#!/bin/bash

if [ "$1" == '-h' ] || [ "$1" == '--help' ]; then
    cat << EOF
Usage: $0 [Default-answer]
Delete all Docker ressources.
root permission not necessary so the binary can be placed in
$HOME/[.local/]bin.

| Ressource  | Answer | Description                |
| ---------- | ------ | -------------------------- |
| Containers | [Y]es  | Remove stopped containers  |
|            | [A]ll  | Remove all containers      |
|            | [N]o   | Skip                       |
|            |        |                            |
| Volumes    | [Y]es  | Remove unused volumes      |
|            | [A]ll  | Remove unused volumes      |
|            | [N]o   | Skip                       |
|            |        |                            |
| Images     | [Y]es  | Remove unused local images |
|            | [A]ll  | Remove all unused images   |
|            | [N]o   | Skip                       |
|            |        |                            |
| Networks   | [Y]es  | Remove unused networks     |
|            | [A]ll  | Remove unused networks     |
|            | [N]o   | Skip                       |
EOF
    exit
fi



PS="$(docker container ls -aq 2> /dev/null)"

if [ "$?" != 0 ] && [ "$EUID" != 0 ]; then
    sudo -- "$0" "$@"
    exit
fi

VOL="$(docker volume ls  -q 2> /dev/null)"
IMG="$(docker images     -q 2> /dev/null)"
NET="$(docker network ls -q 2> /dev/null)"

DEFAULT_NET="$(docker network ls -q -f name=bridge -f name=host -f name=none)"

ANS="$1"
[ -z "$1" ] && READ="read -r ANS"

if [ -n "$PS" ]; then
    docker container ls -a

    echo -n "Prune Containers? [Y/n/a] "
    $READ
    case "${ANS,,}" in
        'y'|'yes'|'')
            echo "$PS" | xargs docker rm 2> /dev/null
            ;;
        'a'|'all')
            echo "$PS" | xargs docker rm -f
            ;;
    esac
fi

if [ -n "$VOL" ]; then
    echo
    docker volume ls

    echo -n "Prune Volumes? [Ya/n] "
    $READ
    case "${ANS,,}" in
        'y'|'yes'|'a'|'all'|'')
            echo "$VOL" | xargs docker volume rm -f 2> /dev/null
            ;;
    esac
fi

if [ -n "$IMG" ]; then
    echo
    docker image ls

    echo -n "Prune Images? [Y/n/a] "
    $READ
    case "${ANS,,}" in
        'y'|'yes'|'')
            for img in $IMG; do
                if docker image inspect "$img" | grep '"RepoTags": \[]' &> /dev/null; then
                    TO_CLEAN="$TO_CLEAN $img"
                fi
            done
            echo "$TO_CLEAN" | xargs docker image rm -f 2> /dev/null
            ;;
        'a'|'all')
            echo "$IMG" | xargs docker image rm -f 2> /dev/null
            ;;
    esac
fi

if [ -n "$NET" ] && [ "$NET" != "$DEFAULT_NET" ]; then
    echo
    docker network ls

    echo -n "Prune Networks? [Ya/n] "
    $READ
    case "${ANS,,}" in
        'y'|'yes'|'a'|'all'|'')
            docker network prune -f
            ;;
    esac
fi