#!/usr/bin/env bash
set -eo pipefail

echo "---> Nodejs Buildpack"

# 1. GET ARGS
layers_dir=$1
plan_path=$3

# 2. DOWNLOAD nodejs
node_layer_dir="${layers_dir}/node"
mkdir -p "${node_layer_dir}"
arch=$(dpkg --print-architecture)  # amd64 arm64
if [[ ${arch} == "amd64" ]]; then
    arch="x64"
fi
# determine nodejs version provided during detection
node_version=$(< "${plan_path}" yj -t | jq -r '.entries[] | select(.name == "nodejs") | .version')
node_name=node-v${node_version}-linux-${arch}
remote_node_version='not found'
if [[ -f "${node_layer_dir}.toml" ]]; then
    remote_node_version=$(< "${node_layer_dir}.toml" yj -t | jq -r .metadata 2>/dev/null || echo 'not found')
fi
if [[ "${node_version}" == "${remote_node_version}" ]] ; then
  echo "---> Reusing Node v${node_version}"
else
  echo "---> Downloading and extracting Node v${node_version}"
  node_url="https://nodejs.org/dist/v${node_version}/${node_name}.tar.xz"
  wget -q -O - "${node_url}" | tar -xJf - --strip-components=1 -C "${node_layer_dir}"
  cat > "${node_layer_dir}.toml" <<EOL
cache = true
build = true
launch = true
metadata = "${node_version}"
EOL
fi

# 3. MAKE node npm AVAILABLE TO THIS SCRIPT
export PATH="${node_layer_dir}/bin:${PATH}"


node_modules_layer_dir="${node_layer_dir}/node_modules"
mkdir -p "${node_modules_layer_dir}"
# Compares previous package.json checksum to the current package.json
local_package_checksum=$(sha256sum package.json | cut -d ' ' -f 1 || echo 'not found')
remote_package_checksum='not found'
if [[ -f "${node_modules_layer_dir}.toml" ]]; then
    remote_package_checksum=$(< "${node_modules_layer_dir}.toml" yj -t | jq -r .metadata 2>/dev/null || echo 'not found')
fi

if [[ -f package.json && "${local_package_checksum}" == "${remote_package_checksum}" ]] ; then
  echo "---> Reusing package.json"
  cp -r "${node_modules_layer_dir}" "./node_modules"
else
  echo "---> Installing package.json with npm install."
  rm "${node_modules_layer_dir}" -rf
  npm install
  if [[ -d "${node_modules_layer_dir}" ]]; then
      rm "${node_modules_layer_dir:?}/*" -rf
			cp -r node_modules/. "${node_modules_layer_dir}/"
  fi
  cat > "${node_modules_layer_dir}.toml" <<EOL
cache = true
build = true
launch = true
metadata = "${local_package_checksum}"
EOL
fi

json_get_key() {
	local file="$1"
	local key="$2"

	if test -f "$file"; then
		jq -c -M --raw-output "$key // \"\"" <"$file" || return 1
	else
		echo ""
	fi
}

build_script=$(json_get_key "package.json" ".scripts.build")
if [[ $build_script ]]; then
  npm run build
fi

generate-launch.sh "${layers_dir}"