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

node_version=14.17.6
nvm_version=0.38.0

# This is a fix for the fact that nvm uses $HOME to determine which
# user account's home directory to ~/.config to.  Ideally, we'd have a
# more systematic fix, like using `sudo -H` everywhere.
export HOME=/root

current_node_version="none"
if node_wrapper_path="$(command -v node)"; then
    current_node_version="$(node --version)"
fi

if [ "$current_node_version" = "v$node_version" ] && [ -L "$node_wrapper_path" ]; then
    echo "Node version $node_version is already installed."
    exit 0
fi

if [ "$current_node_version" != "v$node_version" ] || ! [ -L "$node_wrapper_path" ]; then
    export NVM_DIR=/usr/local/nvm
    # shellcheck source=/dev/null
    if ! [ -e "$NVM_DIR/nvm.sh" ] || {
        . "$NVM_DIR/nvm.sh"
        [ "$(nvm --version)" != "$nvm_version" ]
    }; then
        mkdir -p "$NVM_DIR"
        curl_opts=(-fL)
        if [ -n "${CUSTOM_CA_CERTIFICATES:-}" ]; then
            curl_opts+=(--cacert "${CUSTOM_CA_CERTIFICATES}")
        fi
        curl "${curl_opts[@]}" "https://raw.githubusercontent.com/nvm-sh/nvm/v$nvm_version/install.sh" | bash
        # shellcheck source=/dev/null
        . "$NVM_DIR/nvm.sh"
    fi

    # Tell NVM that we don't want it messing around with $PATH; we'll
    # adjust which npm to use by symlinks below.
    nvm alias default system

    nvm install "$node_version"
    NODE_BIN="$(nvm which $node_version)"

    # Fix messed-up uid=500 and group write bits produced by nvm
    n=${NODE_BIN%/bin/node}
    chown -R root:root "$n"
    chmod -R go-w "$n"

    # Install node symlink to /usr/local/bin
    ln -nsf "$NODE_BIN" /usr/local/bin/node
    ln -nsf "$(dirname "$NODE_BIN")/npm" /usr/local/bin/npm
    ln -nsf "$(dirname "$NODE_BIN")/npx" /usr/local/bin/npx
fi