#!/bin/bash

#Get script name
scrName=`basename ${BASH_SOURCE[0]}`

# help function
function showHelp {
echo -e \\n"Help page for $scrName."\\n
echo -e "Basic test: \\\bin\\\bash $scrName -w {warning_point} -c {critical_point}"\\n
echo "Warning and critical points are optional, default values for warning and critical points are 94% and critical is 97% respectively."
echo "-w : Sets warning point in percentage for Total CPU Usage. Default is 94%."
echo "-c : Sets critical point in percentage for for Total CPU Usage. Default is 97%."
echo -e "-h : Displays the help page."\\n
echo -e "Example: /bin/bash $scrName -w 92 -c 96"\\n
echo -e "Result: [CPU_INFO: 15.70% ] User: 9.60% - System: 3.60% - Idle: 84.30% - IOwait: 2.50%"\\n
echo -e \\n"Author: anokpe.srai@gmail.com"\\n
exit 1
}

#default values for warning and critical
valCW=95
valCC=98

#Regular expression to check positive float number input
pRex='^[0-9]+\.?[0-9]*$'

while getopts :w:c:h FLAG; do
  case $FLAG in
    w)
      if ! [[ $OPTARG =~ $pRex ]] ; then
        echo "error: Use positive digits only" >&2; exit 1
      else
        valCW=$OPTARG
      fi
      ;;
    c)
      if ! [[ $OPTARG =~ $pRex ]] ; then
        echo "error: Use positive digits only" >&2; exit 1
      else
        valCC=$OPTARG
      fi
      ;;
    h)
      showHelp
      ;;
    \?)
      echo -e \\n"No option as -$OPTARG is present!!"
      showHelp
      exit 2
      ;;
  esac
done

shift $((OPTIND-1))

array=($(top -bn 2 -d 1 | grep '^%Cpu' | tail -n 1 | tr -d ':,' | awk '{ printf ( "%.2f %.2f %.2f %.2f %.2f %.2f %.2f %.2f", $2, $4, $6, $8, $10, $12, $14, $16) }'))

cpuUser=${array[0]}
cpuSystem=${array[1]}
cpuNice=${array[2]}
cpuIdle=${array[3]}
cpuUsed_t=$(echo 100 - ${array[3]} | bc)
cpuWA=${array[4]}
cpuHI=${array[5]}
cpuSI=${array[6]}
cpuST=${array[7]}
 

message="[CPU_INFO: $cpuUsed_t% ]  User: $cpuUser% - System: $cpuSystem% - Idle: $cpuIdle% - IOwait: $cpuWA% | - Nice: $cpuNice% - Hardware_interrupts: $cpuHI% - Software_interrupts: $cpuSI% - Steal: $cpuST% "

if (( $(echo "$cpuUsed_t >= $valCC" | bc -l) )); then
  echo -e $message
  $(exit 2)
elif (( $(echo "$cpuUsed_t >= $valCW" | bc -l) )); then
  echo -e $message
  $(exit 1)
else
  echo -e $message
  $(exit 0)
fi