#!/bin/bash
#

SOURCE=/root/gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9
DEST=/sys/firmware/efi/efivars/gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9
needs_nvram_reset="no"

# Colors
CLEAR='\033[0m'
RED='\033[31m'
GREEN='\033[32m'
YELLOW='\033[33m'
ORANGE='\033[31;1m'
BLUE='\033[34m'

# Check for current variables
for prefix in gfx gpu; do
  for var in /sys/firmware/efi/efivars/${prefix}*; do
    # The test below is to avoid empty or nonexistent paths
    if [[ -e "${var}" ]]; then
      echo -e "${YELLOW}Detected:${CLEAR} $var"
      needs_nvram_reset="yes"
    fi
  done
done

echo ""
if [[ ! -e "/sys/firmware/efi/efivars" ]]; then
  # Probably booted legacy
  echo -e "${RED}ERROR:${CLEAR} EFIVARS not found"
elif cmp "$SOURCE" "$DEST" >/dev/null 2>&1; then
  # EFI var matches desired state
  echo -e "${GREEN}Discrete GPU already disabled${CLEAR}"
elif [[ "$needs_nvram_reset" == "yes" ]]; then
  # One or more gfx/gpu EFI vars detected
  echo -e "${RED}ERROR:${CLEAR} Detected the above EFIVARS"
  echo -e "Please reboot and reset the NVRAM"
else
  # No gfx/gpu EFI vars detected so we can apply the fix
  cp "$SOURCE" "$DEST"
  chattr +i "$DEST"
  sync
  umount /sys/firmware/efi/efivars
  echo -e "${GREEN}Discrete GPU successfully disabled${CLEAR}"
  mount -t efivarfs efivarfs /sys/firmware/efi/efivars
fi
echo ""
read -p "Press Enter to poweroff the system... " -r unusedvar
poweroff