#!/bin/bash

# MBB - MyBashBot
# ChangeLog see file CHANGELOG included in distribution

### LOCATION OF THE CONFIGFILE ###
#export MBB_CONFIG="/home/bonsai/etc/mbb.conf"
export MBB_CONFIG="/home/bonsai/devel/bash-scripts/irc-bot/MyBashBot/mbb.conf"

### ERROR CODES ###

export ERR_MBB_NOERR=0
export ERR_MBB_CFG_NXFILE=100
export ERR_MBB_CFG_NXKEYWORD=101
export ERR_MBB_CMDPLGIN_NOPLUGIN=110

function _mbb_getconfentry()
{
	local KEYWORD="$1"

	### check if $MBB_CONFIG is a valid file, else return
	if [ ! -e "$MBB_CONFIG" ]; then
		return $ERR_MBB_CFG_NXFILE
	fi
	
	if (grep -i "^${KEYWORD} " ${MBB_CONFIG} >/dev/null 2>&1); then
		CONTENT=`grep -i "^${KEYWORD} " ${MBB_CONFIG} | sed -n -e 's/^[^ ]\+ \(.*\)$/\1/p'`
		echo ${CONTENT}
		return $ERR_MBB_NOERR
	else
		return $ERR_MBB_CFG_NXKEYWORD
	fi
}
export -f _mbb_getconfentry

function _mbb_displayhelpscreen()
{
	cat <<EOF
MyBashBot, version $MBB_VERSION

Known arguments:
--help or -h		:	this ;-)
--configfile or -f FILE	:	location of the configfile
--version or -V		:	displays version

EOF
}
export -f _mbb_displayhelpscreen


export MBB_CMDHANDLERS=""

function _mbb_registercommandhandler()
{
	# links a function to recieved text in format !$COMMAND
	# the function must have the name _mbb_cmdhandler_$COMMAND and must be reachable from within this shell
	local COMMAND="$1"
	
	if [ -z "$MBB_COMMANDHANDLERS" ]; then
		export MBB_COMMANDHANDLERS=" $COMMAND "
	else
		export MBB_COMMANDHANDLERS="${MBB_COMMANDHANDLERS} ${COMMAND} "
	fi

	return $MBB_ERR_NOERROR
}

function _mbb_callcommandhandler()
{
	local CMD="$1"
	local CMDARGS="$2"
	local SOURCE="$3"
	local TARGET="$4"

	if [ "$CMD" == "reload" ]; then
		echo "PRIVMSG ${TARGET} :reloading..."
		#FUNCLIST=`set | grep "_mbb_commandhandler_[^ ]\+ ()" | sed -n -e 's/^\(_mbb_commandhandler_[^ ]\) .*$/\1/p'`
		FUNCLIST=`set | grep "^_mbb_commandhandler_[^ ]\+ ()" | sed -n -e 's/^\(_mbb_commandhandler_[^ ]\+\) .*$/\1/p'`
	
		for i in $FUNCLIST; do
			unset -f $i
		done
		for i in ${PLUGINSDIR}/*.cmdplugin; do
			source $i
		done
		return $MBB_ERR_NOERROR
	fi
	echo "----DEBUG: _mbb_callcommandhandler called with $@" >&7
	if !(echo "${MBB_COMMANDHANDLERS}" | grep " ${CMD} " >/dev/null 2>&1); then
		# CMD not in list of registered plugins
		return $ERR_MBB_CMDPLGIN_NOPLUGIN
	else		
		# CMD is in list of registeres plugins
		_mbb_commandhandler_${CMD} "${SOURCE}" "${TARGET}" "${CMDARGS}" &
		return $ERR_MBB_NOERROR
	fi
}
export -f _mbb_callcommandhandler

function _mbb_getnickfromident()
{
	local IDENT="$1"

	NICK="`echo "${IDENT}" | sed -n -e 's/\([^!]\)!.*$/\1/p'`"
	echo "${NICK}"
}
export -f _mbb_getnickfromident

function _mbb_gettargetfromPRIVMSGmessage()
{
	local MSG="$1"

	TARGET="`echo "$MSG" | sed -n -e 's/^\([^ ]\+\) .*$/\1/p'`"

	echo "$TARGET"
}

function _mbb_getmessagefromPRIVMSGmessage()
{
	local MSG="$1"
	
	MESSAGE="`echo "${MSG}" | sed -n -e 's/^[^ ]\+ :\(.*\)/\1/p'`"
	echo "${MESSAGE}"
}
export -f _mbb_gettargetfromPRIVMSGmessage _mbb_getmessagefromPRIVMSGmessage


### MAIN ###

export MBB_VERSION="0.2"

while [ ! -z "$1" ]; do
case "$1" in
	--configfile|-f)
			export MBB_CONFIG="$2"
			shift 2
			;;
	--help|-h)
			_mbb_displayhelpscreen
			exit 0
			;;
	--version|-V)
			echo "MyBashBot V${MBB_VERSION}"
			exit 0
			;;
	*)
			echo "unknown argument: $1"
			_mbb_displayhelpscreen
			exit 1
			;;
esac
done


export BOTNICK=`_mbb_getconfentry BotNick`
export BOTUSER=`_mbb_getconfentry BotUser`
export BOTRNAME=`_mbb_getconfentry RealName`
export BOTSRV=`_mbb_getconfentry Server`
export SVRPORT=`_mbb_getconfentry ServerPort`
export BOTCHAN=`_mbb_getconfentry Channel`
export PLUGINSDIR=`_mbb_getconfentry PluginsDir`
export OPLIST=`_mbb_getconfentry Channel`

export OWNPID=$$

# source the plugins
# plugins MUSTS:
# be in a file called <COMMAND>.cmdplugin in the $PLUGINSDIR
# define and export a function named _mbb_commandhandler_${COMMANDNAME}, where commandname is the string between "^!" and " ", the bot may recieve
# call the _mbb_registercommandhandler with the name of the COMMAND to register
# e.g. to register the command "op", the function must be named _mbb_commandhandler_op and must be registered with _mbb_registercommandhandler "op"
# then it will be called with _mbb_commandhandler_op <sourcenick> <targetnickorchannel> <rest of line>
# when the string "^!op" appears in a PRIVMSG recieved by the bot.

echo DEBUG: ${PLUGINSDIR}
for i in ${PLUGINSDIR}/*.cmdplugin; do
	source $i
	echo $i
done

# save FD#0 (stdin) to FD#6 and FD#1 (stdout) to FD#7
exec 6<&0
exec 7>&1

# open the socket, redirect stdin and stdout to that socket (to use old in/out use the filedescriptors above)
SOCKET="/dev/tcp/${BOTSRV}/${SVRPORT}"
exec >$SOCKET
exec <&1

# login procedure
echo DEBUG: "USER ${BOTUSER} 0 * : ${BOTRNAME}\r\n" >&7
echo -en "NICK ${BOTNICK}\r\n"
echo -en "USER ${BOTUSER} 0 * : ${BOTRNAME}\r\n"
#echo -en "JOIN ${BOTCHAN}\r\n"

# sort of main() loop ;)
while read SERVERINPUT; do

	# remove the odd \r's specified in RFC's
	SERVERINPUT="`echo "$SERVERINPUT" | tr -d '\r'`"
	#echo "---DEBUG: ${SERVERINPUT}" >&7

	if (echo "$SERVERINPUT" | grep "^:" >/dev/null 2>&1); then
	# normal message ":<from> <command> <params>"
	:
	ORIGIN="`echo "$SERVERINPUT" | sed -n -e 's/^:\([^ ]\+\) .*$/\1/p'`"
	COMMAND="`echo "$SERVERINPUT" | sed -n -e 's/^:[^ ]\+ \([^ ]\+\) .*$/\1/p'`"
	CMDARGS="`echo "$SERVERINPUT" | sed -n -e 's/^[^ ]\+ [^ ]\+ \(.*\)$/\1/p'`"
	echo "---DEBUG: ${COMMAND} from ${ORIGIN} is \"${CMDARGS}\"" >&7
	# ---DEBUG: PRIVMSG from TheBonsai!~bonsai@pD9E0C2B1.dip.t-dialin.net is "#botchan :!teststring"
	case "$COMMAND" in
		[Nn][Oo][Tt][Ii][Cc][Ee])
						# NOTICE
						echo "<NOTICE ${ORIGIN}> ${CMDARGS}" >&7
						;;
		[Pp][Rr][Ii][Vv][Mm][Ss][Gg])
						# PRIVMSG
						ORIGINNICK="`_mbb_getnickfromident "$ORIGIN"`"
						MSGTARGET="`_mbb_gettargetfromPRIVMSGmessage "$CMDARGS"`"
						MSGBODY="`_mbb_getmessagefromPRIVMSGmessage "$CMDARGS"`"
						
						echo "<$ORIGINNICK -> $MSGTARGET> $MSGBODY" >&7
						if (echo "$MSGBODY" | grep "^\!" >/dev/null 2>&1); then
							# the MSGBODY is "!......", which is probably a command to the mbb
							MSGBODY="${MSGBODY} "
							echo "---MESSAGEBODY is \"${MSGBODY}\"" >&7
							BOTCOMMAND=`echo "$MSGBODY" | sed -n -e 's/^\!\([^ ]\+\) .*$/\1/p'`
							CMDBODY=`echo "$MSGBODY" | sed -n -e 's/^\![^ ]\+ \(.*\)$/\1/p'`
							echo "---BOT TRIGGERED with \"${BOTCOMMAND}\"" >&7
							echo "---where CMDBODY is \"${CMDBODY}\"" >&7
							_mbb_callcommandhandler "$BOTCOMMAND" "$CMDBODY" "$ORIGINNICK" "$MSGTARGET"
							case "$?" in
								$ERR_MBB_NOERROR)
											;;
								$ERR_MBB_CMDPLGIN_NOPLUGIN)
											echo -en "PRIVMSG ${MSGTARGET} :from plugin handler: no such plugin (${BOTCOMMAND})\r\n"
											;;
							esac
						fi
						if (echo "$MSGBODY" | grep "${BOTNICK}" >/dev/null 2>&1); then
							echo -en "PRIVMSG ${MSGTARGET} :${ORIGINNICK}, hm?\r\n"
						fi
						;;
		[Jj][Oo][Ii][Nn])
						ORIGINNICK="`_mbb_getnickfromident "$ORIGIN"`"
						echo -en "PRIVMSG ${MSGTARGET} :Hallo sagen kann jeder... Hallo ${ORIGINNICK} *bleh*\r\n"
						;;
		37[526])
						# RPL_MOTDSTART, RPL_MOTD, RPL_MOTDEND
						echo "<MOTD> ${CMDARGS}" >&7
						;;
		001)
						# RPL_WELCOME
						echo "${ORIGIN} welcomes us, joining ${BOTCHAN}" >&7
						echo -en "JOIN ${BOTCHAN}\r\n" 
						;;
	esac
	else
	# message with COMMAND as first argument, message format is now COMMAND [params] (->RFC2812)
	COMMAND="`echo "$SERVERINPUT" | sed -n -e 's/^\([^ ]\+\) .*$/\1/p'`"
	CMDARGS="`echo "$SERVERINPUT" | sed -n -e 's/^[^ ]\+ :\(.*\)$/\1/p'`"
	
	case "$COMMAND" in
		[Pp][Ii][Nn][Gg])
					echo "PING requested by ${CMDARGS} --> PONG :${CMDARGS}" >&7
					echo -en "PONG :${CMDARGS}\r\n"
					;;
		[Ee][Rr][Rr][Oo][Rr])
					echo "ERROR sent from server, params: \"${CMDARGS}\"" >&7
					;;
		*)
					echo "Currently unknown or misparsed command from server: \"${COMMAND}\" with parameters \"${CMDARGS}\"" >&7
					;;
	esac
	fi
done