#!/usr/bin/env bash

head /etc/os-release --lines 1 | grep 'NixOS$' &>/dev/null; test $? -eq 1; is_nixos=$?
head /etc/os-release --lines 1 | grep 'Arch Linux' &>/dev/null; test $? -eq 1; is_arch_linux=$?

set -e

# NOTE: run this from inside a Linux installation, not from the live USB/CD
# TODO: detect OS and perform OS-specific setup

root_home="/root"
daniel_home="/home/daniel/.home"
nice_home="/home/daniel"
dotfiles="/.config/lytedev-dotfiles"

add_unstable_channel() {
	nix-channel --add https://nixos.org/channels/nixos-unstable nixos-unstable
	nix-channel --update
}

clone_dotfiles() {
	echo "Setting up dotfiles for $USER..."
	mkdir --parents "$1"
	rm --recursive --force "$1"
	git clone "https://git.lyte.dev/lytedev/dotfiles" "$1"
}

symlink_nixos() {
	rm --force "/etc/nixos/lytedev"
	ln --symbolic "$1" "/etc/nixos/lytedev"
}

setup_wallpaper() {
	mkdir --parents "$nice_home/img/walls"
	curl --silent --output "$nice_home/img/walls/clouds_by_souredapply.png" \
		"https://art.ngfiles.com/images/530000/530895_souredapple_clouds.png"
	rm --recursive --force "$daniel_home/.wallpaper"
	ln --symbolic "$nice_home/img/walls/clouds_by_souredapply.png" "$daniel_home/.wallpaper"
}

generate_ssh_key() {
	mkdir --mode 600 --parents "$daniel_home/.ssh"
	keyfile="$daniel_home/.ssh/$(hostname --short)"
	if ! [ -f "$keyfile" ]; then
		ssh-keygen -N '' -t ed25519 -f "$keyfile"
		mkdir --mode 640 --parents "$nice_home/public"
		cp "$keyfile.pub" "$nice_home/public"
	fi
}

fix_dotfiles_origin() {
	pushd "$daniel_home$dotfiles"
	git remote set-url origin "ssh://git@git.lyte.dev:2222/lytedev/dotfiles.git"
	popd
}

setup_home_manager() {
	nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
	nix-channel --update
	nix-shell '<home-manager>' -A install
}

setup_dotfiles() {
	pushd "$daniel_home$dotfiles"
	./bin/setup-dotfiles
	popd
}

distro_specific_root_setup() {
	if test $is_nixos -eq 1; then
		symlink_nixos "$root_home$dotfiles/env/nix/"
		add_unstable_channel
		nixos-rebuild switch # this should create the `daniel` user
	elif test $is_arch_linux -eq 1; then
		"$root_home$dotfiles/env/arch-linux/provision.d/00-add-user.bash"
	fi
}

distro_specific_user_setup() {
	if test $is_nixos -eq 1; then
		FUNC=$(declare -f symlink_nixos)
		sudo sh -c "$FUNC; symlink_nixos \"$daniel_home$dotfiles/env/nix/\""
	elif test $is_arch_linux -eq 1; then
		"$root_home$dotfiles/env/arch-linux/provision.sh"
	fi
}

init_for_root() {
	clone_dotfiles "$root_home$dotfiles"
	distro_specific_root_setup
	clone_dotfiles "$daniel_home$dotfiles"
	chown daniel:users -R "$daniel_home"
	echo "Re-running as user daniel..."
	sudo --user daniel "$daniel_home$dotfiles/bin/init-dotfiles"
}

init_for_daniel() {
	set +x
	clone_dotfiles "$daniel_home$dotfiles"
	generate_ssh_key
	distro_specific_user_setup
	setup_wallpaper
	# TODO: setup ssh/gpg keys
	# TODO: setup password store
	fix_dotfiles_origin
	setup_dotfiles
	# TODO: fetch password store
	# TODO: fetch notes database
}

if [ "$EUID" -eq 0 ]; then
	if test $is_arch_linux -eq 1; then
		pacman -S --needed git
	fi
	init_for_root
else
	init_for_daniel
fi

echo "Here is this machine's public SSH key:"
echo "  $(cat "$daniel_home/.ssh/$(hostname --short).pub")"
echo "It needs to be added to existing cloud-based git accounts"
echo "and other machines before proceeding."
echo
echo "Don't forget to setup GPG keys by importing from an existing machine"
echo "or adding new child keys!"
if test $is_arch_linux -eq 1; then
	echo
	echo 'You will need to set a password for your new user.'
fi
echo
echo "The simplest method for doing this is to run the following:"
echo '  scp -r "$TARGET_MACHINE:~/.gnupg" "$HOME/.gnupg'