#!/bin/bash

# starts a trail container with passed image with a bash prompt
# $1 image name, $2 user 
# user can be also prepended by using u option
# added tag is "latest" by default, use t option for alternate tag
# if p flag is used script will scrub any local image and attempt to download a deployed to docker image

try_container () {

    declare -A arch=( ["x86_64"]="" ["aarch64"]="-arm64")
    local mp;local cuser; local hmp; local bind; local vname; local prod; local priv
    local dkpath; local hostmp; local evar; local hostmap

    [[ $# -lt 1 ]] && echo "image name required to try" && return 1

    declare OPTION; declare OPTARG; declare OPTIND
    OPTIND=0
    while getopts 'pr:t:u:m:h:be:s' OPTION; do
    # echo processing: option:$OPTION argument:$OPTARG index:$OPTIND remaining:${@:$OPTIND}
    case "$OPTION" in
    u)
     cuser=$OPTARG
    ;;  
    b)
     bind=true
    ;; 
    s)
     save=true
    ;; 
    m)
     mp=$OPTARG
    ;; 
    h)
     hmp=$OPTARG
    ;; 
    e)
      evar="-e $OPTARG"
    ;;  
    t)
      TAG=$OPTARG
    ;;  
    p)
      priv=--privileged
    ;;           
    r)
        prod=$OPTARG
        ;;   
    *)  echo unknown run option -$OPTARG
        echo "USAGE: try <options>"
        echo "available options: -t <latest> custom tag "
    ;;
    esac
    done

    shift $((OPTIND - 1))

    [[ ! $1 ]] && echo must supply an image to try && return 1

    # user=${2:-$ruser}
    image=$1
    shift 1

    if [[ $prod ]]; then 
        echo removing any local copy of image $image
        docker image rm $image
        host=prod
      else 
        host=local
        # TODO change this
        image=${image/:/${arch[$(uname -p)]}:}
    fi

    name=${image//\//-}
    image=$image:${TAG:-latest}
    
    docker rm try-$name > /dev/null 2>&1
    if [[ $mp ]]; then 
        if [[ $bind ]];then
            dir=$(realpath "${hmp:-${PWD}/mnt/$mp}")
            vname="try-$name${dir//\//-}"
            mkdir -p $dir
            # echo bind $dir to volume $vname
            docker volume create --driver local \
            --opt type=none \
            --opt device=$dir \
            --opt o=bind "$vname" > /dev/null
          else 
            vname="try-$name-${mp//\//-}"
            hostmap="-e HOST_MAP=$(id -u):$(id -g)"
            dkpath=$(docker info | grep -i "Docker Root Dir" | cut -d':' -f2)/volumes/$vname/_data
            hostmp=${hmp:-${PWD}/mnt/$mp}
            echo via volume $vname
            echo linking $dkpath to $hostmp
            ln -s $dkpath -T $hostmp 
        fi  
    fi

    echo starting container with image: $image, and name $name
    echo at container prompt type \'exit\' to exit from shell and remove trial container

    docker run -i -t --rm $priv $evar $hostmap --entrypoint /opt/scripts/entrypoint.sh \
        $([[ $cuser ]] && echo "--user $cuser") \
        --name try-$name --hostname try-$host-$name \
        $([[ $mp ]] && echo "-v $vname:/$mp") \
        "$image" \
        "$@"
    echo "done with session, removing containter try-$name"
    if [[ $mp ]]; then
        if [[ ! $save ]]; then
            echo removing volume $vname used for mapping  
            docker volume rm $vname > /dev/null
            [[ ! $bind ]] && [[ -h $hostmp ]] && echo "removing link at $hostmp" && rm $hostmp
       fi
    fi
    
    }

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