#! /usr/bin/env dash
# shellcheck disable=SC2086
# shellcheck source=/dev/null
. %SHELL_LIBRARY_PATH
bsc() {
    msg2 "$(btrfs subvolume create "$1" || die "Creating of subvol $1 failed")";
}

mne() {
    mount --mkdir --options compress-force=zstd:15,subvol="$1" $DISK_ROOT "$2" || die "Mounting of $1 failed";
}


available_disks="$(mktmp)";
lsblk -J | jq '.[] | map(.name) | [foreach .[] as $item ({item: null, index: -1}; {$item, index: (.index + 1)})]' > $available_disks;


[ "$(jq '.[]' "$available_disks" | wc -l)" -eq 0 ] && die "No disks found"
msg "Select a disk to format:\n"

i=9999; # nobody will have so many disks attached

while ! jq -e --argjson i "$i" '.[$i]' "$available_disks" > /dev/null 2>&1; do
    for disk in $(jq -c '.[]' "$available_disks" ); do
        printf "%4s) %s \n" "$(echo "$disk" | jq '.index')" "$(echo "$disk" | jq '.item' | tr -d "\"")";
    done
    printf "%4s) Exit\n" "q"
    readp  "Enter a option: " disk

    if [ $disk = "q" ];then
        exit 1
    else
        i="$disk"
    fi
    if jq -e --argjson i "$i" 'nth($i)' "$available_disks"  > /dev/null 2>&1; then
        disk=$(mktmp);
        jq -e --argjson i "$i" 'nth($i)' "$available_disks" > "$disk";
    else
        warning "No disk selected. Select a disk to continue.\n"
    fi
done

readp "Do you really want to delete all data on disk $(jq '.item' "$disk")? [N/y]: " result
case $result in
    [Yy])
        msg "Great, deleting everything..."
        disk="$(jq '.item' "$disk" | tr -d "\"")"
        ;;
    *)
        msg "Sure, keep your data"
        exit 1
        ;;
esac

sgdisk -Z "/dev/${disk}" > /dev/null|| die "Zapping failed"

sgdisk -n 1:0:+550M -n 2:0:"$ENDSECTOR" -t 1:ef00 -t 2:8300 "/dev/${disk}" > /dev/null|| die "Partitioning failed"

case "$disk" in
    "nvme"*)
        export DISK_EFI="/dev/${disk}"p1
        export DISK_ROOT="/dev/${disk}"p2
        ;;
    "sd"* |"vd"*)
        export DISK_EFI="/dev/${disk}"1
        export DISK_ROOT="/dev/${disk}"2
        ;;
    *)
        die "The disk type: ${disk} is not yet supported!"
        ;;
esac

msg "Started Formatting..."
mkfs.fat -F32 "$DISK_EFI" > /dev/null || die "Formatting(fat32) failed"
mkfs.btrfs -f "$DISK_ROOT" > /dev/null || die "Formatting(btrfs) failed"


msg "Mounting..."
mount -t btrfs $DISK_ROOT /mnt
cd /mnt || die "(Bug): no /mnt"
bsc nix-store
bsc persistent-storage
bsc persistent-storage/nixos-config
bsc persistent-storage/.snapshots
bsc swap
cd /
umount -R /mnt
mount -t tmpfs none /mnt
mount --mkdir "$DISK_EFI" /mnt/boot

mne nix-store /mnt/nix
mne persistent-storage /mnt/srv
mne swap /mnt/swap

mount --mkdir --options bind /mnt/srv/nixos-config /mnt/etc/nixos

msg "Finished mounting and generating btrfs subvolumes"

msg "Creating swapfile..."
msg2 "$(btrfs filesystem mkswapfile --size "$(free -m | awk '{if (NR==2) {printf "%sm\n", $2 + 500}}')" /mnt/swap/swapfile)";
msg "Finished creating swapfile!"
msg "Important information:"
msg2 "Swapfile UUID is: $(findmnt -no UUID -T /mnt/swap/swapfile)";
msg2 "Swapfile resume offset is: $(btrfs inspect-internal map-swapfile -r /mnt/swap/swapfile)";
msg2 "Root-disk UUID is: $(lsblk -no UUID -T $DISK_ROOT)";
msg2 "EFI-disk UUID is: $(lsblk -no UUID -T $DISK_EFI)";
warning "This information needs to be entered in the host configuration BEFORE rebuilding it. Otherwise the system won't boot!"

msg "Checking for incompatibilities..."
ssd_or_hdd=$(cat /sys/block/$disk/queue/rotational);
case "$ssd_or_hdd" in
    0)
        msg2 "You seem to use a ssd."
        trim_support=$(lsblk --bytes --json --discard | jq --arg name "$disk" '.blockdevices | .[] | select(.name == $name) | (.["disc-gran"] + .["disc-max"]) != 0');
        case $trim_support in
            "true")
                msg2 "Yay, your ssd supports trim, go on and activate it";
                ;;
            "false")
                msg2 "Nay, your ssd doesn't support trim, go on";
                ;;
           *)
                warning "Your ssd doesn't seem to exists, if this bothers you please open an issue.'";
                ;;
        esac
        ;;
    1)
        msg2 "You seem to use a hdd there is nothing you have to do";
        ;;
    *)
        warning "There is no indicator, which shows, which drive your are using.\n This means, that you have to check yourself, which optimizations you should activate."
        ;;
esac


readp "Do you want to continue with nixos-install? [N/y]: " result
case $result in
    [Yy])
        nix run "git+https://git.sils.li/ene/nixos-config#setup" --experimental-features 'nix-command flakes';
        ;;
    *)
        msg "Sure, do it yourself"
        exit 1
        ;;
esac