{-# LANGUAGE PatternSynonyms #-}

module MusicScroll.TrackSuplement
  ( tsTitle,
    tsArtist,
    tsKeepArtist,
    TrackSuplement (),
    trackSuplement,
    suplement,
    mergeSuplement,
    suplementOnlyArtist,
  )
where

import Data.Text
import MusicScroll.TrackInfo
  ( TrackByPath (..),
    TrackIdentifier,
    TrackInfo (..),
    pattern OnlyMissingArtist,
  )
import Pipes (Pipe)
import qualified Pipes.Prelude as PP (map)

-- | Invariant, always a valid artist text.
data TrackSuplement = TrackSuplement
  { tsTitle :: Text,
    tsArtist :: Text,
    tsKeepArtist :: Bool
  }

trackSuplement :: Text -> Text -> Bool -> Maybe TrackSuplement
trackSuplement title artist keep
  | strip artist == artist = pure (TrackSuplement title artist keep)
  | otherwise = Nothing

suplement :: TrackSuplement -> TrackIdentifier -> TrackInfo
suplement supl = either byPath byInfo
  where
    byPath :: TrackByPath -> TrackInfo
    byPath path =
      TrackInfo
        { tTitle = tsTitle supl,
          tArtist = tsArtist supl,
          tUrl = tpPath path
        }

    byInfo :: TrackInfo -> TrackInfo
    byInfo info = info {tTitle = tsTitle supl, tArtist = tsArtist supl}

mergeSuplement :: Functor m => TrackSuplement -> Pipe TrackIdentifier TrackInfo m a
mergeSuplement = PP.map . suplement

suplementOnlyArtist :: TrackSuplement -> TrackIdentifier -> TrackIdentifier
suplementOnlyArtist supl (Left byPath@OnlyMissingArtist) =
  let trackinfo =
        TrackInfo
          { tTitle = maybe mempty id (tpTitle byPath),
            tArtist = tsArtist supl,
            tUrl = tpPath byPath
          }
   in Right trackinfo
suplementOnlyArtist _ other = other