module Dodge.Creature.Property
    ( crIsArmouredFrom
    , crNearSeg
    , crNearPoint
    ) where
import Dodge.Data
import Dodge.Creature.HandPos
import Geometry

import Data.Maybe
import Control.Lens

-- the use of crOldPos is because the damage position is calculated on the
-- previous frame
-- Not sure if it is a good idea
crIsArmouredFrom :: Point2 -> Creature -> Bool
crIsArmouredFrom p cr = hasFrontArmour p cr

hasFrontArmour :: Point2 -> Creature -> Bool
hasFrontArmour p cr = fromMaybe False $ do
    invid <- cr ^? crEquipment . ix OnChest
    ittype <- cr ^? crInv . ix invid . itType
    return $ FRONTARMOUR == ittype
        && p /= _crOldPos cr 
        && angleVV (unitVectorAtAngle (_crDir cr + frontarmdirection)) (p -.- _crOldPos cr) < pi/2
-- even though angleVV can generate NaN, the comparison seems to deal with it
  where
    frontarmdirection
        | crInStance OneHand cr = 0.5
        | crInStance TwoHandTwist cr = negate 1
        | otherwise = 0

--crOnSeg :: Point2 -> Point2 -> Creature -> Bool
--crOnSeg p1 p2 cr = circOnSeg p1 p2 (_crPos cr) (_crRad cr)

crNearSeg :: Float -> Point2 -> Point2 -> Creature -> Bool
crNearSeg d p1 p2 cr = circOnSeg p1 p2 (_crPos cr) (_crRad cr + d)

crNearPoint :: Float -> Point2 -> Creature -> Bool
crNearPoint d p cr = dist (_crPos cr) p < d + _crRad cr