/********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2004 Wilmer van der Gaast and others                *
  \********************************************************************/

/* Main file (Unix specific part)                                       */

/*
  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 with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  Suite 330, Boston, MA  02111-1307  USA
*/

#include "bitlbee.h"

#include "arc.h"
#include "base64.h"
#include "commands.h"
#include "protocols/nogaim.h"
#include "help.h"
#include "ipc.h"
#include "md5.h"
#include "misc.h"
#include <signal.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <pwd.h>

global_t global;	/* Against global namespace pollution */

static void sighandler( int signal );

static int crypt_main( int argc, char *argv[] );

int main( int argc, char *argv[] )
{
	int i = 0;
	char *old_cwd = NULL;
	struct sigaction sig, old;
	
	if( argc > 1 && strcmp( argv[1], "-x" ) == 0 )
		return crypt_main( argc, argv );
	
	log_init();
	global.conf_file = g_strdup( CONF_FILE_DEF );
	global.conf = conf_load( argc, argv );
	if( global.conf == NULL )
		return( 1 );
	
	b_main_init();
	nogaim_init();
	
	srand( time( NULL ) ^ getpid() );
	global.helpfile = g_strdup( HELP_FILE );
	
	if( global.conf->runmode == RUNMODE_INETD )
	{
		log_link( LOGLVL_ERROR, LOGOUTPUT_IRC );
		log_link( LOGLVL_WARNING, LOGOUTPUT_IRC );
	
		i = bitlbee_inetd_init();
		log_message( LOGLVL_INFO, "Bitlbee %s starting in inetd mode.", BITLBEE_VERSION );

	}
	else if( global.conf->runmode == RUNMODE_DAEMON )
	{
		log_link( LOGLVL_ERROR, LOGOUTPUT_SYSLOG );
		log_link( LOGLVL_WARNING, LOGOUTPUT_SYSLOG );

		i = bitlbee_daemon_init();
		log_message( LOGLVL_INFO, "Bitlbee %s starting in daemon mode.", BITLBEE_VERSION );
	}
	else if( global.conf->runmode == RUNMODE_FORKDAEMON )
	{
		/* In case the operator requests a restart, we need this. */
		old_cwd = g_malloc( 256 );
		if( getcwd( old_cwd, 255 ) == NULL )
		{
			log_message( LOGLVL_WARNING, "Could not save current directory: %s", strerror( errno ) );
			g_free( old_cwd );
			old_cwd = NULL;
		}
		
		i = bitlbee_daemon_init();
		log_message( LOGLVL_INFO, "Bitlbee %s starting in forking daemon mode.", BITLBEE_VERSION );
	}
	if( i != 0 )
		return( i );
	
	if( ( global.conf->user && *global.conf->user ) &&
	    ( global.conf->runmode == RUNMODE_DAEMON || 
	      global.conf->runmode == RUNMODE_FORKDAEMON ) &&
	    ( !getuid() || !geteuid() ) )
	{
		struct passwd *pw = NULL;
		pw = getpwnam( global.conf->user );
		if( pw )
		{
			setgid( pw->pw_gid );
			setuid( pw->pw_uid );
		}
	}

	global.storage = storage_init( global.conf->primary_storage, global.conf->migrate_storage );
	if( global.storage == NULL )
	{
		log_message( LOGLVL_ERROR, "Unable to load storage backend '%s'", global.conf->primary_storage );
		return( 1 );
	}
 	
	/* Catch some signals to tell the user what's happening before quitting */
	memset( &sig, 0, sizeof( sig ) );
	sig.sa_handler = sighandler;
	sigaction( SIGCHLD, &sig, &old );
	sigaction( SIGPIPE, &sig, &old );
	sig.sa_flags = SA_RESETHAND;
	sigaction( SIGINT,  &sig, &old );
	sigaction( SIGILL,  &sig, &old );
	sigaction( SIGBUS,  &sig, &old );
	sigaction( SIGFPE,  &sig, &old );
	sigaction( SIGSEGV, &sig, &old );
	sigaction( SIGTERM, &sig, &old );
	sigaction( SIGQUIT, &sig, &old );
	sigaction( SIGXCPU, &sig, &old );
	
	if( !getuid() || !geteuid() )
		log_message( LOGLVL_WARNING, "BitlBee is running with root privileges. Why?" );
	if( help_init( &global.help, global.helpfile ) == NULL )
		log_message( LOGLVL_WARNING, "Error opening helpfile %s.", HELP_FILE );
	
	b_main_run();
	
	/* Mainly good for restarting, to make sure we close the help.txt fd. */
	help_free( &global.help );
	
	if( global.restart )
	{
		char *fn = ipc_master_save_state();
		
		chdir( old_cwd );
		
		setenv( "_BITLBEE_RESTART_STATE", fn, 1 );
		g_free( fn );
		
		close( global.listen_socket );
		
		if( execv( argv[0], argv ) == -1 )
			/* Apparently the execve() failed, so let's just
			   jump back into our own/current main(). */
			/* Need more cleanup code to make this work. */
			return 1; /* main( argc, argv ); */
	}
	
	return( 0 );
}

static int crypt_main( int argc, char *argv[] )
{
	int pass_len;
	unsigned char *pass_cr, *pass_cl;
	
	if( argc < 4 || ( strcmp( argv[2], "hash" ) != 0 &&
	                  strcmp( argv[2], "unhash" ) != 0 && argc < 5 ) )
	{
		printf( "Supported:\n"
		        "  %s -x enc <key> <cleartext password>\n"
		        "  %s -x dec <key> <encrypted password>\n"
		        "  %s -x hash <cleartext password>\n"
		        "  %s -x unhash <hashed password>\n"
		        "  %s -x chkhash <hashed password> <cleartext password>\n",
		        argv[0], argv[0], argv[0], argv[0], argv[0] );
	}
	else if( strcmp( argv[2], "enc" ) == 0 )
	{
		pass_len = arc_encode( argv[4], strlen( argv[4] ), (unsigned char**) &pass_cr, argv[3], 12 );
		printf( "%s\n", base64_encode( pass_cr, pass_len ) );
	}
	else if( strcmp( argv[2], "dec" ) == 0 )
	{
		pass_len = base64_decode( argv[4], (unsigned char**) &pass_cr );
		arc_decode( pass_cr, pass_len, (char**) &pass_cl, argv[3] );
		printf( "%s\n", pass_cl );
	}
	else if( strcmp( argv[2], "hash" ) == 0 )
	{
		md5_byte_t pass_md5[21];
		md5_state_t md5_state;
		
		random_bytes( pass_md5 + 16, 5 );
		md5_init( &md5_state );
		md5_append( &md5_state, (md5_byte_t*) argv[3], strlen( argv[3] ) );
		md5_append( &md5_state, pass_md5 + 16, 5 ); /* Add the salt. */
		md5_finish( &md5_state, pass_md5 );
		
		printf( "%s\n", base64_encode( pass_md5, 21 ) );
	}
	else if( strcmp( argv[2], "unhash" ) == 0 )
	{
		printf( "Hash %s submitted to a massive Beowulf cluster of\n"
		        "overclocked 486s. Expect your answer next year somewhere around this time. :-)\n", argv[3] );
	}
	else if( strcmp( argv[2], "chkhash" ) == 0 )
	{
		char *hash = strncmp( argv[3], "md5:", 4 ) == 0 ? argv[3] + 4 : argv[3];
		int st = md5_verify_password( argv[4], hash );
		
		printf( "Hash %s given password.\n", st == 0 ? "matches" : "does not match" );
		
		return st;
	}
	
	return 0;
}

static void sighandler( int signal )
{
	/* FIXME: Calling log_message() here is not a very good idea! */
	
	if( signal == SIGTERM )
	{
		static int first = 1;
		
		if( first )
		{
			/* We don't know what we were doing when this signal came in. It's not safe to touch
			   the user data now (not to mention writing them to disk), so add a timer. */
			
			log_message( LOGLVL_ERROR, "SIGTERM received, cleaning up process." );
			b_timeout_add( 1, (b_event_handler) bitlbee_shutdown, NULL );
			
			first = 0;
		}
		else
		{
			/* Well, actually, for now we'll never need this part because this signal handler
			   will never be called more than once in a session for a non-SIGPIPE signal...
			   But just in case we decide to change that: */
			
			log_message( LOGLVL_ERROR, "SIGTERM received twice, so long for a clean shutdown." );
			raise( signal );
		}
	}
	else if( signal == SIGCHLD )
	{
		pid_t pid;
		int st;
		
		while( ( pid = waitpid( 0, &st, WNOHANG ) ) > 0 )
		{
			if( WIFSIGNALED( st ) )
				log_message( LOGLVL_INFO, "Client %d terminated normally. (status = %d)", (int) pid, WEXITSTATUS( st ) );
			else if( WIFEXITED( st ) )
				log_message( LOGLVL_INFO, "Client %d killed by signal %d.", (int) pid, WTERMSIG( st ) );
		}
	}
	else if( signal != SIGPIPE )
	{
		log_message( LOGLVL_ERROR, "Fatal signal received: %d. That's probably a bug.", signal );
		raise( signal );
	}
}

double gettime()
{
	struct timeval time[1];

	gettimeofday( time, 0 );
	return( (double) time->tv_sec + (double) time->tv_usec / 1000000 );
}