#!/usr/bin/env bash

file="$1"

horizontal=0
depth=0
aim=0

while read line; do
	#direction="$(echo "$line" | cut -d ' ' -f 1)"
	direction="${line%% *}"
	#amount="$(echo "$line" | cut -d ' ' -f 2)"
	amount="${line##* }"
	case "$direction" in
		forward)
			horizontal=$((horizontal + amount))
			depth="$((depth + (aim * amount) ))"
			;;
		down) aim="$((aim + amount))" ;;
		up) aim="$((aim - amount))" ;;
	esac
done < <(cat "$file")

echo "Horizontal: $horizontal"
echo "Depth: $depth"
echo "Product: $(( depth * horizontal ))"