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

#include <errno.h>
#include <signal.h>

#include <iostream>
#include <vector>
#include <sstream>

#include "math/mathlib.h"
#include "sys/sys.h"
#include "filesystem/filesystem.h"
#include "core/application.h"
#include "core/core.h"
#include "core/entity.h"
#include "core/func.h"
#include "core/cvar.h"
#include "core/netserver.h"

namespace core
{

Cvar sv_dedicated;
Cvar sv_private;

Cvar net_host;
Cvar net_port;

// return the global application object
Application *application()
{
        return Application::instance();
}

// --------------- engine functions  ------------------------------
void func_print(std::stringstream &args)
{
	char text[MAXCMDSIZE];
	if (args.getline(text, MAXCMDSIZE)) {
		// remove the leading space
		if (text[0] && text[1]) {
			con_print << text+1 << std::endl;
		}
	}
}

void func_help(std::stringstream &args)
{
	con_print << "This is the help function" << std::endl;
}

void func_quit(std::stringstream &args)
{
	if (Application::instance()) {
		Application::instance()->shutdown();
		Application::instance()->quit(0);
	}
}

void func_connect(std::stringstream &args)
{
	std::string host;
	if (!(args >> host))
		host.clear();

	if (Application::instance()) {
		Application::instance()->connect(host);
	}
}

void func_disconnect(std::stringstream &args)
{
	if (Application::instance()) 
		Application::instance()->disconnect();
}

void func_list_func(std::stringstream &args)
{
	func::list();
}

void func_list_var(std::stringstream &args)
{
	cvar::list();
}

void func_list_ent(std::stringstream &args)
{
	entity::list();
}

void func_say(std::stringstream &args)
{
	if (application()->netserver) {
		std::ostringstream osstream;
		osstream << "msg public " << localplayer.name << " " << args.str() << "\n";
		application()->netserver->broadcast(osstream.str());
		con_print << localplayer.name << ": " << args.str() << std::endl;
	} else if (application()->netconnection.connected()) {
		std::ostringstream osstream;
		osstream << args.str() << std::endl;
		application()->netconnection.send(osstream.str());
	} else if (game() && game()->connected) {
		con_print << args.str() << std::endl;
	} else
		con_print << "Not connected.";
}

void func_name(std::stringstream &args) {
	std::string name;
	if (args >> name) {
		if (name.size() > 16) 
			name = name.substr(0,16);
	} else {
		con_print << "name " << localplayer.name << std::endl;
		return;
	}

	if (name == localplayer.name) {
		con_print << "name " << name << std::endl;
		return;
	}

	if (application()->netserver) {
		std::ostringstream osstream;
		osstream << "msg info " << localplayer.name << " renamed to " << name << "\n";
		application()->netserver->broadcast(osstream.str());	
		con_print << "msg info " << localplayer.name << " renamed to " << name << std::endl;
	} else if (application()->netconnection.connected()) {
		std::ostringstream osstream;
		osstream << args.str() << std::endl;
		application()->netconnection.send(osstream.str());
	} else {
		con_print << "name " << name << std::endl;
	}
	localplayer.name = name;
}

// --------------- signal_handler -----------------------------------

extern "C" void signal_handler(int signum)
{
	switch (signum) {
		case SIGHUP:
		case SIGINT:
		case SIGQUIT:
		case SIGTERM:
			if (Application::instance()) {
				con_warn << "Received signal " << signum << ", shutting down..." << std::endl;
				Application::instance()->shutdown();
				Application::instance()->quit(0);
			} else {
				std::cerr << "Received signal " << signum << ", terminated..." << std::endl;
				sys::quit(1);
			}
			break;
		default:
			std::cerr << "Received signal " << signum << ", terminated..." << std::endl;
			sys::quit(1);
			break;
	}
}

// --------------- Application -----------------------------

Application *Application::application_instance = 0;

Application::Application()
{
	if (application_instance) {
		std::cerr << "multiple core::Application instances!" << std::endl;
		sys::quit(2);
	}

	application_instance = this;
	netserver = 0;
	gameinterface_preload = 0;

	sys::signal(SIGHUP, signal_handler);
	sys::signal(SIGINT, signal_handler);
	sys::signal(SIGQUIT, signal_handler);
	sys::signal(SIGTERM, signal_handler);
}

Application::~Application()
{
	application_instance = 0;
	}

Application *Application::instance()
{
	return application_instance;
}

float Application::time() const
{
        return game_time;
}

bool Application::connected() const
{
	return (Application::instance()->netconnection.connected() || 
		(GameInterface::instance() && GameInterface::instance()->connected));
}

void Application::init()
{
	con_debug << "Debug messages enabled" << std::endl;
	con_print << "Initializing core..." << std::endl;
	
	filesystem::init();

	gameinterface_preload = core::GameInterface::gameinterface_instance;
	core::GameInterface::gameinterface_instance = 0;
	if (gameinterface_preload) {
		con_print << "  preloaded game found: " << gameinterface_preload->name() << std::endl;
	}
	game_time = 0;

	// dedicated server, client should have set this to 0
	core::sv_dedicated = core::cvar::get("sv_dedicated", "1", core::cvar::ReadOnly);

	// private server for the client, server should have set this to 0
	core::sv_private = core::cvar::get("sv_private", "0");

	if (sv_dedicated->value())
		localplayer.name = "Console";
	else
		localplayer.name = "Player0";

	// network settings
	core::net_host = core::cvar::get("net_host", "0.0.0.0");
	core::net_port = core::cvar::get("net_port", "8042");
	
	// register our functions
	func::add("print", func_print);
	func::add("help", func_help);
	func::add("quit", func_quit);
	
	func::add("connect", func_connect);
	func::add("disconnect", func_disconnect);
	
	func::add("list_var", func_list_var);
	func::add("list_func", func_list_func);
	func::add("list_ent", func_list_ent);

	func::add("say", func_say);
	func::add("name", func_name);
}

void Application::shutdown()
{
	con_print << "Shutting down core..." << std::endl;
	
	if (game() && game()->connected)
		disconnect();

	if (netserver) {
		delete netserver;
		netserver = 0;
	}

	filesystem::shutdown();
}

void Application::quit(int status)
{
	sys::quit(status);
}

void Application::connect(std::string const &host)
{
	if (game() && game()->connected || netconnection.connected()) {
		con_warn << "Connected. Disconnect first." << std::endl;
		return;
	}
	
	if (game()) {
		// unload previous game
		if (game() != gameinterface_preload)
			delete core::GameInterface::gameinterface_instance;
	}

	if (host.size()) {
		// connect to remote core
		core::GameInterface::gameinterface_instance = 0;
		std::string remotehost(host);
		size_t found = remotehost.find(':');
		unsigned int port = 8042;
		if (found != std::string::npos) {
			std::istringstream str(remotehost.substr(found+1));
			if (str >> port) {
				remotehost.erase(found, std::string::npos);
			} else {
				con_print << "Invalid hostname '" << remotehost << "'" << std::endl;
				return;
			}
		}
		netconnection.connect(remotehost, port);

		if (netconnection.connected()) {
			con_print << "Connected." << std::endl;
		} else {
			netconnection.disconnect();
			con_warn << "Could not connect to '" << host << "'" << std::endl;
		}
	} else {
		// use preloaded game
		core::GameInterface::gameinterface_instance = gameinterface_preload;

		// reset everything
		entity::clear();
		game_time = 0;
	
		if (game()->connected = game()->init()) {
			con_print << "Connected." << std::endl;
		} else {
			con_warn << "Could not connect." << std::endl;
			return;
		}

		if (!netserver && (core::sv_dedicated->value() || core::sv_private->value())) {
			netserver = new NetServer(net_host->text(), (unsigned int)net_port->value());
			if (!netserver->valid()) {
				delete netserver;
				if (core::sv_dedicated->value())
					shutdown();
			}
		}
	}
}

void Application::disconnect()
{
	if (netserver) {
		delete netserver;
		netserver = 0;
	}

	if (netconnection.connected()) {
		netconnection.disconnect();
		con_print << "Disconnected." << std::endl;
		return;
	}

	if (game()) {
		if (!game()->connected) {
			con_warn << "Not connected." << std::endl;
			return;
		}
		
		game()->shutdown();	
		game()->connected = false;
		game_time = 0;	
	
		// remove all entities
		entity::clear();

		// remove all game functions
		for (std::map<std::string, Func>::iterator it = func::registry.begin(); it != func::registry.end(); it++) {
			if ( ((*it).second->flags() & func::Game) == func::Game) {
				delete (*it).second;
				func::registry.erase(it);
			}
		}
	
		// remove all game cvars
		for (std::map<std::string, Cvar>::iterator it = cvar::registry.begin(); it != cvar::registry.end(); it++) {
			if ( ((*it).second->flags() & cvar::Game) == cvar::Game) {
				delete (*it).second;
				cvar::registry.erase(it);
			}
		}
		
		con_print << "Disconnected." << std::endl;
	}
}

void Application::frame(float seconds)
{
	if (seconds == 0.0f)
		return;
	
	if (netconnection.connected()) {
		netconnection.frame(seconds);
		// TODO this should come from server
		game_time += seconds;
	} else {
		if (netserver) {
			// TODO limit netserver frames in local mode
			netserver->frame(seconds);
		}

		if (game() && game()->connected) {
			entity::frame(seconds);
			game_time += seconds;	
			
			game()->frame(seconds);
		}
	}	
	
	// execute commands in the buffer
	commandbuffer::execute();
}

}