#!/bin/bash

csv=$(mktemp)
asleep=0
sort input.txt |
while IFS='[]-:# ' read -r dummy year month day hour minute w1 w2 w3
do
	let asleep && echo $year-$month-$day,$prev,$minute,$id
	case $w1 in
	'Guard') asleep=0 id=$w2 ;;
	'falls') asleep=1 ;;
	'wakes') asleep=0 ;;
	esac
	prev=$minute
done >$csv

sqlite3 <<EOF

create table snoozes (
	date text,
	start integer,
	finish integer,
	id integer
);

.mode csv
.import $csv snoozes

create table opportunities as
	with recursive slots(minute) as (
		values(0)
		union all
		select minute + 1 from slots where minute < 59
	)
	select * from snoozes inner join slots
	on minute >= start and minute < finish;

create table safest as
	select id, minute, count(minute) as safety
	from opportunities
	group by id, minute
	order by safety desc
	limit 1;

select (select id from safest) * (select minute from safest);

EOF
rm $csv