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

#include <string.h>
#include <unistd.h>
#include <errno.h>

#ifndef _WIN32
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#else
#include <windows.h>
#endif

#include <iostream>
#include <sstream>

#include "sys/sys.h"
#include "core/gameserver.h"
#include "core/netclient.h"
#include "core/netserver.h"
#include "core/cvar.h"
#include "core/func.h"
#include "core/core.h"
#include "core/stats.h"
#include "core/zone.h"

#ifdef _WIN32
	typedef int socklen_t;
#endif

namespace core
{

NetServer::NetServer(std::string const host, unsigned int const port)
{
	con_print << "^BInitializing network server..." << std::endl;

	// initialize variables
	netserver_fd = -1;
	netserver_error = true;

	// initialize socket
	netserver_fd = ::socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if (netserver_fd == -1) {
		con_error << "Network can't create socket!" << std::endl;
		//perror("socket");
		return;
	}

	
	// Get the local adress to bind to
	netserver_addr.sin_family = AF_INET;
	netserver_addr.sin_port = htons(port);
	if (host.size()) {
		netserver_addr.sin_addr.s_addr = inet_addr(host.c_str());
		if ( netserver_addr.sin_addr.s_addr == INADDR_NONE) {
			con_error << "Network invalid address " << host << "!" << std::endl;
			return;
		}
	} else {
		netserver_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	}
	memset(netserver_addr.sin_zero, '\0', sizeof(netserver_addr.sin_zero));
	
	// bind the local address to the socket ( note the typecast)
	if (::bind(netserver_fd, (struct sockaddr *) &netserver_addr, sizeof(struct sockaddr)) == -1) {
		con_error << "Network can't bind to local address!" << std::endl;
		//perror("bind");
		return;
	}
	
	con_print << "  listening on " << inet_ntoa(netserver_addr.sin_addr) <<	":" << ntohs(netserver_addr.sin_port) << std::endl;

	// add the listening socket to the file descriptor set
	FD_ZERO(&serverset);
#ifdef _WIN32
	FD_SET((unsigned int) netserver_fd, &serverset);
#else
	FD_SET(netserver_fd, &serverset);
#endif
	netserver_error = false;
}

NetServer::~NetServer()
{
	con_print << "^BShutting down network server..." << std::endl;

	std::string netmsg("disconnect\n");

	// delete all clients
	Clients:: iterator it;
	for (it = clients.begin(); it != clients.end(); it++) {

		// notify the game server
		if ((*it)->state() == NetClient::Connected)	
			server()->player_disconnect((*it)->player());

		(*it)->send_raw(netmsg);
		(*it)->transmit(fd());
		
		delete (*it);
	}
	clients.clear();

	if (valid()) {
#ifdef _WIN32
		closesocket(fd());
#else
		close(fd());
#endif
	}
}

void NetServer::abort() {
	netserver_error = true;
}

// find the client corresponding to a player
NetClient *NetServer::find_client(Player const *player)
{
	for (Clients::iterator it = clients.begin(); it != clients.end(); it++) {
		if ((*it)->player() == player) {
			return (*it);
		}
	}
	return 0;
}

// remove disconnected clients
void NetServer::reap()
{
        for (Clients:: iterator it = clients.begin(); it != clients.end(); ) {
                NetClient *client = *it;

		if (client->client_timeout + NETTIMEOUT < application()->time()) {
			// client timed out, send a disconnect
			send_disconnect((*it));

			// print a message
			std::string message("^B");
			message.append(client->player()->name());
			message.append(" ^Btimed out.");

			if (client->state() == NetClient::Connected) {
				server()->broadcast(message, client->player());
			} else {
				con_print << message << std::endl;
			}
		}

                if (client->error()) {
			
			// notify the game server
			if (client->state() == NetClient::Connected)	
				server()->player_disconnect((*it)->player());

			// remove the client
                        delete client;
			clients.erase(it++);

                } else {
			++it;
		}
        }
}

void NetServer::receive()
{
	if (error())
		return;

	timeval timeout;
	timeout.tv_sec = 0;
	timeout.tv_usec = 2500;
	fd_set readset = serverset;

	int nb = select(fd()+1, &readset, NULL, NULL, &timeout);
	if (nb == -1) {
#ifndef _WIN32
		// ncurses needs SIGWINCH catched
		if (errno == EINTR) {
			return;
		}
#endif
		con_error << "Network error on select()" << std::endl;
		this->abort();
		return;
	}

	if (nb && FD_ISSET(fd(), &readset)) { 

		// receive incoming data
		struct sockaddr_in 	client_addr;
		socklen_t		client_addr_len = sizeof(client_addr);
		memset(recbuf, '\0', sizeof(recbuf));
		ssize_t bytes_received  = ::recvfrom(fd(), recbuf, FRAMESIZE-1, 0, (struct sockaddr *)&client_addr, &client_addr_len);
		if (bytes_received == -1) {
			con_error << "Network error on recvfrom()!" << std::endl;
			this->abort();
			return;
		} else {
			//con_debug << "Incoming data '" << recbuf <<  "'"<< bytes_received << " bytes" << std::endl;
		}
		Stats::network_bytes_received += bytes_received;

		// originator
		std::string client_host (inet_ntoa(client_addr.sin_addr));
		unsigned int client_port = ntohs(client_addr.sin_port);
	
		// get messages from clients
		bool msg_received = false;

		for (Clients::iterator it = clients.begin(); it != clients.end() && !msg_received; it++) {
			NetClient *client = *it;
			
			if ((client->host() == client_host) && (client->port() == (int) client_port)) {
				// receive data
				client->receive(recbuf);
				
				// process parsed messages
				while (client->has_messages()) {
					std::string message;
					client->retreive(message);
					parse_incoming_message(client, message);
				}

				msg_received = true;
			}
		}

		if (!msg_received) {
			// new connection
			// FIXME maxclients
			NetClient *client = client_connect(client_host , client_port);

			if (client) {
				// receive data
				client->receive(recbuf);
				
				// process parsed messages
				while (client->has_messages()) {
					std::string message;
					client->retreive(message);
					parse_incoming_message(client, message);
				}
			}
		}

	}
	
	// remove dead connections
	reap();
}


NetClient * NetServer::client_connect(std::string const host, int const port)
{
	con_debug << "client_connect " << host << ":" << port << "\n";

	NetClient *client = new NetClient(host, port);
	if (client->error()) {
		con_warn << client->host() << ":" << client->port() << " connection failed!\n";
		delete(client);
		return 0;
	}

	clients.push_back(client);
	client->player()->player_dirty = false;
	return client;
}

void NetServer::client_initialize(NetClient *client) {

	// send welcome message
	std::string welcome("^B");
	welcome.append(Cvar::sv_name->str());
	send_message(client, "info", welcome);
	client->transmit(fd());

	// send zones
	for (Zone::Registry::iterator it = Zone::registry().begin();  it != Zone::registry().end(); it++) {
		send_zone_update(client, (*it).second);
	}

	//  send connect completed
	std::string connect("connect\n");
	client->send_raw(connect);
	client->transmit(fd());

	// set client state to pending
	client->client_state = NetClient::Pending;
}

// send updates to one client
void NetServer::client_frame(NetClient *client, float timestamp, float previoustimestamp)
{
	if (client->state() != NetClient::Connected)
		return;

	Zone *zone = client->player()->zone();

	if (zone) {
		if (client->player()->zonechange()) {

			// send zone info
			send_zone_update(client, zone);
	
			// send entities in zone
			if (client->player()->zone()) {	
				for (Zone::Content::iterator it = zone->content().begin(); it != zone->content().end(); it++) {
					Entity *entity = (*it);
		
					if (!entity->entity_destroyed) {
						send_entity_create(client, entity);
					}
				}
			}

			// the actual zone change is send by the "pif" message

		} else {
			// send a server frame marker
			send_frame_marker(client, timestamp, previoustimestamp);
		
			// send updates for entities in the zone
			for (Entity::Registry::iterator it = Entity::registry().begin(); it != Entity::registry().end(); it++) {
				Entity *entity = (*it).second;

				if (entity->zone() == zone) {	
					if (entity->entity_destroyed) {
						if (!entity->entity_created) {
							send_entity_delete(client, entity);
						}
					} else 	if (entity->entity_created) {
						send_entity_create(client, entity);
	
					} else if (entity->oldzone()) {
						// this entity has entered the zone
						send_entity_create(client, entity);
	
					} else if (entity->dirty() && !(entity->flags() & Entity::Static) ) {	
		
						// FIXME only within visual range
						send_entity_update(client, entity);
					}
				} else if (entity->oldzone() == zone) {
					// the entity has left the zone
					send_entity_delete(client, entity);
				}
			}
		}
	}
}

// run a network server frame, send updates to clients
void NetServer::frame(float timestamp, float previoustimestamp)
{
	/* FIXME
		This code has to be rewritten to send per-player updates.
		Players should only receive updates from their current zone
		Fix zonechange events

		Only entities within visual range should send updates (1024 game units?)
		Fix reliable messages
		It would be nice if players with the highest ping got their updates first
	*/

	// send updates to each client
	for (Clients::iterator it = clients.begin(); it != clients.end(); it++) {
		NetClient *client = *it;

		client->transmit(fd());

		if (client->state() == NetClient::Connected)
			client_frame(client, timestamp, previoustimestamp);

		// update player info always gets through
		if (client->player()->dirty() || client->player()->zonechange()) {

			send_player_update(client);

			client->player()->player_dirty = false;
			client->player()->player_zonechange = false;
		}

		client->transmit(fd());
	}
}

// send outgoing messages to clients

/**
 * The following messages can be send to a client
 *
 * frame <timestamp> <previous timestamp>
 * ent <id> <entity create data>
 * die <id> <entity data>
 * sup <entity update data>

 * msg <channel> <text>
 * 	supported message channels are "info" "public" "rcon" and "snd"
 * 	"snd" is a special channel to transmit sound events
 * zone <id> <zone create/update data>
 */

// broadcast a "msg <channel>" message to all clients
void NetServer::broadcast_message(const char *channel, std::string const & message, Player *ignore_player)
{
	if (!channel)
		return;

	std::string msg("msg ");
	msg.append(channel);
	msg += ' ';
	msg.append(message);
	msg += '\n';

	for (Clients::iterator it = clients.begin(); it != clients.end(); it++) {
		if (((*it)->player() && (*it)->player() != ignore_player) && ((*it)->state() == NetClient::Connected)) {
			(*it)->send_raw(msg);
		}
	}
}

// send a "msg <channel>" message to one client
void NetServer::send_message(NetClient *client, const char *channel, std::string const & message)
{
	if (!channel)
		return;

	std::string msg("msg ");
	msg.append(channel);
	msg += ' ';
	msg.append(message);
	msg += '\n';

	client->send_raw(msg);
}

// disconnect a client
void NetServer::send_disconnect(NetClient *client)
{
	client->send_raw("disconnect\n");
	client->transmit(netserver_fd);
	client->abort();
}

// send a "frame" message to a client
void NetServer::send_frame_marker(NetClient *client, float timestamp, float previoustimestamp)
{
	std::ostringstream msg("");
	msg << "frame " << timestamp << " " << previoustimestamp << "\n";

	if (client->state() == NetClient::Connected) {
		client->send_raw(msg.str());
	}
	
}

// send a "ent" create entity message to all clients
void NetServer::send_entity_create(NetClient *client, Entity *entity)
{
	if ((client->state() == NetClient::Connected) && !entity->serverside()) {
		std::ostringstream msg;
		msg << "ent " << entity->id() << " " << entity->type() << " ";
		entity->serialize_server_create(msg);
		msg << '\n';
		client->send_raw(msg.str());
	}
}

// send a "die" delete entity message to a client
void NetServer::send_entity_delete(NetClient *client, Entity *entity)
{
	if ((client->state() == NetClient::Connected) && !entity->serverside()) {
		std::ostringstream msg("");
		msg << "die " << entity->id() <<  '\n';
		client->send_raw(msg.str());
	}
}

// broadcast a "sup" server update entity message to all clients
void NetServer::send_entity_update(NetClient *client, Entity *entity)
{
	if ((client->state() == NetClient::Connected) && !entity->serverside()) {
		std::ostringstream msg;
		msg << "sup " << entity->id() << " ";
		entity->serialize_server_update(msg);
		msg << '\n';

		client->send_raw(msg.str());
	}
}

// send a "zone" update zone message to a client
void NetServer::send_zone_update(NetClient *client, Zone *zone)
{
	std::ostringstream msg;
	msg << "zone " << zone->id() << " ";
	zone->serialize_server_update(msg);
	msg << '\n';
	client->send_raw(msg.str());
}

// send a "pif" update player information to a single player
void NetServer::send_player_update(NetClient *client)
{
	std::ostringstream msg;
	msg << "pif 0 ";
	client->player()->serialize_server_update(msg);	
	msg << '\n';
	client->send_raw(msg.str());
}

// parse incoming client messages

/**
 * The following incoming protocol messages are parsed;
 *
 * disconnect
 * cmd <game command>
 * cup
 * pif
 * ping
 * say <text>
 * priv <player> <text>
 * 
 */
void NetServer::parse_incoming_message(NetClient *client, const std::string & message) 
{
	if (!message.size())
		return;

	std::stringstream msgstream(message);
	
	std::string command;
	msgstream >> command;
	
	// disconnect
	if (command == "disconnect") {
		client->abort();
		return;
	}

	// connection request
	// connect is the first command expected from the client
	if (command == "connect") {
		if (client->state() != NetClient::Connecting)
			return;

		unsigned int protover;
		if (msgstream >> protover) {
			if (protover != PROTOCOLVERSION) {
				// set protocol version mismatch notification
				std::stringstream netmsgstream("");
				netmsgstream << "^WProtocol version mismatch: ";
				netmsgstream << "client " << protover << " server " << PROTOCOLVERSION << "!\n";

				con_print << client->host() << ":" << client->port() << " " << netmsgstream.str() << std::endl;
				send_message(client, "info", netmsgstream.str());

				send_disconnect(client);
			} else {
				client_initialize(client);
			}
		} else {
			std::string message("Unknown client protocol version!");
			con_print << client->host() << ":" << client->port() << " " << message << std::endl;
			
			send_message(client, "info", message);
			send_disconnect(client);
		}
		return;
	}

	// pif - update player information
	// client connection is completed on the first pif
	if (command == "pif") {
		std::string oldname(client->player()->name());
		client->player()->receive_client_update(msgstream);

		if (client->state() == NetClient::Pending) {

			client->client_state = NetClient::Connected;
			server()->player_connect(client->player());

		} else if ((client->state() == NetClient::Connected) && (client->player()->name() != oldname)) {

			std::string netmsg("^B");
			netmsg.append(oldname);
			netmsg.append(" ^Brenamed to ");
			netmsg.append(client->player()->name());
			server()->broadcast(netmsg);
		}
	}

	if (command == "ping") {
		return;
	}

	if (client->state() != NetClient::Connected)
		return;

	// cmd
	if (command == "cmd") {
		if (message.size() > command.size()+1) {
			std::string cmdline(message.substr(command.size()+1));
			server()->exec(client->player(), cmdline);
		}
		return;
	}

	// cup - client update entity
	if (command == "cup") {
		//con_debug << message << "\n";
		unsigned int id;
		if (msgstream >> id) {
			Entity *entity = Entity::find(id);
			if (!entity) {
				con_warn << client->host() << ":" << client->port() << " update for unknown entity " << id << "\n";
				return;
			} 

			if (entity->type() != Entity::Controlable) {
				con_warn << client->host() << ":" << client->port() << " update for non-controlable entity " << id << "\n";
				return;
			}
	
			EntityControlable *entitycontrolable = (EntityControlable *)entity;

			if (entitycontrolable->owner() != client->player()) {
				con_warn << client->host() << ":" << client->port() << " update for not-owned entity " << id << "\n";
				return;
			}

			entitycontrolable->entity_dirty = true;
			entitycontrolable->receive_client_update(msgstream);	
		}
		return;
	}

	// say
	if (command == "say") {		
		if (message.size() > command.size()+1) {
			server()->say(client->player(), message.substr(command.size()+1));
		}
		return;
	}

	// priv
	if (command == "priv") {
		if (message.size() > command.size()+1) {
			server()->private_message(client->player(), message.substr(command.size()+1));
		}
		return;
	}
	
}

}