setup.sh

#!/usr/bin/env bash

# NOTE: this script should not use nix-shell because it assumes nix is not installed!

set -euo pipefail

# source the asserts
source "$(dirname "${BASH_SOURCE[0]}")/init.sh"

function usage() {
	>&2 echo "USAGE: kt setup"
	>&2 echo "Install all of the external dependencies on your OS"
}

if [[ "${#}" -ge 1 ]] && [[ "${1}" = "--help" ]]; then
	usage
	exit 0
fi

# install Nix if it's not yet installed
nix_installed=0
if ! command -v nix &>/dev/null; then
	# if the /nix folder was found but nix was still not found in PATH, try to
	# source the initialization script which should provide the nix command. If
	# the command is still not found, then exit with an error.
	# Otherwise, install nix via the official script.
	if [[ -d /nix ]]; then
		# include nix in the current shell so we can install stuff
		if [[ -r "/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh" ]]; then
			source "/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh"
		fi

		if ! command -v nix &>/dev/null; then
			>&2 echo -e "ERR: I found the folder /nix but I was not able to find the nix executable, did you reload your shell?"
			>&2 echo -e "     Please close your shell and open a new one before running kt setup again"
			exit 1
		fi
	else
		>&2 echo -e ">>> Nix was not found running on your machine, installing it using the official installer."
		sh <(curl https://nixos.org/nix/install) --daemon
		nix_installed=1
	fi

	# include nix in the current shell so we can install stuff
	if [[ -r "/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh" ]]; then
		source "/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh"
	else
		>&2 echo "ERR: unable to automatically enrich the shell with Nix, please restart your shell (or your computer) and run \`kt setup\` again"
		exit 1
	fi

	# make sure nix is now available
	if ! nix-shell -p hello --run 'hello' &>/dev/null; then
		>&2 echo "ERR: Nix was installed but we were not able to get it running in this script, please restart your shell (or your computer) and run \`kt setup\` again"
		exit 1
	fi
fi

# install direnv for loading the shell
if ! command -v direnv &>/dev/null; then
	>&2 echo "INFO: did not find direnv command, installing direnv"
	nix-env -I nixpkgs=./lib/nix/nixpkgs.nix -f '<nixpkgs>' -iA direnv
fi

# install the dependencies globally, mostly for editors that do not support
# loading a shell through nix-shell
if ! command -v dlv &>/dev/null; then
	>&2 echo "INFO: did not find dlv command, installing delve"
	nix-env -I nixpkgs=./lib/nix/nixpkgs.nix -f '<nixpkgs>' -iA delve
fi
if ! command -v docker-credential-ecr-login &>/dev/null; then
	>&2 echo "INFO: did not find docker-credential-ecr-login command, installing amazon-ecr-credential-helper"
	nix-env -I nixpkgs=./lib/nix/nixpkgs.nix -f '<nixpkgs>' -iA amazon-ecr-credential-helper
fi
if ! command -v go &>/dev/null; then
	>&2 echo "INFO: did not find go command, installing go"
	nix-env -I nixpkgs=./lib/nix/nixpkgs.nix -f '<nixpkgs>' -iA go
fi

if [[ "${nix_installed}" == "1" ]]; then
	>&2 echo "INFO: Nix was installed on your computer, congratulations!"
	>&2 echo "      Please restart your shell!"
fi