#!/bin/bash

set -e # Stop on Errors

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

function show_help() {
  echo "$0 -d <device> -h <hostname> [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, s systemd-networkd (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 " -h <hostname> Set the Target Hostname" 
  echo " -s <hddsize>  Only use hddsize for the system partition" 
  echo " -b            Set System Type to BIOS (default: UEFI)"
  echo " -c            Disable Encryption (default: enabled)"
} 

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
       ;;
    3) echo "Installing systemd-networkd"
       systemctl enable --root=/mnt systemd-networkd
       ;;
    *) 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
encryption=1
hddsize="100%"

## Get CLI Options
while getopts 'k:d:n:m:l:h:s:t:bc?' flag; do
  case "${flag}" in
    k) kernel="${OPTARG}" ;;
    n) case "${OPTARG}" in
         n) network=1 ;;
         m) network=2 ;;
         s) network=3 ;;
         *) exit_error "Unknown Network Type Selected, Aborting" ;;
       esac
       ;;
    d) device="${OPTARG}" ;;
    l) locale="${OPTARG}" ;;
    m) keymap="${OPTARG}" ;;
    t) timezone="${OPTARG}" ;;
    b) systype="i386-pc" ;;
    c) encryption=0 ;;
    h) hostname="${OPTARG}" ;;
    s) hddsize="${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 1 esp on \
    mkpart arch 514MiB ${hddsize}
  
  part_esp="/dev/disk/by-partlabel/ESP"
  part_root="/dev/disk/by-partlabel/arch"
  extrapkgs="efibootmgr"
  
  partprobe "${device}"
  sleep 2
  mkfs.fat -F32 -n EFI "${part_esp}"
else
  parted -s "$device" \
    mklabel gpt \
    mkpart grub 1MiB 2MiB \
    set 1 bios_grub on \
    mkpart arch 2MiB 100%
  
  partprobe "${device}"
  sleep 2
  part_root="/dev/disk/by-partlabel/arch"
fi

if [ $encryption -eq 1 ]; then
  echo "Creating Encrypted Root Partition"
  read -s -r -p "Please Enter the Encryption Passhprase: " lukspw
  echo ""
  read -s -r -p "Please Verify the Encryption Passhprase: " lukspw2
  echo ""
  [ "$lukspw" != "$lukspw2" ] && echo "Passphrases don't match!" && exit 1
  echo -n "$lukspw" | cryptsetup luksFormat --type luks1 --cipher aes-xts-plain64 --hash sha512 --key-size 512 "${part_root}" -
  echo -n "$lukspw" | cryptsetup open --key-file - "${part_root}" "cryptroot"
  unset lukspw lukspw2
  root_dev="/dev/mapper/cryptroot"
else
  root_dev="${part_root}"
fi

echo "Creating BTRFS Filesystem"
mkfs.btrfs -f -L archlinux "${root_dev}"

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

btrfs_opts="ssd,noatime,compress=zstd,autodefrag,discard=async"

umount /mnt
echo "Mounting System Subvolumes"
mount -o ${btrfs_opts},subvol=@ "${root_dev}" /mnt
mkdir -p /mnt/{home,data,.snapshots,var/log,var/cache/pacman/pkg,var/lib/machines,var/lib/portables}
mount -o ${btrfs_opts},subvol=@home "${root_dev}" /mnt/home
mount -o ${btrfs_opts},subvol=@data "${root_dev}" /mnt/data
mount -o ${btrfs_opts},subvol=@snapshots "${root_dev}" /mnt/.snapshots
mount -o ${btrfs_opts},subvol=@log "${root_dev}" /mnt/var/log
mount -o ${btrfs_opts},subvol=@pkg "${root_dev}" /mnt/var/cache/pacman/pkg
mount -o ${btrfs_opts},subvol=@machines "${root_dev}" /mnt/var/lib/machines
mount -o ${btrfs_opts},subvol=@portables "${root_dev}" /mnt/var/lib/portables
chattr +C /mnt/var/log /mnt/var/cache/pacman/pkg
if [[ "${systype}" == "x86_64-efi" ]]; then
  mkdir -p /mnt/boot/efi
  mount "${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 iftop iotop tcpdump mtr rsync wget which zip lsof strace openssh inetutils bc man-pages sudo bash-completion

echo "Creating Basic Config Files"
genfstab -U /mnt | sed -e 's/suvolid=[0-9]*,//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

sed -i 's/#COMPRESSION="zstd"/COMPRESSION="zstd"/g' /mnt/etc/mkinitcpio.conf
if [ $encryption -eq 1 ]; then
  sed -i 's/HOOKS=.*/HOOKS=(base udev autodetect keyboard keymap modconf block encrypt filesystems fsck)/g' /mnt/etc/mkinitcpio.conf
  
  UUID=$(blkid ${part_root} | cut -f2 -d'"')
  sed -i 's/#GRUB_ENABLE_CRYPTODISK=y/GRUB_ENABLE_CRYPTODISK=y/g' /mnt/etc/default/grub
  sed -i "s#GRUB_CMDLINE_LINUX_DEFAULT=.*#GRUB_CMDLINE_LINUX_DEFAULT=\"loglevel=3 quiet cryptdevice=UUID=$UUID:cryptroot:allow-discards root=${root_dev}\"#g" /mnt/etc/default/grub
else
  sed -i 's/HOOKS=.*/HOOKS=(base udev autodetect keyboard keymap modconf block filesystems fsck)/g' /mnt/etc/mkinitcpio.conf
fi

arch-chroot /mnt /bin/bash -e <<EOF

  # Timezone and RTC Setup
  ln -sfn /usr/share/zoneinfo/$timezone /etc/localtime
  hwclock --systohc

  # Locales
  echo "Generating Locales"
  locale-gen

  # Initramfs
  echo "Generating Initramfs"
  mkinitcpio -P

  # My Repository
  pacman-key -r 805517CC
  pacman-key --lsign-key 805517CC
  echo '[seiichiro]' >> /etc/pacman.conf
  echo 'SigLevel = Required DatabaseOptional TrustedOnly' >> /etc/pacman.conf
  echo 'Server = http://www.seiichiro0185.org/repo/\$arch' >> /etc/pacman.conf

  echo "Setting up Snapper"
  umount /.snapshots
  rm -r /.snapshots
  snapper --no-dbus -c root create-config /
  btrfs subvolume delete /.snapshots &>/dev/null
  mkdir /.snapshots
  mount -a
  chmod 750 /.snapshots

  echo "Installing Grub"
  if [ "${systype}" == "x86_64-efi" ]; then
    grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=GRUB &>/dev/null
  else
    grub-install --target=i386-pc ${device}
  fi
  grub-mkconfig -o /boot/grub/grub.cfg

EOF

echo "Please set a Password for root"
arch-chroot /mnt /bin/passwd

install_network ${network}

echo "Enabling Services"
systemctl enable sshd grub-btrfs.path --root /mnt

echo -e "\n\nInstallation finished, you may further customize it in /mnt or reboot now"