#!/bin/bash
# depends on sshfs  fuse for ssh
module_load filesystem # mounted
module_load net-utils  # host_reachable
module_load ssh

function smount() {

  local HOST
  local PORT
  local CONFIG=$SSH_CONFIG
  local PORT=22

  declare SSHOPTS
  declare OPTION
  declare OPTARG
  declare OPTIND
  declare MNTUSER
  while getopts 'u:np:o:F:' OPTION; do
    # echo $OPTION $OPTARG
    case "$OPTION" in
    p)
      PORT=$OPTARG
      # echo option d: $DIRS
      ;;
    u)
      MNTUSER=$OPTARG
      ;;  
    n)
      MNTUSER=_NONE_
    ;; 
    o)
      echo "adding sshfs option: $OPTARG"
      SSHOPTS="$SSHOPTS -o $OPTARG"
      ;;    
    F)
      echo "using SSH Config file at: $OPTARG"
      CONFIG=$OPTARG
      ;;

    *)
      echo unknown option $OPTION
      ;;  
    esac
  done

  shift $((OPTIND - 1))

  # first item is nowsource, second is local mount point, third is possbile local user 
  HOST=$(sed 's/.*@\(.*\):.*/\1/' <<<"$1")

  [[ ! $(host_reachable $HOST $PORT) ]] && echo host $HOST not reachable, aborting mount && return 1
  if [[ $(mounted $2) ]]; then
    echo "aborting mount: $1 already mounted at $2"
  else
    mkdir -p $2
    # can add any options after mount point directory like -o default_permissions
    config=$([[ -f $CONFIG ]] && echo "-F $CONFIG")
    if [[ ! $MNTUSER == "_NONE_" ]]; then
    MNTUSER=${MNTUSER:-$USER}
    id=$(id -u ${MNTUSER})
    if [[ $id ]]; then
          SSHOPTS="$SSHOPTS -o uid=$id -o allow_other"
        else
        echo no user ${MNTUSER} on this machine, aborting mount
        return 1
       fi   
     else 
     MNTUSER=""  
     fi    
    args="-p $PORT $SSHOPTS $config $1 $2"
    echo SSHFS $([[ $MNTUSER ]] && echo mounted as user ${MNTUSER}): $args
    sshfs $args
  fi
}

function usmount() {
  if [[ $(mounted $1) ]]; then
    echo "unmounting remote file system at $1"
    fusermount -u $1
  else
    echo "nothing mounted at $1, aborting unmount"
  fi
}

function mntBackup() {
  smount root@$1:/backup /backup/remote -p 22 -o allow_other
}

function umntBackup() {
  usmount /backup/remote
}