#!/usr/bin/env bash

NODE_VERSION=${NODE_VERSION:-v14.15.3}
PREFIX_DIR=${PREFIX_DIR:-/usr/local}

BIN_DIR=${PREFIX_DIR}/bin
NODE_PREFIX_DIR=${PREFIX_DIR}/apps/node
NODE_DEST_DIR=${NODE_PREFIX_DIR}/${NODE_VERSION}
NODE_DEST_BIN_DIR=${NODE_DEST_DIR}/bin
NODE_CURRENT=${NODE_PREFIX_DIR}/current

OS=
ARCH=
case $(uname -s) in
    Linux*)     OS=linux;;
    Darwin*)    OS=darwin;;
    *)          >&2 echo "unsupported os"; return;
esac

case $(uname -m) in
    x86_64*)    ARCH=x64;;
    *)          >&2 echo "unsupported architecture: $(uname -m)"; exit 1;;
esac

[[ -d "${NODE_DEST_DIR}" ]] || sudo mkdir -p "${NODE_DEST_DIR}"

URL=https://nodejs.org/dist/${NODE_VERSION}/node-${NODE_VERSION}-${OS}-${ARCH}.tar.xz

TMP_DIR=
if [[ ! -d ${NODE_DEST_BIN_DIR} ]]; then
    TMP_DIR=$(mktemp --directory)
    DEST_FILE=$TMP_DIR/node.tar.xz
    echo downloading node "$NODE_VERSION" to temp directory "${TMP_DIR}"
    curl --silent --output "${DEST_FILE}" "${URL}"

    sudo tar xf "${DEST_FILE}" --directory "${NODE_DEST_DIR}" --strip-components 1
    sudo chown --recursive root:root "${NODE_DEST_DIR}"
else
    echo node "$NODE_VERSION" already installed
fi

cd "${NODE_PREFIX_DIR}" || exit 1
[[ -s current ]] && sudo unlink current
sudo ln --symbolic "${NODE_VERSION}" current
echo current version set to "${NODE_VERSION}"
cd "${BIN_DIR}" || exit 1
for bin in "${NODE_CURRENT}/bin/"*; do
    [[ -s $bin ]] || sudo ln --symbolic "${NODE_CURRENT}/bin/$bin"
done

if [[ $TMP_DIR != "" ]]; then
    rm -rf "${TMP_DIR}"
    echo removed up temp directory "${TMP_DIR}"
fi