#! /usr/bin/env bash

# Creates macOS boot disk.

printf "macOS Boot Disk Tips\n"
printf "  - Use a USB drive (8GB or higher).\n"
printf "  - Use Disk Utility to format the USB drive as \"Mac OS Extended (Journaled)\".\n"
printf "  - Use Disk Utility to label the USB drive as \"Untitled\".\n"
printf "\nmacOS Boot Disk Usage:\n"
printf "  1. Insert the USB boot disk into the machine to be upgraded.\n"
printf "  2. Reboot the machine.\n"
printf "  3. Hold the POWER (Silicon) or OPTION (Intel) key before the Apple logo appears.\n"
printf "  4. Select the USB boot disk from the menu.\n"
printf "  5. Use Disk Utility to delete and/or erase the hard drive including associated partitions.\n"
printf "  6. Use Disk Utility to create a single \"APFS\" drive as a \"GUID Partition Table\".\n"
printf "  7. Install the new operating system.\n"
printf "\nmacOS Boot Disk Recovery:\n"
printf "  1. Start/restart the machine.\n"
printf "  2. Hold the POWER (Silicon) or COMMAND+R (Intel) keys before the Apple logo appears.\n"
printf "  3. Wait for the macOS installer to load from the recovery partition.\n"
printf "  4. Use the dialog options to launch Disk Utility, reinstall the system, etc.\n"

printf "\nCreating macOS boot disk...\n"

if [[ ! -e "$MAC_OS_BOOT_DISK_CREATOR" ]]; then
  printf "ERROR: macOS installer does not exist: $MAC_OS_BOOT_DISK_CREATOR. Use System Preferences → Software Update to download.\n"
  exit 1
fi

if [[ ! -d "$MAC_OS_BOOT_DISK_PATH" ]]; then
  printf "ERROR: Boot disk must be mounted at: $MAC_OS_BOOT_DISK_PATH.\n"
  exit 1
fi

sudo "$MAC_OS_BOOT_DISK_CREATOR" --volume "$MAC_OS_BOOT_DISK_PATH" --downloadassets --nointeraction