module RPGEngine.Data.Level
-- Everything is exported
where

import GHC.IO (unsafePerformIO)
import System.Directory (getDirectoryContents)
import RPGEngine.Input.Core (ListSelector(..))
import RPGEngine.Data (Level (..), Physical (..), Direction (..), Entity (..), Game (..), Item (..), Player (..), StateBase (..), State (..), X, Y, Layout)
import RPGEngine.Config (levelFolder)

------------------------------ Exported ------------------------------

-- Find first position of a Physical
-- Graceful exit by giving Nothing if there is nothing found.
findFirstOf :: Level -> Physical -> Maybe (X, Y)
findFirstOf l@Level{ index = index } physical = try
    where matches = filter (\(x, y, v) -> v == physical) index
          try     | not (null matches) = Just $ (\(x, y, _) -> (x, y)) $ head matches
                  | otherwise          = Nothing

-- What is located at a given position in the level?
findAt :: (X, Y) -> Level -> Physical
findAt pos lvl@Level{ index = index } = try
    where matches = map (\(_, _, v) -> v) $ filter (\(x, y, v) -> (x, y) == pos) index
          try     | not (null matches) = head matches
                  | otherwise          = Void

directionOffsets :: Direction -> (X, Y)
directionOffsets North  = ( 0,  1)
directionOffsets East   = ( 1,  0)
directionOffsets South  = ( 0, -1)
directionOffsets West   = (-1,  0)
directionOffsets Stay   = ( 0,  0)

getLevelList :: [FilePath]
getLevelList = drop 2 $ unsafePerformIO $ getDirectoryContents levelFolder