post-answer

#! /usr/bin/env bash

# Copyright 2022 Ole Walkenhorst

# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.

set -eu

function usage() {
	echo "Usage: $0 [-h] [-y YEAR] [-d DAY] [-l LEVEL] ANSWER [ANSWER]"
}

LEVEL=1
CURRENTYEAR="$( date +%Y )"
YEAR="$CURRENTYEAR"
TODAY="$( date +%-d )"
DAY="$TODAY"

shopt -s extglob
while getopts ":hy:d:l:" opt; do
	case "$opt" in
		h) usage && exit 0;;
		y) YEAR="$OPTARG";;
		d) DAY="${OPTARG##+(0)}";;
		l) LEVEL="$OPTARG";;
		:) echo "Option '$OPTARG' missing a required argument." && exit 1;;
		\?) echo "Invalid option $OPTARG" && exit 1;;
	esac
done
shift $(( OPTIND - 1 ))

answer=${2:-${1?$( usage )}}

if [[ "$YEAR" -lt 2015 || "$YEAR" -gt "$CURRENTYEAR" ]]; then
	echo "YEAR must be between 2015 and $CURRENTYEAR inclusive." >&2
	exit 1
fi

if [[ "$DAY" -lt 1 || "$DAY" -gt 25 ]]; then
	echo "DAY must be between 1 and 25 inclusive." >&2
	exit 1
fi

level=${2:+2}
level=${level:-$LEVEL}

if [[ "$level" -ne 1 && "$level" -ne 2 ]]; then
	echo "LEVEL must be 1 or 2." >&2
	exit 1
fi

[[ -f '.env' ]] && source '.env'
cookie=${SESSION_COOKIE?SESSION_COOKIE must be set.}

response=$(curl "https://adventofcode.com/$YEAR/day/$DAY/answer" \
             -X POST \
             -H 'Content-Type: application/x-www-form-urlencoded' \
             -H 'Origin: https://adventofcode.com' \
             -H "Referer: https://adventofcode.com/$YEAR/day/$DAY" \
             -H "Cookie: session=$cookie" \
             --data-raw "level=$level&answer=$answer")

correct="That's the right answer"
wrong="That's not the right answer"
limit='You gave an answer too recently'
if [[ "$response" == *"$correct"* ]]; then
	echo "$correct"
	exit 0
elif [[ "$response" == *"$wrong"* ]]; then
	echo "$wrong"
	exit 2
elif [[ "$response" == *"$limit"* ]]; then
	echo "$limit"
	exit 2
else
	echo "$response"
	exit 2
fi