{-|
Module      : Projectile.SWForward
Description : Growing super weapon projectile
Copyright   : (c) Christopher Howard, 2016
License     : GPL-3
Maintainer  : ch.howard@zoho.com
-}

module Projectile.SWForward ( SWForward(..)
                            , new
                            , prj
                            ) where

import Prelude (min, (+), (*), Maybe(..), (-), ($), cos, (||), (.), Double, Bool(..), sin, max)
import Graphics.Gloss.Data.Picture ( Picture(Circle, Color) )
import Graphics.Gloss.Data.Color ( violet )
import Data.WrapAround ( WP, WM, distance )
import GHC.Float ( double2Float )

import Combat
import Animation
import Updating
import qualified Moving as M ( Colliding(..), Moving(..), Locatable(..), newLocation )
import Common
import Math

velocityC = 700

rangeC = 1000

integrityMax = 60

damE = 6

radiusGrowth = 30

data SWForward =
  SWForward { velocity :: Velocity
         , center :: WP
         , rangeLeft :: Double
         , wrapMap :: WM
         , impacted :: Bool
         , clock :: Time
         , integrity :: Double
         , radius :: Double
         }

new a b c (d, e) =
  SWForward { velocity = (x + d, y + e)
           , center = c
           , rangeLeft = rangeC
           , wrapMap = a
           , impacted = False
           , clock = 0.0
           , integrity = integrityMax
           , radius = 2.0
           }
  where (x, y) = appPair ((* velocityC) . ($ b)) (cos, sin)

instance Animation SWForward where

  image s t = Color violet (Circle (double2Float (radius s)))

instance M.Colliding SWForward where

  collisionRadius = radius

instance M.Moving SWForward where

  velocity = velocity

instance M.Locatable SWForward where

  center = center

expirationFormula s = f rangeLeft || f integrity where f g = (zeroOrLess . g) s

instance SimpleTransient SWForward where

  expired = expirationFormula

instance InternallyUpdating SWForward where

  preUpdate s t = s { clock = clock s + t }

  postUpdate s t = s { center = a, rangeLeft = r, radius = q }
    where a = M.newLocation (wrapMap s) (center s) (velocity s) t
          r = max 0 (rangeLeft s - Data.WrapAround.distance (wrapMap s) (center s) a)
          q = min 128.0 ((radius s) + radiusGrowth * t)

instance Damaging SWForward where

  damageEnergy _ = damE

instance Transient SWForward where

  expired' s = if expirationFormula s then Just [] else Nothing

instance Damageable SWForward where

  inflictDamage s d = s { integrity = integrity s - d }

-- | Func abstracting construction of 'SWForward' projectile
prj :: (M.Moving a)
    => a -- ^ object receiving projectile
    -> (a -> WM) -- ^ func which retrieves WM from object
    -> Angle -- ^ firing angle
    -> Projectile
prj a f b = Projectile (new (f a) b (M.center a) (M.velocity a))