{-# LANGUAGE TemplateHaskell #-}

{-|  The WConfd functions for direct configuration manipulation

This module contains the client functions exported by WConfD for
specific configuration manipulation.

-}

{-

Copyright (C) 2014 Google Inc.
All rights reserved.

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PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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-}

module Ganeti.WConfd.ConfigModifications where

import qualified Data.ByteString.UTF8 as UTF8
import Control.Lens.Setter ((.~))
import Control.Lens.Traversal (mapMOf)
import Data.Maybe (isJust)
import Language.Haskell.TH (Name)

import Ganeti.JSON (alterContainerL)
import Ganeti.Locking.Locks (ClientId, ciIdentifier)
import Ganeti.Logging.Lifted (logDebug)
import Ganeti.Objects
import Ganeti.Objects.Lens
import Ganeti.WConfd.ConfigState (csConfigDataL)
import Ganeti.WConfd.Monad (WConfdMonad, modifyConfigWithLock)
import qualified Ganeti.WConfd.TempRes as T


-- | Add a new instance to the configuration, release DRBD minors,
-- and commit temporary IPs, all while temporarily holding the config
-- lock. Return True upon success and False if the config lock was not
-- available and the client should retry.
--
-- TODO: add verifications to this call; the client should have a lock
-- on the name of the instance, and no instance with the given uuid should
-- exist.
addInstance :: Instance -> ClientId -> WConfdMonad Bool
addInstance inst cid = do
  logDebug $ "AddInstance: client " ++ show (ciIdentifier cid)
             ++ " adding instance " ++ uuidOf inst
             ++ " with name " ++ show (instName inst)
  let addInst = csConfigDataL . configInstancesL
                . alterContainerL (UTF8.fromString $ uuidOf inst)
                  .~ Just inst
      commitRes tr = mapMOf csConfigDataL $ T.commitReservedIps cid tr
  r <- modifyConfigWithLock
         (\tr cs -> commitRes tr $ addInst  cs)
         . T.releaseDRBDMinors . UTF8.fromString $ uuidOf inst
  logDebug $ "AddInstance: result of config modification is " ++ show r
  return $ isJust r

-- * The list of functions exported to RPC.

exportedFunctions :: [Name]
exportedFunctions = [ 'addInstance
                    ]