{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes            #-}
{-# LANGUAGE StrictData            #-}
{-# LANGUAGE TypeFamilies          #-}
module Network.MessagePack.Rpc
  ( I.Doc (..)
  , I.Returns
  , I.ReturnsM
  , method
  , rpc
  , docs
  , stubs, Rpc, RpcT (local)
  ) where

import           Control.Monad.Catch              (MonadThrow)
import           Data.Kind                        (Type)
import           Data.Text                        (Text)

import qualified Network.MessagePack.Interface    as I
import qualified Network.MessagePack.Types.Client as Client
import qualified Network.MessagePack.Types.Server as Server

-- Import orphan instances for RpcType and IsReturnType.
-- TODO(SX91): Avoid orphan instances. See issue #7.
import           Network.MessagePack.Client.Basic ()
import           Network.MessagePack.Server.Basic ()


class RpcService rpc where
  type ClientMonad rpc :: Type -> Type
  type ServerMonad rpc :: Type -> Type
  type F rpc
  rpc    :: rpc -> I.ClientType (ClientMonad rpc) (F rpc)
  method :: rpc -> Server.Method (ServerMonad rpc)
  docs   :: rpc -> (Text, I.Doc (F rpc))


type Rpc f = RpcT IO IO f

data RpcT mc ms f = RpcT
  { RpcT mc ms f -> ClientType mc f
rpcPure    :: !(I.ClientType mc f)
  , RpcT mc ms f -> HaskellType f
local      :: !(I.HaskellType f)
  , RpcT mc ms f -> Method ms
methodPure :: !(Server.Method ms)
  , RpcT mc ms f -> Interface f
intfPure   :: !(I.Interface f)
  }

instance forall mc ms (f :: Type). RpcService (RpcT mc ms f) where
  type ClientMonad (RpcT mc ms f) = mc
  type ServerMonad (RpcT mc ms f) = ms
  type F (RpcT mc ms f) = f
  rpc :: RpcT mc ms f
-> ClientType (ClientMonad (RpcT mc ms f)) (F (RpcT mc ms f))
rpc    = RpcT mc ms f
-> ClientType (ClientMonad (RpcT mc ms f)) (F (RpcT mc ms f))
forall (mc :: * -> *) (ms :: * -> *) f.
RpcT mc ms f -> ClientType mc f
rpcPure
  {-# INLINE rpc #-}
  method :: RpcT mc ms f -> Method (ServerMonad (RpcT mc ms f))
method = RpcT mc ms f -> Method (ServerMonad (RpcT mc ms f))
forall (mc :: * -> *) (ms :: * -> *) f. RpcT mc ms f -> Method ms
methodPure
  {-# INLINE method #-}
  docs :: RpcT mc ms f -> (Text, Doc (F (RpcT mc ms f)))
docs RpcT mc ms f
r = (Method ms -> Text
forall (m :: * -> *). Method m -> Text
Server.methodName (Method ms -> Text) -> Method ms -> Text
forall a b. (a -> b) -> a -> b
$ RpcT mc ms f -> Method (ServerMonad (RpcT mc ms f))
forall rpc. RpcService rpc => rpc -> Method (ServerMonad rpc)
method RpcT mc ms f
r, Interface f -> Doc f
forall f. Interface f -> Doc f
I.docs (Interface f -> Doc f) -> Interface f -> Doc f
forall a b. (a -> b) -> a -> b
$ RpcT mc ms f -> Interface f
forall (mc :: * -> *) (ms :: * -> *) f. RpcT mc ms f -> Interface f
intfPure RpcT mc ms f
r)
  {-# INLINE docs #-}


stubs
  :: ( Client.RpcType (I.ClientType mc f)
     , Server.MethodType ms (I.ServerType ms f)
     , I.IsReturnType ms f
     , I.IsDocType f
     , MonadThrow ms
     )
  => Text -> I.Doc f -> I.HaskellType f -> RpcT mc ms f
stubs :: Text -> Doc f -> HaskellType f -> RpcT mc ms f
stubs Text
n Doc f
doc HaskellType f
f = ClientType mc f
-> HaskellType f -> Method ms -> Interface f -> RpcT mc ms f
forall (mc :: * -> *) (ms :: * -> *) f.
ClientType mc f
-> HaskellType f -> Method ms -> Interface f -> RpcT mc ms f
RpcT ClientType mc f
c HaskellType f
f Method ms
m Interface f
i
  where
    c :: ClientType mc f
c = Text -> ClientType mc f
forall a. RpcType a => Text -> a
Client.call Text
n
    m :: Method ms
m = Interface f -> HaskellType f -> Method ms
forall (m :: * -> *) f.
(MonadThrow m, MethodType m (ServerType m f), IsDocType f,
 IsReturnType m f) =>
Interface f -> HaskellType f -> Method m
I.method Interface f
i HaskellType f
f
    i :: Interface f
i = Text -> Doc f -> Interface f
forall f. Text -> Doc f -> Interface f
I.interface Text
n Doc f
doc