#!/bin/sh

## TODO: support for passing files as argument.

_printhelp()
{
    cat <<EOF
Usage: ${1##*/} [-m METHOD] [-v] FILES|FOLDERS

Create an archive from a single or multiples files/folders.

  -h:  Display this help.
  -m:  Choose compression method.
         * gz:  gzip (default).
         * xz:  LZMA.
  -v:  Exclude VCS data. (GNU tar only.)
EOF
}

OPTION_VCS=""
OPTION_METHOD=""
OPTIONS="--owner=root --group=root --numeric-owner"
while getopts ":hm:v" opt; do
    case $opt in
        h)
            _printhelp "$0"
            exit 1
            ;;
        m)
            OPTION_METHOD="${OPTARG}"
            ;;
        v)
            OPTION_VCS="--exclude-vcs"
            ;;
        ?)
            _printhelp "$0"
            exit 1
            ;;
        :)
            echo "Missing argument."
            _printhelp "$0"
            exit 1
            ;;
    esac
done

ARCEXT="tar.gz"
ARCOPT="z"
case $OPTION_METHOD in
    "gz")
        ARCEXT="tar.gz"
        ARCOPT="z"
        ;;
    "xz")
        ARCEXT="tar.xz"
        ARCOPT="J"
        ;;
esac

shift $(($OPTIND - 1))

case $# in
    1)
        FULLPATH="$(realpath "$1")"
        OUTPUT="${FULLPATH}-$(date +%F-%H%M%S).${ARCEXT}"

        (cd "${FULLPATH}/.." && \
            tar ${OPTION_VCS} ${OPTIONS} -${ARCOPT} -cf "$OUTPUT" "${FULLPATH##*/}" )
        ;;

    0)
        FULLPATH="$PWD"
        OUTPUT="${FULLPATH}-$(date +%F-%H%M%S).${ARCEXT}"
        (cd "${FULLPATH}/.." && \
            tar ${OPTION_VCS} ${OPTIONS} -${ARCOPT} -cf "$OUTPUT" "${FULLPATH##*/}" )
        ;;

    *)
        FULLPATH="$PWD"
        OUTPUT="${FULLPATH}/${FULLPATH##*/}-$(date +%F-%H%M%S).${ARCEXT}"

        tar ${OPTION_VCS} ${OPTIONS} -${ARCOPT} -cf "$OUTPUT" "$@"
        ;;
esac