{-# LANGUAGE RankNTypes                 #-}
{-# LANGUAGE TemplateHaskell            #-}
{-# LANGUAGE LambdaCase                 #-}
-- | Internal helpers for generating definitions
module Language.LSP.Types.Utils
  ( rdrop
  , makeSingletonFromJSON
  , makeRegHelper
  , makeExtendingDatatype
  , lspOptions
  ) where

import Control.Monad
import Data.Aeson
import Data.List
import Language.Haskell.TH

-- ---------------------------------------------------------------------

rdrop :: Int -> [a] -> [a]
rdrop :: Int -> [a] -> [a]
rdrop Int
cnt = [a] -> [a]
forall a. [a] -> [a]
reverse ([a] -> [a]) -> ([a] -> [a]) -> [a] -> [a]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Int -> [a] -> [a]
forall a. Int -> [a] -> [a]
drop Int
cnt ([a] -> [a]) -> ([a] -> [a]) -> [a] -> [a]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [a] -> [a]
forall a. [a] -> [a]
reverse

-- | Given a wrapper and a singleton GADT, construct FromJSON
-- instances for each constructor return type by invoking the
-- FromJSON instance for the wrapper and unwrapping
makeSingletonFromJSON :: Name -> Name -> Q [Dec]
makeSingletonFromJSON :: Name -> Name -> Q [Dec]
makeSingletonFromJSON Name
wrap Name
gadt = do
  TyConI (DataD Cxt
_ Name
_ [TyVarBndr]
_ Maybe Kind
_ [Con]
cons [DerivClause]
_) <- Name -> Q Info
reify Name
gadt
  [[Dec]] -> [Dec]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat ([[Dec]] -> [Dec]) -> Q [[Dec]] -> Q [Dec]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (Con -> Q [Dec]) -> [Con] -> Q [[Dec]]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (Name -> Con -> Q [Dec]
makeInst Name
wrap) [Con]
cons

{-
instance FromJSON (SMethod $method) where
  parseJSON = parseJSON >=> \case
      SomeMethod $singleton-method -> pure $singleton-method
      _ -> mempty
-}
makeInst :: Name -> Con -> Q [Dec]
makeInst :: Name -> Con -> Q [Dec]
makeInst Name
wrap (GadtC [Name
sConstructor] [BangType]
args Kind
t) = do
  [Name]
ns <- Int -> Q Name -> Q [Name]
forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM ([BangType] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [BangType]
args) (String -> Q Name
newName String
"x")
  let wrappedPat :: Q Pat
wrappedPat = Pat -> Q Pat
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Pat -> Q Pat) -> Pat -> Q Pat
forall a b. (a -> b) -> a -> b
$ Name -> [Pat] -> Pat
ConP   Name
wrap [Name -> [Pat] -> Pat
ConP Name
sConstructor  ((Name -> Pat) -> [Name] -> [Pat]
forall a b. (a -> b) -> [a] -> [b]
map Name -> Pat
VarP [Name]
ns)]
      unwrappedE :: Q Exp
unwrappedE = Exp -> Q Exp
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Exp -> Q Exp) -> Exp -> Q Exp
forall a b. (a -> b) -> a -> b
$ (Exp -> Exp -> Exp) -> Exp -> [Exp] -> Exp
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' Exp -> Exp -> Exp
AppE (Name -> Exp
ConE Name
sConstructor) ((Name -> Exp) -> [Name] -> [Exp]
forall a b. (a -> b) -> [a] -> [b]
map Name -> Exp
VarE [Name]
ns)
  [d| instance FromJSON $(pure t) where
        parseJSON = parseJSON >=> \case
          $wrappedPat -> pure $unwrappedE
          _ -> mempty
    |]
makeInst Name
wrap (ForallC [TyVarBndr]
_ Cxt
_ Con
con) = Name -> Con -> Q [Dec]
makeInst Name
wrap Con
con -- Cancel and Custom requests
makeInst Name
_ Con
_ = String -> Q [Dec]
forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
"makeInst only defined for GADT constructors"

makeRegHelper :: Name -> DecsQ
makeRegHelper :: Name -> Q [Dec]
makeRegHelper Name
regOptTypeName = do
  Just Name
sMethodTypeName <- String -> Q (Maybe Name)
lookupTypeName String
"SMethod"
  Just Name
fromClientName <- String -> Q (Maybe Name)
lookupValueName String
"FromClient"
  TyConI (DataD Cxt
_ Name
_ [TyVarBndr]
_ Maybe Kind
_ [Con]
allCons [DerivClause]
_) <- Name -> Q Info
reify Name
sMethodTypeName

  let isConsFromClient :: Con -> Q Bool
isConsFromClient (GadtC [Name]
_ [BangType]
_ (AppT Kind
_ Kind
method)) = Kind -> Q Bool
isMethodFromClient Kind
method
      isConsFromClient Con
_ = Bool -> Q Bool
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
False
      isMethodFromClient :: Type -> Q Bool
      isMethodFromClient :: Kind -> Q Bool
isMethodFromClient (PromotedT Name
method) = do
        DataConI Name
_ Kind
typ Name
_ <- Name -> Q Info
reify Name
method
        case Kind
typ of
          AppT (AppT Kind
_ (PromotedT Name
n)) Kind
_ -> Bool -> Q Bool
forall (m :: * -> *) a. Monad m => a -> m a
return (Bool -> Q Bool) -> Bool -> Q Bool
forall a b. (a -> b) -> a -> b
$ Name
n Name -> Name -> Bool
forall a. Eq a => a -> a -> Bool
== Name
fromClientName
          Kind
_ -> Bool -> Q Bool
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
False
      isMethodFromClient Kind
_ = String -> Q Bool
forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
"Didn't expect this type of Method!"

  [Con]
cons <- (Con -> Q Bool) -> [Con] -> Q [Con]
forall (m :: * -> *) a.
Applicative m =>
(a -> m Bool) -> [a] -> m [a]
filterM Con -> Q Bool
isConsFromClient [Con]
allCons

  let conNames :: [Name]
conNames = (Con -> Name) -> [Con] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (\(GadtC [Name
name] [BangType]
_ Kind
_) -> Name
name) [Con]
cons
      helperName :: Name
helperName = String -> Name
mkName String
"regHelper"
      mkClause :: Name -> Q Clause
mkClause Name
name = do
        Name
x <- String -> Q Name
newName String
"x"
        [Q Pat] -> BodyQ -> [DecQ] -> Q Clause
clause [ Name -> [Q Pat] -> Q Pat
conP Name
name [], Name -> Q Pat
varP Name
x ]
               (Q Exp -> BodyQ
normalB (Name -> Q Exp
varE Name
x))
               []
      regOptTcon :: TypeQ
regOptTcon = Name -> TypeQ
conT Name
regOptTypeName
  Dec
fun <- Name -> [Q Clause] -> DecQ
funD Name
helperName ((Name -> Q Clause) -> [Name] -> [Q Clause]
forall a b. (a -> b) -> [a] -> [b]
map Name -> Q Clause
mkClause [Name]
conNames)

  Dec
typSig <- Name -> TypeQ -> DecQ
sigD Name
helperName (TypeQ -> DecQ) -> TypeQ -> DecQ
forall a b. (a -> b) -> a -> b
$
    [t| forall m x. $(conT sMethodTypeName) m
        -> (Show ($regOptTcon m) => ToJSON ($regOptTcon m) => FromJSON ($regOptTcon m) => x)
        -> x |]
  [Dec] -> Q [Dec]
forall (m :: * -> *) a. Monad m => a -> m a
return [Dec
typSig, Dec
fun]

-- | @makeExtendingDatatype name extends fields@ generates a record datatype
-- that contains all the fields of @extends@, plus the additional fields in
-- @fields@.
-- e.g.
-- data Foo = { a :: Int }
-- makeExtendingDatatype "bar" [''Foo] [("b", [t| String |])]
-- Will generate
-- data Bar = { a :: Int, b :: String }
makeExtendingDatatype :: String -> [Name] -> [(String, TypeQ)] -> DecsQ
makeExtendingDatatype :: String -> [Name] -> [(String, TypeQ)] -> Q [Dec]
makeExtendingDatatype String
datatypeNameStr [Name]
extends [(String, TypeQ)]
fields = do
  [VarBangType]
extendFields <- ([[VarBangType]] -> [VarBangType])
-> Q [[VarBangType]] -> Q [VarBangType]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap [[VarBangType]] -> [VarBangType]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat (Q [[VarBangType]] -> Q [VarBangType])
-> Q [[VarBangType]] -> Q [VarBangType]
forall a b. (a -> b) -> a -> b
$ [Name] -> (Name -> Q [VarBangType]) -> Q [[VarBangType]]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
t a -> (a -> m b) -> m (t b)
forM [Name]
extends ((Name -> Q [VarBangType]) -> Q [[VarBangType]])
-> (Name -> Q [VarBangType]) -> Q [[VarBangType]]
forall a b. (a -> b) -> a -> b
$ \Name
e -> do
    TyConI (DataD Cxt
_ Name
_ [TyVarBndr]
_ Maybe Kind
_ [RecC Name
_ [VarBangType]
eFields] [DerivClause]
_) <- Name -> Q Info
reify Name
e
    [VarBangType] -> Q [VarBangType]
forall (m :: * -> *) a. Monad m => a -> m a
return [VarBangType]
eFields
  let datatypeName :: Name
datatypeName = String -> Name
mkName String
datatypeNameStr
      insts :: [TypeQ]
insts = [[t| Read |], [t| Show |], [t| Eq |]]
      constructor :: ConQ
constructor = Name -> [VarBangTypeQ] -> ConQ
recC Name
datatypeName [VarBangTypeQ]
combinedFields
      userFields :: [VarBangTypeQ]
userFields = (((String, TypeQ) -> VarBangTypeQ)
 -> [(String, TypeQ)] -> [VarBangTypeQ])
-> [(String, TypeQ)]
-> ((String, TypeQ) -> VarBangTypeQ)
-> [VarBangTypeQ]
forall a b c. (a -> b -> c) -> b -> a -> c
flip ((String, TypeQ) -> VarBangTypeQ)
-> [(String, TypeQ)] -> [VarBangTypeQ]
forall a b. (a -> b) -> [a] -> [b]
map [(String, TypeQ)]
fields (((String, TypeQ) -> VarBangTypeQ) -> [VarBangTypeQ])
-> ((String, TypeQ) -> VarBangTypeQ) -> [VarBangTypeQ]
forall a b. (a -> b) -> a -> b
$ \(String
s, TypeQ
typ) -> do
        Name -> BangTypeQ -> VarBangTypeQ
varBangType (String -> Name
mkName String
s) (BangQ -> TypeQ -> BangTypeQ
bangType (SourceUnpackednessQ -> SourceStrictnessQ -> BangQ
bang SourceUnpackednessQ
noSourceUnpackedness SourceStrictnessQ
noSourceStrictness) TypeQ
typ)
      combinedFields :: [VarBangTypeQ]
combinedFields = ((VarBangType -> VarBangTypeQ) -> [VarBangType] -> [VarBangTypeQ]
forall a b. (a -> b) -> [a] -> [b]
map VarBangType -> VarBangTypeQ
forall (f :: * -> *) a. Applicative f => a -> f a
pure [VarBangType]
extendFields) [VarBangTypeQ] -> [VarBangTypeQ] -> [VarBangTypeQ]
forall a. Semigroup a => a -> a -> a
<> [VarBangTypeQ]
userFields
      derivs :: [DerivClauseQ]
derivs = [Maybe DerivStrategy -> [TypeQ] -> DerivClauseQ
derivClause Maybe DerivStrategy
forall a. Maybe a
Nothing [TypeQ]
insts]
  (\Dec
a -> [Dec
a]) (Dec -> [Dec]) -> DecQ -> Q [Dec]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> CxtQ
-> Name
-> [TyVarBndr]
-> Maybe Kind
-> [ConQ]
-> [DerivClauseQ]
-> DecQ
dataD ([TypeQ] -> CxtQ
cxt []) Name
datatypeName [] Maybe Kind
forall a. Maybe a
Nothing [ConQ
constructor] [DerivClauseQ]
derivs

-- | Standard options for use when generating JSON instances
-- NOTE: This needs to be in a separate file because of the TH stage restriction
lspOptions :: Options
lspOptions :: Options
lspOptions = Options
defaultOptions { omitNothingFields :: Bool
omitNothingFields = Bool
True, fieldLabelModifier :: String -> String
fieldLabelModifier = String -> String
modifier }
  where
  modifier :: String -> String
  -- For fields called data and type in the spec, we call them xdata and xtype
  -- in haskell-lsp-types to avoid it clashing with the Haskell keywords. This
  -- fixes up the json derivation
  modifier :: String -> String
modifier String
"_xdata" = String
"data"
  modifier String
"_xtype" = String
"type"
  modifier String
xs = Int -> String -> String
forall a. Int -> [a] -> [a]
drop Int
1 String
xs