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

module Projectile.Interceptor ( Interceptor(..)
                            , new
--                            , prj
                            , speed
                            ) where

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

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

velocityC = 900

rangeC = 1200

damE = 4

radiusC = 12.0

speed = velocityC

data Interceptor = Interceptor { velocity :: Velocity
                               , center :: WP
                               , rangeLeft :: Double
                               , wrapMap :: WM
                               , impacted :: Bool
                               , clock :: Time
                               , rt :: RT
                               , angle :: Angle
                               }

new a r b c (d, e) = Interceptor { velocity = (x + d, y + e)
                                 , center = c
                                 , rangeLeft = rangeC
                                 , wrapMap = a
                                 , impacted = False
                                 , clock = 0.0
                                 , rt = r
                                 , angle = b
                                 }
  where (x, y) = appPair ((* velocityC) . ($ b)) (cos, sin)

instance Animation Interceptor where

  image s t = reorient (angle s) c

    where f x = fromMaybe (Color white (Circle r)) (getImage (rt s) x)
          p1 = f "interceptor-1.bmp"
          p2 = f "interceptor-2.bmp"
          p3 = f "interceptor-3.bmp"
          g = ((clock s `remF` 0.3) >)
          c = if g 0.2 then p3 else if g 0.1 then p2 else p1
          r = double2Float radiusC

instance M.Colliding Interceptor where

  collisionRadius _ = radiusC

instance M.Moving Interceptor where

  velocity = velocity

instance M.Locatable Interceptor where

  center = center

instance SimpleTransient Interceptor where

  expired s = impacted s || (zeroOrLess . rangeLeft) s

instance InternallyUpdating Interceptor where

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

  postUpdate s t = s { center = a, rangeLeft = r }
    where a = M.newLocation (wrapMap s) (center s) (velocity s) t
          r = max 0 (rangeLeft s - Data.WrapAround.distance (wrapMap s) (center s) a)

instance Damaging Interceptor where

  damageEnergy _ = damE

instance Transient Interceptor where

  expired' s = if impacted s || (zeroOrLess . rangeLeft) s then Just [] else Nothing

instance Damageable Interceptor where

  inflictDamage s d = if moreThanZero d then s { impacted = True } else s

-- -- | Func abstracting construction of 'Interceptor' 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))