{-# LANGUAGE MultiParamTypeClasses #-}
--
-- Library of AI players
--
module AI where

import Board
import System.Random
import Data.Map(Map)
import qualified Data.Map as Map
import Data.Maybe(catMaybes)
import AI.Gametree
import AI.Minimax
import AI.Eval

import Control.Monad.State


-- | instance the transition system for TZAAR games
instance Transitions Board Move where
  actions = nextMoves
  transition = applyMove

-- | An AI play strategy
-- allows monad for pseudo-random computations
-- (current strategies don't need it)
type Strategy = Board -> State StdGen (Move, Value)

-- | An AI player.
data AI = AI
  { name :: String          -- ^ Unique name
  , description :: String   -- ^ Brief description of AI.
  , strategy :: Strategy    -- ^ The AI strategy.
  }


  {-
aiLevels :: [AI]
aiLevels = catMaybes [lookupAI label aiPlayers | label<-list]
  where list = ["nscout_simple_1",
                "nscout_simple_3",
                "nscout_full_1",
                "nscout_full_3",
                "nscout_full_6",
                "pscout_full_3",
                "pscout_full_6"]
-}
aiLevels = aiPlayers

lookupAI :: String -> [AI] -> Maybe AI
lookupAI label ai_list
  = case [ai | ai<-ai_list, name ai==label] of
    [] -> Nothing
    (ai : _) -> Just ai


aiPlayers :: [AI]
aiPlayers = do (txt0, txt1, search) <- searches
               (txt2, valf) <- valuations
               ply <- [1..6]
               let label = txt0 ++ "_" ++ txt2 ++ "_" ++ show ply
               let desc = txt1 ++ " " ++ txt2 ++ " valuation, ply " ++ show ply
               return AI { name = label
                         , description = desc
                         , strategy = return . searchMove (search valf) ply
                         }
   where searches = [ ("nmax", "Negamax", alphaBeta)
                    , ("nscout", "Negascout", negascout)
                    , ("pscout", "Parallel Negascout", jamboree)
                    ]
         valuations = [ ("simple", simpleVal), ("full", fullVal)]