module AI (aimove) where

import Eval
import Lambda
import GoalTransform

import qualified Data.Array.IO as A

cannon 1 = "dec"
cannon 2 = "S dec dec"
cannon n = "S(" ++ cannon (n-1) ++ ") dec"

keepalive func 0 = "S(" ++ func ++ ")(get)0"
keepalive func 1 = "S(K(S(" ++ func ++ ")(get)))(succ)0"
keepalive func slot = "S(" ++ func ++ ")(S (K get) (K " ++ show slot ++ "))0"

findAliveSlot :: (Game -> Player) -> Turn Int
findAliveSlot player = do
	game <- getGame
	slots <- liftIO $ A.getAssocs (fields $ player game)
	let (slot, _):_ = filter (\(_, (_, vit)) -> vit > 0) slots
	return slot

findHighAliveSlot :: (Game -> Player) -> Turn Int
findHighAliveSlot player = do
	game <- getGame
	slots <- liftIO $ A.getAssocs (fields $ player game)
	let (slot, _):_ = filter (\(_, (_, vit)) -> vit > 0) $ reverse slots
	return slot

aimove :: Turn Goal
aimove = do
	target <- findAliveSlot opponent
	let l = if (target == 255) then "S(dec)(S(get)(I))" else "S(S(K(dec))(K(" ++ show (255-target) ++ ")))(S(get)(I))"
-- 	let l = if (target == 255) then "S(dec)(S(get)(I))" else "S(K(S(dec)(S(get)(I))))(K(" ++ show (255-target) ++ "))"
	let pos = 1 -- if (target == 255) then 1 else 255-target
	haveLoop <- satGoal (0, read l)
	if haveLoop then do
			haveLoop <- satGoal (pos, read l)
			if haveLoop then do
					return (Just pos, read (l ++ "0"))
				else
					return (Just pos, read "get 0")
		else do
			return (Just 0, read l)