#!/usr/local/bin/perl
## ircautores.pl [an irc client to respond automatically]
## version: 0.02 (last modified at 02/03/28)
## Copyright (C) 2002, Ichikawa Hiromitsu (h-i@bigfoot.com)
#
#############

use IO::Socket;
use IO::Select;

############ user settings ###########
##
$ircserver="irc.server.domain"; # irc server
$ircport='6666'; # irc port
$ircnick="robot"; # irc nickname for this robot
$ircpasswd=""; # irc password for connection (option)
$ircrealname="Version Robot"; # irc realname
$ircchannel="#mychannel"; # join the channel and watch it
$interval=300; # interval_proc will be called every $interval sec
##
## end of setting
#############################


############ user code ###########

# called every line of the $ircchannel
sub resp_mesg_proc
{
	my($msg)=shift @_;
	if($msg =~ /^:checkservers/i){
		$buf="PRIVMSG $ircchannel :Now Checking...\r\n";
		$sock->send($buf);

		my($args)="ALL";
		# Is there any arguments?
		if($msg =~ /^:checkservers\ ([0-9a-zA-Z\-\ ]+)/i){
			$args=$1;
			$args="ALL" if(length($args)>100);
		}
		# $args is tainted? no.
		# synchronous call to avoid DOS attack
		system("perl ./checkservers.pl $args");
		# ignore lines to avoid DOS attack
		recv_line_all();
		#
		$buf="PRIVMSG $ircchannel :Any request?\r\n";
		$sock->send($buf);
	}
	if($msg =~ /^:checkalive/i){
		$buf="PRIVMSG $ircchannel :IRC_AutoRes is alive.\r\n";
		$sock->send($buf);
	}
}

# called every $interval second
sub interval_proc
{
#	$buf="PRIVMSG $ircchannel :interval(debug)\r\n";
#	$sock->send($buf);
	# asynchronous call for performance
	system("perl ./checkservers.pl &");
}


################# don't chanage after this ############

# hook for signals
sub donothing
{
}

$SIG{INT} = 'donothing';
$SIG{HUP} = 'donothing';

# subroutine for receiving a line from $sock
sub recv_line
{
	my($data,$sum,$i);

	return "" unless( $myselect->can_read(10) );

	$sum="";
	for(;;){
		$sock->recv($data,1);
		if($data eq ""){
			print "------- Connection Closed...\n";
			return undef;
		}
		last if(($data eq "\r") || ($data eq "\n"));
		$sum=$sum . $data;
	}

	return $sum;
}

# recv line repeatedly and discard the data
sub recv_line_all
{
	my($data);
	do{
		$data=recv_line();
	}while((defined $data)&&($data ne ""));
	if(!defined $data){
		$sock->close();
		return undef;
	}
	return "OK";
}

# connect and negotiate
sub irc_connect
{
	undef $sock;
	print "Connecting.....\n";
	$sock= IO::Socket::INET->new(PeerAddr => $ircserver,
		PeerPort => $ircport,
		Proto    => 'tcp');

	unless(defined $sock){
		print "*** Cannot Connect ***\n";
		return undef;
	}
	print "connected.....\n";

	$myselect = IO::Select->new();
	$myselect->add($sock);

	# send nickname
	$buf="nick $ircnick\r\n";
	$sock->send($buf);

	# send password to connect (option)
	if($ircpasswd ne ""){
		$buf="pass $ircpasswd\r\n";
		$sock->send($buf);
	}

	# send user
	$buf="user $ircnick hostname $ircserver: $ircrealname\r\n";
	$sock->send($buf);

	# read response
	print "recv before.....\n";
	return undef unless(defined recv_line_all() );
	print "recv after.....\n";

	# send join to join the target channel
	if($ircchannel ne ""){
		$buf="join $ircchannel\r\n";
		$sock->send($buf);
	}

	# read response
#	return undef unless(defined recv_line_all() );

	print "send join message.....\n";

	return "OK";
}

# process line
sub proc_line
{
	my($data,$data1,$data2,$data3,$data4);

	# read a line
	$data=recv_line($sock);
	return undef unless(defined $data);

	# do nothing for empty line
	return "OK" if($data eq "");

	# split the message received
	($data1,$data2,$data3,$data4)=split(" ",$data,4);

	# ignore server status
	return "OK" unless(defined $data2);
	return "OK" if($data2 =~ /^[0-9][0-9][0-9]$/);

	# reply PING-PONG
	if( $data1 =~ /^PING$/i ){
		print "PONG>>$data\n";
		$buf="pong $ircserver\r\n";
		$sock->send($buf);
		return "OK";
	}
	return "OK" if($data1 =~ /^NOTICE$/i);
	return "OK" if($data2 =~ /^PONG$/i);

	print ">>$data\n";

	# send CTCP VERSION reply
	if( ($data2 =~ /privmsg/i) && ($data4 =~ /^:\01VERSION/i) ){
		$buf="NOTICE $data3 :\01VERSION IRC_AutoRes.pl_by_ichikawa\01\r\n";
		$sock->send($buf);
		return "OK";
	}

	# extract user
	undef $user;
	if( $data1 =~ /^:(.*)!/ ){
		$user=$1;
	}

	# channel check
	if( ($data2 =~ /privmsg/i) && ($data3 eq $ircchannel) ){
		resp_mesg_proc($data4);
		return "OK";
	}

	# else
	return "OK";
}

# main loop
sub main_loop
{
	print "response ready.....\n";

	$lastinterval=time();
	while(1){
		return unless(defined proc_line());
		if($lastinterval+ $interval< time()){
			interval_proc();
			$lastinterval=time();
		}
	}
	return;
}


# start main routine

START:
while(1){
	if(defined irc_connect() ){
		main_loop();
	}
	sleep(10);
}

################
## EOF