#include "Ip6ToIp4PacketHandler.h"
#include "tins/ethernetII.h"
#include <tins/ip.h>
#include <tins/ipv6.h>
#include "IpAddressTranslator.h"

namespace std
{
	template<typename T, typename ... Args>
	std::unique_ptr<T> make_unique(Args && ... args)
	{
		return std::unique_ptr<T>(new T(std::forward<Args>(args) ...));
	}
}

Ip6ToIp4PacketHandler::Ip6ToIp4PacketHandler()
{}
Ip6ToIp4PacketHandler::~Ip6ToIp4PacketHandler()
{}
bool Ip6ToIp4PacketHandler::handle(const Tins::PDU &pdu, IN IPacketHandler *  callBackHandler)
{
	if (callBackHandler == nullptr)
	{
		return false;
	}

	const Tins::IPv6 * ipv6Pdu = pdu.find_pdu<Tins::IPv6>();
	if(ipv6Pdu == nullptr)
	{
		return false;
	}

	const Tins::EthernetII * ethPdu = pdu.find_pdu<Tins::EthernetII>();
	if(ethPdu == nullptr)
	{
		return false;
	}

	const Tins::PDU * ipPayloadPdu = ipv6Pdu->inner_pdu();
	if(ipPayloadPdu == nullptr)
	{
		return false;
	}

	// convert ipv6 addresses to ipv4 addresses
	const uint32_t srcIp4AddressBytes = IpAddressTranslator::toIpv4AddressBytes(ipv6Pdu->src_addr());
	const uint32_t dstIp4AddressBytes = IpAddressTranslator::toIpv4AddressBytes(ipv6Pdu->dst_addr());
	std::unique_ptr<const Tins::IPv4Address> srcIp4Address = std::make_unique<const Tins::IPv4Address>(srcIp4AddressBytes);
	std::unique_ptr<const Tins::IPv4Address> dstIp4Address = std::make_unique<const Tins::IPv4Address>(dstIp4AddressBytes);

    // create ip4 pdu
	std::unique_ptr<const Tins::IP> ipv4Pdu = std::make_unique<const Tins::IP>(*srcIp4Address, *dstIp4Address);

    // create forwarding frame
	std::unique_ptr<Tins::EthernetII> ptrForwardEthPdu = std::make_unique<Tins::EthernetII>();
	Tins::EthernetII & forwardEthPdu = *ptrForwardEthPdu;
	forwardEthPdu /= *ethPdu;
	forwardEthPdu /= *ipv4Pdu;
	forwardEthPdu /= *ipPayloadPdu;

	// forward frame
	return callBackHandler->handle(forwardEthPdu, this);
}