#!/bin/bash

_legacy_override="/etc/modprobe.d/dell-xps13-dx13260-sidecar-amps.conf"
_legacy_sha256="97f36bce41581ecc6b1d7963cd0dab29c7b1a107b2dd4d17db7a56094a7b7289"

_remove_legacy_override() {
  local actual_sha256 hash_output

  [[ -f $_legacy_override ]] || return 0
  if ! hash_output=$(sha256sum "$_legacy_override"); then
    printf ':: Unable to hash legacy override: %s\n' "$_legacy_override" >&2
    return 1
  fi
  actual_sha256=${hash_output%% *}

  if [[ $actual_sha256 == "$_legacy_sha256" ]]; then
    if ! rm -f -- "$_legacy_override"; then
      printf ':: Unable to remove legacy override: %s\n' "$_legacy_override" >&2
      return 1
    fi
    printf ':: Removed the superseded Dell XPS 13 sidecar amplifier override.\n'
  else
    printf ':: Preserving modified legacy override: %s\n' "$_legacy_override"
  fi
}

_rebuild_boot_images() {
  local output status

  if command -v limine-mkinitcpio >/dev/null 2>&1; then
    output=$(limine-mkinitcpio 2>&1)
    status=$?
    [[ -z $output ]] || printf '%s\n' "$output"

    (( status == 0 )) || return "$status"
    [[ $output != *"ERROR:"* ]] || return 1
  elif command -v mkinitcpio >/dev/null 2>&1; then
    mkinitcpio -P
  else
    printf ':: Unable to rebuild boot images: install mkinitcpio and rebuild before rebooting.\n' >&2
    return 1
  fi
}

apply_sidecar_amp_workaround() {
  _remove_legacy_override || return
  _rebuild_boot_images || return
}

if [[ ${BASH_SOURCE[0]} == "$0" ]]; then
  if (( EUID != 0 )); then
    printf ':: Run dell-xps13-sidecar-amps-apply as root.\n' >&2
    exit 1
  fi

  apply_sidecar_amp_workaround
fi