#!/run/current-system/sw/bin/bash
set -e
trap 'echo "Aborting installation."; exit 1' INT

# set up working directory
mkdir -p /tmp/install_pwd && cd /tmp/install_pwd
rm -rf ./*

# download disko.nix file for defining partitions
echo -n "Downloading partition plan..."
curl -s https://raw.githubusercontent.com/pagedMov/pagedmov-nix-cfg/refs/heads/master/hosts/installer/disko-ext4-singledisk.nix > disko.nix
echo "Done!"

echo
echo "This script is about to format and partition a hard drive."
sleep 2.5
echo -e "\033[4;31mThis process is irreversible and will destroy all data on the drive.\033[0m"
sleep 2.5
echo "Make absolutely sure that you know which drive you are choosing."
sleep 2.5
echo
lsblk -d -o NAME,SIZE
echo
echo -n "Which drive do you wish to sacrifice? "
read -r drive

size=$(lsblk -b -d -o NAME,SIZE | grep "$drive" | awk '{ printf "%.0f\n", $2 / 1024 / 1024 / 1024 }')
size=$((size-1))
root_size_default=$(echo "scale=0;$size * 0.10 / 1" | bc)
nix_size_default=$(echo "scale=0;$size * 0.35 / 1" | bc)

for part in "root" "nix"; do
		echo "You have $size GB remaining to work with on this drive. How big do you want your $part partition?"

		if [ "$part" = "root" ]; then
				echo "Default value is 10% of hard drive space ($root_size_default GB)"
		else
				echo "Default value is 35% of hard drive space ($nix_size_default GB)"
		fi
		echo "Give a positive integer or leave blank to use default value"
	deciding=true

	while $deciding; do
			echo -n "> "
			read -r size_choice

			case "$size_choice" in
					'')
						deciding=false
						;;
					*[!0-9]*)  # Matches non-numeric input
							echo "Invalid input. Please enter a valid positive number."
							;;
					0)  # Matches zero
							echo "Please enter a positive number greater than zero."
							;;
					*)  # Matches positive numbers
							if (( size_choice > size - 50 )); then
									echo "You need to leave more room for the other partitions."
								elif (( size_choice < 5 )); then
									echo "Partition size is too small."
								else
									echo "Valid input: $size_choice"
									deciding=false  # Exit the loop on valid input
							fi
							;;
			esac
	done

	case "$part" in
		"root" )
			if [ -z "$size_choice" ]; then root_size=$root_size_default; else root_size=$size_choice; fi
			size=$((size - root_size))
			;;
		"nix" )
			if [ -z "$size_choice" ]; then nix_size=$nix_size_default; else nix_size=$size_choice; fi
			size=$((size - nix_size))
			;;
	esac
done

echo "Final partition sizes:"
echo "root: $root_size GB"
echo "nix: $nix_size GB"
echo "home: $size GB"

sleep 1

# commence formatting
echo "Commencing formatting/partitioning..." && sleep 0.5
nix --experimental-features "nix-command flakes" run github:nix-community/disko -- --mode disko /tmp/install_pwd/disko.nix --arg device "\"/dev/$drive\"" --arg root_size "\"$root_size\G\"" --arg nix_size "\"$nix_size\G\"" 

mount /dev/disk/by-partlabel/disk-main-root /mnt
mkdir -p /mnt/nix && mount /dev/disk/by-partlabel/disk-main-nix /mnt/nix
mkdir -p /mnt/boot && mount /dev/disk/by-partlabel/disk-main-ESP /mnt/boot
mkdir -p /mnt/home && mount /dev/disk/by-partlabel/disk-main-home /mnt/home 

mkdir -p /mnt/etc
cd /mnt/etc/
[ -d /mnt/etc/nixos ] && rm -rf /mnt/etc/nixos
git clone https://github.com/pagedMov/pagedmov-nix-cfg.git ./nixos

echo "Do you want to install the light or heavy configuration?"
echo "Light configuration does not include gaming or virtualization features; intended for laptops, etc."
echo "Heavy config includes gaming and virtualization features; intended for performant desktop environments."
select config in "Heavy" "Light" "Quit"; do
	case $config in
		"Desktop")
			echo "Installing heavy configuration \`Oganesson\`"
			config="oganesson"
			sleep 0.5
			break
			;;
		"Laptop")
			echo "Installing light configuration \`Mercury\`"
			config="mercury"
			sleep 0.5
			break
			;;
		"Quit")
			echo "Exiting installation..."
			sleep 0.5
			exit 0
			;;
		*)
			echo "Invalid option."
			sleep 0.5
			;;
	esac
done

nixos-install --root /mnt --flake /mnt/etc/nixos#"$config" --no-root-password

echo
echo "Preliminary installation successful!"
echo "Adapting config to your setup..."
echo

cp -r /mnt/etc/nixos /mnt/home/pagedmov/.sysflake
rm -rf /mnt/etc/nixos
ln -s /mnt/home/pagedmov/.sysflake /etc/nixos

nixos-enter <<-HEREDOC
chown -R pagedmov /home/pagedmov/.sysflake
nixos-generate-config --show-hardware-config > /home/pagedmov/.sysflake/hosts/laptop/hardware.nix
NIXOS_SWITCH_USE_DIRTY_ENV=1 nixos-rebuild boot --flake /home/pagedmov/.sysflake#mercury
HEREDOC

echo "INSTALLATION COMPLETE ! !" | toilet -f 3d -w 120 | lolcat -a -s 180
echo "You can now reboot into your new system."
echo "The system configuration flake will be found in your home folder under .sysflake"
echo "/etc/nixos is a symlink leading to the .sysflake folder"