#!/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'

# Functions
function beep () {
  echo -ne '\007'
}
function beeps_bad () {
  # SOS-like?
  beep
  sleep 0.25s
  beep
  sleep 0.25s
  beep

  sleep 0.5s

  beep
  sleep 0.5s
  beep
  sleep 0.5s
  beep

  sleep 0.5s

  beep
  sleep 0.25s
  beep
  sleep 0.25s
  beep
}
function beeps_good () {
  # Two quick beeps
  beep
  sleep 0.25s
  beep
}

echo '## Mac dGPU Disable Tool ##'
echo ''

# 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"
    beeps_bad
elif cmp "$SOURCE" "$DEST" >/dev/null 2>&1; then
    # EFI var matches desired state
    echo -e "${GREEN}Discrete GPU already disabled${CLEAR}"
    beeps_good
elif [[ "$needs_nvram_reset" == "yes" ]]; then
    # One or more gfx/gpu EFI vars detected
    echo -e "${RED}ERROR:${CLEAR} Detected the above EFIVARS"
    echo -e "Please reboot and reset the NVRAM"
    beeps_bad
else
    # No gfx/gpu EFI vars detected so we can apply the fix
    cp "$SOURCE" "$DEST"
    chattr +i "$DEST"
    umount /sys/firmware/efi/efivars
    sync
    echo -e "${GREEN}Discrete GPU successfully disabled${CLEAR}"
    mount -t efivarfs efivarfs /sys/firmware/efi/efivars
    beeps_good
fi
echo ""
read -p "Press Enter to poweroff the system... " -r unusedvar
poweroff