/* Services -- main source file.
 *
 * (C) 2003-2010 Anope Team
 * Contact us at team@anope.org
 *
 * Please read COPYING and README for further details.
 *
 * Based on the original code of Epona by Lara.
 * Based on the original code of Services by Andy Church.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (see the file COPYING); if not, write to the
 * Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id$
 *
 */

#include "services.h"
#include "timers.h"
#include "version.h"
#include "modules.h"

// getrlimit.
#ifndef _WIN32
# include <sys/time.h>
# include <sys/resource.h>
#endif


/******** Global variables! ********/

/* Command-line options: (note that configuration variables are in config.c) */
std::string services_dir;	  /* -dir dirname */
std::string services_bin;	/* Binary as specified by the user */
std::string orig_cwd;		/* Original current working directory */
std::string log_filename = LOG_FILENAME;	  /* -log filename */
int debug = 0;				  /* -debug */
int readonly = 0;			   /* -readonly */
bool LogChan = false;				/* -logchan */
int nofork = 0;				 /* -nofork */
int forceload = 0;			  /* -forceload */
int nothird = 0;				/* -nothrid */
int noexpire = 0;			   /* -noexpire */
int protocoldebug = 0;		  /* -protocoldebug */

std::string binary_dir; /* Used to store base path for Anope */
#ifdef _WIN32
#include <process.h>
#define execve _execve
#endif

/* Set to 1 if we are to quit */
int quitting = 0;

/* Set to 1 if we are to quit after saving databases */
int shutting_down = 0;

/* Contains a message as to why services is terminating */
const char *quitmsg = NULL;

/* Should we update the databases now? */
int save_data = 0;

/* At what time were we started? */
time_t start_time;

/* Parameters and environment */
char **my_av, **my_envp;

/* Moved here from version.h */
const char version_number[] = VERSION_STRING;
const char version_number_dotted[] = VERSION_STRING_DOTTED;
const char version_build[] =
	"build #" BUILD ", compiled " __DATE__ " " __TIME__;
/* the space is needed cause if you build with nothing it will complain */
const char version_flags[] = " " VER_OS;

/******** Local variables! ********/

/* Set to 1 after we've set everything up */
static int started = 0;

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

class ExpireTimer : public Timer
{
 public:
	ExpireTimer(time_t timeout, time_t now) : Timer(timeout, now, true) { }

	void Tick(time_t)
	{
		if (!readonly && !noexpire)
			expire_all();
	}
};

class UpdateTimer : public Timer
{
 public:
	UpdateTimer(time_t timeout, time_t now) : Timer(timeout, now, true) { }

	void Tick(time_t)
	{
		if (!readonly)
			save_databases();
	}
};

Socket *UplinkSock = NULL;

class UplinkSocket : public Socket
{
 public:
	UplinkSocket(const std::string &nTargetHost, int nPort, const std::string &nBindHost = "", bool nIPv6 = false) : Socket(nTargetHost, nPort, nBindHost, nIPv6)
	{
		UplinkSock = this;
	}

	~UplinkSocket()
	{
		UplinkSock = NULL;
	}

	bool Read(const std::string &buf)
	{
		process(buf);
		return true;
	}
};

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

/* Run expiration routines */

extern void expire_all()
{
	if (noexpire || readonly)
	{
		// Definitely *do not* want.
		return;
	}

	FOREACH_MOD(I_OnPreDatabaseExpire, OnPreDatabaseExpire());

	Alog(LOG_DEBUG) << "Running expire routines";
	expire_nicks();
	expire_chans();
	expire_requests();
	expire_akills();
	if (ircd->sgline) {
		expire_sglines();
	}
	if (ircd->sqline) {
		expire_sqlines();
	}
	if (ircd->szline) {
		expire_szlines();
	}
	expire_exceptions();

	FOREACH_MOD(I_OnDatabaseExpire, OnDatabaseExpire());
}

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

void save_databases()
{
	if (readonly)
		return;
	
	EventReturn MOD_RESULT;
	FOREACH_RESULT(I_OnSaveDatabase, OnSaveDatabase());
	Alog(LOG_DEBUG) << "Saving FFF databases";
}

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

/* Restarts services */
void do_restart_services()
{
	if (!readonly) {
		expire_all();
		save_databases();
	}
	Alog() << "Restarting";

	FOREACH_MOD(I_OnPreRestart, OnPreRestart());

	if (!quitmsg)
		quitmsg = "Restarting";
	ircdproto->SendSquit(Config.ServerName, quitmsg);
	/* Process to send the last bits of information before disconnecting */
	socketEngine.Process();
	delete UplinkSock;
	close_log();
	/* First don't unload protocol module, then do so */
	modules_unload_all(false);
	modules_unload_all(true);
	chdir(binary_dir.c_str());
	execve(services_bin.c_str(), my_av, my_envp);
	if (!readonly) {
		open_log();
		log_perror("Restart failed");
		close_log();
	}

	FOREACH_MOD(I_OnRestart, OnRestart());

	exit(1);
}

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

/* Terminates services */

static void services_shutdown()
{
	User *u, *next;

	FOREACH_MOD(I_OnPreShutdown, OnPreShutdown());

	if (!quitmsg)
		quitmsg = "Terminating, reason unknown";
	Alog() << quitmsg;
	if (started && UplinkSock)
	{
		ircdproto->SendSquit(Config.ServerName, quitmsg);
		if (uplink)
			delete [] uplink;
		u = firstuser();
		while (u) {
			next = nextuser();
			delete u;
			u = next;
		}
	}
	/* Process to send the last bits of information before disconnecting */
	socketEngine.Process();
	delete UplinkSock;
	FOREACH_MOD(I_OnShutdown, OnShutdown());
	/* First don't unload protocol module, then do so */
	modules_unload_all(false);
	modules_unload_all(true);
	/* just in case they weren't all removed at least run once */
	ModuleRunTimeDirCleanUp();
}

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

/* If we get a weird signal, come here. */

void sighandler(int signum)
{
	/* We set the quit message to something default, just to be sure it is
	 * always set when we need it. It seems some signals slip through to the
	 * QUIT code without having a valid quitmsg. -GD
	 */
	if (!quitmsg)
		quitmsg = "Services terminating via a signal.";

	if (started)
	{
#ifndef _WIN32
		if (signum == SIGHUP)
		{
			Alog() << "Received SIGHUP: Saving Databases & Rehash Configuration";

			expire_all();
			save_databases();

			if (!read_config(1))
			{
				quitmsg = "Error Reading Configuration File (Received SIGHUP)";
				quitting = 1;
			}

			FOREACH_MOD(I_OnReload, OnReload(true));
			return;

		} else
#endif
		if (signum == SIGTERM)
		{
			signal(SIGTERM, SIG_IGN);
#ifndef _WIN32
			signal(SIGHUP, SIG_IGN);
#endif

			Alog() << "Received SIGTERM, exiting.";

			expire_all();
			save_databases();
			quitmsg = "Shutting down on SIGTERM";
			services_shutdown();
			exit(0);
		}
		else if (signum == SIGINT)
		{
			if (nofork)
			{
				signal(SIGINT, SIG_IGN);
				Alog() << "Received SIGINT, exiting.";
				expire_all();
				save_databases();
				quitmsg = "Shutting down on SIGINT";
				services_shutdown();
				exit(0);
			}
		}
	}


	/* Should we send the signum here as well? -GD */
	FOREACH_MOD(I_OnSignal, OnSignal(quitmsg));

	if (started)
	{
		services_shutdown();
		exit(0);
	}
	else
	{
		if (isatty(2))
		{
			fprintf(stderr, "%s\n", quitmsg);
		}
		else
		{
			Alog() << quitmsg;
		}

		exit(1);
	}
}

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

/** The following comes from InspIRCd to get the full path of the Anope executable
 */
std::string GetFullProgDir(char *argv0)
{
	char buffer[PATH_MAX];
#ifdef _WIN32
	/* Windows has specific API calls to get the EXE path that never fail.
	 * For once, Windows has something of use, compared to the POSIX code
	 * for this, this is positively neato.
	 */
	if (GetModuleFileName(NULL, buffer, PATH_MAX))
	{
		std::string fullpath = buffer;
		std::string::size_type n = fullpath.rfind("\\" SERVICES_BIN);
		services_bin = fullpath.substr(n + 1, fullpath.size());
		return std::string(fullpath, 0, n);
	}
#else
	// Get the current working directory
	if (getcwd(buffer, PATH_MAX))
	{
		std::string remainder = argv0;

		/* Does argv[0] start with /? If so, it's a full path, use it */
		if (remainder[0] == '/')
		{
			std::string::size_type n = remainder.rfind("/" SERVICES_BIN);
			services_bin = remainder.substr(n + 1, remainder.size());
			return std::string(remainder, 0, n);
		}

		services_bin = remainder;
		if (services_bin.substr(0, 2) == "./")
			services_bin = services_bin.substr(2);
		std::string fullpath = std::string(buffer) + "/" + remainder;
		std::string::size_type n = fullpath.rfind("/" SERVICES_BIN);
		return std::string(fullpath, 0, n);
	}
#endif
	return "/";
}

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

static bool Connect()
{
	/* Connect to the remote server */
	std::list<Uplink *>::iterator curr_uplink = Config.Uplinks.begin(), end_uplink = Config.Uplinks.end();
	int servernum = 1;
	for (; curr_uplink != end_uplink; ++curr_uplink, ++servernum)
	{
		uplink_server = *curr_uplink;

		try
		{
			new UplinkSocket(uplink_server->host, uplink_server->port, Config.LocalHost ? Config.LocalHost : "", uplink_server->ipv6);
		}
		catch (SocketException& ex)
		{
			Alog() << "Unable to connect to server" << servernum << " (" << uplink_server->host << ":" << uplink_server->port << "), " << ex.GetReason();
			continue;
		}

		Alog() << "Connected to Server " << servernum << " (" << uplink_server->host << ":" << uplink_server->port << ")";
		return true;
	}

	return false;
}

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

/* Main routine.  (What does it look like? :-) ) */

int main(int ac, char **av, char **envp)
{
	int i;

	my_av = av;
	my_envp = envp;

	char cwd[PATH_MAX] = "";
#ifdef _WIN32
	GetCurrentDirectory(PATH_MAX, cwd);
#else
	getcwd(cwd, PATH_MAX);
#endif
	orig_cwd = cwd;

#ifndef _WIN32
	/* If we're root, issue a warning now */
	if ((getuid() == 0) && (getgid() == 0)) {
		fprintf(stderr,
				"WARNING: You are currently running Anope as the root superuser. Anope does not\n");
		fprintf(stderr,
				"	require root privileges to run, and it is discouraged that you run Anope\n");
		fprintf(stderr, "	as the root superuser.\n");
	}
#endif

	binary_dir = GetFullProgDir(av[0]);
	if (binary_dir[binary_dir.size() - 1] == '.')
		binary_dir = binary_dir.substr(0, binary_dir.size() - 2);
#ifdef _WIN32
	std::string::size_type n = binary_dir.rfind("\\");
	services_dir = binary_dir.substr(0, n) + "\\data";
#else
	std::string::size_type n = binary_dir.rfind("/");
	services_dir = binary_dir.substr(0, n) + "/data";
#endif

	/* Clean out the module runtime directory prior to running, just in case files were left behind during a previous run */
	ModuleRunTimeDirCleanUp();

	/* General initialization first */
	if ((i = init_primary(ac, av)) != 0)
		return i;
	
	Alog(LOG_TERMINAL) << "Anope " << version_number << ", " << version_build;
#ifdef _WIN32
	Alog(LOG_TERMINAL) << "Using configuration file " << services_dir << "\\" << services_conf;
#else
	Alog(LOG_TERMINAL) << "Using configuration file " << services_dir << "/" << services_conf;
#endif

	/* Initialization stuff. */
	if ((i = init_secondary(ac, av)) != 0)
		return i;

	FOREACH_MOD(I_OnPreServerConnect, OnPreServerConnect());

	/* If the first connect fails give up, don't sit endlessly trying to reconnect */
	if (!Connect())
		fatal_perror("Can't connect to any servers");

	ircdproto->SendConnect();
	FOREACH_MOD(I_OnServerConnect, OnServerConnect());

	started = 1;

#ifndef _WIN32
	if (Config.DumpCore)
	{
		rlimit rl;
		if (getrlimit(RLIMIT_CORE, &rl) == -1)
		{
			Alog() << "Failed to getrlimit()!";
		}
		else
		{
			rl.rlim_cur = rl.rlim_max;
			if (setrlimit(RLIMIT_CORE, &rl) == -1)
			{
				Alog() << "setrlimit() failed, cannot increase coredump size";
			}
		}
	}
#endif

	/* Set up timers */
	time_t last_check = time(NULL);
	ExpireTimer expireTimer(Config.ExpireTimeout, last_check);
	UpdateTimer updateTimer(Config.UpdateTimeout, last_check);

	/*** Main loop. ***/
	while (!quitting)
	{
		while (!quitting && UplinkSock)
		{
			time_t t = time(NULL);

			Alog(LOG_DEBUG_2) << "Top of main loop";

			if (!readonly && (save_data || shutting_down))
			{
				if (!noexpire)
					expire_all();
				if (shutting_down)
					ircdproto->SendGlobops(NULL, "Updating databases on shutdown, please wait.");
				save_databases();
				save_data = 0;
			}

			if (shutting_down)
			{
				quitting = 1;
				break;
			}

			if (t - last_check >= Config.TimeoutCheck)
			{
				TimerManager::TickTimers(t);
				last_check = t;
			}

			/* Process any modes that need to be (un)set */
			ModeManager::ProcessModes();

			/* Process the socket engine */
			socketEngine.Process();
		}

		if (quitting)
		{
			/* Disconnect and exit */
			services_shutdown();
		}
		else
		{
			FOREACH_MOD(I_OnServerDisconnect, OnServerDisconnect());

			/* Clear all of our users */
			User *u = firstuser();
			while (u)
			{
				User *unext = nextuser();
				delete u;
				u = unext;
			}

			unsigned j = 0;
			for (; j < (Config.MaxRetries ? Config.MaxRetries : j + 1); ++j)
			{
				Alog() << "Disconnected from the server, retrying in " << Config.RetryWait << " seconds";

				sleep(Config.RetryWait);
				if (Connect())
				{
					ircdproto->SendConnect();
					FOREACH_MOD(I_OnServerConnect, OnServerConnect());
					break;
				}
			}
			if (Config.MaxRetries && j == Config.MaxRetries)
			{
				Alog() << "Max connection retry limit exceeded";
				quitting = 1;
			}
		}
	}

	return 0;
}