{- | Creation of particles in the world.  -}
module Dodge.WorldEvent.SpawnParticle
    ( makeGasCloud
    , makeStaticBall
    , concBall
    , randParticleAt
    ) where
import Dodge.Data
import Dodge.WorldEvent.Shockwave
import RandomHelp
import Picture
import Geometry
import LensHelp

randParticleAt :: (Point2 -> State StdGen Particle) -> Point2 -> World -> World
randParticleAt f p w = w
    & instantParticles .:~ thepart
    & randGen .~ g
  where
    (thepart,g) = runState (f p) (_randGen w)
randEnergyBallAt :: (Point2 -> State StdGen EnergyBall) -> Point2 -> World -> World
randEnergyBallAt f p w = w
    & energyBalls .:~ thepart
    & randGen .~ g
  where
    (thepart,g) = runState (f p) (_randGen w)

makeStaticBall :: Point2 -> World -> World
makeStaticBall p = randEnergyBallAt aStaticBall p . (posEvents .:~ thesparker)
  where
    thesparker = PosEvent SparkSpawner 10 p

concBall :: Point2 -> State g Particle
concBall p = return Shockwave
    { _ptUpdate    = mvShockwave []
    , _ptColor     = white
    , _ptPos       = p
    , _ptRad       = 15
    , _ptDam       = 4
    , _ptPush      = 1
    , _ptMaxTime   = 10
    , _ptTimer     = 10
    }

aStaticBall :: Point2 -> State g EnergyBall
aStaticBall p = return EnergyBall 
    { _ebVel        = 0
    , _ebColor      = blue
    , _ebPos        = p
    , _ebWidth      = 3
    , _ebTimer      = 20
    , _ebEff        = (ELECTRICAL,1)
    , _ebZ = 20
    , _ebRot = 0
    }

-- | Note damgeInRadius by itself never destroys the particle
--damageInRadius :: Float -> Particle -> World -> World
--damageInRadius size pt = damageInArea isClose closeWls pt
--  where
--    p = _ptPos pt
--    closeWls wl = uncurry segOnCirc (_wlLine wl) p size
--    isClose cr = dist p (_crPos cr) < _crRad cr + size

--damageInArea :: (Creature -> Bool) -> (Wall -> Bool) -> Particle -> World -> World
--{-# INLINE damageInArea #-}
--damageInArea crt wlt pt w = damwls damcrs
--  where
--    p = _ptPos pt
--    damcrs = foldl' (flip $ \cr -> fst . hiteff (S.yield (p,Left cr))) w $ IM.filter crt $ _creatures w
--    damwls w' = runIdentity
--        . S.fold_ 
--            (flip $ \wl -> fst . hiteff (S.yield (p,Right wl))) 
--            w' 
--            id
--        . S.filter wlt
--        $ wlsNearPoint p w'
--    hiteff = _ptHitEff pt pt

-- | At writing the radius is half the size of the effect area
makeGasCloud 
    :: Point2   -- ^ Position
    -> Point2   -- ^ Velocity
    -> World 
    -> World
makeGasCloud pos vel w = w
    & clouds    .:~ theCloud
--    & clouds    %~ S.cons theCloud
    & randGen   .~ g
  where 
    theCloud = Cloud 
        {  _clPos = addZ 20 pos
        , _clVel = addZ 0 vel
        , _clPict = \_ -> setLayer MidLayer . setDepth 30 $ color (withAlpha 0.05 col) 
                                          $ circleSolid 20
        , _clRad = 10
        , _clAlt = 25
        , _clTimer = 400
        , _clType = GasCloud
        }
    (col, g) = runState (takeOne [green,yellow]) $ _randGen w
{- Attach poison cloud damage to creatures near cloud.  -}


{- Update of a flamelet.
Applies movement and attaches damage to nearby creatures.  -}
-- This should be unified in many ways with moveFlame
--moveFlamelet :: World -> Particle -> (World, Maybe Particle)
--moveFlamelet w pt 
--    | _ptTimer pt <= 0 = (     w, Nothing)
--    | otherwise        = (ptFlicker pt $ damageInRadius 5 mvPt' w,  Just mvPt')
--  where   
--    mvPt' = pt 
--        & ptTimer    -~ 1
--        & ptPos      .~ _ptPos pt +.+ _ptVel pt
--        & ptVel      .*.*~ 0.8