#!/bin/bash

set -e # Stop on Errors

scriptdir="$(dirname "$(readlink -f "$0")")"

function show_help() {
  echo "$0 -d <device> [options]"
  echo "  A Semi-Automatic Archlinux Install Script"
  echo " -d <device>   Device to Install to"
  echo " -k <kernel>   Kernel Name to Install (default: linux-zen)"
  echo " -n <nm>       Network Management: n NetworkMangager, m NetworkManager + ModemManager, (default: none)"
  echo " -l <locale>   Locale to use (default: de_DE)"
  echo " -m <keymap>   Console Keymap to use (default: de)"
  echo " -t <timezone> Timezone to use (default: Europe/Berlin)" 
  echo " -b            Set System Type to BIOS (default: UEFI)"
} 

function exit_error() {
  echo "$1"
  show_help
  exit 1
}

function install_network() {
  local option=$1
  case $option in
    1) echo "Installing NetworkManager"
       pacstrap /mnt networkmanager
       systemctl enable --root=/mnt NetworkManager
       ;;
    2) echo "Installing NetworkManager an ModemManager"
       pacstrap /mnt networkmanager modemmanager
       systemctl enable --root=/mnt NetworkManager ModemManager
       ;;
    *) echo "No Network Management selected, not installing any" ;;
   esac
}

## Defaults
kernel="linux-zen"
locale="de_DE"
keymap="de"
timezone="Europe/Berlin"
systype="x86_64-efi"
network=0

## Get CLI Options
while getopts 'k:d:n:m:l:h:b?' flag; do
  case "${flag}" in
    k) kernel="${OPTARG}" ;;
    n) case "${OPTARG}" in
         n) network=1 ;;
         m) network=2 ;;
         *) exit_error "Unknown Network Type Selected, Aborting" ;;
       esac
       ;;
    d) device="${OPTARG}" ;;
    l) locale="${OPTARG}" ;;
    m) keymap="${OPTARG}" ;;
    t) timezone="${OPTARG}" ;;
    b) systype="i386-pc" ;;
    h) hostname="${OPTARG}" ;;
    ?) show_help ;;
    *) show_help ;;
  esac
done

if [[ -z "$device" ]]; then
  exit_error "No Installation Device Selected, Aborting"
fi

if [[ -z "$hostname" ]]; then
  exit_error "No Hostname given, Aborting"
fi

## Confirm installation
read -r -p "This will delete the current partition table on $device. Do you agree [y/N]? " response
response=${response,,}
if [[ "$response" =~ ^(yes|y)$ ]]; then
  wipefs -af "$device" &>/dev/null
  sgdisk -Zo "$device" &>/dev/null
else
  exit_error "Installation Aborted by User"
fi

## Select Microcode
if [[ "$(systemd-detect-virt)" == "none" ]]; then
  if [[ "$(grep vendor_id /proc/cpuinfo)" == *"AuthenticAMD"* ]]; then
    microcode=amd-ucode
  else
    microcode=intel-ucode
  fi
  firmware=linux-firmware
fi

echo "Paritioning Disk ${device}"
if [[ "${systype}" == "x86_64-efi" ]]; then
  parted -s "$device" \
    mklabel gpt \
    mkpart ESP fat32 1MiB 513MiB \
    set esp 1 on \
    mkpart cryptroot 512MiB 100%
  
  part_esp="/dev/disk/by-partlabel/ESP"
  part_root="/dev/disk/by-partlabel/cryptroot"
  extrapkgs="efibootmgr"
  
  partprobe "${device}"
  mkfs.fat -F32 -n EFI "${part_esp}"
else
  parted -s "$device" \
    mklabel gpt \
    mkpart grub 1MiB 2MiB \
    set bios_grub 1 on \
    mkpart cryptroot 2MiB 100%
  
  part_root="/dev/disk/by-partlabel/cryptroot"
fi

echo "Creating Encrypted Root Partition"
cryptsetup luksFormat --type luks1 --cipher aes-xts-plain64 --hash sha512 --key-size 512 "${part_root}"
cryptsetup open "${part_root}" "cryptroot"
crypt_root="/dev/mapper/cryptroot"

echo "Creating BTRFS Filesystem"
mkfs.btrfs -L root "$crypt_root"

echo "Creating BRTFS Subvolumes"
mount "${crypt_root}" /mnt
for sv in "@" "@home" "@data" "@snapshot" "@log" "@pkg" "@machines" "@portables"; do
  btrfs su cr "/mnt/${sv}"
done

umount /mnt
echo "Mounting System Subvolumes"
mount -o ssd,noatime,space_cache,compress=zstd,subvol=@ "${crypt_root}" /mnt
mkdir -p /mnt/{home,data,.snapshots,var/log,var/cache/pacman/pkg,var/lib/machines,var/lib/portables}
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@home "${crypt_root}" /mnt/home
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@data "${crypt_root}" /mnt/data
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@snapshots "${crypt_root}" /mnt/.snapshots
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@log "${crypt_root}" /mnt/var/log
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@pkg "${crypt_root}" /mnt/var/cache/pacman/pkg
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@machines "${crypt_root}" /mnt/var/lib/machines
mount -o ssd,noatime,space_cache.compress=zstd,autodefrag,discard=async,subvol=@portables "${crypt_root}" /mnt/var/lib/portables
chattr +C /mnt/var/log /mnt/var/cache/pacman/pkg
if [[ "${systype}" == "x86_64-efi" ]]; then
  mount "${part_esp}" /mnt/boot/efi
fi

echo "Installing Base System Packages"
pacstrap /mnt base $kernel $microcode $firmware $extrapkgs btrfs-progs grub grub-btrfs snapper vim git tmux htop lsof strace openssh

echo "Creating Basic Config Files"
genfstab -U /mnt | sed -e 's#suvolid=.*,##g;s#subvol=/.*##g' >> /mnt/etc/fstab

echo "${hostname}" >> /mnt/etc/hostname
cat > /mnt/etc/hosts <<EOF
127.0.0.1 localhost
::1       localhost
127.0.1.1 ${hostname}.localdomain ${hostname}
EOF

echo "$locale.UTF-8 UTF-8"  > /mnt/etc/locale.gen
echo "LANG=$locale.UTF-8" > /mnt/etc/locale.conf
echo "KEYMAP=$keymap" > /mnt/etc/vconsole.conf

if [ -d "${scriptdir}/etc" ]; then
  cp -r "${scriptdir}/etc/"* /mnt/etc/
fi