#!/usr/bin/env bash

private_key="${MADD_PRIV_KEY:-"/etc/ssh/ssh_host_ed25519_key"}"
public_key="${MADD_PUB_KEY:-"$private_key.pub"}"

hostname="${MADD_HOSTNAME:-"$(hostname -s)"}"
requested_ip=$MADD_IP # TODO: Obtain IP automatically

endpoint=$MADD_ENDPOINT

echo "(MADD) Updating DNS..."
echo
echo " Endpoint: $endpoint"
echo "Priv. key: $private_key"
echo " Pub. key: $public_key"
echo " Hostname: $hostname"
echo "       IP: $requested_ip" 
echo

# Generate the request and receive the identifier to sign
identifier=$(curl "$endpoint/request/$hostname/$requested_ip" --fail-with-body --data-binary @$public_key 2>/dev/null)

# Sign the request using the SSH key
signed=$(echo -n "$identifier $hostname $requested_ip" | ssh-keygen -Y sign -f $private_key -n madd 2>/dev/null)

# Escape slashes in the identifier
identifier_escaped=$(sed "s|/|%2F|g" <<< "$identifier")

# Submit the signed request
curl "$endpoint/signed/$identifier_escaped" --fail-with-body --data "$signed"