#!/bin/sh
# vim: set ts=2 sw=2 et:
set -u


################################################################################
##
## Variables initializations
##

set |grep -q '^XDG_CONFIG_HOME' || XDG_CONFIG_HOME="$HOME/.config"
SSHFS_DIR="$XDG_CONFIG_HOME/sshfs-mapper"
SSHFS_CONFIG="$SSHFS_DIR/config"
SSHFS_MOUNT=1
SSHFS_HOSTS_SELECTION=0


################################################################################
##
## Functions definitions
##

read_conf() {
	local config=$1
	local var=$2
	local value="`eval echo \`cat $config |grep "^$2=" |sed "s/$2=//"\``"
	echo "$value"
}

do_mount() {
  local remotedir=$1
  local localdir=$2
  local remoteport=$3

  sshfs \
    -o allow_root \
    -o idmap=user \
    -o uid=`id -u` \
    -o gid=`id -g` \
    -o reconnect \
    -o workaround=all \
    -o cache_timeout=240 \
    -o Ciphers=arcfour \
    -o Port=$remoteport \
    $remotedir \
    $localdir

  #-o compression=yes
}

do_umount() {
  local remotedir=$1
  local localdir=$2
  fusermount -u $localdir
}

do_usage() {
  cat >&2 <<EOF
Usage: `basename $0` [options]
-h	Show this help and exit.
-i	Initialize user configuration.
-u	Umount user maps.
EOF
exit 1
}

do_initialize()
{
  echo "Initializing user maps..."
  if [ -d "$SSHFS_DIR" ]; then
    echo -e "\nERROR: Configuration directory already exists!" >&2 
    echo "To erase your setup, please manually remove directory \"$SSHFS_DIR\" first." >&2
    exit 1
  else
    mkdir -p "$SSHFS_DIR" 
    cat > "$SSHFS_DIR/config" <<EOF
MOUNTPOINT=\$HOME/mnt
LINKTO=\$HOME
EOF

    cat > "$SSHFS_DIR/default.map" <<EOF
REMOTE_USER=\$USER
REMOTE_HOST=example.com
REMOTE_PORT=22

MAP=RemoteDocs /home/\$USER/Documents
MAP=RemoteMusic /home/\$USER/Music
EOF
    echo -e "\nManually edit configuration files in \"$SSHFS_DIR\""
    echo "to adjust sshfs-mapper configuration to your settings."
    echo -e "\nType \"man sshfs-mapper\" to get more help."

    exit 0
  fi
}


################################################################################
##
## Parse options and mount/umount
##

#TODO:while getopts h:u o
while getopts hiu o
do
  case "$o" in
    i)  # init (copy config files in user HOME)
        do_initialize
        ;;
    u)  # umount
        echo "Umounting..."
        SSHFS_MOUNT=0
        ;;
#    s)  # only selected hosts
#        #SSHFS_HOST_SELECTION=1
#        SSHFS_HOST_PATTERN="$OPTARG"
#        ;;
    h)
    	do_usage
	;;
    [?]) 
      do_usage
        ;;
  esac
done

[ ! -d $SSHFS_DIR ] && mkdir $SSHFS_DIR
[ ! -d $SSHFS_DIR ] && {
	echo -e "\nERROR: Unable to create $SSHFS_DIR" >&2
	exit 1
}

[ ! -f "$SSHFS_CONFIG" ] && {
	echo "MOUNTPOINT=\$HOME/mnt" >> "$SSHFS_CONFIG"
}
[ ! -f "$SSHFS_CONFIG" ] && {
	echo -e "\nERROR: Unable to find config file." >&2
	exit 1
}

mountpoint=$( read_conf "$SSHFS_CONFIG" MOUNTPOINT )
[ "x$mountpoint" = "x" ] && {
	echo -e "\nERROR: Mountpoint undefined." >&2
  echo "Edit mountpoint definition in \"$SSHFS_CONFIG\"" >&2
	exit 1;
}
echo "MOUNTPOINT=$mountpoint"

for map_file in `find "$SSHFS_DIR" -type f -name '*.map' `; do
	remote_host=$( read_conf $map_file REMOTE_HOST )
	remote_user=$( read_conf $map_file REMOTE_USER )
	remote_port=$( read_conf $map_file REMOTE_PORT )
	map=$( read_conf $map_file MAP )
	echo "Map: $remote_user@$remote_host"

  nc -z $remote_host $remote_port > /dev/null 2>&1
  if [ $? != 0 ]; then
    echo "  ERROR: can't find the server at $remote_host:$remote_port"
    continue
  fi

  map_count=0
  map_name=""
  remote_dir=""
  for map_item in $map; do
    [ $map_count = 0 ] && map_name=$map_item
    [ $map_count = 1 ] && remote_dir=$map_item
    map_count=$(( ( $map_count + 1 ) % 2 ))
    [ $map_count = 0 ] && {
      echo "  $map_name => $remote_dir"
      if ! mount | grep -q " $mountpoint/$map_name " ; then
        [ $SSHFS_MOUNT = 1 ] && {
          mkdir -p $mountpoint/$map_name
          do_mount $remote_user@$remote_host:$remote_dir $mountpoint/$map_name $remote_port
          rm -f $HOME/$map_name
          ln -s $mountpoint/$map_name $HOME/$map_name
        }
      else
        [ $SSHFS_MOUNT = 0 ] && {
          do_umount $remote_user@$remote_host:$remote_dir $mountpoint/$map_name
          rm -f $HOME/$map_name
        }
        [ $SSHFS_MOUNT = 1 ] && echo "    (Already mounted on $mountpoint/$map_name)"
      fi 
    }
	done
done