#!/usr/bin/env bash

if [ ! -f /usr/src/linux/.config ] && [ -f /proc/config.gz ] ; then
  echo "**************** building kernel  ***********"

  LWD="$PWD"
  TIMESTAMP=$(date +%F-%H_%M_%S)
  cd /usr/src/linux || exit 1

  zcat /proc/config.gz > .config

  make olddefconfig
  mount /boot

  (make -j5 CC="ccache gcc" && make install && make modules_install && make firmware_install) > "buildlog-$TIMESTAMP" || tail -n 20 "buildlog-$TIMESTAMP"

  GRUBMKONFIG="$(which grub2-mkconfig)"
  if [[ -z "$GRUBMKONFIG" ]] ; then
    GRUBMKONFIG="$(which grub-mkconfig)"
  fi

  if [[ -f /boot/grub2/grub.cfg && -n "$GRUBMKONFIG" ]] ; then
    "$GRUBMKONFIG" -o /boot/grub2/grub.cfg
  elif [[ -f /boot/grub/grub.cfg && -n "$GRUBMKONFIG" ]] ; then
    "$GRUBMKONFIG" -o /boot/grub/grub.cfg
  else
    echo "please update bootloader manually!"
  fi
  cd "${LWD}" || exit 1
fi