/*
 * Copyright (c) 2010-2019 Belledonne Communications SARL.
 *
 * This file is part of Liblinphone.
 *
 * This program 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.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "bctoolbox/defs.h"

#include "streams.h"
#include "media-session.h"
#include "media-session-p.h"
#include "core/core.h"
#include "c-wrapper/c-wrapper.h"
#include "call/call.h"
#include "conference/participant.h"
#include "utils/payload-type-handler.h"
#include "conference/params/media-session-params-p.h"

#include "linphone/core.h"


using namespace::std;

LINPHONE_BEGIN_NAMESPACE


/*
 * Stream implementation.
 */


Stream::Stream(StreamsGroup &sg, const OfferAnswerContext &params) : mStreamsGroup(sg), mStreamType(params.getLocalStreamDescription().type), mIndex(params.streamIndex){
	setPortConfig();
	initMulticast(params);
	memset(&mInternalStats, 0, sizeof(mInternalStats));
}

void Stream::setMain(){
	mIsMain = true;
}

LinphoneCore *Stream::getCCore()const{
	return getCore().getCCore();
}

Core &Stream::getCore()const{
	return *getMediaSession().getCore();
}

MediaSession &Stream::getMediaSession()const{
	return mStreamsGroup.getMediaSession();
}

MediaSessionPrivate &Stream::getMediaSessionPrivate()const{
	return *getMediaSession().getPrivate();
}

void Stream::fillLocalMediaDescription(OfferAnswerContext & ctx){
}

bool Stream::prepare(){
	mState = Preparing;
	return false;
}

void Stream::finishPrepare(){
	mState = Stopped;
}

void Stream::tryEarlyMediaForking(const OfferAnswerContext &ctx){
}

void Stream::render(const OfferAnswerContext & ctx, CallSession::State targetState){
	mState = Running;
}

void Stream::sessionConfirmed(const OfferAnswerContext &ctx){
}

void Stream::stop(){
	mState = Stopped;
	mInternalStats.number_of_stops++;
}

void Stream::setIceCheckList(IceCheckList *cl){
}

void Stream::iceStateChanged(){
}

void Stream::connectToMixer(StreamMixer *mixer){
	mMixer = mixer;
}

void Stream::disconnectFromMixer(){
	mMixer = nullptr;
}

StreamMixer * Stream::getMixer()const{
	return mMixer;
}

void Stream::setRandomPortConfig () {
	mPortConfig.rtpPort = -1;
	mPortConfig.rtcpPort = -1;
}

int Stream::selectRandomPort (pair<int, int> portRange) {
	unsigned int rangeSize = static_cast<unsigned int>(portRange.second - portRange.first);
	
	for (int nbTries = 0; nbTries < 100; nbTries++) {
		bool alreadyUsed = false;
		unsigned int randomInRangeSize = (bctbx_random() % rangeSize) & (unsigned int)~0x1; /* Select an even number */
		int triedPort = ((int)randomInRangeSize) + portRange.first;
		/*If portRange.first is even, the triedPort will be even too. The one who configures a port range that starts with an odd number will
		 * get odd RTP port numbers.*/
		
		for (const bctbx_list_t *elem = linphone_core_get_calls(getCCore()); elem != nullptr; elem = bctbx_list_next(elem)) {
			LinphoneCall *lcall = static_cast<LinphoneCall *>(bctbx_list_get_data(elem));
			shared_ptr<MediaSession> session = static_pointer_cast<MediaSession>(LinphonePrivate::Call::toCpp(lcall)->getActiveSession());
			if (session->getPrivate()->getStreamsGroup().isPortUsed(triedPort)) {
				alreadyUsed = true;
				break;
			}
		}
		if (!alreadyUsed){
			lInfo() << "Port " << triedPort << " randomly taken from range [ " << portRange.first << " , " << portRange.second << "]";
			return triedPort;
		}
	}

	lError() << "Could not find any free port!";
	return -1;
}

int Stream::selectFixedPort (pair<int, int> portRange) {
	for (int triedPort = portRange.first; triedPort < (portRange.first + 100); triedPort += 2) {
		bool alreadyUsed = false;
		for (const bctbx_list_t *elem = linphone_core_get_calls(getCCore()); elem != nullptr; elem = bctbx_list_next(elem)) {
			LinphoneCall *lcall = static_cast<LinphoneCall *>(bctbx_list_get_data(elem));
			shared_ptr<MediaSession> session = static_pointer_cast<MediaSession>(LinphonePrivate::Call::toCpp(lcall)->getActiveSession());
			if (session->getPrivate()->getStreamsGroup().isPortUsed(triedPort)) {
				alreadyUsed = true;
				break;
			}
		}
		if (!alreadyUsed)
			return triedPort;
	}

	lError() << "Could not find any free port !";
	return -1;
}

void Stream::setPortConfig(pair<int, int> portRange) {
	if ((portRange.first <= 0) && (portRange.second <= 0)) {
		setRandomPortConfig();
	} else {
		if (portRange.first == portRange.second) {
			/* Fixed port */
			mPortConfig.rtpPort = selectFixedPort(portRange);
		} else {
			/* Select random port in the specified range */
			mPortConfig.rtpPort = selectRandomPort(portRange);
		}
	}
	if (mPortConfig.rtpPort == -1) setRandomPortConfig();
	else mPortConfig.rtcpPort = mPortConfig.rtpPort + 1;
}

pair<int, int> Stream::getPortRange(LinphoneCore * core, const SalStreamType type) {
	int minPort = 0, maxPort = 0;
	switch(type){
		case SalAudio:
			linphone_core_get_audio_port_range(core, &minPort, &maxPort);
		break;
		case SalVideo:
			linphone_core_get_video_port_range(core, &minPort, &maxPort);
		break;
		case SalText:
			linphone_core_get_text_port_range(core, &minPort, &maxPort);
		break;
		case SalOther:
		break;
	}

	return make_pair(minPort, maxPort);
}

void Stream::setPortConfig(){
	setPortConfig(Stream::getPortRange(getCCore(), getType()));
}

void Stream::initMulticast(const OfferAnswerContext &params) {
	mPortConfig.multicastRole = params.getLocalStreamDescription().multicast_role;
	lInfo() << *this << ": multicast role is ["
		<< sal_multicast_role_to_string(mPortConfig.multicastRole) << "]";
	
	if (mPortConfig.multicastRole == SalMulticastReceiver){
		mPortConfig.multicastIp = params.getRemoteStreamDescription().rtp_addr;
		mPortConfig.rtpPort = params.getRemoteStreamDescription().rtp_port;
		mPortConfig.rtcpPort = 0; /* RTCP is disabled for multicast */
	}else if (mPortConfig.multicastRole == SalMulticastSender){
		if (getType() == SalAudio && getMediaSession().getPrivate()->getParams()->audioMulticastEnabled()){
			mPortConfig.multicastIp = linphone_core_get_audio_multicast_addr(getCCore());
		} else if (getType() == SalVideo && getMediaSession().getPrivate()->getParams()->videoMulticastEnabled()){
			mPortConfig.multicastIp = linphone_core_get_video_multicast_addr(getCCore());
		}
		/* multicastRtpPort is the one that will be advertised.
		 * However, the socket that will send to the multicast address/port does need need to bind on this port.
		 * It should not to avoid port conflicts with multicast receivers that may run on the same host.
		 * The bind() will be done on a random port instead.
		 */
		mPortConfig.multicastRtpPort = mPortConfig.rtpPort;
		if (mPortConfig.multicastRtpPort == -1) {
			/* we have to choose the multicast port now and the system can't choose it for us.*/
			mPortConfig.multicastRtpPort = selectRandomPort(make_pair(1024,65535));
		}
		setRandomPortConfig();
	}
}

bool Stream::isPortUsed(int port)const{
	return port == mPortConfig.rtpPort || port == mPortConfig.rtcpPort || port == mPortConfig.multicastRtpPort;
}

IceService & Stream::getIceService()const{
	return mStreamsGroup.getIceService();
}

const string & Stream::getPublicIp() const{
	if (!mPortConfig.multicastIp.empty()){
			return mPortConfig.multicastIp;
	}
	return getMediaSessionPrivate().getMediaLocalIp();
}


void Stream::finish(){
}

LINPHONE_END_NAMESPACE
