#!/bin/bash (source)

# unionImplementation is defined in Scripts/Directories.conf

function Union_Backend() {
   local union=
   for union in "${unionImplementations[@]}"
   do
      case "$union" in
         "funionfs") GetSupportedFilesystems | grep -q "fuse" && funionfs -V &> /dev/null ;;
         "unionfs") GetSupportedFilesystems | grep -q "unionfs" ;;
         "unionfs-fuse") GetSupportedFilesystems | grep -q "fuse" && unionfs -V &> /dev/null ;;
      esac
      [ $? = 0 ] && echo "$union" && break
   done
}

function Union_Is_Supported() {
   local union=`Union_Backend`
   [ "$union" ] && return 0 || return 1
}

function Union_Mount() {
   local union="$1"
   case "$union" in
      "funionfs") $sudo_exec funionfs -o dirs="$2" -o nonempty none "$3" ;;
      "unionfs")  $sudo_exec mount -t unionfs -o dirs="$2" none "$3" ;;
      "unionfs-fuse") $sudo_exec unionfs -o cow -o nonempty "$2" "$3";;
   esac
}

function Union_Add() {
   local union="$1"
   case "$union" in
      "funionfs") false ;;
      "unionfs") $sudo_exec mount -t unionfs -o remount,add=:"$2" none "$3" ;;
      "unionfs-fuse") false ;;
   esac
}

function Union_Umount() {
   local mp=
   local union="$1"
   shift
   case "$union" in
      "funionfs") for mp in $@; do $sudo_exec fusermount -u "$mp"; done ;;
      "unionfs")  for mp in $@; do $sudo_exec umount "$mp"; done ;;
      "unionfs-fuse") for mp in $@; do $sudo_exec fusermount -u "$mp"; done ;;
   esac
}