#!/usr/bin/env bash

set -u

usage() {
cat <<EOF
Usage: sync-tree [-h] [-c] [-x] SOURCE/ DEST/
  Make the DEST tree match SOURCE as closely as possible
OPTIONS:
  -h
    Display help
EOF
}

while getopts "h" OPTION
do
    case "$OPTION" in
        h) usage; exit 0;;
        ?) usage 1>&2; exit 1;;
    esac
done

shift $(($OPTIND - 1)) || exit $?

if ! test $# -eq 2
then
    usage 1>&2
    exit 1
fi

src="$1"
dest="$2"

rsync_opts="-aH --delete"

rsync_version=$(rsync --version)
if [[ ! "$rsync_version" =~ "ACLs" ]] || [[ "$rsync_version" =~ "no ACLs" ]]; then
    echo "Not syncing ACLs (not supported by available rsync)" 1>&2
else
    case $OSTYPE in
        cygwin|darwin|netbsd)
            echo "Not syncing ACLs (not yet supported on $OSTYPE)" 1>&2
            ;;
        *)
            rsync_opts="$rsync_opts -A"
            ;;
    esac
fi

xattrs_available=''
if [[ ! "$rsync_version" =~ "xattrs" ]] || [[ "$rsync_version" =~ "no xattrs" ]]; then
    echo "Not syncing xattrs (not supported by available rsync)" 1>&2
else
    xattrs_available=yes
fi


# rsync may fail if -X is specified and the filesystems don't support
# xattrs.

if test "$xattrs_available"; then
    rsync $rsync_opts -X "$src" "$dest"
    if test $? -ne 0; then
        # Try again without -X
        exec rsync $rsync_opts "$src" "$dest"
    fi
else
    exec rsync $rsync_opts "$src" "$dest"
fi