#!/usr/bin/env sh

# This is the install script for 'garn'.

set -eu



test_nix_installation () {
  nix --version 1> /dev/null 2> /dev/null
}

install_nix () {
  TMP=$(mktemp -d)

  curl --proto '=https' --tlsv1.2 -sSfL https://garn.io/nix-installer.sh -o "$TMP/nix-installer.sh"
  chmod u+x "$TMP/nix-installer.sh"

  export NIX_INSTALLER_BINARY_ROOT=https://garn.io
  "$TMP/nix-installer.sh" \
    install \
    --extra-conf "extra-substituters = https://cache.garnix.io" \
    --extra-conf "extra-trusted-public-keys = cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=" \
    --diagnostic-endpoint=""

  set +eu
  # shellcheck source=/dev/null
  . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
  set -eu
}

test_cache_configured () {
  nixConfig=$(nix --extra-experimental-features 'nix-command flakes' show-config) &&
  (echo "$nixConfig" | grep --quiet "^substituters.*cache\.garnix\.io") &&
  (echo "$nixConfig" | grep --quiet "^trusted-public-keys.*cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=") &&
  true
}

configure_cache () {
  echo extra-substituters = https://cache.garnix.io | sudo tee -a /etc/nix/nix.conf > /dev/null
  echo extra-trusted-public-keys = cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g= | sudo tee -a /etc/nix/nix.conf > /dev/null

  echo trying to restart the nix-daemon...
  # This ignores errors, for single-user installations.
  if test "$(uname)" = "Linux" ; then
    sudo systemctl restart nix-daemon.service || true
  elif test "$(uname)" = "Darwin" ; then
    sudo launchctl kickstart -k system/org.nixos.nix-daemon || true
  else
    echo "Unknown system: $(uname)"
    echo Cancelling installation.
    exit 1
  fi
}

echo
echo NIX INSTALLATION
echo ================

if test_nix_installation; then
  echo Hooray, nix is already installed:
  nix --version
else
  cat << EOF
Welcome to the 'garn' installer!

'garn' depends on nix, but it seems that you don't have a nix
installation. This installer will install nix for you. It uses the
'nix-installer' by Determinate Systems. For more information, see
https://github.com/DeterminateSystems/nix-installer.

This installer will ask for your admin password to install nix.

If in the future you want to uninstall Nix, use:

$ /nix/nix-installer uninstall

EOF

  printf "Should I install nix now? [y/n] "
  read -r SHOULD_INSTALL_NIX
  if test "$SHOULD_INSTALL_NIX" != y; then
    echo Cancelling installation.
    exit 1
  fi
  install_nix
  test_nix_installation || (echo "Failed to install nix, cancelling installation." && exit 1)
  echo nix is now installed:
  nix --version
fi

echo
echo BINARY CACHE CONFIGURATION
echo ==========================

if test_cache_configured; then
  echo Hooray, the garnix cache is configured.
elif true >> /etc/nix/nix.conf; then
  echo For \'garn\' to work well, nix needs to use the garnix.io binary
  echo cache. But the cache configuration cannot be found. This
  echo installer will modify /etc/nix/nix.conf to add the garnix.io binary cache.
  echo
  printf "Should I add the garnix.io binary cache to /etc/nix/nix.conf now (requires sudo)? [y/n] "
  read -r SHOULD_CONFIGURE_CACHE
  if test "$SHOULD_CONFIGURE_CACHE" != y; then
    echo Cancelling installation.
    exit 1
  fi
  configure_cache
  test_cache_configured || (echo "Failed to configure the garnix cache, cancelling installation." && exit 1)
  echo The garnix cache is now configured.
else
  echo "For 'garn' to work well, Nix needs to use the garnix.io binary"
  echo "cache. But Nix currently isn't configured to use that cache."
  echo
  echo "This installer attempted to add the cache config to /etc/nix/nix.conf,"
  echo "but that file was not writable (you may be using NixOS)."
  echo "Please add the following lines to your Nix config and restart your nix-daemon:"
  echo "    extra-substituters = https://cache.garnix.io"
  echo "    extra-trusted-public-keys = cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g="
  echo
  echo "On non-NixOS systems you can add these lines to /etc/nix/nix.conf."
  echo "On NixOS you can add these to nix.extraOptions in /etc/nixos/configuration.nix."
  echo
  echo "Once you have added these lines please re-run this installer."
  exit 1
fi

echo "installing 'garn'..."
nix --extra-experimental-features 'nix-command flakes' profile install -L "github:garnix-io/garn/v0.0.20"
echo "testing 'garn' installation..."
garn --help

echo "Success! 'garn' is now installed."