#!/bin/bash -x

set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?"' ERR

# # fai's setup-storage won't do btrfs on luks,
# # so we do it ourself :)

partition=false

# keyfiles generated like:
# head -c 2048 /dev/urandom | od | s dd of=/q/root/luks/host-demohost
luks_dir=/var/lib/fai/config/distro-install-common/luks

letters=(a)

if ifclass VM; then
    d=/dev/vd
else
    d=/dev/sd
fi

if ifclass TWO_DISK; then
    skiptask partition
    devs=(${d}{a,b})
    [[ -e /dev/md127 ]] || partition=true
elif ifclass ONE_DISK; then
    skiptask partition
    devs=(${d}a)
else
    exit
fi

# somewhat crude detection of wehter to partition
for dev in ${devs[@]}; do
    for part in ${dev}{1,2,3,4}; do
        [[ -e $part ]] || partition=true
    done
done


boot_end=504

! ifclass tp || letters=(a b)

md() { ((${#letters[@]} > 1)); }

if md; then
    # if partition with md0, then reboot into the installer,
    # it becomes md127. So might as well start with 127 for simplicity.
    crypt=md127
else
    crypt=${d##/dev/}a3
fi



# 1.5 x based on https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Installation_Guide/sect-disk-partitioning-setup-x86.html#sect-custom-partitioning-x86
swap_end=$(( $(grep ^MemTotal: /proc/meminfo| awk '{print $2}') * 3/(${#letters[@]} * 2 ) / 1000 + boot_end ))MiB

shopt -s nullglob
if $partition; then
    mkdir -p /tmp/fai
    for dev in ${devs[@]}; do
        for x in /dev/md*; do [[ -d $x ]] || mdadm --stop $x; done
        for x in $dev[0-9]; do wipefs -a $x; done
        parted -s $dev mklabel gpt
        # gpt ubuntu cloud image uses ~4. fai uses 1 MiB. ehh, i'll do 4.
        # also, using MB instead of MiB causes complains about alignment.
        parted -s $dev mkpart primary "ext3" 4MB ${boot_end}MiB
        parted -s $dev set 1 boot on
        parted -s $dev mkpart primary "linux-swap" ${boot_end}MiB $swap_end
        parted -s -- $dev mkpart primary "" $swap_end -0
        parted -s $dev set 3 raid on
        parted -s $dev mkpart primary "" 1MiB 4MiB
        parted -s $dev set 4 bios_grub on
        # the mkfs failed randomly on a vm, so I threw a sleep in here.
        sleep .1
        mkfs.ext4 -F ${dev}1
    done
    if md; then
        yes | mdadm --create /dev/$crypt --level=raid0 --force --run \
                    --raid-devices=${#devs[@]} ${devs[@]/%/3} || [[ $? == 141 ]]
    fi

    yes YES | cryptsetup luksFormat /dev/$crypt $luks_dir/host-$HOSTNAME \
                         -c aes-cbc-essiv:sha256 -s 256 || [[ $? == 141 ]]
    yes $(cat $luks_dir/traci) | \
        cryptsetup luksAddKey --key-file \
                   $luks_dir/host-$HOSTNAME /dev/$crypt || [[ $? == 141 ]]
    # this would remove the keyfile. we will do that manually later.
    #    yes 'test' | cryptsetup luksRemoveKey /dev/... \
        #                            /key/file || [[ $? == 141 ]]
    cryptsetup luksOpen /dev/$crypt crypt_dev_$crypt --key-file \
               $luks_dir/host-$HOSTNAME
    parted ${devs[0]} set 1 boot on
    mkfs.btrfs -f /dev/mapper/crypt_dev_$crypt
    mount /dev/mapper/crypt_dev_$crypt /mnt
    cd /mnt
    btrfs subvolume create a
    btrfs subvolume create root
    btrfs subvolume set-default $(btrfs subvolume list . | grep 'root$' | awk '{print $2}') .
    cd /
    umount /mnt
else
    for dev in ${devs[@]}; do
        mkfs.ext4 -F ${dev}1
    done
    yes $(cat $luks_dir/traci) | \
        cryptsetup luksOpen /dev/$crypt crypt_dev_$crypt || [[ $? == 141 ]]
    sleep 1
    mount -o subvolid=0 /dev/mapper/crypt_dev_$crypt /mnt
    # systemd creates subvolumes we want to delete.
    s=($(btrfs subvolume list --sort=-path /mnt |
                sed -rn 's#^.*path\s*(root/\S+)\s*$#\1#p'))
    for subvol in ${s[@]}; do btrfs subvolume delete /mnt/$subvol; done
    btrfs subvolume set-default 0 /mnt
    btrfs subvolume delete /mnt/root
    btrfs subvolume create /mnt/root
    btrfs subvolume set-default $(btrfs subvolume list /mnt | grep 'root$' | awk '{print $2}') /mnt
    umount /mnt
fi

cat > /tmp/fai/crypttab <<EOF
crypt_dev_$crypt  /dev/$crypt  none  keyscript=/root/keyscript,discard,luks
EOF

for dev in ${devs[@]}; do
    cat >> /tmp/fai/crypttab <<EOF
swap ${dev}2  /dev/urandom  swap,cipher=aes-xts-plain64,size=256,hash=ripemd160
EOF
done

# this is duplicated in arch-init
cat > /tmp/fai/fstab <<EOF
/dev/mapper/crypt_dev_$crypt  /  btrfs  noatime,subvol=/root  0 0
/dev/mapper/crypt_dev_$crypt  /a  btrfs  noatime,subvol=/a  0 0
${devs[0]}1  /boot  ext4  noatime  0 2
EOF


cat >/tmp/fai/disk_var.sh <<EOF
ROOT_PARTITION=\${ROOT_PARTITION:-/dev/mapper/crypt_dev_$crypt}
BOOT_PARTITION=\${BOOT_PARTITION:-${devs[0]}1}
BOOT_DEVICE=\${BOOT_DEVICE:-"${devs[0]}"}
SWAPLIST=\${SWAPLIST:-"${devs[@]/%/2}"}
EOF