/*
   net/netconnection.cc
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#include <zlib.h>

#include <sstream>

#include "sys/sys.h"
#include "core/application.h"
#include "core/gameconnection.h"
#include "core/netconnection.h"
#include "core/player.h"
#include "core/stats.h"

namespace core 
{

NetConnection::NetConnection()
{
	connection_timeout = core::application()->time();
	connection_state = Connecting;

	receive_compressed = false;
	received_compressed_size = 0;
	compressed_size = 0;
}

NetConnection::~NetConnection()
{
	disconnect();
}

void NetConnection::abort()
{
	connection_error= true;
}

void NetConnection::connect(std::string const &to_host, int to_port)
{
	connection_error = false;
	connection_fd = -1;
	connection_state = Connecting;

	if (valid())
		return;
		
	// resolve serverhostname
	struct hostent *serverhostent;
	serverhostent = gethostbyname(to_host.c_str());
	if (!serverhostent) {
		con_warn << "Could not resolve '" << to_host.c_str() << "'" << std::endl;
		abort();
		return;
	}
	
	// Get a socket file descriptor
	connection_fd = socket(PF_INET, SOCK_DGRAM, 0);
	if (connection_fd == -1) {
		//con_error << "Network socket() failed!" << std::endl;
		abort();
		return;
	}
	
	// make the connection
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(to_port);
	// FIXME inet_addr can still fail
	server_addr.sin_addr.s_addr = inet_addr(inet_ntoa(*((struct in_addr *)serverhostent->h_addr)));
	memset(server_addr.sin_zero, '\0', sizeof server_addr.sin_zero);
	if (server_addr.sin_addr.s_addr == INADDR_NONE) {
		con_error << "Network invalid address " << to_host << "!" << std::endl;
		abort();
		return;
	}
	
	connection_host = to_host;
	connection_port = to_port;
	connection_error = false;

	FD_ZERO(&clientset);
#ifdef _WIN32
	FD_SET((unsigned int) fd(), &clientset);
#else
	FD_SET(fd(), &clientset);
#endif

	connection_timeout = application()->time();
	connection_keepalive = application()->time();

	game()->localplayer()->player_dirty = true;

	con_print << "Connecting to " << inet_ntoa(*((struct in_addr *)serverhostent->h_addr))  << ":" << to_port << "..." << std::endl;
}

void NetConnection::disconnect()
{
	if (connection_fd != -1) {
		sendq.clear();
		sendq.assign("disconnect\n");
		transmit();

		FD_ZERO(&clientset);
#ifdef _WIN32
		closesocket(connection_fd);
#else
		close(connection_fd);
#endif
	}
	
	connection_fd = -1;
	connection_error = false;
	connection_host.clear();
	connection_port = 0;
	connection_state = Connecting;
}

bool NetConnection::has_messages() const
{
	return (recvq.size() > 0);
}

void NetConnection::retreive(std::string & message)
{
	if (recvq.size() > 0) {
		message.assign(recvq.front());
		recvq.pop_front();
	} else {
		message.clear();
	}
}

// receive data and decode it into lines
void NetConnection::receive()
{
	// TODO: binary mode data transfer
	if (error() || invalid())
		return;

	ssize_t		bytes_received;
	
	memset(recvbuf, 0, BLOCKSIZE);
	bytes_received = ::recv(connection_fd, recvbuf, BLOCKSIZE-1, 0);
	Stats::network_bytes_received += bytes_received;
	connection_timeout = core::application()->time();

	if (bytes_received == 0) {
		con_print << "^BDisconnected." << std::endl;
		abort();
		return;
	} else if (bytes_received < 0) {
		con_error << "Network receive() error!" << std::endl;
		//perror("recv");
		abort();
		return;
	}

	const char *c = recvbuf;

	while (bytes_received) {
		if (receive_compressed) {
			zrecvbuf[received_compressed_size] = *c;
			received_compressed_size++;

			if (compressed_size == received_compressed_size) {
				// uncompress
				char zunbuf[BLOCKSIZE*2];
				memset(zunbuf, 0, sizeof(zunbuf));
				uLong zunbuf_size = (uLong) BLOCKSIZE*2 - 1;

				int status = uncompress((Bytef *) zunbuf, &zunbuf_size, (Bytef *) zrecvbuf, (uLong) compressed_size);

				if (status != Z_OK) {
					con_warn << "zlib error " << status << " uncompressing incoming datablock!\n";
				} else {
					const char *zc = zunbuf;
					while (*zc) {
						if  (( *zc == '\n') || (*zc == '\r')) { 
							if (messageblock.size()) {
								recvq.push_back(messageblock);
								messageblock.clear();
							}
						} else {
							if (messageblock.size() < FRAMESIZE) {
								messageblock += *zc;
							} else {
								con_warn << "Incoming uncompressed message exceeds " << FRAMESIZE << " bytes!\n";
								messageblock.clear();
							}
						}
						zc++;
					}
				}

				// reset
				receive_compressed = false;
				received_compressed_size = 0;
				compressed_size = 0;
			}
		} else if (!messageblock.size() && (bytes_received > 3 ) && ( *c == '\xff') &&  (*(c+1) == '\xff')) {

				receive_compressed = true;
				received_compressed_size = 0;
				compressed_size = (uLong) (*(unsigned char *)(c+2) + (*(unsigned char *)(c+3) << 8));
				c += 3;
				bytes_received -= 3;
				memset(zrecvbuf, 0, sizeof(zrecvbuf));
				if (compressed_size > BLOCKSIZE) {
					con_warn << "Incoming compressed datablock exceeds " << BLOCKSIZE << " bytes!\n";
					receive_compressed = false;
				}

		} else if  (( *c == '\n') || (*c == '\r')) { 
			if (messageblock.size()) {
 				recvq.push_back(messageblock);
				messageblock.clear();
			}
		} else {
			if (messageblock.size() < FRAMESIZE) {
				messageblock += *c;
			} else {
				con_warn << "Incoming message exceeds " << FRAMESIZE << " bytes!\n";
				messageblock.clear();
			}
		}
		c++;
		bytes_received--;
	}

}

void NetConnection::frame(float seconds)
{
	timeval timeout;
	timeout.tv_sec = 0;
	timeout.tv_usec = 0;
	fd_set readset = clientset;

	int nb = select(fd()+1, &readset, NULL, NULL, &timeout);
	if (nb == 0) {
		if (connection_timeout + NETTIMEOUT < core::application()->time()) {
			con_error << "Connection timeout!\n";
			abort();
		}
		return;
	}
	if (nb == -1) {
		con_error << "Network error on select()" << std::endl;
		//perror("select");
		abort();
	}

	while (FD_ISSET(this->fd(), &readset) && !error()) {
		receive();

		while (has_messages()) {
			std::string message;
			retreive(message);
			parse_incoming_message(message);
		}

		nb = select(fd()+1, &readset, NULL, NULL, &timeout);
		if (nb == 0) {
			return;
		}
		if (nb == -1) {
			con_error << "Network error on select()" << std::endl;
			//perror("select");
			abort();
		}
	}
}

void NetConnection::send(std::string const &msg)
{
	sendq.append(msg);
}

void NetConnection::transmit()
{

	if (error() || invalid())
		return;
	
	if (!sendq.size()) {
		if (connection_keepalive + NETTIMEOUT /2 < application()->time()) {
			sendq.assign("ping\n");
		} else {
			return;
		}
	} else if (sendq.size() >= BLOCKSIZE - 16) {
		con_warn << "Outgoing data exceeds " << BLOCKSIZE - 16 << " bytes!\n";
		sendq.clear();
		return;
	}
	
	ssize_t 	bytes_sent = 0;
	
	while (sendq.size()) {
		bytes_sent = ::sendto(connection_fd, sendq.c_str(), sendq.size(), 0, (struct sockaddr *)&server_addr, sizeof(server_addr));
		if (bytes_sent <= 0) {
			con_error << "Network send() error!" << std::endl;
			//perror("send");
			abort();
			return;
		}
		
		// assert (bytes_sent <= sendbuf.size());
		sendq.erase(0, bytes_sent);
		Stats::network_bytes_sent += bytes_sent;
	}

	connection_keepalive = application()->time();
}

// parse incoming client messages
/**
 * The following incoming messages are parsed;
 *
 * connect
 * disconnect
 * msg info <text>
 * msg public <name> <text>
 * msg snd <soundname>
 * die
 * ent
 * frame
 * sup
 * pif
 */
void NetConnection::parse_incoming_message(const std::string & message)
{
	std::istringstream msgstream(message);
	
	std::string command;
	msgstream >> command;
	
	if (command == "msg") {
		std::string level;
		if (msgstream >> level) {
			if (level =="info") {
				if (message.size() > 9) {
					application()->notify_message(message.substr(9));
				}
			} else if (level == "public") {
				// FIXME - separate sender nickname
				if (message.size() > 11) {
					application()->notify_message(message.substr(11));
					application()->notify_sound("com/chat.wav");
				}
				
			} else if (level == "snd") {
				if (message.size() > 8) {
					application()->notify_sound(message.substr(8).c_str());
				}
			}
		}
	} else if (command == "connect") {

		connection_state = Connected;
		con_print << "^BConnected." << std::endl;
		return;

	} else if (command == "disconnect") {

		con_error << "Server disconnected!" << std::endl;
		abort();

	} else if (command == "ping") {

	} else if (command == "frame") {
		float timestamp, prevtimestamp;
		if ((msgstream >> timestamp) && (msgstream >> prevtimestamp)) {
			game()->reset_clientstate(timestamp, prevtimestamp);
		}

	} else if (command == "die") {
		unsigned int id;
		if (msgstream >> id) {
			//con_debug << "Received die entity id " << id << std::endl;
			Entity *e = Entity::find(id);
			if (localcontrol() == e) 
				localplayer()->player_control = 0;
			if (e)
				Entity::remove(id);
		}
	} else if (command == "ent") {
		unsigned int type;
		if (msgstream >> type) {
			//con_debug << "Received create entity type " << type << std::endl;
			switch (type) 
			{
			case Entity::Default:
				game()->update_entity_clientstate(new Entity(msgstream));
				break;
			case Entity::Dynamic:
				game()->update_entity_clientstate(new EntityDynamic(msgstream));
				break;
			case Entity::Controlable:
				game()->update_entity_clientstate(new EntityControlable(msgstream));
				break;
			case Entity::Globe:
				game()->update_entity_clientstate(new EntityGlobe(msgstream));
				break;
			default:
				con_warn << "Create for unknown entity type " << type << std::endl;
				break;
			}
		}
	} else if (command == "sup") {
		if (connection_state == Connected) 
		{
			unsigned int id;
			if (msgstream >> id) {
				//con_debug << "Received update entity id " << id << std::endl;
				Entity *entity = Entity::find(id);
				if (!entity) {
					con_warn << "Update for unknown entity " << id << std::endl;
				} else 
					entity->recieve_server_update(msgstream);
			}
		}

	} else if (command == "pif") {
		//con_debug << "Received update player info" << std::endl;
		connection()->localplayer()->recieve_server_update(msgstream);
	}
	
}

}