#!/bin/bash

# Source https://pentacent.medium.com/nginx-and-lets-encrypt-with-docker-in-less-than-5-minutes-b4b8a60d3a71

if ! [ -x "$(command -v docker)" ]; then
  echo 'Error: docker is not installed.' >&2
  exit 1
fi

if ! [ -x "$(command -v compose)" ]; then
  echo 'Error: docker compose is not installed.' >&2
  exit 1
fi

domains=(example.org www.example.org)
rsa_key_size=4096
data_path="./certbot"
email="" # Adding a valid address is strongly recommended
staging=0 # Set to 1 if you're testing your setup to avoid hitting request limits

if [ -d "$data_path" ]; then
  read -p "Existing data found for $domains. Continue and replace existing certificate? (y/N) " decision
  if [ "$decision" != "Y" ] && [ "$decision" != "y" ]; then
    exit
  fi
fi

if [ ! -e "$data_path/ssl-dhparams.pem" ]; then
  echo "### Generating ssl-dhparams.pem ..."
  docker compose run --rm --entrypoint "\
    openssl dhparam -out /etc/letsencrypt/ssl-dhparams.pem 4096" certbot
  echo
fi

echo "### Creating dummy certificate for $domains ..."
path="/etc/letsencrypt/live/$domains"
mkdir -p "$data_path/live/$domains"
docker compose run --rm --entrypoint "\
  openssl req -x509 -nodes -newkey rsa:$rsa_key_size -days 1\
    -keyout '$path/privkey.pem' \
    -out '$path/fullchain.pem' \
    -subj '/CN=localhost'" certbot
echo

if [ ! -e "$data_path/lets-encrypt-x3-cross-signed.pem" ]; then
  echo "### Downloading lets-encrypt-x3-cross-signed.pem ..."
  wget -O $data_path/lets-encrypt-x3-cross-signed.pem \
  "https://letsencrypt.org/certs/lets-encrypt-x3-cross-signed.pem"
  echo
fi

echo "### Starting nginx ..."
docker compose up --force-recreate -d nginx
echo

echo "### Deleting dummy certificate for $domains ..."
docker compose run --rm --entrypoint "\
  rm -Rf /etc/letsencrypt/live/$domains && \
  rm -Rf /etc/letsencrypt/archive/$domains && \
  rm -Rf /etc/letsencrypt/renewal/$domains.conf" certbot
echo

echo "### Requesting Let's Encrypt certificate for $domains ..."
#Join $domains to -d args
domain_args=""
for domain in "${domains[@]}"; do
  domain_args="$domain_args -d $domain"
done

# Select appropriate email arg
case "$email" in
  "") email_arg="--register-unsafely-without-email" ;;
  *) email_arg="--email $email" ;;
esac

# Enable staging mode if needed
if [ $staging != "0" ]; then staging_arg="--staging"; fi

docker compose run --rm --entrypoint "\
  certbot certonly --non-interactive --webroot -w /var/www/html \
    $staging_arg \
    $email_arg \
    $domain_args \
    --rsa-key-size $rsa_key_size \
    --agree-tos \
    --force-renewal" certbot
echo

echo "### Reloading nginx ..."
docker compose exec nginx nginx -s reload