#!/bin/bash
export BTRFS_BIN=$(which btrfs)
module_load confirm
module_load helpers

# set this for sudo
# ALL ALL = (root) NOPASSWD:/bin/btrfs

make_subvol() {
  local usesudo
  local uid
  local gid
  [[ $EUID -ne 0 ]] && usesudo=sudo
  uid=${2:-$USER}
  gid=${3:-$uid}
  echo $usesudo $BTRFS_BIN subvolume create $1
  $usesudo $BTRFS_BIN subvolume create $1
  echo $usesudo chown $uid:$gid $1
  $usesudo chown $uid:$gid $1
}

del_subvol() {
  local usesudo; local delete
  [[ $1 == "-d" ]] && delete=true && shift
  [[ $EUID -ne 0 ]] && usesudo=sudo
  if $usesudo $BTRFS_BIN subvolume show "$1" &> /dev/null; then
    if [[ -v PS1 && ! $delete ]]; then
     confirm "DELETE the subvolume $(realpath "$1") (pass -d to avoid confirm)" || return 1
    fi
    $usesudo $BTRFS_BIN subvolume delete $1
   else 
    echo "$1 not a btrfs subvolume, nothing to delete"
  fi

}

# make_base_subvols() {
#   svols="shell admin opt data docker images temp"
#   BTRFSDATAROOT=${BTRFSDATAROOT:-/mnt/data}
#   # cd $BTRFSDATAROOT || exit
#   for svol in $svols; do
#     make_subvol $BTRFSDATAROOT/$svol $@
#   done
# }

#ssudo mount -o subvol=opt /dev/sda4 /test

snapshot_restore () {
  local src=$1
  local dest=$2
  local name=${3:-$(echo $src| rev | cut -f 2- -d '.' | rev)}
  local usesudo
  echo copying $src at $PWD to $2 then renaming to $name
  # TODO check for snapshot, strip volume from source path, remove extra snapshot when done
  [[ $EUID -ne 0 ]] && usesudo=sudo
  $usesudo $BTRFS_BIN send $src | $usesudo $BTRFS_BIN -q receive $dest
  # cd $2 || return
  $usesudo $BTRFS_BIN subvolume snapshot $dest/$src $dest/$name  
  # todo check for snapshot then delete transfered one
}



subvolume_size () {
 local all;
 [[ $1 == "-a" ]] && all=true 
 if [[ $all ]]; then 
 sudo $BTRFS_BIN qgroup show "${2:-$PWD}" --kbytes | tail -n +3
 str=$(sudo $BTRFS_BIN qgroup show "${2:-$PWD}" --kbytes | tail -n +3);
else
  sudo $BTRFS_BIN qgroup show "${2:-$PWD}" --kbytes | grep $1
  str=$(sudo $BTRFS_BIN qgroup show "${2:-$PWD}" --kbytes  | grep $1)
fi
# echo $str

subvolumeFolderSize=0;

while read line; do
  FIELDS=( $line )
  thisLineKb="${FIELDS[2]/'.00KiB'/''}";
  # echo $thisLineKb
  subvolumeFolderSize=$((subvolumeFolderSize+thisLineKb));
done <<< "$str"

[[ $all ]] && echo "size of entire filesystem at ${2:-$PWD}" || echo size of subvolumes/snapshots $1 at "${2:-$PWD}"
echo $subvolumeFolderSize KB
echo "~ $((subvolumeFolderSize/1024)) MB"
echo "~ $((subvolumeFolderSize/1024/1024)) GB"

}

find_subvolumes() {
  dir=${1:-.}
  dep=${2:-1}
  sudo /bin/find "$dir" -maxdepth $dep -type d -exec bash -c '
   for d do
      subv=$(basename $d)
      sudo $BTRFS_BIN subvolume show "$d" >/dev/null 2>&1 && printf "%s\n" "$subv"
   done' find-sh {} +
}

folder_snapshot() {

  for sv in $(find_subvolumes $1 1); do
    if [[ -d $2/$sv ]]; then
      echo snapshot $sv already exists in $2. You must manually delete target snapshots!
    else
      sudo $BTRFS_BIN sub snap $1/$sv $2
    fi
  done

}

mount_subvolume () {
  echo sudo mount $1 -o subvol=$2 $3
  if mountpoint $3; then
  echo $3 already a mountpoint, aborting subvolume mount
  else
  mkdir -p $3
  sudo mount $1 -o subvol=$2 $3
  fi
}

named_snapshot () {
local usage; local subvol; local target; local run; local usesudo
[[ $1 == "-r" ]] && run=true && shift
[[ $EUID -ne 0 ]] && usesudo=sudo
subvol=$(realpath "$1")
usage="usage: named_snapshot <-r> <subvolume/snapshot> <new extension name> <optional target directory>"
if sudo $BTRFS_BIN subvolume show "$1" &> /dev/null; then
    # if [[ -v PS1 && ! $delete ]]; then
[[ ! $2 ]] && echo no extension name for named snapshot && echo $usage && return 1
if [[ $3 ]]; then
  [[ ! -d $3 ]] && echo "target directory $3 does not exist, can not make snapshot" && echo $usage && return 2
  target=$(realpath "$3")/$(basename "$(rm_ext "$subvol")").$2
 else 
  target="$(rm_ext "$subvol").$2"  
fi  
[[ -v PS1 && ! $run ]] && confirm "make snapshot of $subvol to $target (pass -r to avoid confirm )" || return 4  
$usesudo "$BTRFS_BIN" sub snap "$subvol" "$target"
else 
echo "$subvol not a btrfs subvolume, can't make named snapshot"
echo $usage
return 3
fi

}

# alias
alias btvl="sudo $BTRFS_BIN subvolume list"
alias btrfs="sudo $BTRFS_BIN"
alias btsub="sudo $BTRFS_BIN subvolume"







# sudo find / -type d -exec sh -c '
#    for d do
#       btrfs subvolume show "$d" >/dev/null 2>&1 && printf "%s\n" "$d"
#    done' find-sh {} +
# You may want to exclude paths that are beyond suspicion. The following code excludes /proc, /sys and /dev:

# sudo find / -type d \( \
#      \( -path /proc -prune \) -o \
#      \( -path /sys -prune \) -o \
#      \( -path /dev -prune \) -o \
#      \( -exec sh -c '
#         for d do
#            btrfs subvolume show "$d" >/dev/null 2>&1 && printf "%s\n" "$d"
#         done
#      ' find-sh {} + \) \)