#!/bin/bash -e

# template for bash scripts

# internal use only
append_msg() {
    if test $# -ne 0; then
        echo -en ":\e[0m \e[1m$*"
    fi
    echo -e "\e[0m"
}

# write a notice
notice() {
    if test $# -eq 0; then
        return
    fi
    echo -e "\e[1m$*\e[0m" 1>&3
}

# write error message
error() {
    echo -en "\e[1;31merror" 1>&2
    append_msg $* 1>&2
}

# write a warning message
warning() {
    echo -en "\e[1;33mwarning" 1>&2
    append_msg $* 1>&2
}

# write a success message
success() {
    echo -en "\e[1;32msuccess" 1>&2
    append_msg $* 1>&2
}

# commandline parameter evaluation
filter="until=168h"
while test $# -gt 0; do
    case "$1" in
        (--help|-h) less <<EOF
SYNOPSIS

  $0 [OPTIONS]

OPTIONS

  --help, -h                 show this help
  --filter, -f <filter>      define filter (default: $filter)
  --install, -i              install to daily crontab

DESCRIPTION

Cleanup docker. Removes all docker container that are not running,
then removes all unused docker images.

EOF
                    exit;;
        (--filter|-f) shift; filter="$1";;
        (--install|-i) sudo cp $0 /etc/cron.daily/docker-prune; exit;;
        (*) error "unknow option $1, try $0 --help"; exit 1;;
    esac
    if test $# -eq 0; then
        error "missing parameter, try $0 --help"; exit 1
    fi
    shift;
done

# run a command, print the result and abort in case of error
# option: --no-check: ignore the result, continue in case of error
run() {
    check=1
    while test $# -gt 0; do
        case "$1" in
            (--no-check) check=0;;
            (*) break;;
        esac
        shift;
    done
    echo -en "\e[1m-> running:\e[0m $* ..."
    result=$($* 2>&1)
    res=$?
    if test $res -ne 0; then
        if test $check -eq 1; then
            error "failed with return code: $res"
            if test -n "$result"; then
                echo "$result"
            fi
            exit 1
        else
            warning "ignored return code: $res"
        fi
    else
        success
    fi
}

# error handler
function traperror() {
    set +x
    local err=($1) # error status
    local line="$2" # LINENO
    local linecallfunc="$3"
    local command="$4"
    local funcstack="$5"
    for e in ${err[@]}; do
        if test -n "$e" -a "$e" != "0"; then
            error "line $line - command '$command' exited with status: $e (${err[@]})"
            if [ "${funcstack}" != "main" -o "$linecallfunc" != "0" ]; then
                echo -n "   ... error at ${funcstack} "
                if [ "$linecallfunc" != "" ]; then
                    echo -n "called at line $linecallfunc"
                fi
                echo
            fi
            exit $e
        fi
    done
    success
    exit 0
}

# catch errors
trap 'traperror "$? ${PIPESTATUS[@]}" $LINENO $BASH_LINENO "$BASH_COMMAND" "${FUNCNAME[@]}" "${FUNCTION}"' ERR SIGINT INT TERM EXIT

##########################################################################################

if test -z "$filter"; then
    run docker container prune -f
    run docker volume prune -f
    run docker image prune -a -f
else
    run docker container prune -f --filter "$filter"
    run docker volume prune -f
    run docker image prune -a -f --filter "$filter"
fi