authenticated-atom-forums

#! /usr/bin/env bash

# © 2023 Unvanquished Developers
# MIT License https://spdx.org/licenses/MIT.html

export shell_opts="${shell_opts:--u -e -o pipefail}"
set ${shell_opts}

script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
cd "${script_dir}"

. 'irc-atom-notice.conf'
. 'credentials-forums.conf'

# Not a bad thing to do
chmod og-rwx 'credentials-forums.conf'

if [ -z "${1:-}" ]
then
	echo 'ERROR: missing url' &>2
	false
fi

forum_url="${1}"

atom_url="${forum_url}/app.php/feed"
forum_login_url="${forum_url}/ucp.php?mode=login"

forum_cache_dir="${cache_dir}/forums"
cookie_file="${forum_cache_dir}/cookies.txt"
login_page="${forum_cache_dir}/login.html"
sid_file="${forum_cache_dir}/sid.txt"
token_file="${forum_cache_dir}/token.txt"
time_file="${forum_cache_dir}/time.txt"
output_file="${forum_cache_dir}/output.txt"
config_file="${forum_cache_dir}/config.txt"

mkdir -p "${forum_cache_dir}"
chmod go-rwx "${forum_cache_dir}"

curl --silent \
	--output "${login_page}" \
	--cookie-jar "${cookie_file}" \
	"${forum_login_url}"

grep 'id="login"' "${login_page}" \
| sed -e 's/^.*sid=\([0-9a-z]*\)".*$/\1/' \
> "${sid_file}"

grep 'name="creation_time"' "${login_page}" \
| sed -e 's/^.*value="\([0-9a-z]*\)".*$/\1/' \
> "${time_file}"

grep 'name="form_token"' "${login_page}" \
| sed -e 's/^.*value="\([0-9a-z]*\)".*$/\1/' \
> "${token_file}"

sid_string="$(cat "${sid_file}")"
time_string="$(cat "${time_file}")"
token_string="$(cat "${token_file}")"

# It looks like the “viewonline” option
# is to not be listed as online…
cat > "${config_file}" <<EOF
--form login="Login"
--form autologin='on'
--form viewonline='on'
--form username="${forums_username}"
--form password="${forums_password}"
--form sid="${sid_string}"
--form creation_time="${time_string}"
--form form_token="${token_string}"
--form redirect="${atom_url}"
EOF

# Retry 5 times
for i in {1..5}
do
	curl --silent \
		--location \
		--output "${output_file}" \
		--cookie "${cookie_file}" \
		--cookie-jar "${cookie_file}" \
		--config "${config_file}" \
		"${forum_login_url}&sid=${sid_string}"

	output_format="$(head -n 2 "${output_file}" | tail -n 1)"

	case "${output_format}" in
		'<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en-gb">')
			cat "${output_file}"
			break
			;;
	esac

	sleep 1s;
done

rm "${cookie_file}"
rm "${login_page}"
rm "${sid_file}"
rm "${token_file}"
rm "${time_file}"
rm "${output_file}"
rm "${config_file}"
rmdir "${forum_cache_dir}"