module Homework.Ch01.Hanoi where

import qualified Data.HashMap.Strict as HashMap

newtype Peg = Peg ()

data Move = Move {moveFrom :: String, moveTo :: String} deriving (Eq, Show)

data Disc = Disc {discSize :: Int}

hanoi :: Int -> String -> String -> String -> Either String [Move]
hanoi numDisks pegLabelA pegLabelB pegLabelC =
  let _pegs =
        HashMap.fromList
          [ (pegLabelA, fillPegWithDiscs),
            (pegLabelB, []),
            (pegLabelC, [])
          ]
   in Right
        [ Move "a" "c",
          Move "a" "b",
          Move "c" "b"
        ]
  where
    fillPegWithDiscs :: [Disc]
    fillPegWithDiscs = Disc <$> [1 .. numDisks] -- start here: make sure this is initialized correctly