IPv4Events
	{
	private:
		uint8_t Protocol;

	protected:
		IPv4Events(IPv4Protocols Protocol);
		~IPv4Events();

	public:
		uint8_t GetProtocol() { return Protocol; }

		virtual bool OnIPv4PacketReceived(InternetProtocol SourceIP, InternetProtocol DestinationIP, uint8_t *Data, size_t Length)
		{
			UNUSED(SourceIP);
			UNUSED(DestinationIP);
			UNUSED(Data);
			UNUSED(Length);
			warn("Not implemented");
			return false;
		}
	};
}

#endif // !__FENNIX_KERNEL_IPv4_H__