#!/bin/sh
set -eu
umask 077

ROOT=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
domain=${1:-}
target=${2:-"$ROOT/.env.production"}

usage() {
  echo "Usage: $0 DOMAIN [OUTPUT_FILE]" >&2
}

if [ -z "$domain" ]; then
  usage
  exit 1
fi

if ! printf '%s\n' "$domain" |
  grep -Eq '^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?(\.[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?)+$'; then
  echo "DOMAIN must be a lowercase ASCII DNS hostname without a scheme, port, or path." >&2
  exit 1
fi

for command in awk docker grep mktemp openssl stat; do
  if ! command -v "$command" >/dev/null 2>&1; then
    echo "Required command is unavailable: $command" >&2
    exit 1
  fi
done

if [ ! -S /var/run/docker.sock ]; then
  echo "/var/run/docker.sock is unavailable; run this on the target Docker host." >&2
  exit 1
fi

if [ -e "$target" ]; then
  echo "Refusing to overwrite existing deployment environment: $target" >&2
  exit 1
fi

target_dir=$(dirname -- "$target")
if [ ! -d "$target_dir" ]; then
  echo "Output directory does not exist: $target_dir" >&2
  exit 1
fi

postgres_password=$(openssl rand -hex 32)
secret_key_base=$(openssl rand -hex 64)
handover_secret=$(openssl rand -hex 64)
release_cookie=$(openssl rand -hex 64)
metrics_token=$(openssl rand -hex 32)
docker_socket_gid=$(stat -c '%g' /var/run/docker.sock)

http_bind_address=${PRODUCTION_HTTP_BIND_ADDRESS:-127.0.0.1}
trusted_proxy_ips=${PRODUCTION_TRAEFIK_TRUSTED_IPS:-REPLACE_WITH_VERIFIED_PROXY_IP_OR_CIDR}
smtp_relay=${PRODUCTION_SMTP_RELAY:-REPLACE_WITH_TRANSACTIONAL_SMTP_RELAY}
smtp_port=${PRODUCTION_SMTP_PORT:-587}
smtp_username=${PRODUCTION_SMTP_USERNAME:-}
smtp_password=${PRODUCTION_SMTP_PASSWORD:-}
smtp_auth=${PRODUCTION_SMTP_AUTH:-always}
smtp_tls=${PRODUCTION_SMTP_TLS:-always}
smtp_ssl=${PRODUCTION_SMTP_SSL:-false}
email_from_address=${PRODUCTION_EMAIL_FROM_ADDRESS:-"contact@$domain"}

tmp=$(mktemp "$target_dir/.production-env.XXXXXX")
trap 'rm -f "$tmp"' EXIT HUP INT TERM
chmod 600 "$tmp"

DOMAIN=$domain \
HTTP_BIND_ADDRESS_VALUE=$http_bind_address \
DOCKER_SOCKET_GID_VALUE=$docker_socket_gid \
TRUSTED_PROXY_IPS_VALUE=$trusted_proxy_ips \
POSTGRES_PASSWORD_VALUE=$postgres_password \
DATABASE_URL_VALUE="ecto://postgres:$postgres_password@db/who_need_help" \
SECRET_KEY_BASE_VALUE=$secret_key_base \
HANDOVER_SECRET_VALUE=$handover_secret \
RELEASE_COOKIE_VALUE=$release_cookie \
METRICS_TOKEN_VALUE=$metrics_token \
SMTP_RELAY_VALUE=$smtp_relay \
SMTP_PORT_VALUE=$smtp_port \
SMTP_USERNAME_VALUE=$smtp_username \
SMTP_PASSWORD_VALUE=$smtp_password \
SMTP_AUTH_VALUE=$smtp_auth \
SMTP_TLS_VALUE=$smtp_tls \
SMTP_SSL_VALUE=$smtp_ssl \
EMAIL_FROM_ADDRESS_VALUE=$email_from_address \
  awk '
    BEGIN {
      replacement["HTTP_BIND_ADDRESS"] = ENVIRON["HTTP_BIND_ADDRESS_VALUE"]
      replacement["DOCKER_SOCKET_GID"] = ENVIRON["DOCKER_SOCKET_GID_VALUE"]
      replacement["TRAEFIK_TRUSTED_IPS"] = ENVIRON["TRUSTED_PROXY_IPS_VALUE"]
      replacement["PHX_HOST"] = ENVIRON["DOMAIN"]
      replacement["PHX_SCHEME"] = "https"
      replacement["PHX_URL_PORT"] = "443"
      replacement["WNH_DEBUG_BASE_URL"] = "https://" ENVIRON["DOMAIN"]
      replacement["WNH_BASE_URL"] = "https://" ENVIRON["DOMAIN"]
      replacement["POSTGRES_PASSWORD"] = ENVIRON["POSTGRES_PASSWORD_VALUE"]
      replacement["DATABASE_URL"] = ENVIRON["DATABASE_URL_VALUE"]
      replacement["SECRET_KEY_BASE"] = ENVIRON["SECRET_KEY_BASE_VALUE"]
      replacement["HANDOVER_SECRET"] = ENVIRON["HANDOVER_SECRET_VALUE"]
      replacement["RELEASE_COOKIE"] = ENVIRON["RELEASE_COOKIE_VALUE"]
      replacement["METRICS_TOKEN"] = ENVIRON["METRICS_TOKEN_VALUE"]
      replacement["SMTP_RELAY"] = ENVIRON["SMTP_RELAY_VALUE"]
      replacement["SMTP_PORT"] = ENVIRON["SMTP_PORT_VALUE"]
      replacement["SMTP_USERNAME"] = ENVIRON["SMTP_USERNAME_VALUE"]
      replacement["SMTP_PASSWORD"] = ENVIRON["SMTP_PASSWORD_VALUE"]
      replacement["SMTP_AUTH"] = ENVIRON["SMTP_AUTH_VALUE"]
      replacement["SMTP_TLS"] = ENVIRON["SMTP_TLS_VALUE"]
      replacement["SMTP_SSL"] = ENVIRON["SMTP_SSL_VALUE"]
      replacement["EMAIL_FROM_ADDRESS"] = ENVIRON["EMAIL_FROM_ADDRESS_VALUE"]
      replacement["CODEX_SESSION_ID"] = "not-configured"
    }
    {
      separator = index($0, "=")
      key = separator > 1 ? substr($0, 1, separator - 1) : ""

      if (key in replacement) {
        print key "=" replacement[key]
      } else {
        print
      }
    }
  ' "$ROOT/.env.example" >"$tmp"

mv "$tmp" "$target"
chmod 600 "$target"
trap - EXIT HUP INT TERM

unset postgres_password secret_key_base handover_secret release_cookie metrics_token

echo "Generated independent deployment secrets without printing them."
echo "Created mode-0600 environment: $target"
echo "Run scripts/validate-production-env.sh '$target' '$domain' after configuring the verified proxy and SMTP values."