/*******************************************************************************
*
*		File	 : bbirc.c
*		Author	 : ceeg
*		Created  : Tue May 22 05:46:13 2007
*		Modified : Wed May 23 15:59:49 2007
*		Website  : www.chrisgillis.net
*
*	=== bbIRC is a barebonesIRC bot. I'll add stuff when I feel like it. My 
* 	    code is probably crap and will destroy your PC so don't run it :)
*
*  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; if not, write to the Free Software
*  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*******************************************************************************/

/* First things first, we must include all necessary header files
 * Note I have commented each line with the functions the header
 * provides access to
 */

/* The only headers included that are related to sockets are inet.h
 * and socket.h
 */
 
#include <stdio.h> 		/* printf() */
#include <stdlib.h>		/* atoi() */
#include <string.h>		/* we'll use some string funcs, also memset() */
#include <stdarg.h>  	/* for variable argument lists */

#include <arpa/inet.h>  /* sockaddr_in, inet_addr() */
#include <sys/socket.h> /* socket(), connect(), send(), recv() */
#include <unistd.h>		/* close() */

/* I've defined a datatype called IrcConnection that will hold
 * all of the variables related to connecting to an IRC server
 */
	 
typedef struct {
	/* The socket our server will transmit data on */
	int sock;
	/* The server address */
	struct sockaddr_in ircServerAddr;
	/* The port we're going to connect on */
	unsigned short ircServerPort;
	/* A pointer to char for storing the IP */
	char *serverIp;
	/* A pointer to char for storing the bots nick */
	char *nickname;
	/* A pointer to char for storing the channel to join */
	char *channel;
} IrcConnection;

#define RECVBUFSIZE 1024 			  /* The size alloted to the buffer we're going to use
			  			   * for the recv() buffer */
						 
#define VERSION 0.1				  /* Version number */


void DieWithError( char *errorMessage ); 	  /* outputs errorMessage and quits */
int IrcSend( IrcConnection *, char *format, ...); /* sends a message over an IrcConnection */

int main ( int argc, char *argv[] )
{
	char recvBuf[RECVBUFSIZE];	/* buffer used for storing recv() messages */
	unsigned short bytesRcvd = 0;	/* used for indexing recvBuf after recv() */
	char pongedOnce = 0; 		/* bot sent pong? */
	char inChannel  = 0; 		/* bot joined a channel? */
	char *match;			/* used for matching messages */
	
	/* Create a pointer to IrcConnection */
	IrcConnection con, *irc = &con; 
	
	/* Check correct size of argc */
	if ( (argc < 4) || (argc > 5) )
	{
		fprintf(stderr, "Usage: %s <Server IP> <Nick> <Channel> [port]\n", argv[0]);
		exit(1);
	}
	
	/* Assign values to irc struct */
	irc->serverIp = argv[1];
	irc->nickname = argv[2];
	irc->channel  = argv[3];
	
	/* explicit port? */
	if ( argc == 5 )
		irc->ircServerPort = atoi(argv[4]);	/* set port to specified */
	else
		irc->ircServerPort = 6667;		/* or use standard */
	
	/* init the socket */
	if ((irc->sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
		DieWithError("Error: socket() failed.");
	
	/* To my knowledge, it is required on some systems to zero the structure
	 * Please correct me if i'm wrong/out of date on this
	 */
	
	memset(&(irc->ircServerAddr), 0, sizeof(irc->ircServerAddr));
	/* internet address family */
	irc->ircServerAddr.sin_family		= AF_INET;
	/* server ip */	
	irc->ircServerAddr.sin_addr.s_addr	= inet_addr(irc->serverIp);  
	/* http://retran.com/beej/htonsman.html */
	irc->ircServerAddr.sin_port			= htons(irc->ircServerPort); 
	
	/* It's about time we got to connect() right? */
	if (connect(irc->sock, (struct sockaddr *) &(irc->ircServerAddr), sizeof(irc->ircServerAddr)) < 0)
		DieWithError("Error: connect() failed.");
	
	/* Well shoot, if it's gotten this far you're connected to an IRC server.
	 * Not for long though ;)
	 * We need to send a few strings to the server so it doesnt boot us off!
	 * NICK <nickname>
	 * USER nick nick nick :nick
	 */
	
	if (IrcSend(irc, "NICK %s\nUSER %s . . :%sv%.1f\n", irc->nickname, irc->nickname, irc->nickname, VERSION) < 0)
		DieWithError("Error: sending nick/usr failed.");		
	
	/* After you send a USER and a NICK you HAVE to start receiving. The server
	 * will likely send a "PING :<string>" message and you MUST reply to it with
	 * "PONG :<string>" where <string> == <string>, this is so the server can 
	 * remove dropped connections 
	 */
	
	/* ============= Main Loop ============= */
	while (1) /* repeat until terminated */
	{
		if ((bytesRcvd = recv(irc->sock, recvBuf, RECVBUFSIZE-1, 0)) <= 0)
			DieWithError("recv failed\n");

		recvBuf[bytesRcvd] = '\0';
		printf(recvBuf);
		
		/* We now effectively have a message stored in our recv buffer 
		 * It would be good if we could search it for PING
		 * y hullo thar, string.h
		 */
		if ((match = strstr(recvBuf, "PING")) != NULL)
		{
			/* A pong message is in the format PONG :<string>
			 * "PING :" is 6chars. match+6 is the start of the string we have
		 	 * to reply back with.
			 */
			IrcSend( irc, "PONG :%s\n", match+6 );
			printf("PONG!\n");
			pongedOnce = 1; /* so we can join a channel (gotta send pong first) */
		}
		
		if((pongedOnce == 1) && (inChannel == 0))
		{
			IrcSend(irc, "JOIN #%s\n", irc->channel);
			inChannel++;
			IrcSend(irc, "PRIVMSG #%s :%s\n", irc->channel, "WOMP WOMP WOMP.");
		}		
	}
	return 0;
}

/* DieWithError 
 */
void DieWithError( char *errorMsg )
{
	perror(errorMsg);
	exit(1);
}

/* IrcSend
 *  = treat it like sprintf on an IrcConnection
 */
int IrcSend( IrcConnection * ircon, char *format, ...)
{
	va_list args;
	char *buffer = malloc(1024);
	unsigned int bufLen;
	int retn = 0;
	
	va_start(args, format);
	vsprintf(buffer, format, args);
	va_end(args);
	
	bufLen = strlen(buffer);
	if (send(ircon->sock, buffer, bufLen, 0) == bufLen) 
		goto out;
	else 
	{
		retn = -1;
		goto out;
	}
	
	out:
		free(buffer);
		return retn;
}