#!/bin/sh

set -e
OUT="$1"

find_node() {
  NODE="${NODE_DIR}/bin/node"
  CE_NODE="/opt/compiler-explorer/node/bin/node"
  SYS_NODE="$(which node 2>/dev/null || true)"
  SYS_NODEJS="$(which nodejs 2>/dev/null || true)"

  if test -x "${NODE}" -a -n "${NODE_DIR}"; then
    echo "${NODE}"
  elif test -x "${CE_NODE}"; then
    echo "${CE_NODE}"
  elif test -x "${SYS_NODE}"; then
    echo "${SYS_NODE}"
  elif test -x "${SYS_NODEJS}"; then
    echo "${SYS_NODEJS}"
  else
    echo >&2 "Unable to find a node"
  fi
}

NODE="$(find_node)"

NODE_MIN_VERSION=18
NODE_VERSION_USED=20
NODE_VERSION=$(${NODE} --version)
NODE_MAJOR_VERSION=$(echo "${NODE_VERSION}" | cut -f1 -d. | sed 's/^v//g')

if test "${NODE_MAJOR_VERSION}" -lt ${NODE_MIN_VERSION}; then
  echo >&2 "Compiler Explorer is known not to run with versions prior to v${NODE_MIN_VERSION}"
  echo >&2 "Visit https://nodejs.org/ for installation instructions for newer versions"
  echo >&2 "To configure where we look for node, set NODE_DIR to its installation base"
  exit 1
fi

if test ${NODE_VERSION_USED} -ne "${NODE_MAJOR_VERSION}"; then
  echo >&2 "Warning: Compiler Explorer is only tested against v${NODE_VERSION_USED}.x, but v${NODE_MAJOR_VERSION} was found."
  echo >&2 "Note that you might find issues if you decide to keep this version"
  echo >&2 "Visit https://nodejs.org/ for installation instructions for the required version"
  echo >&2 "To configure where we look for node, set NODE_DIR to its installation base"
fi

echo "${NODE}" >"${OUT}"