{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TemplateHaskell #-}

-- |
-- Module      :  Text.URI.QQ
-- Copyright   :  © 2017–present Mark Karpov
-- License     :  BSD 3 clause
--
-- Maintainer  :  Mark Karpov <markkarpov92@gmail.com>
-- Stability   :  experimental
-- Portability :  portable
--
-- Quasi-quoters for compile-time construction of URIs and refined text
-- values.
--
-- All of the quasi-quoters in this module can be used in an expression
-- context. With the @ViewPatterns@ language extension enabled, they may
-- also be used in a pattern context (since /0.3.2.0/).
module Text.URI.QQ
  ( uri,
    scheme,
    host,
    username,
    password,
    pathPiece,
    queryKey,
    queryValue,
    fragment,
  )
where

import Control.Exception (Exception (..), SomeException)
import Data.Text (Text)
import qualified Data.Text as T
import Language.Haskell.TH.Lib (appE, viewP)
import Language.Haskell.TH.Quote (QuasiQuoter (..))
import Language.Haskell.TH.Syntax (Lift (..))
import Text.URI.Parser.Text
import Text.URI.Types

-- | Construct a 'URI' value at compile time.
uri :: QuasiQuoter
uri :: QuasiQuoter
uri = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m URI
mkURI

-- | Construct a @'RText' 'Scheme'@ value at compile time.
scheme :: QuasiQuoter
scheme :: QuasiQuoter
scheme = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'Scheme)
mkScheme

-- | Construct a @'RText' 'Host'@ value at compile time.
host :: QuasiQuoter
host :: QuasiQuoter
host = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'Host)
mkHost

-- | Construct a @'RText' 'Username'@ value at compile time.
username :: QuasiQuoter
username :: QuasiQuoter
username = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'Username)
mkUsername

-- | Construct a @'RText' 'Password'@ value at compile time.
password :: QuasiQuoter
password :: QuasiQuoter
password = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'Password)
mkPassword

-- | Construct a @'RText' 'PathPiece'@ value at compile time.
pathPiece :: QuasiQuoter
pathPiece :: QuasiQuoter
pathPiece = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'PathPiece)
mkPathPiece

-- | Construct a @'RText' 'QueryKey'@ value at compile time.
queryKey :: QuasiQuoter
queryKey :: QuasiQuoter
queryKey = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'QueryKey)
mkQueryKey

-- | Construct a @'RText 'QueryValue'@ value at compile time.
queryValue :: QuasiQuoter
queryValue :: QuasiQuoter
queryValue = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'QueryValue)
mkQueryValue

-- | Construct a @'RText' 'Fragment'@ value at compile time.
fragment :: QuasiQuoter
fragment :: QuasiQuoter
fragment = forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ forall (m :: * -> *). MonadThrow m => Text -> m (RText 'Fragment)
mkFragment

----------------------------------------------------------------------------
-- Helpers

-- | Lift a smart constructor for refined text into a 'QuasiQuoter'.
--
-- The 'Eq' constraint is technically unnecessary here, but the pattern
-- generated by 'quotePat' will only work if the type has an 'Eq' instance.
liftToQQ :: (Eq a, Lift a) => (Text -> Either SomeException a) -> QuasiQuoter
liftToQQ :: forall a.
(Eq a, Lift a) =>
(Text -> Either SomeException a) -> QuasiQuoter
liftToQQ Text -> Either SomeException a
f =
  QuasiQuoter
    { quoteExp :: String -> Q Exp
quoteExp = \String
str ->
        case Text -> Either SomeException a
f (String -> Text
T.pack String
str) of
          Left SomeException
err -> forall (m :: * -> *) a. MonadFail m => String -> m a
fail (forall e. Exception e => e -> String
displayException SomeException
err)
          Right a
x -> forall t (m :: * -> *). (Lift t, Quote m) => t -> m Exp
lift a
x,
      quotePat :: String -> Q Pat
quotePat = \String
str ->
        case Text -> Either SomeException a
f (String -> Text
T.pack String
str) of
          Left SomeException
err -> forall (m :: * -> *) a. MonadFail m => String -> m a
fail (forall e. Exception e => e -> String
displayException SomeException
err)
          Right a
x -> forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE [|(==)|] (forall t (m :: * -> *). (Lift t, Quote m) => t -> m Exp
lift a
x) forall (m :: * -> *). Quote m => m Exp -> m Pat -> m Pat
`viewP` [p|True|],
      quoteType :: String -> Q Type
quoteType = forall a. HasCallStack => String -> a
error String
"This usage is not supported",
      quoteDec :: String -> Q [Dec]
quoteDec = forall a. HasCallStack => String -> a
error String
"This usage is not supported"
    }