{-# LANGUAGE UnicodeSyntax #-}
module SoccerFun.Field where

import SoccerFun.Geometry
import SoccerFun.Types (Other (other))

data Field = Field
	{fwidth ∷ FieldWidth, -- ^ width of ball field (64m <=width <=75m)
	 flength ∷ FieldLength -- ^ height of ball field (100m<=height<=110m)
	} deriving Show

type FieldWidth = Metre
type FieldLength = Metre

defaultField ∷ Field
defaultField = Field { fwidth = 75.0, flength = 110.0 }

inPenaltyArea ∷ Field → Home → Position → Bool
inPenaltyArea field home pos = northEdge <= py pos && py pos <= southEdge && if home == West then px pos <= westEdge else px pos >= eastEdge where
	northEdge = (fwidth field) / 2.0 - radiusPenaltyArea
	southEdge = (fwidth field) / 2.0 + radiusPenaltyArea
	westEdge = penaltyAreaDepth
	eastEdge = (flength field) - penaltyAreaDepth

data Home = West | East deriving (Eq,Show)

instance Other Home where
	other West = East
	other East = West

isWest ∷ Home → Bool
isWest West = True
isWest _ = False

isEast ∷ Home → Bool
isEast East = True
isEast _ = False

-- | goalPoles yields the py coordinates of the north pole and south pole of the goal (note that north < south).
goalPoles ∷ Field → (Metre,Metre)
goalPoles field = (northPole,southPole) where
	northPole = ((fwidth field)-goalWidth)/2.0
	southPole = northPole + goalWidth

-- | Official metrics of a ball field:
radiusCentreCircle = 9.15 ∷ Float
goalWidth = 7.32 :: Float
goalHeight = 2.44 :: Float
goalAreaDepth = 5.50 :: Float
radiusCornerKickArea = 0.90 :: Float
-- | not official, taken for rendering
goalPoleWidth = 0.3 :: Float
-- | not official, taken for rendering
radiusCentreSpot = 0.3 :: Float

radiusPenaltySpot = 0.2 ∷ Metre
radiusPenaltyArea = 9.15 ∷ Metre

penaltyAreaDepth = 16.50 ∷ Metre
penaltySpotDepth = 11.00 ∷ Metre