/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
 * See: http://www.inspircd.org/wiki/index.php/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include "inspircd.h"
#include <signal.h>

#ifndef WIN32
	#include <dirent.h>
	#include <unistd.h>
	#include <sys/resource.h>
	#include <dlfcn.h>
	#include <getopt.h>

	/* Some systems don't define RUSAGE_SELF. This should fix them. */
	#ifndef RUSAGE_SELF
		#define RUSAGE_SELF 0
	#endif
#endif

#include <fstream>
#include "xline.h"
#include "socketengine.h"
#include "inspircd_se_config.h"
#include "socket.h"
#include "command_parse.h"
#include "exitcodes.h"
#include "caller.h"

using irc::sockets::insp_ntoa;
using irc::sockets::insp_inaddr;
using irc::sockets::insp_sockaddr;

InspIRCd* SI = NULL;
int* mysig = NULL;


/* Burlex: Moved from exitcodes.h -- due to duplicate symbols */
const char* ExitCodes[] =
{
		"No error", /* 0 */
		"DIE command", /* 1 */
		"execv() failed", /* 2 */
		"Internal error", /* 3 */
		"Config file error", /* 4 */
		"Logfile error", /* 5 */
		"POSIX fork failed", /* 6 */
		"Bad commandline parameters", /* 7 */
		"No ports could be bound", /* 8 */
		"Can't write PID file", /* 9 */
		"SocketEngine could not initialize", /* 10 */
		"Refusing to start up as root", /* 11 */
		"Found a <die> tag!", /* 12 */
		"Couldn't load module on startup", /* 13 */
		"Could not create windows forked process", /* 14 */
		"Received SIGTERM", /* 15 */
};

void InspIRCd::Cleanup()
{
	std::vector<std::string> mymodnames;
	int MyModCount = this->GetModuleCount();

	if (Config)
	{
		for (unsigned int i = 0; i < Config->ports.size(); i++)
		{
			/* This calls the constructor and closes the listening socket */
			delete Config->ports[i];
		}

		Config->ports.clear();
	}

	/* Close all client sockets, or the new process inherits them */
	for (std::vector<userrec*>::const_iterator i = this->local_users.begin(); i != this->local_users.end(); i++)
	{
		(*i)->SetWriteError("Server shutdown");
		(*i)->CloseSocket();
	}

	/* We do this more than once, so that any service providers get a
	 * chance to be unhooked by the modules using them, but then get
	 * a chance to be removed themsleves.
	 */
	for (int tries = 0; tries < 3; tries++)
	{
		MyModCount = this->GetModuleCount();
		mymodnames.clear();

		if (MyModCount)
		{
			/* Unload all modules, so they get a chance to clean up their listeners */
			for (int j = 0; j <= MyModCount; j++)
				mymodnames.push_back(Config->module_names[j]);

			for (int k = 0; k <= MyModCount; k++)
				this->UnloadModule(mymodnames[k].c_str());
		}
	}

	/* Close logging */
	if (this->Logger)
		this->Logger->Close();

	/* Cleanup Server Names */
	for(servernamelist::iterator itr = servernames.begin(); itr != servernames.end(); ++itr)
		delete (*itr);
}

void InspIRCd::Restart(const std::string &reason)
{
	/* SendError flushes each client's queue,
	 * regardless of writeability state
	 */
	this->SendError(reason);

	this->Cleanup();

	/* Figure out our filename (if theyve renamed it, we're boned) */
	std::string me;

#ifdef WINDOWS
	char module[MAX_PATH];
	if (GetModuleFileName(NULL, module, MAX_PATH))
		me = module;
#else
	me = Config->MyDir + "/inspircd";
#endif

	if (execv(me.c_str(), Config->argv) == -1)
	{
		/* Will raise a SIGABRT if not trapped */
		throw CoreException(std::string("Failed to execv()! error: ") + strerror(errno));
	}
}

void InspIRCd::ResetMaxBans()
{
	for (chan_hash::const_iterator i = chanlist->begin(); i != chanlist->end(); i++)
		i->second->ResetMaxBans();
}

/** Because hash_map doesnt free its buckets when we delete items (this is a 'feature')
 * we must occasionally rehash the hash (yes really).
 * We do this by copying the entries from the old hash to a new hash, causing all
 * empty buckets to be weeded out of the hash. We dont do this on a timer, as its
 * very expensive, so instead we do it when the user types /REHASH and expects a
 * short delay anyway.
 */
void InspIRCd::RehashUsersAndChans()
{
	user_hash* old_users = this->clientlist;
	user_hash* old_uuid  = this->uuidlist;
	chan_hash* old_chans = this->chanlist;

	this->clientlist = new user_hash();
	this->uuidlist = new user_hash();
	this->chanlist = new chan_hash();

	for (user_hash::const_iterator n = old_users->begin(); n != old_users->end(); n++)
		this->clientlist->insert(*n);

	delete old_users;

	for (user_hash::const_iterator n = old_uuid->begin(); n != old_uuid->end(); n++)
		this->uuidlist->insert(*n);

	delete old_uuid;

	for (chan_hash::const_iterator n = old_chans->begin(); n != old_chans->end(); n++)
		this->chanlist->insert(*n);

	delete old_chans;
}

void InspIRCd::CloseLog()
{
	if (this->Logger)
		this->Logger->Close();
}

void InspIRCd::SetSignals()
{
#ifndef WIN32
	signal(SIGALRM, SIG_IGN);
	signal(SIGHUP, InspIRCd::SetSignal);
	signal(SIGPIPE, SIG_IGN);
	signal(SIGCHLD, SIG_IGN);
#endif
	signal(SIGTERM, InspIRCd::SetSignal);
}

void InspIRCd::QuickExit(int status)
{
	exit(0);
}

bool InspIRCd::DaemonSeed()
{
#ifdef WINDOWS
	printf_c("InspIRCd Process ID: \033[1;32m%lu\033[0m\n", GetCurrentProcessId());
	return true;
#else
	signal(SIGTERM, InspIRCd::QuickExit);

	int childpid;
	if ((childpid = fork ()) < 0)
		return false;
	else if (childpid > 0)
	{
		/* We wait here for the child process to kill us,
		 * so that the shell prompt doesnt come back over
		 * the output.
		 * Sending a kill with a signal of 0 just checks
		 * if the child pid is still around. If theyre not,
		 * they threw an error and we should give up.
		 */
		while (kill(childpid, 0) != -1)
			sleep(1);
		exit(0);
	}
	setsid ();
	umask (007);
	printf("InspIRCd Process ID: \033[1;32m%lu\033[0m\n",(unsigned long)getpid());

	signal(SIGTERM, InspIRCd::SetSignal);

	rlimit rl;
	if (getrlimit(RLIMIT_CORE, &rl) == -1)
	{
		this->Log(DEFAULT,"Failed to getrlimit()!");
		return false;
	}
	else
	{
		rl.rlim_cur = rl.rlim_max;
		if (setrlimit(RLIMIT_CORE, &rl) == -1)
			this->Log(DEFAULT,"setrlimit() failed, cannot increase coredump size.");
	}

	return true;
#endif
}

void InspIRCd::WritePID(const std::string &filename)
{
	std::string fname = (filename.empty() ? "inspircd.pid" : filename);
	if (*(fname.begin()) != '/')
	{
		std::string::size_type pos;
		std::string confpath = this->ConfigFileName;
		if ((pos = confpath.rfind("/")) != std::string::npos)
		{
			/* Leaves us with just the path */
			fname = confpath.substr(0, pos) + std::string("/") + fname;
		}
	}
	std::ofstream outfile(fname.c_str());
	if (outfile.is_open())
	{
		outfile << getpid();
		outfile.close();
	}
	else
	{
		printf("Failed to write PID-file '%s', exiting.\n",fname.c_str());
		this->Log(DEFAULT,"Failed to write PID-file '%s', exiting.",fname.c_str());
		Exit(EXIT_STATUS_PID);
	}
}

InspIRCd::InspIRCd(int argc, char** argv)
	: ModCount(0),
	  GlobalCulls(this),

	 /* Functor initialisation. Note that the ordering here is very important. */
	 HandleProcessUser(this),
	 HandleIsNick(this),
	 HandleIsIdent(this),
	 HandleFindDescriptor(this),
	 HandleFloodQuitUser(this),

	 /* Functor pointer initialisation. Must match the order of the list above */
	 ProcessUser(&HandleProcessUser),
	 IsNick(&HandleIsNick),
	 IsIdent(&HandleIsIdent),
	 FindDescriptor(&HandleFindDescriptor),
	 FloodQuitUser(&HandleFloodQuitUser)

{

	int found_ports = 0;
	FailedPortList pl;
	int do_version = 0, do_nofork = 0, do_debug = 0, do_nolog = 0, do_root = 0;    /* flag variables */
	char c = 0;

	modules.resize(255);
	factory.resize(255);
	memset(&server, 0, sizeof(server));
	memset(&client, 0, sizeof(client));

        SocketEngineFactory* SEF = new SocketEngineFactory();
	SE = SEF->Create(this);
	delete SEF;

	this->s_signal = 0;

	this->unregistered_count = 0;

	this->clientlist = new user_hash();
	this->uuidlist = new user_hash();
	this->chanlist = new chan_hash();

	this->Config = new ServerConfig(this);

	this->Config->argv = argv;
	this->Config->argc = argc;

	if (chdir(Config->GetFullProgDir().c_str()))
	{
		printf("Unable to change to my directory: %s\nAborted.", strerror(errno));
		exit(0);
	}

	this->Config->opertypes.clear();
	this->Config->operclass.clear();
	this->SNO = new SnomaskManager(this);
	this->TIME = this->OLDTIME = this->startup_time = time(NULL);
	this->time_delta = 0;
	this->next_call = this->TIME + 3;
	srand(this->TIME);

	*this->LogFileName = 0;
	strlcpy(this->ConfigFileName, CONFIG_FILE, MAXBUF);

	struct option longopts[] =
	{
		{ "nofork",	no_argument,		&do_nofork,	1	},
		{ "logfile",	required_argument,	NULL,		'f'	},
		{ "config",	required_argument,	NULL,		'c'	},
		{ "debug",	no_argument,		&do_debug,	1	},
		{ "nolog",	no_argument,		&do_nolog,	1	},
		{ "runasroot",	no_argument,		&do_root,	1	},
		{ "version",	no_argument,		&do_version,	1	},
		{ 0, 0, 0, 0 }
	};

	while ((c = getopt_long_only(argc, argv, ":f:", longopts, NULL)) != -1)
	{
		switch (c)
		{
			case 'f':
				/* Log filename was set */
				strlcpy(LogFileName, optarg, MAXBUF);
			break;
			case 'c':
				/* Config filename was set */
				strlcpy(ConfigFileName, optarg, MAXBUF);
			break;
			case 0:
				/* getopt_long_only() set an int variable, just keep going */
			break;
			default:
				/* Unknown parameter! DANGER, INTRUDER.... err.... yeah. */
				printf("Usage: %s [--nofork] [--nolog] [--debug] [--logfile <filename>] [--runasroot] [--version] [--config <config>]\n", argv[0]);
				Exit(EXIT_STATUS_ARGV);
			break;
		}
	}

	if (do_version)
	{
		printf("\n%s r%s\n", VERSION, REVISION);
		Exit(EXIT_STATUS_NOERROR);
	}

#ifdef WIN32

	// Handle forking
	if(!do_nofork)
	{
		DWORD ExitCode = WindowsForkStart(this);
		if(ExitCode)
			Exit(ExitCode);
	}

	// Set up winsock
	WSADATA wsadata;
	WSAStartup(MAKEWORD(2,0), &wsadata);

	ChangeWindowsSpecificPointers(this);
#endif
	if (!ServerConfig::FileExists(this->ConfigFileName))
	{
		printf("ERROR: Cannot open config file: %s\nExiting...\n", this->ConfigFileName);
		this->Log(DEFAULT,"Unable to open config file %s", this->ConfigFileName);
		Exit(EXIT_STATUS_CONFIG);
	}

	printf_c("\033[1;32mInspire Internet Relay Chat Server, compiled %s at %s\n",__DATE__,__TIME__);
	printf_c("(C) InspIRCd Development Team.\033[0m\n\n");
	printf_c("Developers:\t\t\033[1;32mBrain, FrostyCoolSlug, w00t, Om, Special, pippijn, peavey, Burlex\033[0m\n");
	printf_c("Others:\t\t\t\033[1;32mSee /INFO Output\033[0m\n");

	/* Set the finished argument values */
	Config->nofork = do_nofork;
	Config->forcedebug = do_debug;
	Config->writelog = !do_nolog;

	strlcpy(Config->MyExecutable,argv[0],MAXBUF);

	if (!this->OpenLog(argv, argc))
	{
		printf("ERROR: Could not open logfile %s: %s\n\n", Config->logpath.c_str(), strerror(errno));
		Exit(EXIT_STATUS_LOG);
	}

	this->stats = new serverstats();
	this->Timers = new TimerManager(this);
	this->Parser = new CommandParser(this);
	this->XLines = new XLineManager(this);
	Config->ClearStack();
	Config->Read(true, NULL);

	if (!do_root)
		this->CheckRoot();
	else
	{
		printf("* WARNING * WARNING * WARNING * WARNING * WARNING * \n\n");
		printf("YOU ARE RUNNING INSPIRCD AS ROOT. THIS IS UNSUPPORTED\n");
		printf("AND IF YOU ARE HACKED, CRACKED, SPINDLED OR MUTILATED\n");
		printf("OR ANYTHING ELSE UNEXPECTED HAPPENS TO YOU OR YOUR\n");
		printf("SERVER, THEN IT IS YOUR OWN FAULT. IF YOU DID NOT MEAN\n");
		printf("TO START INSPIRCD AS ROOT, HIT CTRL+C NOW AND RESTART\n");
		printf("THE PROGRAM AS A NORMAL USER. YOU HAVE BEEN WARNED!\n");
		printf("\nInspIRCd starting in 20 seconds, ctrl+c to abort...\n");
		sleep(20);
	}

	this->SetSignals();

	if (!Config->nofork)
	{
		if (!this->DaemonSeed())
		{
			printf("ERROR: could not go into daemon mode. Shutting down.\n");
			Log(DEFAULT,"ERROR: could not go into daemon mode. Shutting down.");
			Exit(EXIT_STATUS_FORK);
		}
	}

	SE->RecoverFromFork();

	this->Modes = new ModeParser(this);
	this->AddServerName(Config->ServerName);
	CheckDie();
	int bounditems = BindPorts(true, found_ports, pl);

	for(int t = 0; t < 255; t++)
		Config->global_implementation[t] = 0;

	memset(&Config->implement_lists,0,sizeof(Config->implement_lists));

	printf("\n");

	this->Res = new DNS(this);

	this->LoadAllModules();
	/* Just in case no modules were loaded - fix for bug #101 */
	this->BuildISupport();
	InitializeDisabledCommands(Config->DisabledCommands, this);

	if ((Config->ports.size() == 0) && (found_ports > 0))
	{
		printf("\nERROR: I couldn't bind any ports! Are you sure you didn't start InspIRCd twice?\n");
		Log(DEFAULT,"ERROR: I couldn't bind any ports! Are you sure you didn't start InspIRCd twice?");
		Exit(EXIT_STATUS_BIND);
	}

	if (Config->ports.size() != (unsigned int)found_ports)
	{
		printf("\nWARNING: Not all your client ports could be bound --\nstarting anyway with %d of %d client ports bound.\n\n", bounditems, found_ports);
		printf("The following port(s) failed to bind:\n");
		int j = 1;
		for (FailedPortList::iterator i = pl.begin(); i != pl.end(); i++, j++)
		{
			printf("%d.\tIP: %s\tPort: %lu\n", j, i->first.empty() ? "<all>" : i->first.c_str(), (unsigned long)i->second);
		}
	}
#ifndef WINDOWS
	if (!Config->nofork)
	{
		if (kill(getppid(), SIGTERM) == -1)
		{
			printf("Error killing parent process: %s\n",strerror(errno));
			Log(DEFAULT,"Error killing parent process: %s",strerror(errno));
		}
	}

	if (isatty(0) && isatty(1) && isatty(2))
	{
		/* We didn't start from a TTY, we must have started from a background process -
		 * e.g. we are restarting, or being launched by cron. Dont kill parent, and dont
		 * close stdin/stdout
		 */
		if (!do_nofork)
		{
			fclose(stdin);
			fclose(stderr);
			fclose(stdout);
		}
		else
		{
			Log(DEFAULT,"Keeping pseudo-tty open as we are running in the foreground.");
		}
	}
#else
	WindowsIPC = new IPC(this);
	if(!Config->nofork)
	{
		WindowsForkKillOwner(this);
		FreeConsole();
	}
#endif


	/*
	 * Initialise UID. XXX, we need to read SID from config, and use it instead of 000.
	 * For an explanation as to exactly how this works, and why it works this way, see GetUID().
	 *   -- w00t
	 */
	int i;


	/* Generate SID */
        size_t sid = 0;
	if (Config->sid)
	{
		sid = Config->sid;
	}
	else
	{
		for (const char* x = Config->ServerName; *x; ++x)
			sid = 5 * sid + *x;
		for (const char* y = Config->ServerDesc; *y; ++y)
			sid = 5 * sid + *y;
		sid = sid % 999;

		Config->sid = sid;
	}
	current_uid[0] = sid / 100 + 48;
	current_uid[1] = ((sid / 10) % 10) + 48;
	current_uid[2] = sid % 10 + 48;

	/* Initialise UID */
	for(i = 3; i < UUID_LENGTH - 1; i++)
		current_uid[i] = 'A';

	printf("\nInspIRCd is now running!\n");
	Log(DEFAULT,"Startup complete.");

	this->WritePID(Config->PID);
}

void InspIRCd::DoOneIteration(bool process_module_sockets)
{
#ifndef WIN32
	static rusage ru;
#else
	static time_t uptime;
	static struct tm * stime;
	static char window_title[100];
#endif

	/* time() seems to be a pretty expensive syscall, so avoid calling it too much.
	 * Once per loop iteration is pleanty.
	 */
	OLDTIME = TIME;
	TIME = time(NULL);

	/* Run background module timers every few seconds
	 * (the docs say modules shouldnt rely on accurate
	 * timing using this event, so we dont have to
	 * time this exactly).
	 */
	if (TIME != OLDTIME)
	{
		if (TIME < OLDTIME)
			WriteOpers("*** \002EH?!\002 -- Time is flowing BACKWARDS in this dimension! Clock drifted backwards %d secs.",abs(OLDTIME-TIME));
		if ((TIME % 3600) == 0)
		{
			this->RehashUsersAndChans();
			FOREACH_MOD_I(this, I_OnGarbageCollect, OnGarbageCollect());
		}
		Timers->TickTimers(TIME);
		this->DoBackgroundUserStuff(TIME);

		if ((TIME % 5) == 0)
		{
			XLines->expire_lines();
			FOREACH_MOD_I(this,I_OnBackgroundTimer,OnBackgroundTimer(TIME));
			Timers->TickMissedTimers(TIME);
		}
#ifndef WIN32
		/* Same change as in cmd_stats.cpp, use RUSAGE_SELF rather than '0' -- Om */
		if (!getrusage(RUSAGE_SELF, &ru))
		{
			gettimeofday(&this->stats->LastSampled, NULL);
			this->stats->LastCPU = ru.ru_utime;
		}
#else
		WindowsIPC->Check();

		if(Config->nofork)
		{
			uptime = Time() - startup_time;
			stime = gmtime(&uptime);
			snprintf(window_title, 100, "InspIRCd - %u clients, %u accepted connections - Up %u days, %.2u:%.2u:%.2u",
				LocalUserCount(), stats->statsAccept, stime->tm_yday, stime->tm_hour, stime->tm_min, stime->tm_sec);
			SetConsoleTitle(window_title);
		}
#endif
	}

	/* Call the socket engine to wait on the active
	 * file descriptors. The socket engine has everything's
	 * descriptors in its list... dns, modules, users,
	 * servers... so its nice and easy, just one call.
	 * This will cause any read or write events to be
	 * dispatched to their handlers.
	 */
	this->SE->DispatchEvents();

	/* if any users was quit, take them out */
	this->GlobalCulls.Apply();

	/* If any inspsockets closed, remove them */
	this->InspSocketCull();

	if (this->s_signal)
	{
		this->SignalHandler(s_signal);
		this->s_signal = 0;
	}

}

void InspIRCd::InspSocketCull()
{
	for (std::map<InspSocket*,InspSocket*>::iterator x = SocketCull.begin(); x != SocketCull.end(); ++x)
	{
		SE->DelFd(x->second);
		x->second->Close();
		delete x->second;
	}
	SocketCull.clear();
}

int InspIRCd::Run()
{
	while (true)
	{
		DoOneIteration(true);
	}
	/* This is never reached -- we hope! */
	return 0;
}

/**********************************************************************************/

/**
 * An ircd in four lines! bwahahaha. ahahahahaha. ahahah *cough*.
 */

int main(int argc, char** argv)
{
	SI = new InspIRCd(argc, argv);
	mysig = &SI->s_signal;
	SI->Run();
	delete SI;
	return 0;
}

/* this returns true when all modules are satisfied that the user should be allowed onto the irc server
 * (until this returns true, a user will block in the waiting state, waiting to connect up to the
 * registration timeout maximum seconds)
 */
bool InspIRCd::AllModulesReportReady(userrec* user)
{
	if (!Config->global_implementation[I_OnCheckReady])
		return true;

	for (int i = 0; i <= this->GetModuleCount(); i++)
	{
		if (Config->implement_lists[i][I_OnCheckReady])
		{
			int res = modules[i]->OnCheckReady(user);
			if (!res)
				return false;
		}
	}
	return true;
}

int InspIRCd::GetModuleCount()
{
	return this->ModCount;
}

time_t InspIRCd::Time(bool delta)
{
	if (delta)
		return TIME + time_delta;
	return TIME;
}

int InspIRCd::SetTimeDelta(int delta)
{
	int old = time_delta;
	time_delta = delta;
	this->Log(DEBUG, "Time delta set to %d (was %d)", time_delta, old);
	return old;
}

void InspIRCd::AddLocalClone(userrec* user)
{
	clonemap::iterator x = local_clones.find(user->GetIPString());
	if (x != local_clones.end())
		x->second++;
	else
		local_clones[user->GetIPString()] = 1;
}

void InspIRCd::AddGlobalClone(userrec* user)
{
	clonemap::iterator y = global_clones.find(user->GetIPString());
	if (y != global_clones.end())
		y->second++;
	else
		global_clones[user->GetIPString()] = 1;
}

int InspIRCd::GetTimeDelta()
{
	return time_delta;
}

void InspIRCd::SetSignal(int signal)
{
	*mysig = signal;
}