#!/bin/bash


if ! which fusermount &> /dev/null; then
 echo unabled to load bindfs module because bindfs is not installed
 exit 1
fi   

# echo loading bindfs

export BFS_MOUNT_DIR=${BFS_MOUNT_DIR:-/mnt/bfs}

if [ -v PS1 ]; then
 alias rbfsu="dir_rebind_user"
 alias rbfs="dir_rebind"
 alias bfsu="dir_bind_user"
 alias bfs="dir_bind"
 alias bfsum="dir_bind_unmount"
 alias bfse="bfs_vscode"
 
 if [[ ! -d $BFS_MOUNT_DIR ]]; then
  sudo mkdir $BFS_MOUNT_DIR 2> /dev/null
  sudo chown $USER:$USER $BFS_MOUNT_DIR
 fi
fi

mounted () {
 mountpoint "$1" &> /dev/null && echo yes || return 1
}

dir_bind_unmount () {
   local usesudo
   local mp=${1:-$PWD}
   [[ ! $(mounted $mp) ]] && echo no mountpoint at $mp && mp=$BFS_MOUNT_DIR/$(basename $mp) 
   [[ ! $(mounted $mp) ]] && echo no mountpoint at $mp either, aborting && return 1
   [[ $EUID -ne 0 ]] && usesudo=sudo
   if $usesudo fusermount -u $mp; then 
     echo unmounted $mp, removing empty mountpoint directory
     rm -rf $mp 
    else 
     echo error, unable to unmount $mp 
   fi
}

dir_bind_user () {
  local usesudo; local dir;local user;local group;local mp
 
if [ $# -lt 3 ]; then
 echo "minimum 3 args needed to rebind <user? <source dir> <mountpoint>"
 echo passed were $@
 return 1
fi 

[[ $EUID -ne 0 ]] && usesudo=sudo

[[ $(id -u $1 2> /dev/null) ]] || { echo user $1 does not exist can not continue; return 2; }

dir=$(realpath $2)
mp=$3
[[ $(mounted $mp) ]] && echo something already mounted at $mp, aborting && return 1
if ! $usesudo mkdir -p $mp; then echo unable to make mountpoint aborting; return 2; fi
$usesudo chown $1:$1 $mp
user=$(stat -c '%u' $dir)
group=$(stat -c '%g' $dir)
$usesudo bindfs --force-user=$1 --force-group=$1 --create-for-user=$user --create-for-group=$group --chown-ignore --chgrp-ignore $dir $mp
[[ $? -gt 0 ]] && echo error in call to bindfs

if [[ $(mounted $mp) ]]; then
   echo $dir has been mounted at $mp for user $1
   echo "to unmount use:    dir_bind_unmount $mp   or  bfsum $mp"  
 else
  echo unable to mount $dir at $mp as user $user
fi

}

dir_bind () {
dir=${1:-$PWD} 
mp=${2:-$BFS_MOUNT_DIR/$(basename "$dir")}
dir_bind_user $USER $dir $mp
if [ -v PS1 ]; then
  if [[ $BFSEDIT ]]; then /opt/bin/vscode $mp 1>/dev/null ; else xdg-open $mp; fi 
  echo $BFSEDIT 
  echo enter \"u\" to unmount, otherwise any other key will leave mounted
  unset BFSEDIT
  read -n1 ans
  echo -e "\n"
  [[ $ans == "u" ]] && dir_bind_unmount $mp
fi
}

dir_rebind () {
dir_bind_user $USER $1 $1
}

dir_rebind_user () {
dir_bind_user $1 $2 $2
}

bfs_vscode () {
BFSEDIT="When done editing FIRST close your vscode window then"  
dir_bind "$@"
}


(return 0 2>/dev/null) || dir_bind_user $@