/*
   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 <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"

#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;
	}

	/*
	// set socket options
	socklen_t yes = 1;
	if (::setsockopt(netserver_fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(socklen_t)) == -1) {
		con_error << "Network can't set socket options!" << std::endl;
		//perror("setsockopt");
		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
	std::list<NetClient *>:: 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(netmsg);
		(*it)->transmit(fd());
		
		delete (*it);
	}
	clients.clear();

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

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

// remove disconnected clients
void NetServer::reap()
{
        for (std::list<NetClient *>:: iterator it = clients.begin(); it != clients.end(); it++) {
                NetClient *client = *it;

		if (client->client_timeout + NETTIMEOUT < application()->time()) {
			// client timed out, send a disconnect
			std::string netmsg("disconnect\n");
			(*it)->send(netmsg);
			(*it)->transmit(fd());
			(*it)->abort();

			// 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
                        clients.erase(it);
                        delete client;
                        it=clients.begin();
                }
        }
}


void NetServer::transmit()
{
	for (std::list<NetClient *>::iterator it = clients.begin(); it != clients.end(); it++) {
		(*it)->transmit(fd());
	}
}

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 (std::list<NetClient *>::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::ostringstream netmsg;
	netmsg.str("");
	netmsg << "msg info ^B" << Cvar::sv_name->str() << "\n";
	client->send(netmsg.str());
	client->transmit(fd());

	// send entities
	std::map<unsigned int, Entity *>::iterator it;
	for (it=Entity::registry.begin(); it != Entity::registry.end(); it++) {
		netmsg.str("");
		netmsg << "ent ";
		(*it).second->serialize(netmsg);
		netmsg << "\n";
		client->send(netmsg.str());
	}
	netmsg.str("connect\n");
	client->send(netmsg.str());

	client->transmit(fd());
}

void NetServer::send(NetClient * client, std::string const & message)
{
	client->send(message);
}

// send a message to all clients
void NetServer::broadcast(std::string const & message, Player *ignore_player)
{
	//std::cout << "NetServer: " << osstream.str();
	for (std::list<NetClient *>::iterator it = clients.begin(); it != clients.end(); it++) {
		NetClient *client = *it;
		if (!client->error() && (client->state() == NetClient::Connected) && client->player() != ignore_player)
			client->send(message);
	}
}

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

// parse incoming client messages
/**
 * The following incoming protocol messages are parsed;
 *
 * disconnect
 * cmd <game command>
 * cup
 * pif
 * ping
 * say <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;
	}

	// pif - update player information
	// pif is the first command expected from the client
	if (command == "pif") {
		std::string oldname(client->player()->name());
		client->player()->recieve_client_update(msgstream);

		if (client->state() == NetClient::Connecting) {
			client->client_state = NetClient::Connected;
			client_initialize(client);
			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";
				
			} else {
				entity->entity_dirty = true;
				entity->recieve_client_update(msgstream);
			}
			
		}
		return;
	}

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

}