#include "NdpToArpPacketHandler.h"
#include <tins/ethernetII.h>
#include <tins/arp.h>
#include <tins/icmpv6.h>
#include <tins/ipv6.h>
#include <tins/ip_address.h>
#include <tins/ipv6_address.h>
#include "IpAddressTranslator.h"

NdpToArpPacketHandler::NdpToArpPacketHandler()
{
}

NdpToArpPacketHandler::~NdpToArpPacketHandler()
{
}

bool NdpToArpPacketHandler::handle(IN const Tins::PDU & pdu, IN IPacketHandler * callBackHandler)
{
	// callback handler requeried
	if (callBackHandler == nullptr)
	{
		return false;
	}

	// get ipv6 packet
	const Tins::IPv6 * ipPdu = pdu.find_pdu<Tins::IPv6>();
	if(ipPdu == nullptr)
	{
		return false;
	}

	// get ipcmp packet, which has the target address field
	const Tins::ICMPv6 * ndpPdu = pdu.find_pdu<Tins::ICMPv6>();
	if(ndpPdu == nullptr || !ndpPdu->has_target_addr())
	{
		return false;
	}

	// translate target address to ipv4
	const Tins::IPv6Address & targetIp6Address = ndpPdu->target_addr();
	UPtrIPv4Address targetIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(targetIp6Address));

	// create arp pdu
	Tins::ICMPv6::hwaddress_type senderHwAddr;
	const Tins::ICMPv6::option * ptrHwAddressOption;
	const Tins::ICMPv6::Types ndpType = ndpPdu->type();
	if (ndpType == Tins::ICMPv6::Types::NEIGHBOUR_SOLICIT)
	{
		ptrHwAddressOption = ndpPdu->search_option(Tins::ICMPv6::OptionTypes::SOURCE_ADDRESS);
		if (ptrHwAddressOption == nullptr)
		{
			const Tins::EthernetII * ethNsPdu = pdu.find_pdu<Tins::EthernetII>();
			if(ethNsPdu == nullptr)
			{
				return false;
			}

			senderHwAddr = ethNsPdu->src_addr();
		}
		else
		{
			senderHwAddr = ptrHwAddressOption->to<Tins::ICMPv6::hwaddress_type>();
		}

		// create arp request
		const Tins::IPv6Address & senderIp6Address = ipPdu->src_addr();
		UPtrIPv4Address senderIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(senderIp6Address));
		Tins::EthernetII arpRequest = Tins::ARP::make_arp_request(*targetIp, *senderIp, senderHwAddr);
		return callBackHandler->handle(arpRequest, this);
	}

	if (ndpType == Tins::ICMPv6::Types::NEIGHBOUR_ADVERT)
	{
		const Tins::EthernetII * ethNaPdu = pdu.find_pdu<Tins::EthernetII>();
		if(ethNaPdu == nullptr)
		{
			return false;
		}

		ptrHwAddressOption = ndpPdu->search_option(Tins::ICMPv6::OptionTypes::TARGET_ADDRESS);
		if (ptrHwAddressOption == nullptr)
		{
			senderHwAddr = ethNaPdu->src_addr();
		}
		else
		{
			senderHwAddr = ptrHwAddressOption->to<Tins::ICMPv6::hwaddress_type>();
		}

		// create arp reply
		const Tins::IPv6Address & dstIp6Address = ipPdu->dst_addr();
		UPtrIPv4Address dstIp = std::make_unique<Tins::IPv4Address>(IpAddressTranslator::toIpv4AddressBytes(dstIp6Address));
		Tins::EthernetII arpReply = Tins::ARP::make_arp_reply(*dstIp, *targetIp, ethNaPdu->dst_addr(), senderHwAddr);
		return callBackHandler->handle(arpReply, this);
	}

	return false;// callBackHandler->handle(outestPdu, this);
}