#!/usr/bin/env bash

# Install the Nix package manager as a secondary package manager.
# This can sometimes be useful for getting more recent packages.

set -e
set -x

# Abort installation if Nix is already installed
if [ -d /nix ]; then
  exit 0
fi

# Workaround to make a single user install work as root
if [ "${USER:-}" == "root" ] || [ "${UID:-}" == "0" ]; then
  mkdir -p /etc/nix
  echo "build-users-group =" > /etc/nix/nix.conf
fi

# Download the Nix installer and it's signature from NixOS.org
curl -so install-nix https://releases.nixos.org/nix/nix-2.18.1/install

# Run the installer
sh ./install-nix

# Source the nix profile 
cat << EOF > ~/.bashrc
# Source nix if it's installed
if [ -r ~/.nix-profile/etc/profile.d/nix.sh ]; then
  . ~/.nix-profile/etc/profile.d/nix.sh
fi
EOF

# Remove the installer and signature
rm -f ./install-nix

# Enable flakes and the nix command
mkdir -p ~/.config/nix
cat <<EOF > ~/.config/nix/nix.conf
experimental-features = flakes nix-command
EOF