#!/bin/sh
set -eu

usage() {
    echo "$0: BACKUP_SOURCE REGISTRY_DOMAIN"
}

if [ "${1:-}" = -h ] || [ "${1:-}" = --help ]
then
    usage
    exit 0
fi

if [ "$#" -ne 2 ]
then
    usage
    exit 1
fi

command -v skopeo >/dev/null || { echo 'skopeo is missing.' >&2; exit 2; }

src="$1"
registry="$2"

# There's an assumption here that filenames don't have spaces (or other such
# characters) as the image format prohibits that and I don't want to deal with
# such issues right now.

images="$(find "$src" -maxdepth 1 -mindepth 1 -type d -printf '%f\n')"
if [ -z "$images" ]
then
    echo 'No images found,' >&2
    exit 3
fi

returncode=0
for image in $images
do
    tags="$(find "$src/$image" -maxdepth 1 -mindepth 1 -type f -name '*.tar' -printf '%f\n' | sed 's/\.tar$//g')"
    if [ -z "$tags" ]
    then
        echo "No tags found for image $image, skipping." >&2
        continue
    fi
    for tag in $tags
    do
        echo "Restoring $image:$tag" >&2
        if skopeo copy "docker-archive://$src/$image/$tag.tar" "docker://$registry/$image:$tag"
        then
            echo "Restore finished successfully." >&2
        else
            echo "Restore failed, continuing with other image." >&2
            returncode=1
        fi
    done
done

if [ "$returncode" -gt 0 ]
then
    echo 'Restoration failed for some images.'
fi
exit "$returncode"