mermet_mnt         := mermet
mermet_rpool       := rpool
mermet_bpool       := bpool
mermet_disk        := $(shell sed -ne 's/^device: \(.*\)/\1/p' bootstrap/$(mermet_mnt)/etc/sfdisk.txt)
mermet_cipher :=
#mermet_cipher      := aes-128-gcm
mermet_autotrim    :=
mermet_reservation := 40G

mermet-wipeout: mermet-umount
	sudo zpool labelclear -f $(mermet_disk)-part3 || true
	sudo zpool labelclear -f $(mermet_disk)-part5 || true
	sudo $$(which sgdisk) --zap-all $(mermet_disk)

mermet-partition:
	sudo modprobe zfs
	sudo $$(which sfdisk) $(mermet_disk) <bootstrap/$(mermet_mnt)/etc/sfdisk.txt
	sudo $$(which sgdisk) --randomize-guids $(mermet_disk)
	sudo partprobe

mermet-format:
	# DOC: https://github.com/zfsonlinux/zfs/wiki/Debian-Buster-Root-on-ZFS
	sudo mkdir -p /mnt/$(mermet_mnt)
	blkid -t TYPE=ext2 $(mermet_disk)-part3; test $$? != 2 || \
	mkfs.ext2 $(mermet_disk)-part3
	# bpool
	## NOTE: enable only ZFS features supported by GRUB
	#sudo zpool list $(mermet_bpool) 2>/dev/null || \
	#sudo zpool create -o ashift=12 -d \
	# -o feature@allocation_classes=enabled \
	# -o feature@async_destroy=enabled \
	# -o feature@bookmarks=enabled \
	# -o feature@embedded_data=enabled \
	# -o feature@empty_bpobj=enabled \
	# -o feature@enabled_txg=enabled \
	# -o feature@extensible_dataset=enabled \
	# -o feature@filesystem_limits=enabled \
	# -o feature@hole_birth=enabled \
	# -o feature@large_blocks=enabled \
	# -o feature@lz4_compress=enabled \
	# -o feature@project_quota=enabled \
	# -o feature@resilver_defer=enabled \
	# -o feature@spacemap_histogram=enabled \
	# -o feature@spacemap_v2=enabled \
	# -o feature@userobj_accounting=enabled \
	# -o feature@zpool_checkpoint=enabled \
	# -o feature@multi_vdev_crash_dump=disabled \
	# -o feature@large_dnode=disabled \
	# -o feature@sha512=disabled \
	# -o feature@skein=disabled \
	# -o feature@edonr=disabled \
	# -O normalization=formD \
	# -R /mnt/$(mermet_mnt) $(mermet_bpool) $(mermet_disk)-part3
	#sudo zfs set \
	# acltype=posixacl \
	# canmount=off \
	# compression=lz4 \
	# devices=off \
	# relatime=on \
	# xattr=sa \
	# mountpoint=/ \
	# $(mermet_bpool)
	
	# swap
	# FIXME: configure with a volatile key in configuration.nix
	#blkid -t TYPE=crypto_LUKS $(mermet_disk)-part4; test $$? != 2 || \
	#sudo cryptsetup luksFormat --cipher aes-xts-plain64 --key-size 256 --hash sha256 $(mermet_disk)-part4
	#sudo cryptsetup luksOpen $(mermet_disk)-part4 mermet-swap
	#blkid -t TYPE=swap /dev/mapper/mermet--swap; test $$? != 2 || \
	#sudo mkswap --check --label swap
	#sudo cryptsetup luksClose $(mermet_disk)-part4 mermet-swap
	# rpool
	sudo zpool list $(mermet_rpool) 2>/dev/null || \
	sudo zpool create -o ashift=12 \
	 $(if $(mermet_cipher),-O encryption=$(mermet_cipher) \
	 -O keyformat=passphrase \
	 -O keylocation=prompt) \
	 -O normalization=formD \
	 -R /mnt/$(mermet_mnt) $(mermet_rpool) $(mermet_disk)-part5
	sudo zfs set \
	 acltype=posixacl \
	 atime=off \
	 $(if $(mermet_autotrim),autotrim=on) \
	 canmount=off \
	 compression=lz4 \
	 dnodesize=auto \
	 relatime=on \
	 $(if $(mermet_reservation),reservation=$(mermet_reservation)) \
	 xattr=sa \
	 mountpoint=/ \
	 $(mermet_rpool)
	# /
	# NOTE: mountpoint=legacy is required to let NixOS mount the ZFS filesystems.
	sudo zfs list $(mermet_rpool)/root 2>/dev/null || \
	sudo zfs create \
	 -o canmount=on \
	 -o mountpoint=legacy \
	 $(mermet_rpool)/root
	# /boot
	#sudo zfs list $(mermet_bpool)/boot 2>/dev/null || \
	#sudo zfs create \
	# -o canmount=on \
	# -o mountpoint=legacy \
	# $(mermet_bpool)/boot
	# /boot/efi
	sudo blkid $(mermet_disk)-part2 -t TYPE=vfat || \
	sudo mkfs.vfat -F 32 -s 1 -n EFI $(mermet_disk)-part2
	# /*
	for p in \
	 home \
	 nix \
	 nix/var \
	 var \
	 var/cache \
	 var/log \
	 var/mail \
	 var/tmp \
	 var/www \
	 ; do \
		sudo zfs list $(mermet_rpool)/"$$p" 2>/dev/null || \
		sudo zfs create \
		 -o canmount=on \
		 -o mountpoint=legacy \
		 $(mermet_rpool)/"$$p" ; \
	 done
	sudo zfs set \
	 com.sun:auto-snapshot=false \
	 $(mermet_rpool)/nix
	sudo zfs set \
	 sync=always \
	 $(mermet_rpool)/nix/var
	sudo zfs set \
	 com.sun:auto-snapshot=false \
	 $(mermet_rpool)/var/cache
	sudo zfs set \
	 com.sun:auto-snapshot=false \
	 sync=disabled \
	 $(mermet_rpool)/var/tmp

mermet-mount:
	# scan needed zpools
	#sudo zpool list $(mermet_bpool) || \
	#sudo zpool import -f $(mermet_bpool)
	sudo zpool list $(mermet_rpool) || \
	sudo zpool import -f $(mermet_rpool)
	# load encryption key
	zfs get -H encryption $(mermet_rpool) | \
	grep -q '^$(mermet_rpool)\s*encryption\s*off' || \
	zfs get -H keystatus $(mermet_rpool) | \
	grep -q '^$(mermet_rpool)\s*keystatus\s*available' || \
	sudo zfs load-key $(mermet_rpool)
	# /
	sudo mkdir -p /mnt/$(mermet_mnt)
	sudo mountpoint /mnt/$(mermet_mnt) || \
	sudo mount -v -t zfs $(mermet_rpool)/root /mnt/$(mermet_mnt)
	# /boot
	sudo mkdir -p /mnt/$(mermet_mnt)/boot
	sudo mountpoint /mnt/$(mermet_mnt)/boot || \
	sudo mount -v $(mermet_disk)-part3 /mnt/$(mermet_mnt)/boot
	#sudo mount -v -t zfs $(mermet_bpool)/boot /mnt/$(mermet_mnt)/boot
	# /boot/efi
	sudo mkdir -p /mnt/$(mermet_mnt)/boot/efi
	sudo mountpoint /mnt/$(mermet_mnt)/boot/efi || \
	sudo mount -v $(mermet_disk)-part2 /mnt/$(mermet_mnt)/boot/efi
	# /*
	for p in \
	 home \
	 nix \
	 nix/var \
	 var \
	 var/cache \
	 var/log \
	 var/mail \
	 var/tmp \
	 var/www \
	 ; do \
		sudo mkdir -p /mnt/$(mermet_mnt)/"$$p"; \
		sudo mountpoint /mnt/$(mermet_mnt)/"$$p" || \
		sudo mount -v -t zfs $(mermet_rpool)/"$$p" /mnt/$(mermet_mnt)/"$$p" ; \
	 done
	sudo chmod 1777 /mnt/$(mermet_mnt)/var/tmp

mermet-bootstrap: mermet-mount
	sudo mkdir -p bootstrap/$(mermet_mnt)/etc/nixos
	sudo rm -rf "/mnt/$(mermet_mnt)/etc/nixos"
	sudo mkdir -p /mnt/$(mermet_mnt)/etc
	sudo install -D -o root -g root -m 600 \
	 bootstrap/$(mermet_mnt)/etc/dropbear/host-ecdsa-key \
	 /mnt/$(mermet_mnt)/etc/dropbear/host-ecdsa-key
	sudo cp -vr \
	 bootstrap/$(mermet_mnt)/etc/nixos \
	 /mnt/$(mermet_mnt)/etc/
	#test "$$(sudo grub-probe /mnt/$(mermet_mnt)/boot)" = zfs
	# NOTE: nixos-install will install GRUB following configuration.nix
	# BIOS
	#sudo grub-install $(mermet_disk)
	# UEFI
	#sudo grub-install \
	# --target=x86_64-efi \
	# --efi-directory=/mnt/$(mermet_mnt)/boot/efi \
	# --bootloader-id=nixos \
	# --recheck \
	# --no-floppy
	sudo NIX_PATH="$$NIX_PATH" PATH="$$PATH" $$(which nixos-install) \
	 --root /mnt/$(mermet_mnt) \
	 --no-root-passwd

mermet-umount:
	for p in \
	 boot/efi \
	 boot \
	 home \
	 nix/var \
	 nix \
	 var/cache \
	 var/log \
	 var/mail \
	 var/tmp \
	 var/www \
	 var \
	 "" \
	 ; do \
		! sudo mountpoint /mnt/$(mermet_mnt)/"$$p" || \
		sudo umount -v /mnt/$(mermet_mnt)/"$$p" ; \
	 done
	! sudo zpool list $(mermet_rpool) 2>/dev/null || \
	zfs get -H encryption $(mermet_rpool) | \
	grep -q '^$(mermet_rpool)\s*encryption\s*off' || \
	zfs get -H keystatus $(mermet_rpool) | \
	grep -q '^$(mermet_rpool)\s*keystatus\s*unavailable' || \
	sudo zfs unload-key $(mermet_rpool)
	#! sudo zpool list $(mermet_bpool) 2>/dev/null || \
	#sudo zpool export $(mermet_bpool)
	! sudo zpool list $(mermet_rpool) 2>/dev/null || \
	sudo zpool export $(mermet_rpool)