#!/bin/bash

#TODO: group flags into one command
# like -I == $i -a

function usage() {
    cat << EOF
Usage: $0 -hcCviIna
Options:
    -h  Show this help and exits
    -c  Remove stopped containers
    -C  Remove all containers
    -v  Remove unused volumes
    -i  Remove unused images
    -I  Remove all images
    -n  Remove unused networks
    -a  All of the above, equivalent of -CvIn
EOF
    exit 0
}

function add_opt() {
    local RESULT

    RESULT="$(unset "1")"
    for o in "$@"; do
        if [ "$((RESULT & o))" == 0 ]; then
            RESULT="$((RESULT + o))"
        fi
    done
    echo "$RESULT"
}

if ! [ -w "/var/run/docker.sock" ] && [ "$EUID" != 0 ]; then
    exec sudo -- "$0" "$@"
fi

c=1
C=2
v=4
i=8
I=16
n=32
a="$((c + C + v + I + n))"

CLEAN=0
while getopts hcCviIna o; do
    case "$o" in
        h)
            usage
            ;;
        c)
            CLEAN="$(add_opt "$CLEAN" "$c")"
            ;;
        C)
            CLEAN="$(add_opt "$CLEAN" "$c" "$C")"
            ;;
        v)
            CLEAN="$(add_opt "$CLEAN" "$v")"
            ;;
        i)
            CLEAN="$(add_opt "$CLEAN" "$i")"
            ;;
        I)
            CLEAN="$(add_opt "$CLEAN" "$I")"
            ;;
        n)
            CLEAN="$(add_opt "$CLEAN" "$n")"
            ;;
        a)
            CLEAN="$(add_opt "$CLEAN" "$c" "$C" "$v" "$I" "$n")"
            ;;
        *)
            exit 1
            ;;
    esac
done


VALUES=(
    "$a"
    "$((c + i + n))"
    "$((c + I + n))"
    "$((c + v + n))"
    "$c"
    "$v"
    "$i"
    "$I"
    "$n"
)

SYS="docker system"
CON="docker container"
VOL="docker volume"
IMG="docker image"
NET="docker network"
PRUNE="prune -f"
COMMANDS=(
    "$SYS $PRUNE -a --volumes"
    "$SYS $PRUNE"
    "$SYS $PRUNE -a"
    "$SYS $PRUNE --volumes"
    "$CON $PRUNE"
    "$VOL $PRUNE"
    "$IMG $PRUNE"
    "$IMG $PRUNE -a"
    "$NET $PRUNE"
)

if [ "$((CLEAN & "$C"))" == "$C" ]; then
    $CON ls -aq | xargs $CON stop
fi


for idx in "${!VALUES[@]}"; do
    mask="${VALUES[$idx]}"
    if [ "$((CLEAN & mask))" == "$mask" ]; then
        bash -c "${COMMANDS[$idx]}"
        CLEAN="$((CLEAN - mask))"
    fi
done