module Map.Creation
where

import Map.Types

import Data.Array
import System.Random

-- entirely empty map, only uses the minimal constructor
mapEmpty :: PlayMap
mapEmpty = array ((0,0), (199,199)) [((a,b), Node (a,b) (fromIntegral a, (if even b then (fromIntegral b) else(fromIntegral b) - 0.5), 1) Grass BNothing NoPlayer NoPath Plain []) | a <- [0..199], b <- [0..199]]

exportedMap :: IO PlayMap
exportedMap = do mounts <- mnt
                 return $ aplAll mounts mapEmpty

-- | Generate a new Map of given Type and Size
--
--   TODO:
--   1. Should take Size -> Type -> Playmap
--   2. plug together helper-functions for that terraintype
newMap :: MapType -> (Int, Int) -> PlayMap
newMap = undefined

aplByPlace :: (Node -> Node) -> ((Int,Int) -> Bool) -> PlayMap -> PlayMap
aplByPlace f g mp = array (bounds mp) (map (\(ab,c) -> if g ab then (ab, f c) else (ab,c)) (assocs mp))

aplByNode :: (Node -> Node) -> (Node -> Bool) -> PlayMap -> PlayMap
aplByNode f g mp = array (bounds mp) (map (\(ab,c) -> (if g c then (ab, f c) else (ab,c))) (assocs mp)) 

aplAll :: [a -> a] -> a -> a
aplAll fs m = foldl (\ n f -> f n) m fs

aplAllM :: Monad m => [m a -> m a] -> m a -> m a
aplAllM fs x = foldl (\ n f -> f n) x fs

-- general 3D-Gaussian
gauss3Dgeneral :: Floating q =>
                  q    -- ^ Amplitude
                  -> q -- ^ Origin on X-Achsis
                  -> q -- ^ Origin on Z-Achsis
                  -> q -- ^ Sigma on X
                  -> q -- ^ Sigma on Z
                  -> q -- ^ Coordinate in question on X
                  -> q -- ^ Coordinate in question on Z
                  -> q -- ^ elevation on coordinate in question
gauss3Dgeneral amp x0 z0 sX sZ x z = amp * exp(-(((x-x0)^(2 :: Int)/(2 * sX^(2 :: Int)))+((z-z0)^(2 :: Int)/(2 * sZ^(2 :: Int)))))

-- | Basic Terrain-Generator. Will not implement "abnormal" Stuff for given Biome
--   (like Deserts on Grass-Islands or Grass on Deserts)
--
--   TODO: Implement Desert-Generator
heightToTerrain :: MapType -> YCoord -> TileType
heightToTerrain GrassIslandMap y
                | y < 0.1   = Ocean
                | y < 0.2   = Beach
                | y < 1     = Grass
                | y < 3     = Hill
                | otherwise = Mountain
heightToTerrain _ _ = undefined


lake :: Int -> PlayMap -> PlayMap
lake = undefined

river :: Int -> PlayMap -> PlayMap
river = undefined

mnt :: IO [PlayMap -> PlayMap]
mnt = do g <- newStdGen
         let seeds = take 50 $ randoms g
         return $ map gaussMountain seeds

gaussMountain :: Int -> PlayMap -> PlayMap
gaussMountain seed mp = aplByPlace (liftUp c) (\(_,_) -> True) mp
  where
    gs  = map mkStdGen (map (*seed) [1..])
    c   = let ((a,b), (x,y)) = bounds mp in (head (randomRs (a,x) (gs !! 0)), (head (randomRs (b,y) (gs !! 1))))
    amp = head $ randomRs ((2.0, 5.0) :: (Float, Float)) (gs !! 2)
    sig = head $ randomRs ((1.0, 15.0) :: (Float, Float)) (gs !! 3)
    htt = heightToTerrain

    -- TODO: Fix Lambda to True with sensible function, maybe rework giveNeighbourhood in Map.Map
    liftUp :: (Int, Int) -> Node -> Node
    liftUp (gx,gz) (Node (x,z) (rx,rz,y) _ b pl pa r s) = let y_neu = max y e
                                                          in  Node (x,z) (rx, rz, y_neu) (htt GrassIslandMap y_neu) b pl pa r s
      where e = gauss3Dgeneral amp (fromIntegral gx) (fromIntegral gz) sig sig rx rz

-- | Makes sure the edges of the Map are mountain-free
makeIsland :: PlayMap -> PlayMap
makeIsland = undefined -- tomorrow....