#!/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
		                - nohup
		                - trash
		                - tmpdir
		                - docker
		                - email
		                - 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() {
	pass show velhinho/0-andreh-password | head -n1 | sudo -iS guix system delete-generations
	pass show velhinho/0-andreh-password | head -n1 | sudo -iS guix gc --optimize -d
	guix home delete-generations
	guix gc --optimize -d
}

gc_nohup() {
	find ~/ -type f -name 'nohup.out' -exec rm -vf "{}" \;
}

gc_trash() {
	yes | trash-empty
}

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

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

gc_email() {
	notmuch search --output=files --exclude=false tag:killed |
		xargs -I{} rm -vf "{}"
}

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_nohup
	gc_trash
	gc_tmpdir
	gc_docker
	gc_email
	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)"

printf 'Disk space:\n'
printf '  before: %s\n' "$BEFORE"
printf '  after:  %s\n' "$AFTER"