#!/usr/bin/env nuxr-nuxsh

nux.use nuxfs

VFS_SOURCES_FILE=".vfs.sources"

CURRENT_SOURCES_FILE=$(nuxfs.closest "$VFS_SOURCES_FILE");
if [ -f "$CURRENT_SOURCES_FILE" ] {
  CURRENT_MOUNT="${CURRENT_SOURCES_FILE%/*}";
  declare -gA CURRENT_SOURCES
  nux.log debug "Current VFS mount: ${CURRENT_MOUNT%/*}";

  while read name path; do
    CURRENT_SOURCES[${name}]="$path"
  done < "$CURRENT_SOURCES_FILE"
}

function vfs.path name {
  echo ${CURRENT_SOURCES[$name]};
}

function vfs.path.real file {
  for root in "${CURRENT_SOURCES[@]}" ; do
    if [ -e "$root/$file" ] {
      echo $root/$file;
      return 0;
    }
  done
}


@namespace task. {


##   list::
##     Lists all **mergerfs** based virtual filesystems managed by **vfs** tool
  function :list {
    echo "1"
  }

##   info::
##     Displays info about current path
  function :info {
    nux.log debug "VFS mount: ${CURRENT_MOUNT}";
    echo "path:" $CURRENT_MOUNT;
    echo "sources:"
    for key in "${!CURRENT_SOURCES[@]}"; do
      echo "  $key: ${CURRENT_SOURCES[$key]}";
    done

  }
##   switch:: <storage> <path+>
##     Moves specified **paths** to named **storage** for particular **vfs**.
##     This is ideal for marking files as keep or migrating them to remote,
##     rather then local.
  function :switch storage {
    target="$(vfs.path "$storage")"
    nux.log debug "Target path $target"
    for f in "$@" ; do
      relative_path=$(realpath --relative-to="$CURRENT_MOUNT" $f);
      target_dir="$target/${relative_path%/*}"
      real_file="$(vfs.path.real "$relative_path")"
      nux.log debug "Target directory: $target_dir";
      nuxfs.info $f moving from "$NC_LightPurple${real_file}$NC_No" to "$NC_LightPurple$target_dir"
      mkdir -p "$target_dir";
      mv "$real_file" "$target_dir";
    done
  }
##   mount:: <target> <name:path> [<name:path>+]
##     Creates **mergerfs** mount for specified pairs of storage **name** and
##     **path**
  function :mount target {
    local mount_paths="";
    nux.log debug "MergerFS mount: $target"

    source_tempfs="$(mktemp -d)"
    for source in "$@" ; do
      source_name="${source%%:*}"
      source_path="$(realpath "${source#*:}")"
      source_path="${source_path%/}"
      nux.log debug "  Source: $source_name Path: $source_path";
      mount_paths="$mount_paths:${source_path}"
      echo "$source_name $source_path" >> "$source_tempfs/.vfs.sources"
    done
    echo "temp $source_tempfs" >> "$source_tempfs/$VFS_SOURCES_FILE"

    mergerfs_options="$source_tempfs:${mount_paths}"
    nux.log debug "MergerFS command:" $mergerfs_options;
    mergerfs "$mergerfs_options" "$target"
    (cd $target; vfs info )
  }
##   unmount:: <target>
##     Unmounts target VFS filesystem.
  function :unmount {
    fusermount -u "$target"
    nuxfs.info "${CURRENT_SOURCES[temp]}" removing temporary metadata.
    rm -rf "${CURRENT_SOURCES[temp]}"

  }
}