{-# LANGUAGE BangPatterns #-}
module Dodge.Block where
import Dodge.Data
import Dodge.Base
import Dodge.SoundLogic

import Geometry
import Picture.Data

import Control.Lens

import Data.List

import Data.Function
import qualified Data.IntMap.Strict as IM
import System.Random
import Control.Monad.State

updateBlocks :: World -> World
updateBlocks w = (\w' -> seq (_wallsZone w') w') $ flip (foldr removeFromZone) deadPanes 
                    $ over walls (\wls -> wls `seq` IM.filter (not . blockIsDead) wls)
                 degradeBlocks 
--                    w                
   where  degradeBlocks = deadBlocks `seq` foldr killBlock w deadBlocks
          removeFromZone :: Wall -> World -> World
          removeFromZone bl = over (wallsZone . ix x . ix y) (IM.delete (_wlID bl))
            where (x,y) = zoneOfPoint $ pHalf (_wlLine bl !! 0) (_wlLine bl !! 1)
          deadPanes = filter blockIsDead (IM.elems $ _walls w)
          deadBlocks = nubBy ((==) `on` _blIDs) deadPanes
          blockIsDead wl = case wl ^? blHP of Just x  -> x <= 0
                                              Nothing -> False

killBlock :: Wall -> World -> World
killBlock bl w =  f bl .
                  flip (foldr unshadow)
--                  flip (foldr (\i -> set (walls . ix i . blVisible) (True)))
                         (_blShadows bl)
                        $ w
    where
        f bl@(Block {_blDegrades = (x:xs)}) = degradeBlock bl . hitSound bl
        f bl          = hitSound' bl
        hitSound bl | _wlIsSeeThrough bl = soundMultiFrom sos (soundid+8) 25 0 
                    | otherwise = soundMultiFrom sos soundid 25 0 
        hitSound' bl | _wlIsSeeThrough bl = soundMultiFrom sos (soundid+4) 25 0 
                     | otherwise = soundMultiFrom sos soundid 25 0 
        sos = [BlockDegradeSound 0,BlockDegradeSound 1]
        (soundid,_) = randomR (29,32) $ _randGen w
        unshadow :: Int -> World -> World
        unshadow bid w = case w ^? walls . ix bid of 
                            Just b  -> let (x,y) = zoneOfPoint $ pHalf (_wlLine b !! 0) (_wlLine b !! 1)
                                       in  w & wallsZone . ix x . ix y . ix bid . blVisible %~ \_ -> True
                            Nothing -> w

degradeBlock :: Wall -> World -> World
degradeBlock bl w = let blid = _wlID bl
                        bls = map (\i -> _walls w IM.! i) (_blIDs $ _walls w IM.! blid)
                        ps = reverse $ orderPolygon $ nub $ concatMap _wlLine bls
                        (newPs,g) = runState (shrinkPolygon 0.5 ps) $ _randGen w
                        (x:xs) = _blDegrades bl
                    in  addBlock newPs (x + _blHP bl) (_wlColor bl) (_wlIsSeeThrough bl) xs $ set randGen g w

pushPointTowardsBy :: RandomGen g => Float -> Point2 -> [Point2] -> State g Point2
pushPointTowardsBy x p ps = do
    xs <- sequence $ take (length ps) $ repeat $ state $ randomR (0, x / (fromIntegral $ length ps))
    let toAdd p' y = y *.* (p' -.- p)
    return $ p +.+ foldr1 (+.+) (zipWith toAdd ps xs)

shrinkPolygon :: RandomGen g => Float -> [Point2] -> State g [Point2]
shrinkPolygon x ps = sequence $ map (flip (pushPointTowardsBy x) ps) ps


addBlock :: [Point2] -> Int -> Color -> Bool -> [Int] -> World -> World
addBlock (p:ps) hp col isSeeThrough degradability w 
    | hp <= 0 && degradability == [] = w
    | hp <= 0 = addBlock (p:ps) (head degradability + hp) col isSeeThrough (tail degradability) w
    | otherwise = over wallsZone (flip (IM.foldr wallInZone) blocks)
      $ over walls (IM.union blocks) w
--addBlock (p:p':ps) w = over walls (IM.insert i b) w
    where 
        lines = zip (p:ps) (ps ++ [p])
        i = newKey $ _walls w
        is = [i.. i + length lines-1]
        blocks = IM.fromList $ zip is 
                  $ zipWith (\j (a,b) -> Block { _wlLine = [a,b]
                                               , _wlID = j
                                            --   , _wlColor = greyN 0.5
                                               , _wlColor = col
                                               , _wlDraw = Nothing
                                               , _wlSeen = False
                                               , _blIDs = is
                                               , _blHP = hp
                                               , _wlIsSeeThrough = isSeeThrough
                                               , _blVisible = True
                                               , _blShadows = []
                                               , _blDegrades = degradability
                                               }
                             ) is lines
        wallInZone wl | dist (_wlLine wl !! 0) (_wlLine wl !! 1) <= 2*zoneSize 
                          = insertIMInZone x y wlid wl
                      | otherwise = flip (foldr (\(a,b) -> insertIMInZone a b wlid wl)) ips
          where (x,y) = zoneOfPoint $ (pHalf (_wlLine wl !! 0) (_wlLine wl !! 1))
                wlid  = _wlID wl
                ips = map zoneOfPoint $ divideLine (2*zoneSize) (_wlLine wl !! 0) (_wlLine wl !! 1)