/*
 * Copyright (c) 2012 Yoann Blein
 * Licensed under the simplified BSD license.
 * See Documentation/Licenses/BSD-simplified.txt for more information.
 */

#include <Swiften/ScreenSharing/RTPSessionImpl.h>

#include <Swiften/ScreenSharing/RTPException.h>
#include <Swiften/Network/BoostUDPSocket.h>
#include <Swiften/Base/boost_bsignals.h>
#include <Swiften/Network/UDPSocket.h>
#include <Swiften/Base/Log.h>

#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <boost/bind.hpp>

#include <rtppacket.h>
#include <rtpsourcedata.h>
#include <rtpsessionparams.h>
#include <rtpipv4address.h>
#include <rtpipv6address.h>

#include <arpa/inet.h>

namespace Swift {

Sender::Sender(boost::shared_ptr<UDPSocket> udpSocket)
	: udpSocket(udpSocket), jRTPLocalAddress(RTPSessionImpl::nativeAddressToJRTPAddress(udpSocket->getLocalAddress())) {
}

Sender::~Sender()
{
	delete jRTPLocalAddress;
}

bool Sender::SendRTP(const void *data, size_t len) {
	send(data, len);
	return true;
}

bool Sender::SendRTCP(const void* data, size_t len) {
	send(data, len);
	return true;
}

bool Sender::ComesFromThisSender (const jrtplib::RTPAddress* address) {
	return jRTPLocalAddress->IsSameAddress(address);
}

void Sender::send(const void* data, size_t len) {
	uint8_t* uint8Data = (uint8_t*)data;
	udpSocket->send(SafeByteArray(uint8Data, uint8Data + len));
}

RTPSessionImpl::RTPSessionImpl(boost::shared_ptr<UDPSocket> udpSocket, const RTPPayloadType& payloadType)
	: udpSocket(udpSocket), payloadType(payloadType), jRTPRemotePeer(nativeAddressToJRTPAddress(udpSocket->getRemoteAddress())), sender(udpSocket)
{
	jrtplib::RTPExternalTransmissionParams transparams(&sender, 0);
	jrtplib::RTPSessionParams sessparams;
	// IMPORTANT: The local timestamp unit MUST be set, otherwise RTCP Sender Report info will be calculated wrong
	sessparams.SetOwnTimestampUnit(1.0 / payloadType.getClockrate());

	checkError(Create(sessparams, &transparams, jrtplib::RTPTransmitter::ExternalProto));

	packetInjecter = static_cast<jrtplib::RTPExternalTransmissionInfo*>(GetTransmissionInfo())->GetPacketInjector();

	udpSocket->onDataRead.connect(boost::bind(&RTPSessionImpl::handleDataRead, this, _1));
	udpSocket->listen();
}

RTPSessionImpl::~RTPSessionImpl()
{
	delete jRTPRemotePeer;
}

void RTPSessionImpl::poll()
{
	checkError(Poll()); // Required if threading disabled
}

void RTPSessionImpl::checkIncomingPackets()
{
	// session.BeginDataAccess(); // useless without threading
	if (GotoFirstSourceWithData() && GetCurrentSourceInfo()->GetRTPDataAddress()->IsSameAddress(jRTPRemotePeer)) {
		do {
			jrtplib::RTPPacket *pack;
			while ((pack = GetNextPacket()) != NULL) {
				onIncomingPacket(pack->GetPayloadData(), pack->GetPayloadLength(), pack->HasMarker());
				DeletePacket(pack);
			}
		} while (GotoNextSourceWithData());
	}
	// session.EndDataAccess(); // useless without threading
}

void RTPSessionImpl::sendPacket(const SafeByteArray& data, int timestampinc, bool marker)
{
	checkError(SendPacket((void*)(data.data()), data.size(), payloadType.getID(), marker, timestampinc));
	poll();
}

void RTPSessionImpl::injectData(const SafeByteArray& data)
{
	packetInjecter->InjectRTPorRTCP((void*)(data.data()), data.size(), *jRTPRemotePeer);
	checkIncomingPackets();
	poll();
}

void RTPSessionImpl::stop(int maxWaitMs)
{
	BYEDestroy(jrtplib::RTPTime(0, maxWaitMs * 1000), "", 0);
	udpSocket->close();
}

void RTPSessionImpl::sendSLIFeedback(int pictureID)
{
	// Send an SLI as negative feedback. VP8: 0, total number of macroblocks, pictureID (6 bits)
	int first = 0; // 13 bits
	int number = 0; // 13 bits // TODO : Find the total	number of macroblocks per frame

	uint32_t data = 0;
	data |= first << 19;
	data |= (number & 2047) << 6;
	data |= (pictureID & 63);

	SendUnknownPacket(false, PSFB, PSFB_SLI, (void*)&data, sizeof(uint32_t));
}

void RTPSessionImpl::sendRPSIFeedback(int pictureID)
{
	// Send an RPSI as positive feedback. With VP8, it only contains the picture ID (7 bits)
	int pb = 9; // trailing padding bits
	int pt = payloadType.getID(); // payload type (7 bits)

	uint32_t data = 0;
	data |= pb << 24;
	data |= (pt & 127) << 16;
	data |= (pictureID & 127) << 9;

	SendUnknownPacket(false, PSFB, PSFB_RPSI, (void*)&data, sizeof(uint32_t));
}

size_t RTPSessionImpl::getMaxRTPPayloadSize() const
{
	jrtplib::RTPSessionParams sessparams;
	return sessparams.GetMaximumPacketSize();
}

void RTPSessionImpl::OnUnknownPacketType(jrtplib::RTCPPacket* rtcpPack, const jrtplib::RTPTime& /*receivetime*/, const jrtplib::RTPAddress* senderAddress)
{
	if (!senderAddress->IsSameAddress(jRTPRemotePeer))
		return;

	uint8_t* data = rtcpPack->GetPacketData();
	size_t len = rtcpPack->GetPacketLength();
	jrtplib::RTCPCommonHeader* rtcpHdr = (jrtplib::RTCPCommonHeader*)data;
	int type = rtcpHdr->packettype;
	if (type != PSFB)
		return;

	int subtype = rtcpHdr->count;
	switch (subtype) {
		case PSFB_SLI:
			parseSLIFeedBack(data + 8, len - 8);
			break;
		case PSFB_RPSI:
			parseRPSIFeedBack(data + 8, len - 8);
			break;
		default:
			break;
	}
}

void RTPSessionImpl::checkError(int rtperr) const
{
	if (rtperr < 0)
		throw RTPException(jrtplib::RTPGetErrorString(rtperr));
}

void RTPSessionImpl::handleDataRead(boost::shared_ptr<SafeByteArray> data)
{
	injectData(*data);
}

void RTPSessionImpl::parseSLIFeedBack(uint8_t* data, size_t len)
{
	SWIFT_LOG(debug) << "Got SLI feedback (negative)" << std::endl;

	if (len < 4)
		return;
	int pictureID = data[len - 1] & 63; // pictureID correspond to the 6 last bits
	onSLIFeedback(pictureID);
}

void RTPSessionImpl::parseRPSIFeedBack(uint8_t* data, size_t len)
{
	SWIFT_LOG(debug) << "Got RPSI feedback (postive)" << std::endl;

	if (len < 4)
		return;
	int pb = data[0]; // First byte : trailing padding bits
	uint32_t intData = *((uint32_t*)(data));
	intData >>= pb; // remove padding bits
	int pictureID = (intData & 127); // pictureID correspond to the 7 last bits
	onRPSIFeedback(pictureID);

}

jrtplib::RTPAddress* RTPSessionImpl::nativeAddressToJRTPAddress(const HostAddressPort& hostAddressPort)
{
	jrtplib::RTPAddress* jrtpAddress = 0;
	std::string ipAddress = hostAddressPort.getAddress().toString();
	uint16_t port = boost::numeric_cast<uint16_t>(hostAddressPort.getPort());

	if (hostAddressPort.getAddress().getRawAddress().is_v4()) {
		// Split address
		std::vector<std::string> subStrings;
		boost::algorithm::split(subStrings, ipAddress, boost::is_any_of("."));
		// Cast sub strings array to array of byte
		uint8_t ipNumbers[4];
		for (int i = 0; i < std::min(4, (int)subStrings.size()); ++i)
			ipNumbers[i] = boost::numeric_cast<uint8_t>(boost::lexical_cast<int>(subStrings[i]));

		jrtpAddress = new jrtplib::RTPIPv4Address(ipNumbers, port);
	}
	else if (hostAddressPort.getAddress().getRawAddress().is_v6()) {
		in6_addr addr;
		inet_pton(AF_INET6, ipAddress.c_str(), &addr);
		jrtpAddress = new jrtplib::RTPIPv6Address(addr, port);
	}
	return jrtpAddress;
}

}