/*
    PIP - Platform Independent Primitives
    Peer - named I/O ethernet node
    Copyright (C) 2013  Ivan Pelipenko peri4ko@gmail.com

    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 "pipeer.h"

#define _PIPEER_PORT_SYNC_START 13313
#define _PIPEER_PORT_SYNC_END   13353
#define _PIPEER_IP_MULTICAST    "239.13.3.12"
#define _PIPEER_MSG_SIZE        8192

PIPeer::PIPeer(const PIString & name): PIObject() {
	rec_mc = rec_bc = false;
	setName(name);
	self_info.name = name_;
	self_info.dist = 0;
	//joinMulticastGroup("239.240.241.242");
	srand(uint(PITimer::elapsed_system_m()));
	//id_ = name() + "_" + PIString::fromNumber(rand());
	CONNECT2(void, void * , int, &timer, timeout, this, timerEvent);
	PIStringList sl = PIEthernet::allAddresses();
	sl.removeAll("127.0.0.1"); sl << "127.0.0.1";
	initMulticasts(sl);
	initEths(sl);
	//piCout << "Peer" << name_;
	timer.addDelimiter(5);
	timer.start(1000);
	sendSelfInfo();
}


PIPeer::~PIPeer() {
	piForeach (PIEthernet * i, mc_eths)
		i->stopThreadedRead();
	sendSelfRemove();
	destroyMulticasts();
	piForeach (PIEthernet * i, eths)
		delete i;
	eths.clear();
}


void PIPeer::timerEvent(void * data, int delim) {
	switch (delim) {
	case 5: // 5 s
		syncPeers();
		break;
	}
	//send("broadcast", 9);
}


void PIPeer::initEths(const PIStringList & al) {
	PIEthernet * ce;
	PIEthernet::InterfaceList il = PIEthernet::interfaces();
	const PIEthernet::Interface * cint = 0;
	piForeachC (PIString & a, al) {
		ce = new PIEthernet();
		ce->setParameters(0);
		ce->setDebug(false);
		for (int p = _PIPEER_PORT_SYNC_START; p < 65536; ++p) {
			ce->setReadAddress(a, p);
			if (ce->open()) {
				eths << ce;
				cint = il.getByAddress(a);
				self_info.addresses << ce->path();
				self_info.netmasks << (cint == 0 ? "255.255.255.0" : cint->netmask);
				CONNECT2(bool, void * , int, ce, threadedReadEvent, this, dataRead);
				ce->startThreadedRead();
				//piCout << "dc binded to" << ce->path();
				//piCout << "add eth" << ta;
				break;
			}
		}
	}
}


void PIPeer::initMulticasts(const PIStringList & al) {
	destroyMulticasts();
	PIEthernet * ce;
	PIEthernet::InterfaceList il = PIEthernet::interfaces();
	const PIEthernet::Interface * cint;
	PIStringList nal = al;
	PIString nm;
	nal << "main" << "bc";
	rec_mc = rec_bc = false;
	piForeachC (PIString & a, nal) {
		bool is_main = (a == "main");
		bool is_bc = (a == "bc");
		ce = new PIEthernet();
		ce->setParameters((is_main || is_bc) ? PIEthernet::Broadcast : 0);
		ce->setDebug(false);
		//cint = il.getByAddress(a);
		//nm = (cint == 0) ? "255.255.255.0" : cint->netmask;
		ce->setSendIP(is_bc ? "255.255.255.255" : _PIPEER_IP_MULTICAST);
		//piCout << "mc try" << a << nm << ce->sendIP();
		for (int p = _PIPEER_PORT_SYNC_START; p < _PIPEER_PORT_SYNC_END; ++p) {
			ce->setReadAddress(((is_main || is_bc) ? "255.255.255.255" : a) + ":" + PIString::fromNumber(p));
			ce->close();
			if (!ce->open()) continue;
			if (is_main) if (!ce->joinMulticastGroup(_PIPEER_IP_MULTICAST)) continue;
			//piCout << "mc binded to" << ce->path();
			mc_eths << ce;
			if (is_main || is_bc) {
				if (is_main) rec_mc = true;
				if (is_bc) rec_bc = true;
				CONNECT2(bool, void * , int, ce, threadedReadEvent, this, multicastRead);
				ce->startThreadedRead();
				if (is_bc) ce->setParameter(PIEthernet::Broadcast, false);
			}
			break;
		}
	}
	piForeachC (PIString & a, al) {
		ce = new PIEthernet();
		ce->setParameters(PIEthernet::Broadcast);
		ce->setDebug(false);
		cint = il.getByAddress(a);
		nm = (cint == 0) ? "255.255.255.0" : cint->netmask;
		ce->setSendIP(PIEthernet::getBroadcast(a, nm));
		//piCout << "mc BC try" << a << nm << ce->sendIP();
		for (int p = _PIPEER_PORT_SYNC_START; p < _PIPEER_PORT_SYNC_END; ++p) {
			ce->setReadAddress(a + ":" + PIString::fromNumber(p));
			ce->close();
			if (!ce->open()) continue;
			//piCout << "BC binded to" << ce->path();
			mc_eths << ce;
			break;
		}
	}
	if (!rec_mc) piCoutObj << "[PIPeer \"" + name_ + "\"] Can`t find suitable network interface for multicast receive, check for exists at least one interface with multicasting enabled!";
	if (!rec_bc) piCoutObj << "[PIPeer \"" + name_ + "\"] Can`t find suitable network interface for broadcast receive, check for exists at least one interface with broadcasting enabled!";
}


void PIPeer::destroyMulticasts() {
	piForeach (PIEthernet * i, mc_eths) {
		i->leaveMulticastGroup(_PIPEER_IP_MULTICAST);
		delete i;
	}
	mc_eths.clear();
}


PIPeer::PeerInfo * PIPeer::quickestPeer(const PIString & to) {
	if (!addresses_map.contains(to)) return 0;
	//piCout << "*** search quickest peer" << to;
	PIVector<PeerInfo * > tp = addresses_map[to];
	PeerInfo * dp = 0;
	int mping = 99999;
	for (int i = 0; i < tp.size_s(); ++i) {
		if (mping > tp[i]->ping) {
			mping = tp[i]->ping;
			dp = tp[i];
		}
	}
	//piCout << "*** search quickest peer: found" << dp->name;
	return dp;
}


bool PIPeer::sendToNeighbour(PIPeer::PeerInfo * peer, const PIByteArray & ba) {
	if (peer->_neth == 0) return false;
	//piCout << "send to" << peer->name << peer->_naddress << ba.size_s() << "bytes";
	diag_d.sended(ba.size_s());
	return peer->_neth->send(peer->_naddress, ba.data(), ba.size_s());
}


bool PIPeer::send(const PIString & to, const void * data, int size) {
	PeerInfo * dp = quickestPeer(to);
	if (dp == 0) {
		//piCoutObj << "[PIPeer \"" + name_ + "\"] Can`t find peer \"" << to << "\"!";
		return false;
	}
	PIByteArray ba;
	ba << int(4) << self_info.name << to << int(0) << size;
	PIByteArray fmsg(data, size), cmsg;
	int msg_count = (size - 1) / _PIPEER_MSG_SIZE + 1;
	for (int i = 0; i < msg_count; ++i) {
		int csize = (i == msg_count - 1) ? ((size - 1) % _PIPEER_MSG_SIZE + 1) : _PIPEER_MSG_SIZE;
		cmsg.clear();
		cmsg.append(ba);
		cmsg << msg_count << i;
		cmsg.append(fmsg.data(i * _PIPEER_MSG_SIZE), csize);
		if (!sendToNeighbour(dp, cmsg)) return false;
	}
	return true;
}


bool PIPeer::dataRead(uchar * readed, int size) {
	diag_d.received(size);
	PIByteArray ba(readed, size), sba;
	int type, cnt, rec_size;
	PIString from, to;
	ba >> type >> from >> to >> cnt >> rec_size;
	//piCout << "[PIPeer \"" + name_ + "\"] Received packet" << type << from << to << cnt << rec_size;
	if (type == 4) { // data packet
		if (to == self_info.name) { // my packet
			int msg_count, cmsg;
			ba >> msg_count >> cmsg;
			//piCout << "[PIPeer \"" + name_ + "\"] Received packet" << type << from << to << cnt << rec_size << msg_count << cmsg;
			if (cmsg == 0 && msg_count == 1) {
				dataReceived(from, ba);
				dataReceivedEvent(from, ba);
				return true;
			}
			PeerInfo * fp = const_cast<PeerInfo * >(getPeerByName(from));
			if (fp == 0) return true;
			PeerData & pd(fp->_data);
			if (cmsg == 0) {
				//piCout << "[PIPeer \"" + name_ + "\"] Packet clear" << rec_size;
				pd.clear();
				pd.msg_count = msg_count;
			}
			//piCout << "[PIPeer \"" + name_ + "\"] Packet add" << cmsg << ba.size_s();
			pd.addData(ba);
			if (pd.isFullReceived()) {
				dataReceived(from, pd.data);
				dataReceivedEvent(from, pd.data);
				//piCout << "[PIPeer \"" + name_ + "\"] Packet received" << pd.data.size_s();
			}
			return true;
		}
		PeerInfo * dp = quickestPeer(to);
		if (dp == 0) {
			//piCoutObj << "[PIPeer \"" + name_ + "\"] Can`t find peer \"" << to << "\"!";
			return true;
		}
		cnt++;
		if (cnt > 100 || from == dp->name) return true;
		sba << type << from << to << cnt << rec_size;
		sba.append(ba);
		//piCoutObj << "[PIPeer \"" + name_ + "\"] Translate data packet" << type << from << to << cnt << rec_size;
		sendToNeighbour(dp, sba);
	}
	return true;
}


bool PIPeer::multicastRead(uchar * data, int size) {
	PIMutexLocker locker(mc_mutex);
	diag_s.received(size);
	int header;
	PeerInfo pi;
	PIByteArray ba(data, size);
	PIVector<PeerInfo> rpeers;
	ba >> header >> pi.name;
	//piCout << "read type" << header << "from" << pi.name;
	if (pi.name == name_) return true;
	//piCout << "analyz ...";
	switch (header) {
	case 1: // new peer accepted
		//piCout << "new peer packet ...";
		if (hasPeer(pi.name)) break;
		ba >> pi.dist >> pi.addresses >> pi.netmasks >> pi.neighbours;
		pi.sync = 0;
		if (pi.dist == 0) {
			pi.addNeighbour(self_info.name);
			self_info.addNeighbour(pi.name);
		}
		peers << pi;
		//piCoutObj << "[PIPeer \"" + name_ + "\"] new peer \"" << pi.name << "\"" << " dist " << pi.dist;
		pi.dist++;
		sendSelfInfo();
		sendPeerInfo(pi);
		findNearestAddresses();
		peerConnected(pi.name);
		peerConnectedEvent(pi.name);
		//piCout << "new peer packet ok";
		break;
	case 2: // remove peer accepted
		//piCout << "remove peer packet ...";
		if (removePeer(pi.name)) {
			//piCoutObj << "[PIPeer \"" + name_ + "\"] remove peer \"" << pi.name << "\"";
			if (pi.dist == 0) {
				pi.removeNeighbour(self_info.name);
				self_info.removeNeighbour(pi.name);
			}
			sendPeerRemove(pi.name);
			findNearestAddresses();
			peerDisconnected(pi.name);
			peerDisconnectedEvent(pi.name);
		}
		//piCout << "remove peer packet ok";
		break;
	case 3: // sync peers
		//piCout << "sync packet ...";
		ba >> pi.addresses >> pi.netmasks >> pi.neighbours >> rpeers;
		rpeers << pi;
		//piCout << "[PIPeer \"" + name_ + "\"] rec sync " << rpeers.size_s() << " peers";
		for (uint i = 0; i < rpeers.size(); ++i) {
			PeerInfo & rpeer(rpeers[i]);
			//piCout << " to sync " << rpeer.name;
			if (rpeer.name == name_) continue;
			bool exist = false;
			for (uint j = 0; j < peers.size(); ++j) {
				PeerInfo & peer(peers[j]);
				if (peer.name == rpeer.name) {
					//piCout << "synced " << peer.name;
					peer.addresses == rpeer.addresses;
					peer.netmasks == rpeer.netmasks;
					peer.addNeighbours(rpeer.neighbours);
					rpeer.neighbours = peer.neighbours;
					if (peer.name == pi.name) peer.sync = 0;
					exist = true;
					break;
				}
			}
			if (exist) continue;
			peers << rpeer;
			peers.back().dist++;
			findNearestAddresses();
			peerConnected(rpeer.name);
			peerConnectedEvent(rpeer.name);
		}
		//piCout << "***";;
		//piCout << self_info.name << self_info.neighbours;
		piForeach (PeerInfo & i, peers) {
			if (i.dist == 0) {
				self_info.addNeighbour(i.name);
				i.addNeighbour(self_info.name);
			}
			//piCout << i.name << i.neighbours;
		}
		break;
	}
	return true;
}


void PIPeer::sendMulticast(const PIByteArray & ba) {
	piForeach (PIEthernet * e, mc_eths) {
		for (int p = _PIPEER_PORT_SYNC_START; p < _PIPEER_PORT_SYNC_END; ++p) {
			e->setSendPort(p);
			//errorClear();
			//piCout << "send to" << e->sendAddress() << e->send(ba);
			//piCout << PIEthernet::ethErrorString();
			e->send(ba);
			diag_s.sended(ba.size_s());
		}
	}
}


void PIPeer::sendPeerInfo(const PeerInfo & info) {
	PIByteArray ba;
	ba << int(1) << info.name << info.dist << info.addresses << info.netmasks << info.neighbours;
	sendMulticast(ba);
}


void PIPeer::sendPeerRemove(const PIString & peer) {
	PIByteArray ba;
	ba << int(2) << peer;
	sendMulticast(ba);
}


void PIPeer::syncPeers() {
	//piCout << "[PIPeer \"" + name_ + "\"] sync " << peers.size_s() << " peers";
	PIString pn;
	bool change = false;
	for (uint i = 0; i < peers.size(); ++i) {
		PeerInfo & cp(peers[i]);
		if (cp.sync > 3 && cp.dist == 0) {
			pn = cp.name;
			//piCoutObj << "[PIPeer \"" + name_ + "\"] sync: remove " << pn;
			peers.remove(i);
			sendPeerRemove(pn);
			--i;
			piForeach (PeerInfo & p, peers)
				p.removeNeighbour(pn);
			self_info.removeNeighbour(pn);
			peerDisconnected(pn);
			peerDisconnectedEvent(pn);
			change = true;
			continue;
		}
		cp.sync++;
	}
	if (change) findNearestAddresses();
	PIByteArray ba;
	ba << int(3) << self_info.name << self_info.addresses << self_info.netmasks << self_info.neighbours << peers;
	sendMulticast(ba);
}


void PIPeer::findNearestAddresses() {
	//piCout << "[PIPeer \"" + name_ + "\"] findNearestAddresses";
	addresses_map.clear();
	int max_dist = -1;
	static PIMap<PIString, PeerInfo * > peers_;
	peers_.clear();
	self_info._nuses.resize(self_info.neighbours.size());
	self_info._nuses.fill(0);
	self_info._first = &self_info;
	peers_[self_info.name] = &self_info;
	piForeach (PeerInfo & i, peers) {
		i._nuses.resize(i.neighbours.size());
		i._nuses.fill(0);
		i._first = 0;
		peers_[i.name] = &i;
		if (max_dist < i.dist)
			max_dist = i.dist;
		if (i.dist > 0) continue;
		i._naddress.clear();
		i._neth = 0;
		PIString mma, ma;
		bool af = false;
		for (int mi = 0; mi < self_info.addresses.size_s(); ++mi) {
			PIString & m(self_info.addresses[mi]), & mmask(self_info.netmasks[mi]);
			if (af) break;
			ma = m;
			//mma = m.left(m.findLast("."));
			mma = PIEthernet::applyMask(m, mmask);
			for (int ii = 0; ii < i.addresses.size_s(); ++ii) {
				PIString & r(i.addresses[ii]), & rmask(i.netmasks[ii]);
				if (mma == PIEthernet::applyMask(r, rmask)) {
					i._naddress = r;
					//piCout << "_naddress" << i.name << "=" << r;
					af = true;
					break;
				}
			}
		}
		if (!af) continue;
		//piCout << "  peer" << i.name << ma;
		piForeach (PIEthernet * e, eths)
			if (e->readAddress() == ma) {
				i._neth = e;
				break;
			}
		//piCout << i.name << i._naddress;
	}
	PIVector<PeerInfo * > cwave, nwave;
	PeerInfo * npeer;
	cwave << &self_info;
	for (int d = 0; d <= max_dist; ++d) {
		if (cwave.isEmpty()) break;
		nwave.clear();
		piForeach (PeerInfo * p, cwave) {
			int ns = p->neighbours.size_s();
			for (int n = 0; n < ns; ++n) {
				if (p->_nuses[n] >= ns) continue;
				p->_nuses[n]++;
				npeer = peers_[p->neighbours[n]];
				if (npeer == 0) continue;
				if (d == 0) npeer->_first = npeer;
				else {
					if (d == 1) npeer->_first = p;
					else npeer->_first = p->_first;
				}
				nwave << npeer;
			}
		}
		cwave = nwave;
		//piCout << "wave" << d;
		for (int i = 0; i < cwave.size_s(); ++i) {
			//piCout << " peer" << cwave[i]->name << Hex << (uint)(cwave[i]->_first);
			if (cwave[i]->_first == 0) {cwave.remove(i); --i; continue;}
			if (addresses_map.contains(cwave[i]->name)) {cwave.remove(i); --i; continue;}
		}
		for (int i = 0; i < cwave.size_s(); ++i) {
			PIVector<PeerInfo * > & pl(addresses_map[cwave[i]->name]);
			if (!pl.contains(cwave[i]->_first))
				pl << cwave[i]->_first;
		}
	}
	/*piCout << " **   addresses map   **";
	piForeachC (napair & i, addresses_map)
		piCout << i.first << i.second;
	piCout << " ** addresses map end **";*/
}