module Dodge.HeldScroll (
    doHeldScroll,
) where

--import Dodge.Base.You
import Control.Lens hiding ((<|), (|>))
import Data.Sequence
import Dodge.Data.Creature
import Dodge.Data.World
import Data.Maybe
--import LensHelp hiding ((|>), (<|))
-- should be able to just import data.item

doHeldScroll :: HeldScroll -> Float -> Creature -> World -> World
doHeldScroll hs = case hs of
    HeldScrollDoNothing -> const . const id
    HeldScrollZoom -> const . const id
    HeldScrollCharMode{} -> overYourItem $ \x _ -> itUse . heldScroll . hsCharMode %~ cycleSignum x
  where
    overYourItem f x cr w =  fromMaybe w $ do
        i <- cr ^? crManipulation . manObject . inInventory . ispItem
        return $ w & cWorld . lWorld . creatures . ix 0 . crInv . ix i %~ f x cr

cycleSignum :: Float -> Seq a -> Seq a
cycleSignum x
    | x > 0 = cycleL
    | otherwise = cycleR

cycleL, cycleR :: Seq a -> Seq a
cycleL (x :<| xs) = xs |> x
cycleL xs = xs
cycleR (xs :|> x) = x <| xs
cycleR xs = xs