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

# Non-interactive Btrfs installer using the flake in this repo.
# Defaults: DISK=/dev/vda TARGET_HOST=nanuqsaurus

DISK=${DISK:-/dev/vda}
TARGET_HOST=${TARGET_HOST:-nanuqsaurus}

SCRIPT_DIR=$(cd -- "$(dirname "${BASH_SOURCE[0]}")" && pwd)
REPO_ROOT=$(cd -- "${SCRIPT_DIR}/.." && pwd)

clear

echo "[1/7] Partitioning ${DISK}"
printf "label: gpt\n,550M,U\n,,L\n" | sfdisk "${DISK}"

echo "[2/7] Formatting"
mkfs.fat -F 32 "${DISK}1"
mkfs.btrfs -f "${DISK}2"

echo "[3/7] Creating Btrfs subvolumes"
mkdir -p /mnt
mount "${DISK}2" /mnt
btrfs subvolume create /mnt/root
btrfs subvolume create /mnt/home
btrfs subvolume create /mnt/nix
umount /mnt

echo "[4/7] Mounting subvolumes"
mount -o compress=zstd,subvol=root "${DISK}2" /mnt
mkdir -p /mnt/{home,nix,boot}
mount -o compress=zstd,subvol=home "${DISK}2" /mnt/home
mount -o compress=zstd,subvol=nix "${DISK}2" /mnt/nix
mount "${DISK}1" /mnt/boot

echo "[5/7] Copying flake to /etc/nixos"
mkdir -p /mnt/etc/nixos
if command -v rsync >/dev/null 2>&1; then
  rsync -a --exclude '.git' --exclude 'result' --exclude 'node_modules' "${REPO_ROOT}/" /mnt/etc/nixos/
else
  (cd "${REPO_ROOT}" && tar -cf - --exclude=.git --exclude=result --exclude=node_modules .) | (cd /mnt/etc/nixos && tar -xf -)
fi

echo "[6/7] Generating hardware config"
mkdir -p /mnt/etc/nixos/hosts
nixos-generate-config --root /mnt --show-hardware-config > "/mnt/etc/nixos/hosts/local-${TARGET_HOST}-hardware.nix"

host_file="/mnt/etc/nixos/hosts/local-${TARGET_HOST}.nix"
if [ ! -e "${host_file}" ]; then
  cat > "${host_file}" <<EOF
{ inputs, ... }:

{
  imports = [
    inputs.lix-module.nixosModules.lixFromNixpkgs
    ../modules/system/base.nix
    ../modules/system/packages.nix
    ../modules/system/home-manager-skel.nix
    ../modules/desktop/gnome-minimal.nix
    ../modules/users/admin.nix
    ./local-${TARGET_HOST}-hardware.nix
  ];

  networking.hostName = "${TARGET_HOST}";
}
EOF
fi

echo "[7/7] Installing ${TARGET_HOST} via flake (local-${TARGET_HOST})"
nixos-install --root /mnt --flake "/mnt/etc/nixos#local-${TARGET_HOST}" --no-root-passwd |& tee /tmp/nixos-install.log
echo "Install log saved to /tmp/nixos-install.log"

echo "Install complete. You can reboot now."