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

namespace core
{

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

// --------------- engine functions  ------------------------------
void func_print(std::string const &args)
{
	con_print << args << "\n";
}

void func_help(std::string const &args)
{
	con_print << "This is the help function\n";
}

void func_quit(std::string const  &args)
{
	application()->shutdown();
	application()->quit(0);
}

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

	application()->connect(host);
}

void func_disconnect(std::string const  &args)
{
	application()->disconnect();
}

// FIXME this is a game function
void func_say(std::string const &args)
{
	if (application()->netserver) {
		std::ostringstream osstream;
		osstream << "msg public " << Player::local.name() << " " << args << "\n";
		application()->netserver->broadcast(osstream.str());
		con_print << Player::local.name() << ": " << args << "\n";
	} else if (application()->netconnection.connected()) {
		std::ostringstream osstream;
		osstream << args << "\n";
		application()->netconnection.send(args);
	} else if (game() && game()->connected) {
		con_print << args << "\n";
	} else
		con_print << "Not connected.";
}

void func_name(std::string const &args) {
	std::istringstream argstream(args);
	std::string name;
	if (argstream >> name) {
		if (name.size() > 16) 
			name = name.substr(0,16);
	} else {
		con_print << "name " << Player::local.name() << "\n";
		return;
	}

	if (name == Player::local.name()) {
		con_print << "name " << name << "\n";
		return;
	}

	if (application()->netserver) {
		std::ostringstream osstream;
		osstream << "msg info " << Player::local.name() << " renamed to " << name << "\n";
		application()->netserver->broadcast(osstream.str());	

		con_print << "msg info " << Player::local.name() << " renamed to " << name << "\n";
	} else if (application()->netconnection.connected()) {
		std::ostringstream osstream;
		osstream << "name " << name << "\n";
		application()->netconnection.send(osstream.str());

		con_print << "name " << name << "\n";
	} else {
		con_print << "name " << name << "\n";
	}

	Player::local.player_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...\n";
				application()->shutdown();
				application()->quit(0);
			} else {
				std::cerr << "Received signal " << signum << ", terminated...\n";
				application()->quit(1);
			}
			break;
		default:
			std::cerr << "Received signal " << signum << ", terminated...\n";
			application()->quit(1);
			break;
	}
}

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

Application *Application::application_instance = 0;

Application::Application()
{
	if (application_instance) {
		std::cerr << "multiple core::Application instances!\n";
		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\n";
	con_print << "Initializing core...\n";
	
	filesystem::init();

	CommandBuffer::init();

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

	// dedicated server should set this to 1
	Cvar::sv_dedicated = Cvar::get("sv_dedicated", "0", Cvar::ReadOnly);

	// client can set this to 1
	Cvar::sv_private = Cvar::get("sv_private", "0");

	if (Cvar::sv_dedicated->value())
		Player::local.player_name = "Console";
	else
		Player::local.player_name = "Player0";

	// network settings
	Cvar::net_host = Cvar::get("net_host", "0.0.0.0");
	Cvar::net_port = Cvar::get("net_port", "8042");
	
	// register our engine 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("say", func_say);
	Func::add("name", func_name);
}

void Application::shutdown()
{
	con_print << "Shutting down core...\n";

	if (connected())
		disconnect();

	// remove our engine functions
	Func::remove("print");
	Func::remove("help");
	Func::remove("quit");
	
	Func::remove("connect");
	Func::remove("disconnect");
	
	Func::remove("say");
	Func::remove("name");

	CommandBuffer::shutdown();

	filesystem::shutdown();
}

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

// clear all game realted objects
void Application::clear()
{
	// remove all entities
	for (std::map<unsigned int, Entity*>::iterator it = Entity::registry.begin(); it != Entity::registry.end(); it++) {
		delete (*it).second;
	}
	Entity::registry.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);
		}
	}
}

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

	clear();

	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 << "'\n";
				return;
			}
		}
		netconnection.connect(remotehost, port);

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

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

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

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

	if (netconnection.connected()) {
		netconnection.disconnect();
		con_print << "Disconnected.\n";
		return;
	}

	if (game()) {
		if (!game()->connected) {
			con_warn << "Not connected.\n";
			return;
		}
		
		game()->shutdown();	
		game()->connected = false;
		game_time = 0;	
	
		clear();
		
		con_print << "Disconnected.\n";
	}
}

void Application::frame(float seconds)
{
	if (seconds == 0.0f)
		return;

	// execute commands in the buffer
	CommandBuffer::exec();

	// update entities
	if (connected()) {
		std::map<unsigned int, Entity *>::iterator it;
		for (it=Entity::registry.begin(); it != Entity::registry.end(); it++) {
			Entity *entity = (*it).second;
			if ((entity->type() == Entity::Controlable) || (entity->type() == Entity::Dynamic)) {
				entity->frame(seconds);
			}
		}
	}

	// netstuff 
	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) {
			game_time += seconds;	
			
			game()->frame(seconds);
		}
	}	
}

}