Work time calculator

worktime-calculator.sh

#!/bin/zsh

if [ "$1" = "--help" -o "$1" = "-h" -o $# -gt 4 ]; then
	echo "Simple calculator for same-day office hour calculation\n"

	echo "Usage: $0 [-h] [start] [end] [break] [output]\n"
	echo "   start: Start of working or '0' to use the system boot time. Format hh:mm"
	echo "     end: End of working or '0' to use the current time. Format hh:mm"
	echo "   break: Minutes to be subtracted from work time. AKA lunch break, etc."
	echo "  output: Use 'short' for a one-line output.\n\n"

	echo "Examples: "
	echo "  Use explicit times: "
	echo "    $0 8:05 17:20 45\n"
	echo "  Use system boot and current time:" 
 	echo "    $0 0 0 60\n"
	echo "  If you restarted your system during the day specify your start time:"
	echo "    $0 8:20 0 60\n"
	echo "  Predict your office hours at 5pm:"
	echo "    $0 0 17:00 30\n\n"

	echo "Sample output:"
	echo "  $0 8:00 17:00 45"
	echo "     Work Start      08:00"
	echo "     Work End        17:00"    
	echo "     Break           45 min"   
	echo "     Worktime        08h 15m 00s"
	echo "     WT Decimal      8.25h\n\n"
	echo "  $0 8:00 17:00 45 short"
	echo "     2024-01-04 14:08:20	08:00	17:00	45	08h 15m 00s	8.25h"
	exit 1
fi


typeset -gA worktime=()

function calculate() {
  local INARG=$1
  local OUTARG=$2
  local BREAK=$3
  local SHORT=$4

  if [ "$INARG" = "0" ] || [ -z "$INARG" ]; then
 	  INARG=`who -b | awk '{ print $4 }'`
  fi
  local IN=$(date +'%H:%M' -d $INARG)

  if [ -z "$OUTARG" ] || [ "$OUTARG" = "-" ] || [ "$OUTARG" = "0" ]; then
 	  OUTARG=$(date +'%H:%M')
  fi
  local OUT=$(date +'%H:%M' -d $OUTARG)

  if [ -z "$BREAK" ]; then
	  local BREAK=0
  fi

  if [ -z "$SHORT" ] || [ "$SHORT" != "short" ]; then
	SHORT="normal"
  fi

  local TS_START="$(date +'%m-%d-%Y')@:$IN:00"    
  local TS_END="$(date +'%m-%d-%Y')@:$OUT:00"
  local seconds=$(( ($(date2sec "$TS_END") - $(date2sec "$TS_START")) ))
  bseconds=$(( BREAK * 60 ))
  local workseconds=$(expr $seconds - $bseconds)
  seconds2array $workseconds


  if [ "$SHORT" = "normal" ]; then
	printf "%-15s %-11s\n" "Work Start" $IN
	printf "%-15s %-11s\n" "Work End" $OUT 
	printf "%-15s %-15s\n" "Break" "$BREAK min"
	printf "%-15s %-s" "Worktime" ""
  else
	printf "%s\t%s\t%s\t%s\t" "`date +'%F %H:%M:%S'`" $IN $OUT $BREAK
  fi

  (( ${worktime[DAY]} > 0 )) && printf '%02dd ' ${worktime[DAY]}
  (( ${worktime[HOUR]} > 0 )) && printf '%02dh ' ${worktime[HOUR]}
  (( ${worktime[MIN]} > 0 )) && printf '%02dm ' ${worktime[MIN]}
  (( ${worktime[DAY]} > 0 || ${worktime[HOUR]} > 0 || ${worktime[MIN]} > 0 )) 
  printf '%02ds' ${worktime[SEC]} 

  if [ "$SHORT" = "normal" ]; then
	printf "\n%-15s %s" "WT Decimal"
  else 
	printf "\t" 
  fi
  printf '%.2fh\n' ${worktime[DEC]}
}

function date2sec { 
  date -d "$(sed 's|-|/|g; s|@| |; s|:| |' <<<"$*")" +%s; 
}

function seconds2array {
  local T=$1
  local D=$((T/60/60/24))
  local H=$((T/60/60%24))
  local M=$((T/60%60))
  local S=$((T%60))
  local DEC=$(( H + (M/60.0) ))
  worktime[DAY]=$D
  worktime[HOUR]=$H
  worktime[MIN]=$M
  worktime[SEC]=$S
  worktime[DEC]=$DEC
}

calculate "$@"