avail

#!/bin/bash

#Preferences
lunch=true
weekends=true
remote=true
remote_title="Remote work"
calendar="Calendar"
days=14
day_start="09:00"
day_end="17:00"
lunch_start="12:00"
lunch_end="13:00"
minimum_duration=60 #minutes

next_day () {
	date=$(gdate -d "$date + 1 day" "+%Y-%m-%d") #Go to next day
	weekday=$(gdate -d "$date" "+%A")
	if [ $weekends = true ]; then
		if [[ "$weekday" = "Saturday" || "$weekday" = "Sunday" ]]; then
			next_day
		fi
	fi
	free_from=$day_start
	date_printed=false
}

print_date () {
	month=$(gdate -d "$date" "+%B")
	day=$((10#$(gdate -d "$date" "+%d"))) #Remove leading zero
	if (! $first_row); then
		echo ""
	fi
	echo -n "$weekday, $month $day at "
	date_printed=true
	first_row=false
}

print_time () {
	dash_printed=false
	
	if ($date_printed); then
		echo -n ", "
	else
		print_date
	fi
	
	start_hours=$((10#$(gdate -d "$1" "+%I"))) #Remove leading zero
	start_minutes=$(gdate -d "$1" "+%M")
	end_hours=$((10#$(gdate -d "$2" "+%I"))) #Remove leading zero
	end_minutes=$(gdate -d "$2" "+%M")
	
	if [ "$start_minutes" = "00" ]; then
		echo -n "$start_hours"
	else
		echo -n "$start_hours:$start_minutes – "
		dash_printed=true
	fi
	
	if [ "$end_minutes" = "00" ]; then
		if (! $dash_printed); then
			echo -n "–"
		fi
		echo -n "$end_hours"
	else
		if (! $dash_printed); then
			echo -n " – "
		fi
		echo -n "$end_hours:$end_minutes"
	fi
}

#Override preferences with flags
while getopts 'lwrR:c:d:s:e:S:E:m:' option; do
	case "$option" in
		l)
			lunch=!lunch #Reverse preference for lunch breaks
			;;
		w)
			weekends=!weekends #Reverse preference for lunch breaks
			;;
		r)
			remote=!$remote #Reverse preference for remote meeting
			;;
		R)
			remote_title=${OPTARG} #Specify remote work day title
			;;
		c)
			calendar=${OPTARG} #Specify calendar
			;;
		d)
			days=${OPTARG} #Provide availability for specified number of days
			;;
		s)
			day_start=$(gdate -d "${OPTARG}" "+%H:%M") #Specify start time for each day
			;;
		e)
			day_end=$(gdate -d "${OPTARG}" "+%H:%M") #Specify end time for each day
			;;
		S)
			lunch_start=$(gdate -d "${OPTARG}" "+%H:%M") #Specify start time for lunch break
			;;
		E)
			lunch_end=$(gdate -d "${OPTARG}" "+%H:%M") #Specify end time for lunch break
			;;
		m)
			minimum_duration=${OPTARG} #Specify minimum duration of times available, in minutes
			;;
	esac
done

#Initialize
date=$(gdate -d today "+%Y-%m-%d")
weekday=$(gdate -d $date "+%A")
end_date=$(gdate -d "$date + $days days" "+%Y-%m-%d")
first_row=true

#Start running here
next_day #Start with tomorrow, and skip weekend days

#Look up events in Apple calendar database
events=$(icalbuddy -ic "$calendar" -iep datetime,title -po datetime,title -ps "^ | ^" -nrd -nc -df "%Y-%m-%d" -b "" eventsFrom:$date to:$end_date)

#List available times between events
while IFS= read -r line; do
	
	event_date=${line:0:10}
	
	while [ "$event_date" \> "$date" ] #Event on later date
	do
		if [ $(datediff -f "%M" $free_from $day_end) -ge $minimum_duration ]; then
			print_time $free_from $day_end
			#If there are no events during or after lunch, no lunch break is reserved. That is intentional. It most often means that totally unscheduled days are listed as entirely available. 
		fi
		next_day
	done
	
	if [ "$event_date" = "$date" ]; then
		if [ "${line:11:1}" = "|" ]; then #All-day event
			if [[ "${line:13:${#remote_title}}" != "$remote_title" || $remote != true ]]; then #Not remote work day, or not looking for remote meeting time
				next_day
			fi
		elif [ "${line:11:1}" = "-" ]; then #Date range
			if [[ "${line:26:${#remote_title}}" != "$remote_title" || $remote != true ]]; then #Not remote work day, or not looking for remote meeting time
				date=$(gdate -d "${line:13:10}" "+%Y-%m-%d") #Go to last day
				next_day
			fi
		else #Timed event on correct date
			start=${line:14:5}
			stop=${line:22:5}
			if [ "$start" \> "$free_from" ]; then
				if [ $lunch = true ] && [ "$free_from" \< "$lunch_start" ] && [ "$start" \> "$lunch_start" ]; then
					if [ $(datediff -f "%M" $free_from $lunch_start) -ge $minimum_duration ]; then
						print_time $free_from $lunch_start
					fi
					if [ "$start" \> "$lunch_end" ] && [ $(datediff -f "%M" $lunch_end $start) -ge $minimum_duration ]; then
						print_time $lunch_end $start
					fi
				elif [ $(datediff -f "%M" $free_from $start) -ge $minimum_duration ]; then
					print_time $free_from $start
				fi
			fi
			if [ ! "$stop" \< "$day_end" ]; then #Event ends at or after end of workday
				next_day
			elif [ "$stop" \> "$free_from" ]; then #Event ends after known free time
				free_from=$stop
				if [ $lunch = true ] && [ ! "$free_from" \< "$lunch_start" ] && [ "$free_from" \< "$lunch_end" ]; then #Event ends during lunch
					free_from=$lunch_end
				fi
			fi
		fi
	fi
done <<< "$events"

#List available times after all events
while [ ! "$end_date" \< "$date" ]
do
	print_time $free_from $day_end
	next_day
done

echo ""