#!/usr/bin/env nix
#!nix shell nixpkgs#rsync nixpkgs#zsh --command zsh

setopt ERR_EXIT PIPE_FAIL

# load module to parse command line arguments
zmodload zsh/zutil

# parse any possible additional drive declarations
zparseopts -D -E -A opts -- h x

# enable XTRACE shell option for full debugging output of scripts
if (( ${+opts[-x]} )); then
	set -x
fi

DIR="${0:h}"
FLAKE="https://arrakis.bitgnome.net/nipsy/git/nix/"
HOSTNAME="${1}"
TARGET="${2}"

if [[ -z "${TARGET}" ]] || (( ${+opts[-h]} )); then
	<<EOF >&2
usage: ${0:t} [ -h ] [ -x ] hostname target

	-h		this message
	-x		enable shell debug
	hostname	hostname of nixosConfigurations defined host in our flake
	target		PXE booted, SSH root accessible, installation target
EOF
	exit 1
fi

<<EOF

++++++++	The disk(s) on ${TARGET} are about to get wiped!
WARNING!	NixOS will be re-installed as ${HOSTNAME}.
++++++++	This is a destructive operation!!!

EOF

read -q '?Are you sure? [y/N] '
echo

if [[ "${REPLY}" == "y" ]]; then

	ssh root@${TARGET} rm -rf /etc/nixos
	ssh root@${TARGET} git clone ${FLAKE} /etc/nixos

	ssh root@${TARGET} nix run github:nix-community/disko -- \
		--mode destroy,format,mount \
		--yes-wipe-all-disks \
		/etc/nixos/hosts/${HOSTNAME}/disks.nix

	ssh root@${TARGET} nixos-install --flake /etc/nixos#${HOSTNAME}

	if [[ "${?}" -eq 0 ]]; then
		echo 'Unmounting file systems...' >&2
		ssh root@${TARGET} mount | grep -v zfs | awk '$3 ~ /^\/mnt\// {print $3}' | xargs -i{} ssh root@${TARGET} umount -lf {}
		echo 'Unmounting ZFS file systems...' >&2
		while ! ssh root@${TARGET} umount -t zfs -a; do echo 'attempting to umount all ZFS file systems' >&2; sleep 1; done
		echo 'Exporting zpool...' >&2
		while ! ssh root@${TARGET} zpool export -a; do echo 'attempting to export all zpools' >&2; sleep 1; done
		echo 'Rebooting!' >&2
		ssh root@${TARGET} reboot
	fi
fi