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

/* The IRC-based UI (for now the only one)                              */

/*
  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"

GSList *irc_connection_list;

static char *set_eval_charset( set_t *set, char *value );

irc_t *irc_new( int fd )
{
	irc_t *irc;
	struct sockaddr_storage sock;
	socklen_t socklen = sizeof( sock );
	char *host = NULL, *myhost = NULL;
	irc_user_t *iu;
	set_t *s;
	bee_t *b;
	
	irc = g_new0( irc_t, 1 );
	
	irc->fd = fd;
	sock_make_nonblocking( irc->fd );
	
	irc->r_watch_source_id = b_input_add( irc->fd, GAIM_INPUT_READ, bitlbee_io_current_client_read, irc );
	
	irc->status = USTATUS_OFFLINE;
	irc->last_pong = gettime();
	
	irc->nick_user_hash = g_hash_table_new( g_str_hash, g_str_equal );
	irc->watches = g_hash_table_new( g_str_hash, g_str_equal );
	
	strcpy( irc->umode, UMODE );
	
	irc->iconv = (GIConv) -1;
	irc->oconv = (GIConv) -1;
	
	if( global.conf->hostname )
	{
		myhost = g_strdup( global.conf->hostname );
	}
	else if( getsockname( irc->fd, (struct sockaddr*) &sock, &socklen ) == 0 ) 
	{
		char buf[NI_MAXHOST+1];

		if( getnameinfo( (struct sockaddr *) &sock, socklen, buf,
		                 NI_MAXHOST, NULL, 0, 0 ) == 0 )
		{
			myhost = g_strdup( ipv6_unwrap( buf ) );
		}
	}
	
	if( getpeername( irc->fd, (struct sockaddr*) &sock, &socklen ) == 0 )
	{
		char buf[NI_MAXHOST+1];

		if( getnameinfo( (struct sockaddr *)&sock, socklen, buf,
		                 NI_MAXHOST, NULL, 0, 0 ) == 0 )
		{
			host = g_strdup( ipv6_unwrap( buf ) );
		}
	}
	
	if( host == NULL )
		host = g_strdup( "localhost.localdomain" );
	if( myhost == NULL )
		myhost = g_strdup( "localhost.localdomain" );
	
	//if( global.conf->ping_interval > 0 && global.conf->ping_timeout > 0 )
	//	irc->ping_source_id = b_timeout_add( global.conf->ping_interval * 1000, irc_userping, irc );

	irc_connection_list = g_slist_append( irc_connection_list, irc );
	
	b = irc->b = bee_new();
	
	s = set_add( &b->set, "away_devoice", "true", NULL/*set_eval_away_devoice*/, irc );
	s = set_add( &b->set, "buddy_sendbuffer", "false", set_eval_bool, irc );
	s = set_add( &b->set, "buddy_sendbuffer_delay", "200", set_eval_int, irc );
	s = set_add( &b->set, "charset", "utf-8", set_eval_charset, irc );
	//s = set_add( &b->set, "control_channel", irc->channel, NULL/*set_eval_control_channel*/, irc );
	s = set_add( &b->set, "default_target", "root", NULL, irc );
	s = set_add( &b->set, "display_namechanges", "false", set_eval_bool, irc );
	s = set_add( &b->set, "handle_unknown", "root", NULL, irc );
	s = set_add( &b->set, "lcnicks", "true", set_eval_bool, irc );
	s = set_add( &b->set, "ops", "both", NULL/*set_eval_ops*/, irc );
	s = set_add( &b->set, "private", "true", set_eval_bool, irc );
	s = set_add( &b->set, "query_order", "lifo", NULL, irc );
	s = set_add( &b->set, "root_nick", ROOT_NICK, NULL/*set_eval_root_nick*/, irc );
	s = set_add( &b->set, "simulate_netsplit", "true", set_eval_bool, irc );
	s = set_add( &b->set, "to_char", ": ", set_eval_to_char, irc );
	s = set_add( &b->set, "typing_notice", "false", set_eval_bool, irc );

	irc->root = iu = irc_user_new( irc, ROOT_NICK );
	iu->host = g_strdup( myhost );
	iu->fullname = g_strdup( ROOT_FN );
	
	iu = irc_user_new( irc, NS_NICK );
	iu->host = g_strdup( myhost );
	iu->fullname = g_strdup( ROOT_FN );
	
	irc->user = g_new0( irc_user_t, 1 );
	irc->user->host = g_strdup( host );
	
	conf_loaddefaults( irc );
	
	/* Evaluator sets the iconv/oconv structures. */
	set_eval_charset( set_find( &b->set, "charset" ), set_getstr( &b->set, "charset" ) );
	
	irc_write( irc, ":%s NOTICE AUTH :%s", irc->root->host, "BitlBee-IRCd initialized, please go on" );
	
	g_free( myhost );
	g_free( host );
	
	return irc;
}

/* immed=1 makes this function pretty much equal to irc_free(), except that
   this one will "log". In case the connection is already broken and we
   shouldn't try to write to it. */
void irc_abort( irc_t *irc, int immed, char *format, ... )
{
	if( format != NULL )
	{
		va_list params;
		char *reason;
		
		va_start( params, format );
		reason = g_strdup_vprintf( format, params );
		va_end( params );
		
		if( !immed )
			irc_write( irc, "ERROR :Closing link: %s", reason );
		
		ipc_to_master_str( "OPERMSG :Client exiting: %s@%s [%s]\r\n",
	                           irc->user->nick ? irc->user->nick : "(NONE)", irc->root->host, reason );
	     	
		g_free( reason );
	}
	else
	{
		if( !immed )
			irc_write( irc, "ERROR :Closing link" );
		
		ipc_to_master_str( "OPERMSG :Client exiting: %s@%s [%s]\r\n",
	        	           irc->user->nick ? irc->user->nick : "(NONE)", irc->root->host, "No reason given" );
	}
	
	irc->status |= USTATUS_SHUTDOWN;
	if( irc->sendbuffer && !immed )
	{
		/* Set up a timeout event that should shut down the connection
		   in a second, just in case ..._write doesn't do it first. */
		
		b_event_remove( irc->r_watch_source_id );
		irc->r_watch_source_id = 0;
		
		b_event_remove( irc->ping_source_id );
		irc->ping_source_id = b_timeout_add( 1000, (b_event_handler) irc_free, irc );
	}
	else
	{
		irc_free( irc );
	}
}

static gboolean irc_free_hashkey( gpointer key, gpointer value, gpointer data );

void irc_free( irc_t * irc )
{
	log_message( LOGLVL_INFO, "Destroying connection with fd %d", irc->fd );
	
	/*
	if( irc->status & USTATUS_IDENTIFIED && set_getbool( &irc->b->set, "save_on_quit" ) ) 
		if( storage_save( irc, NULL, TRUE ) != STORAGE_OK )
			irc_usermsg( irc, "Error while saving settings!" );
	*/
	
	irc_connection_list = g_slist_remove( irc_connection_list, irc );
	
	/*
	while( irc->queries != NULL )
		query_del( irc, irc->queries );
	*/
	
	while( irc->users )
	{
		irc_user_t *iu = irc->users->data;
		irc_user_free( irc, iu->nick );
	}
	
	if( irc->ping_source_id > 0 )
		b_event_remove( irc->ping_source_id );
	if( irc->r_watch_source_id > 0 )
		b_event_remove( irc->r_watch_source_id );
	if( irc->w_watch_source_id > 0 )
		b_event_remove( irc->w_watch_source_id );
	
	closesocket( irc->fd );
	irc->fd = -1;
	
	g_hash_table_foreach_remove( irc->nick_user_hash, irc_free_hashkey, NULL );
	g_hash_table_destroy( irc->nick_user_hash );
	
	g_hash_table_foreach_remove( irc->watches, irc_free_hashkey, NULL );
	g_hash_table_destroy( irc->watches );
	
	if( irc->iconv != (GIConv) -1 )
		g_iconv_close( irc->iconv );
	if( irc->oconv != (GIConv) -1 )
		g_iconv_close( irc->oconv );
	
	g_free( irc->sendbuffer );
	g_free( irc->readbuffer );
	
	g_free( irc->password );
	
	g_free( irc );
	
	if( global.conf->runmode == RUNMODE_INETD ||
	    global.conf->runmode == RUNMODE_FORKDAEMON ||
	    ( global.conf->runmode == RUNMODE_DAEMON &&
	      global.listen_socket == -1 &&
	      irc_connection_list == NULL ) )
		b_main_quit();
}

static gboolean irc_free_hashkey( gpointer key, gpointer value, gpointer data )
{
	g_free( key );
	
	return( TRUE );
}

static char **irc_splitlines( char *buffer );

void irc_process( irc_t *irc )
{
	char **lines, *temp, **cmd;
	int i;

	if( irc->readbuffer != NULL )
	{
		lines = irc_splitlines( irc->readbuffer );
		
		for( i = 0; *lines[i] != '\0'; i ++ )
		{
			char *conv = NULL;
			
			/* [WvG] If the last line isn't empty, it's an incomplete line and we
			   should wait for the rest to come in before processing it. */
			if( lines[i+1] == NULL )
			{
				temp = g_strdup( lines[i] );
				g_free( irc->readbuffer );
				irc->readbuffer = temp;
				i ++;
				break;
			}
			
			if( irc->iconv != (GIConv) -1 )
			{
				gsize bytes_read, bytes_written;
				
				conv = g_convert_with_iconv( lines[i], -1, irc->iconv,
				                             &bytes_read, &bytes_written, NULL );
				
				if( conv == NULL || bytes_read != strlen( lines[i] ) )
				{
					/* GLib can do strange things if things are not in the expected charset,
					   so let's be a little bit paranoid here: */
					if( irc->status & USTATUS_LOGGED_IN )
					{
						irc_usermsg( irc, "Error: Charset mismatch detected. The charset "
						                  "setting is currently set to %s, so please make "
						                  "sure your IRC client will send and accept text in "
						                  "that charset, or tell BitlBee which charset to "
						                  "expect by changing the charset setting. See "
						                  "`help set charset' for more information. Your "
						                  "message was ignored.",
						                  set_getstr( &irc->b->set, "charset" ) );
						
						g_free( conv );
						conv = NULL;
					}
					else
					{
						irc_write( irc, ":%s NOTICE AUTH :%s", irc->root->host,
						           "Warning: invalid characters received at login time." );
						
						conv = g_strdup( lines[i] );
						for( temp = conv; *temp; temp ++ )
							if( *temp & 0x80 )
								*temp = '?';
					}
				}
				lines[i] = conv;
			}
			
			if( lines[i] && ( cmd = irc_parse_line( lines[i] ) ) )
			{
				irc_exec( irc, cmd );
				g_free( cmd );
			}
			
			g_free( conv );
			
			/* Shouldn't really happen, but just in case... */
			if( !g_slist_find( irc_connection_list, irc ) )
			{
				g_free( lines );
				return;
			}
		}
		
		if( lines[i] != NULL )
		{
			g_free( irc->readbuffer );
			irc->readbuffer = NULL;
		}
		
		g_free( lines );
	}
}

/* Splits a long string into separate lines. The array is NULL-terminated
   and, unless the string contains an incomplete line at the end, ends with
   an empty string. Could use g_strsplit() but this one does it in-place.
   (So yes, it's destructive.) */
static char **irc_splitlines( char *buffer )
{
	int i, j, n = 3;
	char **lines;

	/* Allocate n+1 elements. */
	lines = g_new( char *, n + 1 );
	
	lines[0] = buffer;
	
	/* Split the buffer in several strings, and accept any kind of line endings,
	 * knowing that ERC on Windows may send something interesting like \r\r\n,
	 * and surely there must be clients that think just \n is enough... */
	for( i = 0, j = 0; buffer[i] != '\0'; i ++ )
	{
		if( buffer[i] == '\r' || buffer[i] == '\n' )
		{
			while( buffer[i] == '\r' || buffer[i] == '\n' )
				buffer[i++] = '\0';
			
			lines[++j] = buffer + i;
			
			if( j >= n )
			{
				n *= 2;
				lines = g_renew( char *, lines, n + 1 );
			}

			if( buffer[i] == '\0' )
				break;
		}
	}
	
	/* NULL terminate our list. */ 
	lines[++j] = NULL;
	
	return lines;
}

/* Split an IRC-style line into little parts/arguments. */
char **irc_parse_line( char *line )
{
	int i, j;
	char **cmd;
	
	/* Move the line pointer to the start of the command, skipping spaces and the optional prefix. */
	if( line[0] == ':' )
	{
		for( i = 0; line[i] && line[i] != ' '; i ++ );
		line = line + i;
	}
	for( i = 0; line[i] == ' '; i ++ );
	line = line + i;
	
	/* If we're already at the end of the line, return. If not, we're going to need at least one element. */
	if( line[0] == '\0')
		return NULL;
	
	/* Count the number of char **cmd elements we're going to need. */
	j = 1;
	for( i = 0; line[i] != '\0'; i ++ )
	{
		if( line[i] == ' ' )
		{
			j ++;
			
			if( line[i+1] == ':' )
				break;
		}
	}	

	/* Allocate the space we need. */
	cmd = g_new( char *, j + 1 );
	cmd[j] = NULL;
	
	/* Do the actual line splitting, format is:
	 * Input: "PRIVMSG #bitlbee :foo bar"
	 * Output: cmd[0]=="PRIVMSG", cmd[1]=="#bitlbee", cmd[2]=="foo bar", cmd[3]==NULL
	 */

	cmd[0] = line;
	for( i = 0, j = 0; line[i] != '\0'; i ++ )
	{
		if( line[i] == ' ' )
		{
			line[i] = '\0';
			cmd[++j] = line + i + 1;
			
			if( line[i+1] == ':' )
			{
				cmd[j] ++;
				break;
			}
		}
	}
	
	return cmd;
}

/* Converts such an array back into a command string. Mainly used for the IPC code right now. */
char *irc_build_line( char **cmd )
{
	int i, len;
	char *s;
	
	if( cmd[0] == NULL )
		return NULL;
	
	len = 1;
	for( i = 0; cmd[i]; i ++ )
		len += strlen( cmd[i] ) + 1;
	
	if( strchr( cmd[i-1], ' ' ) != NULL )
		len ++;
	
	s = g_new0( char, len + 1 );
	for( i = 0; cmd[i]; i ++ )
	{
		if( cmd[i+1] == NULL && strchr( cmd[i], ' ' ) != NULL )
			strcat( s, ":" );
		
		strcat( s, cmd[i] );
		
		if( cmd[i+1] )
			strcat( s, " " );
	}
	strcat( s, "\r\n" );
	
	return s;
}

void irc_write( irc_t *irc, char *format, ... ) 
{
	va_list params;

	va_start( params, format );
	irc_vawrite( irc, format, params );	
	va_end( params );

	return;
}

void irc_write_all( int now, char *format, ... )
{
	va_list params;
	GSList *temp;	
	
	va_start( params, format );
	
	temp = irc_connection_list;
	while( temp != NULL )
	{
		irc_t *irc = temp->data;
		
		if( now )
		{
			g_free( irc->sendbuffer );
			irc->sendbuffer = g_strdup( "\r\n" );
		}
		irc_vawrite( temp->data, format, params );
		if( now )
		{
			bitlbee_io_current_client_write( irc, irc->fd, GAIM_INPUT_WRITE );
		}
		temp = temp->next;
	}
	
	va_end( params );
	return;
} 

void irc_vawrite( irc_t *irc, char *format, va_list params )
{
	int size;
	char line[IRC_MAX_LINE+1];
		
	/* Don't try to write anything new anymore when shutting down. */
	if( irc->status & USTATUS_SHUTDOWN )
		return;
	
	memset( line, 0, sizeof( line ) );
	g_vsnprintf( line, IRC_MAX_LINE - 2, format, params );
	strip_newlines( line );
	
	if( irc->oconv != (GIConv) -1 )
	{
		gsize bytes_read, bytes_written;
		char *conv;
		
		conv = g_convert_with_iconv( line, -1, irc->oconv,
		                             &bytes_read, &bytes_written, NULL );

		if( bytes_read == strlen( line ) )
			strncpy( line, conv, IRC_MAX_LINE - 2 );
		
		g_free( conv );
	}
	g_strlcat( line, "\r\n", IRC_MAX_LINE + 1 );
	
	if( irc->sendbuffer != NULL )
	{
		size = strlen( irc->sendbuffer ) + strlen( line );
		irc->sendbuffer = g_renew ( char, irc->sendbuffer, size + 1 );
		strcpy( ( irc->sendbuffer + strlen( irc->sendbuffer ) ), line );
	}
	else
	{
		irc->sendbuffer = g_strdup(line);
	}
	
	if( irc->w_watch_source_id == 0 )
	{
		/* If the buffer is empty we can probably write, so call the write event handler
		   immediately. If it returns TRUE, it should be called again, so add the event to
		   the queue. If it's FALSE, we emptied the buffer and saved ourselves some work
		   in the event queue. */
		/* Really can't be done as long as the code doesn't do error checking very well:
		if( bitlbee_io_current_client_write( irc, irc->fd, GAIM_INPUT_WRITE ) ) */
		
		/* So just always do it via the event handler. */
		irc->w_watch_source_id = b_input_add( irc->fd, GAIM_INPUT_WRITE, bitlbee_io_current_client_write, irc );
	}
	
	return;
}

int irc_check_login( irc_t *irc )
{
	if( irc->user->user && irc->user->nick )
	{
		if( global.conf->authmode == AUTHMODE_CLOSED && !( irc->status & USTATUS_AUTHORIZED ) )
		{
			irc_send_num( irc, 464, ":This server is password-protected." );
			return 0;
		}
		else
		{
			irc_channel_t *ic;
			irc_user_t *iu = irc->user;
			
			irc->user = irc_user_new( irc, iu->nick );
			irc->user->user = iu->user;
			irc->user->fullname = iu->fullname;
			g_free( iu->nick );
			g_free( iu );
			
			irc->umode[0] = '\0';
			/*irc_umode_set( irc, "+" UMODE, 1 );*/
			
			if( global.conf->runmode == RUNMODE_FORKDAEMON || global.conf->runmode == RUNMODE_DAEMON )
				ipc_to_master_str( "CLIENT %s %s :%s\r\n", irc->user->host, irc->user->nick, irc->user->fullname );
			
			irc->status |= USTATUS_LOGGED_IN;
			
			/* This is for bug #209 (use PASS to identify to NickServ). */
			if( irc->password != NULL )
			{
				char *send_cmd[] = { "identify", g_strdup( irc->password ), NULL };
				
				/*irc_setpass( irc, NULL );*/
				/*root_command( irc, send_cmd );*/
				g_free( send_cmd[1] );
			}
			
			irc_send_login( irc );
			
			ic = irc_channel_new( irc, ROOT_CHAN );
			irc_channel_set_topic( ic, CONTROL_TOPIC );
			irc_channel_add_user( ic, irc->user );
			
			return 1;
		}
	}
	else
	{
		/* More information needed. */
		return 0;
	}
}



static char *set_eval_charset( set_t *set, char *value )
{
	irc_t *irc = set->data;
	GIConv ic, oc;

	if( g_strcasecmp( value, "none" ) == 0 )
		value = g_strdup( "utf-8" );

	if( ( ic = g_iconv_open( "utf-8", value ) ) == (GIConv) -1 )
	{
		return NULL;
	}
	if( ( oc = g_iconv_open( value, "utf-8" ) ) == (GIConv) -1 )
	{
		g_iconv_close( ic );
		return NULL;
	}
	
	if( irc->iconv != (GIConv) -1 )
		g_iconv_close( irc->iconv );
	if( irc->oconv != (GIConv) -1 )
		g_iconv_close( irc->oconv );
	
	irc->iconv = ic;
	irc->oconv = oc;

	return value;
}