module RPGEngine.Input.Level
( putCoords
, findFirst
, whatIsAt
) where
import RPGEngine.Data (Level (..), Y, X, Physical(..))

-- Map all Physicals onto coordinates
putCoords :: Level -> [(X, Y, Physical)]
putCoords l@Level{ layout = lay } = concatMap (\(a, bs) -> map (\(b, c) -> (b, a, c)) bs) numberedList
    where numberedStrips = zip [0::Int .. ] lay
          numberedList   = map (\(x, strip) -> (x, zip [0::Int ..] strip)) numberedStrips

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

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