#!/bin/bash

make_tag () {

local tag

# generate a full image name with tag
# $1 name, $2 user(or repo), $3 repo  

[[ $# -lt 1 ]] && echo "image base name required" && exit 

declare OPTION; declare OPTARG; declare OPTIND
while getopts 'at:r:u:' OPTION; do
# echo processing: option:$OPTION argument:$OPTARG index:$OPTIND remaining:${@:$OPTIND}
case "$OPTION" in
r)  
    REPO=$OPTARG
    ;;
u)
    RUSER=$OPTARG
;;  
t)
    TAG=$OPTARG
    ;;    
a)  # add -arm64 to image
    arm=arm64
    ;;      
*)  echo unknown run option -$OPTARG
    echo "USAGE: tag <options>"
    echo "available options:  -a add -arm64 to tag, -d delete tag "
;;
esac
done

shift $((OPTIND - 1))

tag=$( echo $1 | cut -s -d ":" -f2)
tag=${tag:-$TAG}
name=${1%:*}
user=${2:-$RUSER}
repo=${3:-$REPO}  

tag=$([[ $repo ]] && echo ${repo}/)$([[ $user ]] && echo ${user}/)$name$([[ $arm ]] && echo -arm64):${tag:-latest}

echo $tag

}

# if script was executed then call the function
(return 0 2>/dev/null) || make_tag $@