#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  gc [TYPE]
		  gc -h
	EOF
}

help() {
	cat <<-'EOF'


		Options:
		  -h, --help    show this message

		  TYPE          what to do GC on (default: all):
		                - guix
		                - nix
		                - trash
		                - tmpdir
		                - docker
		                - vcs


		Free disk space system-wide.


		Examples:

		  Just run it, for all:

		    $ gc


		  Cleanup tmpdir:

		    $ gc tmpdir
	EOF
}

for flag in "$@"; do
	case "$flag" in
		--)
			break
			;;
		--help)
			usage
			help
			exit
			;;
		*)
			;;
	esac
done

while getopts 'h' flag; do
	case "$flag" in
		h)
			usage
			help
			exit
			;;
		*)
			usage >&2
			exit 2
			;;
	esac
done
shift $((OPTIND - 1))


disk() {
	df -h . |
		awk 'NR == 2 { printf "%s - %s/%s\n", $4, $3, $2 }'
}


gc_guix() {
	if [ ! -e /gnu/ ]; then
		return
	fi

	guix home delete-generations 1m
	guix gc -d 1m

	if [ -e /var/guix/profiles/system ]; then
		pass show "$(hostname)"/andreh | head -n1 | sudo -iS guix system delete-generations 1m
		pass show "$(hostname)"/andreh | head -n1 | sudo -iS guix gc -d 1m
	fi
}

gc_nix() {
	if [ ! -e /nix/ ]; then
		return
	fi

	PROFILES='
	/nix/var/nix/profiles/per-user/root/channels
	/nix/var/nix/profiles/system
	'

	for p in $PROFILES; do
		pass show "$(hostname)"/andreh | head -n1 |
			sudo -iS nix-env --delete-generations old -p "$p"
	done
	nix-env --delete-generations old
	nix-store --gc
	nix-collect-garbage -d
}

gc_trash() {
	yes | trash-empty
}

gc_tmpdir() {
	find "${TMPDIR:-/tmp}" -atime +10 -exec rm -vf "{}" \; ||:
}

gc_docker() {
	if ! command -v docker; then
		return
	fi

	yes | docker system prune -a
	docker rmi  "$(docker images -a -q)"              ||:
	docker rm   "$(docker ps -a -f status=exited -q)" ||:
	docker stop "$(docker ps -a -q)"                  ||:
	docker rm   "$(docker ps -a -q)"                  ||:
	yes | docker volume prune
	yes | docker container prune
}

gc_vcs() {
	repos -e ~/dev/go/ -e ~/dev/quicklisp/ -e ~/dev/archive/ ~/dev/ |
		xargs -I% -P4 x vcs -C% gc OR true
}


gc_all() {
	set -x
	gc_guix
	gc_nix
	gc_trash
	gc_tmpdir
	gc_docker
	gc_vcs
	set +x
}

TYPE="${1:-all}"
CMD=gc_"$TYPE"
if ! command -v "$CMD" >/dev/null; then
	printf 'Invalid TYPE: "%s".\n\n' "$TYPE" >&2
	usage >&2
	exit 2
fi


BEFORE="$(disk)"
"$CMD"
AFTER="$(disk)"

cat <<-EOF
	Disk space:
	  before: $BEFORE
	  after:  $AFTER
EOF