timeuntil

#!/bin/bash

# Set some variables
homeDir=$(ls -d ~)
file="${homeDir}/.timeuntil"
if [ ! -e $file ]; then
	touch $file
elif [ ! -f $file ]; then
	echo "Invalid countdown file: $file"
	exit 1
fi
now=$(date +%s)
records=$(cat $file | base64 -d)
numRecords=$(echo $records | grep -o '::' | wc -l)
usage="\
Usage: $(basename $0) [--short|-s]              #get time until destination
       $(basename $0) [--add|-a] \"time\" \"name\"  #assign time to the name
       $(basename $0) [--trim|-t]               #remove old trackers
       $(basename $0) [--reset|-r]              #reset trackers"
doShort=false

# Option handling
if [ $# -gt 0 ]; then
	case $1 in
		# Add a new record
		--add|-a)
			if [ $# -ne 3 ]; then
				echo "$usage"
				exit 1
			fi
			records+="$(echo $3 | tr -d ':'):"$(date -d "$2" +%s)"::"
			echo $records | base64 > $file
			;;
		# Reset the record file
		--reset|-r)
			echo -n '' > $file
			exit
			;;
		# Short output lines
		--short|-s)
			doShort=true
			;;
		# Remove old records (time before now)
		--trim|-t)
			records=$(echo $records | awk -F:: -v "now=${now}" ' {
				for (i=1; i<NF; i++) {
					split($i, r, ":")
					if (r[2] < now) {
						next
					}
					printf("%s::", $i)
				}
			}')
			echo $records | base64 > $file
			;;
		# Print help
		--help|-h)
			echo "$usage"
			exit
			;;
		# Wat
		*)
			echo "$usage"
			exit 1
			;;
	esac
fi

# Process records
echo $records | sed 's/::/\n/g' | sed '/^$/d' | while IFS= read record; do
	recordName=$(echo $record | cut -d: -f1)
	recordTime=$(echo $record | cut -d: -f2)
	
	# Set the difference, determine if it's old
	timeDiff=$(( $recordTime - $now ))
	if [ $timeDiff -lt 1 ]; then 
		echo "$recordName already happened."
		records="${records#$record"::"}"
		numRecords=$(( $numRecords - 1 ))
		continue
	fi
	
	# Chunk it down to weeks
	seconds=$(( $timeDiff % 60 ))
	timeDiff=$(( $timeDiff - $seconds ))
	
	minutes=$(( $timeDiff % 3600 / 60 ))
	timeDiff=$(( $timeDiff - $minutes ))
	
	hours=$(( $timeDiff % 86400 / 3600 ))
	timeDiff=$(( $timeDiff - $hours ))
	
	days=$(( $timeDiff % 604800 / 86400 ))
	timeDiff=$(( $timeDiff - $hours ))
	
	weeks=$(( $timeDiff / 604800 ))
	
	# Print this record, omitting unnecessary bits.
	printLine=''
	if [ "$doShort" == "true" ]; then
		[ $weeks -ne 0 ] && { [ $weeks -gt 1 ] && printLine+="$weeks wks, " || printLine+="$weeks wk, "; }
		[ $days -ne 0 ] && { [ $days -gt 1 ] && printLine+="$days days, " || printLine+="$days day, "; }
		[ $hours -ne 0 ] && { [ $hours -gt 1 ] && printLine+="$hours hrs, " || printLine+="$hours hr, "; }
		[ $minutes -ne 0 ] && { [ $minutes -gt 1 ] && printLine+="$minutes mins, " || printLine+="$mintues min, "; }
		printLine="${printLine%,*} til $recordName."
	else
		[ $weeks -ne 0 ] && { [ $weeks -gt 1 ] && printLine+="$weeks weeks, " || printLine+="$weeks week, "; }
		[ $days -ne 0 ] && { [ $days -gt 1 ] && printLine+="$days days, " || printLine+="$days day, "; }
		[ $hours -ne 0 ] && { [ $hours -gt 1 ] && printLine+="$hours hours, " || printLine+="$hours hour, "; }
		[ $minutes -ne 0 ] && { [ $minutes -gt 1 ] && printLine+="$minutes minutes, " || printLine+="$mintues minute, "; }
		[ $seconds -ne 0 ] && { [ $seconds -gt 1 ] && printLine+="$seconds seconds, " || printLine+="$seconds seconds, "; }
		printLine="${printLine%,*} until $recordName."
	fi
	echo "$printLine"
done