#!/bin/bash
function checkVariables {
  if [[ -z $DISK ]]; then
    printf "System drive (DISK) is not set\n"
    exit 99
  fi

  if [[ -z $HOSTNAME ]]; then
    printf "Hostname (HOSTNAME) is not set\n"
    exit 99
  fi

  if [[ -z $USERNAME ]]; then
    printf "Username (USERNAME) is not set\n"
    exit 99
  fi

  if [[ -z $PASSWORD ]]; then
    printf "Password (PASSWORD) is not set\n"
    exit 99
  fi
}

function preChrootStep {
  if [[ $(whoami) != "root" ]]; then
    printf "This script has to be run as root"
    exit 1
  fi

  if ! ls /sys/firmware/efi/efivars > /dev/null 2>&1; then
    printf "This script can only be run when booted in UEFI mode\n"
    exit 1
  fi

  if ! ping -c 1 archlinux.org > /dev/null 2>&1; then
    printf "Unable to ping archlinux.org, check internet connectivity\n"
    exit 1
  fi

  printf "Arch installation\n"
  read -p "System drive: " DISK
  read -p "Hostname: " HOSTNAME
  read -p "Username: " USERNAME
  PASSWORD=$(openssl passwd -6) || exit $?

  LOGFILE="archInstall.$(date +%Y%m%d-%H%M%S).log"

  printf "Installing arch on ${DISK}\n" | tee -a $LOGFILE

  BLOCK_INFO=$(lsblk -n --output PATH,TYPE)
  printf "$BLOCK_INFO" | grep -e " disk$" | grep -e "^${DISK} " > /dev/null 2>&1
  if (( $? > 0 )); then
    printf "${DISK} does not seem to be a disk\n" | tee -a $LOGFILE
    exit 2
  fi

  if (( $(printf "$BLOCK_INFO" | grep -e " part$" | wc -l) > 0 )); then
    printf "${DISK} already has several partitions\n" | tee -a $LOGFILE
    read -p "Do you really wish to continue and erase all partitions? [N/y] " CONTINUE
    if [[ ! $CONTINUE =~ ^[yY]$ ]]; then
      printf "Exiting due to user input\n" | tee -a $LOGFILE
      exit 0
    fi
  fi

  printf "Loading keymap\n" | tee -a $LOGFILE
  loadkeys sv-latin1 || exit $?

  printf "Creating partitions\n" | tee -a $LOGFILE
  (
    echo g      # New partition table
    echo n      # New partition
    echo p      # Primary partition
    echo 1      # Partition number
    echo        # First sector (use default)
    echo +1024M # Last sector
    echo n      # New partition
    echo p      # Primary partition
    echo 2      # Partition number
    echo        # First sector (use default)
    echo        # Last sector (use default)
    echo t      # Set type
    echo 1      # Select partition
    echo 1      # Set type EFI
    echo t      # Select partition
    echo 2      # Selection partition
    echo 20     # Set type Linux file system
    echo w      # Write changes
  ) | fdisk -W always ${DISK} >> $LOGFILE 2>&1 || exit $?

  BOOTPART="${DISK}p1"
  ROOTPART="${DISK}p2"

  printf "Creating LUKS2 container\n" | tee -a $LOGFILE
  cryptsetup luksFormat --type luks2 ${ROOTPART} 2>&1 | tee -a $LOGFILE || exit $?

  printf "Decrypt LUKS2 container\n" | tee -a $LOGFILE
  cryptsetup open ${ROOTPART} cryptlvm 2>&1 | tee -a $LOGFILE || exit $?

  printf "Setup LVM volumes\n" | tee -a $LOGFILE
  pvcreate /dev/mapper/cryptlvm >> $LOGFILE 2>&1 || exit $?
  vgcreate VolGroup1 /dev/mapper/cryptlvm >> $LOGFILE 2>&1 || exit $?
  lvcreate -l 100%FREE VolGroup1 -n root
  lvreduce -L -256M VolGroup1/root >> $LOGFILE 2>&1 || exit $?

  printf "Creating filesystems\n" | tee -a $LOGFILE
  mkfs.fat -F32 ${BOOTPART} >> $LOGFILE 2>&1 || exit $?
  mkfs.ext4 /dev/Volgroup1/root >> $LOGFILE 2>&1 || exit $?

  printf "Mount filesystems\n" | tee -a $LOGFILE
  mount /dev/VolGroup1/root /mnt
  mkdir -p /mnt/boot
  mount ${BOOTPART} /mnt/boot

  printf "Creating swap file\n" | tee -a $LOGFILE
  SWAPSIZE=$(free --giga | grep Mem: | awk '{printf "%dG", $2 * 1.5}')
  mkswap -U clear --size $SWAPSIZE --file /mnt/swapfile >> $LOGFILE 2>&1 || exit $?
  swapon /mnt/swapfile >> $LOGFILE 2>&1 || exit $?

  PACSTRAPPKGS="base linux linux-firmware linux-headers networkmanager efibootmgr vim sudo sed git lvm2"

  printf "Checking CPU manufacturer\n" | tee -a $LOGFILE
  CPU=$(lscpu | grep "^Vendor ID:" | awk '{ print $3 }')

  if [[ ! -z $CPU ]]; then
    if [[ "$CPU" == "GenuineIntel" ]]; then
      PACSTRAPPKGS="${PACSTRAPPKGS} intel-ucode"
    elif [[ "$CPU" == "AuthencticAMD" ]]; then
      PACSTRAPPKGS="${PACSTRAPPKGS} amd-ucode"
    fi
  fi

  printf "Installing base system\n" | tee -a $LOGFILE
  pacstrap -K /mnt ${PACSTRAPPKGS} >> $LOGFILE 2>&1 || exit $?

  printf "Generate fstab\n" | tee -a $LOGFILE
  genfstab -U /mnt >> /mnt/etc/fstab || exit $?
}

function chrootStep {
  checkVariables

  printf "Setting up time\n"  | tee -a $LOGFILE
  ln -sf /usr/share/zoneinfo/Europe/Stockholm /etc/localtime || exit $?
  hwclock --systohc || exit $?

  printf "Setting up locale\n" | tee -a $LOGFILE
  sed -i -e 's/^#\(en_US.UTF-8\)/\1/' /etc/locale.gen || exit $?
  sed -i -e 's/^#\(sv_SE.UTF-8\)/\1/' /etc/locale.gen || exit $?
  locale-gen >&2 || exit $?

  echo "LANG=en_US.UTF-8" > /etc/locale.conf
  echo "LC_TIME=sv_SE.UTF-8" >> /etc/locale.conf
  echo "KEYMAP=sv-latin1" > /etc/vconsole.conf

  printf "Setting hostname to $HOSTNAME\n"
  echo "$HOSTNAME" > /etc/hostname

  printf "Add wheel to sudoers\n"
  echo "%wheel ALL=(ALL) ALL" > /etc/sudoers.d/wheel
  sed -i -e 's/^#\(%wheel ALL=(ALL) ALL\)/\1/' /etc/sudoers || exit $?

  printf "Creating user\n" | tee -a $LOGFILE
  useradd -m $USERNAME -G wheel >&2 || exit $?
  echo "${USERNAME}:${PASSWORD}" | chpasswd -e >&2 || exit $?

  printf "Setting temporary root password\n" | tee -a $LOGFILE
  echo "root:root" | chpasswd >&2 || exit $?

  printf "Starting and enabling NetworkManager\n" | tee -a $LOGFILE
  systemctl enable NetworkManager >&2 || exit $?
  systemctl start NetworkManager >&2 || exit $?

  printf "Add decryption kernel options\n" | tee -a $LOGFILE
  LUKSUUID=$(blkid | grep "${ROOTPART}" | sed -E 's/^.*\bUUID\b="(\S+)".*$/\1/') || exit $?
  mkdir -p /etc/cmdline.d >&2 || exit $?
  echo "rd.luks.name=${LUKSUUID}=cryptlvm root=/dev/VolGroup1/root rw rootfstype=ext4 rd.shell=0 rd.emergency=reboot" > /etc/cmdline.d/root.conf

  printf "Add LUKS related hooks to mkinitcpio.conf" | tee -a $LOGFILE
  for OPT in systemd keyboard sd-vconsole sd-encrypt lvm2; do
    sed -i -E '/^HOOKS=.*\b'$OPT'\b/!s/^(HOOKS=.*)\)$/\1 '$OPT'\)/' /etc/mkinitcpio.conf >&2 || exit $?
  done

  printf "Rebuild kernel\n" | tee -a $LOGFILE
  mkinitcpio -p linux 2>&1 || exit $?

  printf "Install bootloader (systemd)\n" | tee -a $LOGFILE
  bootctl install
  
  printf "Exiting chroot\n" | tee -a $LOGFILE
  exit
}

function postChrootStep {
  printf "Cleanup\n" | tee -a $LOGFILE
  cp $LOGFILE /mnt/$LOGFILE
  cd /
  swapoff /mnt/swapfile
  umount -R /mnt
}

if [[ $1 == "chroot" ]]; then
  chrootStep
  exit
fi

# Run preChroot operations
preChrootStep

# Run chroot operations
printf "Adding install script to mount directory\n" | tee -a $LOGFILE
cp $0 /mnt/

printf "Chrooting arch\n" | tee -a $LOGFILE
DISK="${DISK}" \
  HOSTNAME="${HOSTNAME}" \
  USERNAME="${USERNAME}" \
  PASSWORD="${PASSWORD}" \
  ROOTPART="${ROOTPART}" \
  arch-chroot /mnt /$(basename $0) chroot 2>> $LOGFILE | tee -a $LOGFILE
if (( ${PIPESTATUS[0]} > 0 )); then
  exit ${PIPESTATUS[0]}
fi

# Run postchroot operations
postChrootStep

printf "Base installation completed, logfile at $LOGFILE.\nReboot and proceed with goodies.\nRemember to change/deactivate root login\n" | tee -a $LOGFILE