{-# LANGUAGE RankNTypes #-}

module System.Zfs.Dataset where

import Control.Monad
import Control.Monad.IO.Class
import qualified System.Zfs.Lowlevel as L
import System.Zfs.Types
import System.Zfs.Errors
import Foreign.C.String
import Foreign.Ptr
import Foreign.ForeignPtr
import Foreign.Marshal.Alloc
import Foreign.Storable

-- | Create a filesystem
createFilesystem :: String -> Zfs ()
createFilesystem path = withZfs $ \z -> do
    cpath <- newCString path
    props <- alloca $ \nvptr -> do
      L.nvlist_alloc nvptr 1 1
      peek nvptr
    r <- L.zfs_create z cpath 1 {- ZFS_TYPE_FILESYSTEM -} props
    if r /= 0
      then yieldZError z
      else return $ Right ()

-- | Create a block volume (path, block size, vol size)
createVolume :: String -> Integer -> Integer -> Zfs ()
createVolume path blocksize volsize = withZfs $ \z -> do
  cpath <- newCString path
  props <- alloca $ \nvptr -> do
    L.nvlist_alloc nvptr 1 1
    peek nvptr
  str_volsize <- newCString "volsize"
  str_volblocksize <- newCString "volblocksize"
  L.nvlist_add_uint64 props str_volsize $ fromIntegral volsize
  L.nvlist_add_uint64 props str_volblocksize $ fromIntegral blocksize
  r <- L.zfs_create z cpath 4 {- ZFS_TYPE_VOLUME -} props
  if r /= 0
    then yieldZError z
    else return $ Right ()

-- | Destroy a dataset.
destroyDataset :: Zdataset -> Zfs ()
destroyDataset (Zdataset fptr) = withZfs $ \z ->
  withForeignPtr fptr $ \ptr -> do
    r <- L.zfs_destroy ptr False
    if r /= 0
      then yieldZError z
      else return $ Right ()
  

-- | Gets the name of some Zfs
getDatasetName :: Zdataset -> Zfs String
getDatasetName (Zdataset fptr) = withZfs $ \z -> do
  cstr <- withForeignPtr fptr L.zfs_get_name
  str <- peekCString cstr
  return $ Right str