module Huihua.Warning
  ( HuihuaWarning (..),
    showWarnings,
    Warn,
    warnError,
    warnEither,
    warnMaybe,
  )
where

import Control.Category ((>>>))
import Data.Bool
import Data.List qualified as List
import Data.These
import Prelude

data HuihuaWarning
  = HuihuaError String
  | NYI
  | EmptyStack1
  | EmptyStack2
  | ApplyFunction
  | NotBox
  | TypeMismatch
  | SizeMismatch
  | RankMismatch
  | NotNat
  | EmptyArray
  | NotArray
  | NoScalarOp
  | OutOfBounds
  | NoOpenArray
  | NotReduceable
  | ApplyNonOperator
  | RaggedInternal
  | NoIdentity
  | BadPick
  | BadTake
  deriving (Eq, Ord, Show)

showWarnings :: [HuihuaWarning] -> String
showWarnings = List.nub >>> fmap show >>> unlines

-- | A type synonym for the common returning type of many functions. A common computation pipeline is to take advantage of the 'These' Monad instance eg
type Warn a = These [HuihuaWarning] a

-- | Convert any warnings to an 'error'
warnError :: Warn a -> a
warnError = these (showWarnings >>> error) id (\xs a -> bool (error (showWarnings xs)) a (null xs))

-- | Returns Left on any warnings
warnEither :: Warn a -> Either [HuihuaWarning] a
warnEither = these Left Right (\xs a -> bool (Left xs) (Right a) (null xs))

-- | Returns results, if any, ignoring warnings.
warnMaybe :: Warn a -> Maybe a
warnMaybe = these (const Nothing) Just (\_ a -> Just a)