#!/bin/sh
# Setup an archlinux system to a media

[ "$USER" = root ] || exec sudo "$0" "$@"

version='yoda-0.3'

help() {
  echo 'usage: yoda [-CV] [-u user] dev
Install arch to a bootable dev. Media dev is entirely erased then
provisionned with an EFI boot partition and a root partition.

The following steps are performed:
0: prepare device (erase/randomize). Long.
1: partition a 256MB GPT boot and a root partition (the rest)
2: encrypt root partition (dm-crypt + LUKS)
3: format partitions
4: mount partitions
5: install phase 1 (pacstrap)
6: install phase 2 (chroot actions)

options:
-C       crypt root partition with dm-crypt+LUKS
-S steps skips some steps (i.e. -S 02 to avoid crypt)
-u user  create user login and transfer ssh credentials
-V       print version
'
}

die() { echo "$0: fatal: $@" >&2; exit 1; }

# return 1 in any of arg is to be skipped, 0 otherwise
skip() {
  for i; do
    case $toskip in (*$i*) return 0;; esac
  done
  return 1
}

# return 1 if any of the required commands is missing
prereq() {
  ok='ok'
  for cmd in cryptsetup dd fdisk mkfs.fat mkfs.ext4 mkfs.xfs mount pacstrap genfstab arch-chroot
  do
    command -v "$cmd" >/dev/null ||  { ok=''; echo "$cmd not found"; }
  done
  test "$ok"
}

# Step 0: Prepare by wiping all data and randomize (very long).
step0() {
	cryptsetup open --type plain -d /dev/urandom "$dev" to_be_wiped
	dd if=/dev/zero of=/dev/mapper/to_be_wiped bs=1M status=progress || true
	cryptsetup close to_be_wiped
}

# Step 1: Partitions: GPT boot EFI 256 MB, encrypted root: all the rest.
step1() {
	fdisk "$dev" << \EOT
g
n


+256M
t
1
n



p
w
EOT
}

# Step 2: Encrypt root partition.
step2() {
  rootpart="/dev/mapper/$par"
	cryptsetup -y -v luksFormat ${dev}${ppref}2
	cryptsetup open ${dev}${ppref}2 $par
}

# Step 3: Format partitions.
step3() {
	mkfs.fat -F32 "${dev}${ppref}1"
	mkfs.xfs "$rootpart"
}

# Step 4: Mount partitions.
step4() {
	mount "$rootpart" /mnt
	mkdir /mnt/boot
	mount ${dev}${ppref}1 /mnt/boot
  trap cleanup EXIT
}

# Step 5: install some packages.
step5() {
	#pacstrap /mnt base linux linux-firmware vi wireless_tools wpa_supplicant
	pacstrap /mnt base mkinitcpio
	genfstab -U /mnt > /mnt/etc/fstab
}

# Step 6: further configs
step6() {
  # Remove root password.
  sed -i -r 's/^root:[^:]+:/root::/' /mnt/etc/shadow

  # Configure initramfs
  skip 2 &&
    hooks="base udev autodetect modconf block filesystems keyboard fsck" ||
    hooks="base systemd keyboard sd-vconsole modconf block autodetect sd-encrypt filesystems fsck"
  cat > /mnt/etc/mkinitcpio.conf << EOT
MODULES=()
BINARIES=()
FILES=()
HOOKS=($hooks)
EOT

  cat > /mnt/etc/mkinitcpio.d/linux.preset << \EOT
# mkinitcpio preset file for the 'linux' package

ALL_config="/etc/mkinitcpio.conf"
ALL_kver="/boot/vmlinuz-linux"

PRESETS=('default')

#default_config="/etc/mkinitcpio.conf"
default_image="/boot/initramfs-linux.img"
#default_options=""
EOT

	cat > /mnt/etc/hosts << \EOT
127.0.0.1	localhost
::1		localhost
127.0.1.1	yoda.localdomain yoda
EOT

	cat > /mnt/etc/locale.gen << \EOT
en_US.UTF-8 UTF-8
en_GB.UTF-8 UTF-8
fr_FR.UTF-8 UTF-8
EOT

	echo yoda > /mnt/etc/hostname
	echo 'KEYMAP=fr-latin1' > /mnt/etc/vconsole.conf
	echo 'LANG=en_GB.UTF-8' > /mnt/etc/locale.conf
	ln -sf /usr/share/zoneinfo/Europe/Paris /mnt/etc/localtime

  cat > /mnt/etc/systemd/network/20-wired.network << \EOT
[Match]
Name=e*

[Network]
DHCP=ipv4

[DHCP]
RouteMetric=10
EOT

  cat > /mnt/etc/systemd/network/25-wireless.network << \EOT
[Match]
Name=wl*

[Network]
DHCP=ipv4

[DHCP]
RouteMetric=20
EOT

  cat > /mnt/etc/systemd/resolved.conf << \EOT
[Resolve]
DNSSEC=no
DNSOverTLS=no
EOT

  packages="linux linux-firmware intel-ucode amd-ucode sof-firmware \
    xfsprogs dosfstools sudo vi wireless_tools wpa_supplicant openssh arch-install-scripts"

	arch-chroot /mnt << EOT
locale-gen
pacman --noconfirm -S $packages
systemctl enable systemd-networkd
systemctl enable systemd-resolved
systemctl enable wpa_supplicant@wlan0
systemctl enable sshd
bootctl --path=/boot install
EOT

  cp "$myself" /mnt/usr/bin/yoda
  if [ "$user" ]; then
    useradd -R /mnt -m "$user"
    cp -a "/home/$user/.ssh" "/mnt/home/$user/.ssh"
    echo "$user ALL=(ALL) ALL" > "/mnt/etc/sudoers.d/01_$user"
  fi

  mkdir -p /mnt/etc/wpa_supplicant
  cat /etc/wpa_supplicant/wpa_supplicant*.conf > /mnt/etc/wpa_supplicant/wpa_supplicant-wlan0.conf

	cat > /mnt/boot/loader/loader.conf << \EOT
default arch
timeout 4
console-mode max
EOT

  if skip 2; then
    uid=$(blkid -p -s UUID -o value "${dev}${ppref}2")
    rdopt="root=/dev/disk/by-uuid/$uid"
  else 
    uid=$(blkid -p -s UUID -o value "${dev}${ppref}2")
    rdopt="rd.luks.name=$uid=root root=/dev/mapper/root"
  fi
	cat > /mnt/boot/loader/entries/arch.conf << EOT
title Yoda Arch Linux
linux /vmlinuz-linux
initrd /intel-ucode.img
initrd /amd-ucode.img
initrd /initramfs-linux.img
options $rdopt net.ifnames=0 rw
EOT
}

cleanup() {
	echo "Flushing and unmounting $dev"
	umount /mnt/boot /mnt
	cryptsetup close "$par"
	echo "$dev is ready"
}

# Main
toskip='02'
while getopts :CFH:S:u:V opt; do
  case $opt in
    (C) toskip=$(echo "$toskip" | sed 's/[02]//g') ;;
    (S) toskip="$toskip$OPTARG" ;;
    (u) user=$OPTARG;;
    (V) echo $version && exit ;;
    (*) help; exit 1 ;;
  esac
done
shift $((OPTIND - 1))

[ "$1" ] && dev=$1 || die 'no device'

par=${dev##*/}root
case $dev in (*nvme*) ppref='p';; esac
rootpart="${dev}${ppref}2"
myself=$(type -p $0)

prereq || exit 1

echo -n "Device $dev will be completely erased. Continue ? Y/N "
read -r resp && [ "$resp" = 'Y' ] || exit

skip 0 || step0
skip 1 || step1
skip 2 || step2
skip 3 || step3
skip 4 || step4
skip 5 || step5
skip 6 || step6

# vim: ts=2 sw=2 et