#!/bin/sh
set -e

if [ "$#" != "2" ]; then
	echo "incorrect number of arguments"
	echo "arg1 target device"
	echo "arg2 luks pass"
	exit 1
fi
DEV_ID=$1
PASS=$2

DEV_CAPACITY=128
DISTRO_CAPACITY=120
NUM_DISTROS=4
PART_ID_EFI=1
PART_ID_EFI_SIZE=2
PART_ID_LUKS=3
PART_ID_LUKS_SIZE=32
PART_ROOTS_SIZE=$(($(($((DISTRO_CAPACITY - PART_ID_EFI_SIZE)) - PART_ID_LUKS_SIZE)) / $((NUM_DISTROS - 1))))
PART_ROOTS_SIZE_MOD=4

# set keyboard console layout
#ls -R /usr/share/kbd/keymaps
sudo loadkeys us

# verify uefi mode
ls -R /sys/firmware/efi/efivars

# connect to internet
#ip link
ping -c 3 archlinux.org

# if target device partitioned, destroy
if [ -e "/dev/${DEV_ID}1" ]; then
  #sudo umount -R /mnt
  #sudo cryptsetup luksClose cryptroot
  sudo wipefs -a "/dev/${DEV_ID}"
  #sudo sfdisk --delete /dev/${DEV_ID}
  sudo shred --verbose --random-source=/dev/urandom -n1 --zero "/dev/${DEV_ID}"
fi

partition_disk () {
  # partition disk
  # For gpt partition table:
  # Partition 1 should be EFI System Partition of about 128MB
  # Partition 2 should be the boot partition of about 128MB
  # Partition 3 should be the root partition. Give it the rest of the free space.

  # For dos/bios partition table:
  # Partition 1 should be the boot partition of about 128MB.
  # Partition 2 should be the root partition. Give it the rest of the free space.

  # dos|#1 boot 128MB|#2 root free space
  #echo -e "n\np\n1\n2048\n+128M\nn\np\n2\n\n\n\n\nw" | sudo fdisk /dev/${DEV_ID}

  # gpt|#1 EFI 256MB|#2 boot 4MB|#3 root rest of space
  #echo -e "g\nn\n1\n2048\n+128M\nn\n2\n\n+128M\nn\3\n\n\n\n\nt\n1\n1\nw" | sudo fdisk /dev/${DEV_ID}

  # gpt|#1 EFI 2048MB|#2 partition 18G|#3 root rest of space
  #echo -e "g\nn\np\n1\n2048\n+2048M\nn\np\n2\n\n+18G\nn\np\n3\n\n\nw" | sudo fdisk /dev/${DEV_ID}

  total_part_size=0
  echo "PART_ROOTS_SIZE $PART_ROOTS_SIZE"
  echo "1 $PART_ID_EFI_SIZE"
  CMD='g\nn\np\n1\n2048\n+'$PART_ID_EFI_SIZE'G\nt\n1\n'

  i=2
  while [ "$i" -le $((NUM_DISTROS + 1)) ]; do 
    if [ $i -eq $PART_ID_LUKS ]; then
      CMD=${CMD}'n\np\n'$i'\n\n+'$PART_ID_LUKS_SIZE'G\n'
      echo "$i $PART_ID_LUKS_SIZE"
      total_part_size=$((total_part_size + PART_ID_LUKS_SIZE))
    else
      MOD=$PART_ROOTS_SIZE_MOD
      if [ $((i % 2)) -eq 0 ]; then
        MOD=$((PART_ROOTS_SIZE - PART_ROOTS_SIZE_MOD))
      else
        MOD=$(( PART_ROOTS_SIZE + PART_ROOTS_SIZE_MOD))
      fi
      echo "$i $MOD"
      total_part_size=$((total_part_size + MOD))
      CMD=${CMD}'n\np\n'$i'\n\n+'$MOD'G\n'
    fi
    i=$((i + 1))
  done
  CMD=${CMD}'n\np\n\n\n\n\nw'
  echo "$((NUM_DISTROS + 2)) $((DEV_CAPACITY - total_part_size)) storage"
  echo "1-$((NUM_DISTROS + 1)) $total_part_size"

  echo 'echo -e "'"$CMD"'" | sudo fdisk /dev/'"$DEV_ID"
  eval 'echo -e "'"$CMD"'" | sudo fdisk /dev/'"$DEV_ID"
} # end partition_disk
partition_disk

encrypt_root () {
  # LUKS encryption
  sudo modprobe dm-crypt
  sudo modprobe dm-mod

  # luks1
  #printf "%b" "$PASS" | sudo cryptsetup luksFormat --type luks1 --use-urandom --key-size 512 --hash sha512 --iter-time 3000 "/dev/${DEV_ID}${PART_ID_LUKS}" -

  # luks2
  printf "%b" "$PASS" | sudo cryptsetup --type luks2 --verify-passphrase --sector-size 4096 --verbose luksFormat "/dev/${DEV_ID}${PART_ID_LUKS}" -

  # open root partition
  printf "%b" "${PASS}" | sudo cryptsetup open "/dev/${DEV_ID}${PART_ID_LUKS}" cryptroot -
} # end encrypt_root
encrypt_root

# format partitions
format_partitions () {
  sudo mkfs.fat -F32 -n "EFI" "/dev/${DEV_ID}${PART_ID_EFI}"
  #sudo mkfs.ext4 -L BOOT /dev/${DEV_ID}${PART_ID_LUKS}
  #sudo mkfs.ext4 -L ROOT /dev/mapper/cryptroot
  sudo mkfs.btrfs -L ROOT /dev/mapper/cryptroot

  # gpt: create btrfs subvolumes
  sudo mount /dev/mapper/cryptroot /mnt
  sudo btrfs subvolume create /mnt/@
  sudo btrfs subvolume create /mnt/@home
  sudo btrfs subvolume create /mnt/@snapshots
  sudo btrfs subvolume create /mnt/@var_cache_pacman_pkg
  #sudo btrfs subvolume create /mnt/@var_log
  sudo mkdir /mnt/@/home
  sudo mkdir -p /mnt/@/.btrfs/snapshots
  #sudo mkdir -p /mnt/@/var/log
  sudo mkdir -p /mnt/@/var/cache/pacman/pkg
  sudo umount -R /mnt
} # end format_partitions
format_partitions

create_swap () {
  # swap file 512MB
  sudo dd if=/dev/zero of=/mnt/swapfile bs=1M count=512
  sudo chmod 0600 /mnt/swapfile
  sudo mkswap /mnt/swapfile
  sudo swapon
} # end create_swap

mount_partitions () {
  # dos: mount partitions
  #sudo mount /dev/${DEV_ID}${PART_ID_LUKS} /mnt
  #sudo mkdir /mnt/boot
  #sudo mount /dev/${DEV_ID}1 /mnt/boot

  # gpt: mount btrfs root partitions
  sudo mount -o ssd,noatime,compress=zstd:1,space_cache=v2,autodefrag,subvol=@ /dev/mapper/cryptroot /mnt
  sudo mount -o ssd,noatime,compress=zstd:1,space_cache=v2,autodefrag,subvol=@home /dev/mapper/cryptroot /mnt/home
  sudo mount -o ssd,noatime,compress=zstd:1,space_cache=v2,autodefrag,subvol=@snapshots /dev/mapper/cryptroot /mnt/.btrfs/snapshots
  sudo mount -o ssd,noatime,compress=zstd:1,space_cache=v2,autodefrag,subvol=@var_cache_pacman_pkg /dev/mapper/cryptroot /mnt/var/cache/pacman/pkg
  #sudo mount -o ssd,noatime,compress=zstd:1,space_cache=v2,autodefrag,subvol=@var_log /dev/mapper/cryptroot /mnt/var/log

  create_swap

  # gpt: mount EFI system partitions
  #sudo mount /dev/mapper/cryptroot /mnt
  #sudo mkdir /mnt/boot
  #sudo mount /dev/${DEV_ID}1 /mnt/boot
  sudo mkdir /mnt/efi
  sudo mount "/dev/${DEV_ID}${PART_ID_EFI}" /mnt/efi
} # end mount_partitions
mount_partitions

# install kernel - linux{-lts,-zen,-hardened} amd-ucode
basestrap /mnt linux linux-firmware amd-ucode

# install base packages
#basestrap /mnt base base-devel cryptsetup openrc elogind-openrc
basestrap /mnt base base-devel cryptsetup runit elogind-runit

# generate fstab
sudo fstabgen -U /mnt | sudo tee -a /mnt/etc/fstab
# remove btrfs subvolid
sudo sed -i 's/subvolid=[0-9]*,//g' /mnt/etc/fstab