{-# OPTIONS_GHC -fplugin GHC.TypeLits.KnownNat.Solver #-}

{-# LANGUAGE DataKinds            #-}
{-# LANGUAGE PolyKinds            #-}
{-# LANGUAGE TypeFamilies         #-}
{-# LANGUAGE TypeOperators        #-}
{-# LANGUAGE UndecidableInstances #-}

module CacheMap
    ( spec
    ) where

import Prelude hiding (lookup)

import Criterion.Main (bench, env, nf, whnf)
import Data.Kind (Type)
import Data.Maybe (fromJust)
import Data.Proxy (Proxy (..))
import Data.Typeable (Typeable)
import GHC.Exts (fromList)
import GHC.TypeLits (type (+), KnownNat, Nat)

import Data.TypeRepMap.Internal (TypeRepMap (..), WrapTypeable (..), empty, insert, lookup)

import Spec (BenchSpec (..))


spec :: BenchSpec
spec = BenchSpec
    { benchLookup = Just $ \name ->
        env (mkMap 10000) $ \ ~bigMap ->
            bench name $ nf tenLookups bigMap
    , benchInsertSmall = Just $ \name ->
        bench name $ whnf (inserts empty 10) (Proxy @ 99999)
    , benchInsertBig = Just $ \name ->
        env (mkMap 10000) $ \ ~bigMap ->
            bench name $ whnf (inserts bigMap 1) (Proxy @ 99999)
    , benchUpdateSmall = Just $ \name ->
        env (mkMap 10) $ \ ~smallMap ->
            bench name $ whnf (inserts smallMap 10) (Proxy @ 0)
    , benchUpdateBig = Just $ \name ->
        env (mkMap 10000) $ \ ~bigMap ->
            bench name $ whnf (inserts bigMap 10) (Proxy @ 0)
    }

tenLookups
    :: TypeRepMap (Proxy :: Nat -> Type)
    -> ( Proxy 10, Proxy 20, Proxy 30, Proxy 40
       , Proxy 50, Proxy 60, Proxy 70, Proxy 80
       )
tenLookups tmap = (lp, lp, lp, lp, lp, lp, lp, lp)
  where
    lp :: forall (a :: Nat) . Typeable a => Proxy a
    lp = fromJust $ lookup tmap

inserts
    :: forall a . (KnownNat a)
    => TypeRepMap (Proxy :: Nat -> Type)
    -> Int
    -> Proxy (a :: Nat)
    -> TypeRepMap (Proxy :: Nat -> Type)
inserts !c 0 _ = c
inserts !c n x = inserts
    (insert x c)
    (n-1)
    (Proxy :: Proxy (a + 1))

mkMap :: Int -> IO (TypeRepMap (Proxy :: Nat -> Type))
mkMap n = pure $ fromList $ buildBigMap n (Proxy :: Proxy 0) []


buildBigMap
    :: forall a . (KnownNat a)
    => Int
    -> Proxy (a :: Nat)
    -> [WrapTypeable (Proxy :: Nat -> Type)]
    -> [WrapTypeable (Proxy :: Nat -> Type)]
buildBigMap 1 x = (WrapTypeable x :)
buildBigMap n x = (WrapTypeable x :) . buildBigMap (n - 1) (Proxy :: Proxy (a + 1))