/*
   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 net_host;
Cvar net_port;

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

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();
}
// --------------- 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()
{
	netserver = 0;

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

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

	// dedicated or not, client should have set this to 0
	core::sv_dedicated = core::cvar::get("sv_dedicated", "1", core::cvar::ReadOnly);
	if (sv_dedicated->value())
		localplayer.name = "Console";
	else
		localplayer.name = "Player";

	// 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);

	if (game())
		game()->connected = false;
	current_time = 0;
}

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()
{
	if (!game()) {
		con_warn << "No game module loaded!" << std::endl;
		return;
	}
	
	if (game()->connected) {
		con_warn << "Connected. Disconnect first." << std::endl;
	}
	
	entity::clear();
	game()->current_time = 0;
	
	if (game()->connected = game()->init()) {
		con_print << "Connected." << std::endl;
	} else {
		con_warn << "Connect failed." << std::endl;
		return;
	}
	if (core::sv_dedicated->value() && !netserver) {
		netserver = new NetServer(net_host->text(), (unsigned int)net_port->value());
	}
}

void Application::disconnect()
{
	if (!game()) {
		con_warn << "No game module loaded!" << std::endl;
		return;
	}
	
	if (!game()->connected) {
		con_warn << "Not connected." << std::endl;
		return;
	}

	game()->shutdown();
	
	game()->connected = false;
	game()->current_time = 0;
	
	// remove all entities
	entity::clear();

	// TODO remove all game functions

	// TODO remove all game cvars
	
	con_print << "Disconnected." << std::endl;
}

void Application::frame(float seconds)
{
	current_time += seconds;
	
	if (netserver) {
		// TODO limit netserver frames in local mode
		netserver->frame(seconds);
	}

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

}