#!/bin/bash

#define the delta limit - difference between previous and current check
#this is the difference in drop, not in raise.
baddelta="100" 
#define the bad value limit - the minimum value size we will accept as being
#normal - i.e. if the current value is less than $badval then there is an issue.
badval="100"


################################################################################
# End user should not need to change anything below this line.
################################################################################


#Lets pull in and define some variables.

#The hostname of the machine we will be checking
HOST=$1
#The type of machine we're checking - streamer, catalogue
TYPE=$2
#The attribute we're checking - anon, sub, cache
ATTR=$3

#set default values to avoid if issues
delta="0"
curdelta="0"
value="0"
#set our temp file, this file is used for storing the previous $value
#one temp file per host per type per attribute - saves confusion.
#it will be inherited as $oldval
tmp=/tmp/$HOST.$TYPE.$ATTR.jmx.get.tmp


#general sanity check
if [ -z $HOST ] || [ -z $TYPE ] || [ -z $ATTR ]
then

    echo "Missing Parameters"
    exit 2

fi

#more silly sanity checking
touch $tmp

#inherit our $oldval from the temp file
. $tmp


#check what type we're dealing with and assign the correct url dependant on type
if [ $TYPE == "streamer" ]
then

    urltype="fm.last.ticketstream.monitor.Status"

elif [ $TYPE == "catalogue" ]
then

    urltype="fm.last.catalogue.monitor.Status"

fi


#same for attribute.
if [ $ATTR == "anon" ]
then

    attribute="NumAnon"

elif [ $ATTR == "sub" ]
then

    attribute="NumLoggedIn"

elif [ $ATTR == "cache" ]
then

    attribute="CacheSizes"

else

    #I don't know, it could happen...
    echo "OMG, It's a Lion on line 59..."
    exit 2

fi

#sanity check for the $oldval inheritance - first run this won't be set
#so we'll set it to zero if that is the case.
if [ -z $oldval ]
then

    oldval=0

fi

#create our URL.
URL="http://gimli.int.last.fm:4041/getattribute?objectname="$HOST""$TYPE":type="$urltype"&attribute="$attribute""


#nitty gritty begins...

function getvalue {

##this is the most pointless function ever, but, using a function just in case it gets complicated.

#declare only valid for this function, stripping everything but the value out
#with cut and passing to a global.
value=$(GET "$URL" | grep -o "value=\".*\"" | sed -e 's/\"//g' | cut -d"=" -f2)

}

#figure out what the delta is.
function getdelta {

    if [ $oldval -lt $value ]
    then
        
    	#Because I'm paranoid, and I can.
        touch $tmp

    #<= is important, saves hitting line 97 repeatedly
    elif [ $value -le $oldval ]
    then

        delta="$(( $oldval - $value ))"

    else
        
    	#it would be thoroughly bad to arrive here, we shouldn't, but, we could.
        echo "We really shouldn't be on line 97"
        exit 2

    fi
}

function rotate {

    #export our oldvalue to the temp file for use next time around
    echo "oldval=$value" > $tmp

}

function checkerr {


    #let the error checking commence
    if [ $value -lt $badval ]
    then

    	#if the value is less than our bad value, then this is bad.
        echo "Value is less than expected - $value"
        exit 2

    elif [ $delta -gt $baddelta ]
    then

    	#if the delta is out of range, this is also bad.
        echo "Delta is too large - $delta"
        exit 2

    else
        
    	#all is good.
        echo "Value is - $value, Delta is - $delta"
        exit 0

    fi
}

getvalue
getdelta
rotate
checkerr