{-# LANGUAGE RankNTypes                 #-}
{-# LANGUAGE TypeApplications           #-}

module DenseBench
  ( benchSuite
  ) where

import Prelude hiding (quotRem, gcd)
import Gauge.Main
import Data.Euclidean (Euclidean(..), GcdDomain(..))
import Data.Poly
import qualified Data.Poly.Semiring as S (toPoly)
import Data.Semiring (Semiring(..), Ring, Mod2(..))
import qualified Data.Semiring as S (fromIntegral)
import qualified Data.Vector as V
import qualified Data.Vector.Unboxed as U

benchSuite :: Benchmark
benchSuite = bgroup "dense" $ concat
  [ map benchAdd      [100, 1000, 10000]
  , map benchMul      [100, 1000, 10000]
  , map benchEval     [100, 1000, 10000]
  , map benchDeriv    [100, 1000, 10000]
  , map benchIntegral [100, 1000, 10000]
  , map benchQuotRem  [10, 100]
  , map benchGcd      [10, 100]
  , map benchGcdRat   [10, 20, 40]
  , map benchGcdM     [10, 100, 1000]
  ]

benchAdd :: Int -> Benchmark
benchAdd k = bench ("add/" ++ show k) $ nf (doBinOp (+)) k

benchMul :: Int -> Benchmark
benchMul k = bench ("mul/" ++ show k) $ nf (doBinOp (*)) k

benchEval :: Int -> Benchmark
benchEval k = bench ("eval/" ++ show k) $ nf doEval k

benchDeriv :: Int -> Benchmark
benchDeriv k = bench ("deriv/" ++ show k) $ nf doDeriv k

benchIntegral :: Int -> Benchmark
benchIntegral k = bench ("integral/" ++ show k) $ nf doIntegral k

benchQuotRem :: Int -> Benchmark
benchQuotRem k = bench ("quotRem/" ++ show k) $ nf doQuotRem k

benchGcd :: Int -> Benchmark
benchGcd k = bench ("gcd/Integer/" ++ show k) $ nf (doGcd @Integer) k

benchGcdRat :: Int -> Benchmark
benchGcdRat k = bench ("gcd/Rational/" ++ show k) $ nf (doGcd @Rational) k

benchGcdM :: Int -> Benchmark
benchGcdM k = bench ("gcd/Mod2/" ++ show k) $ nf (getMod2 . doGcd @Mod2) k

doBinOp :: (forall a. Num a => a -> a -> a) -> Int -> Int
doBinOp op n = U.sum zs
  where
    xs = toPoly $ U.generate n (* 2)
    ys = toPoly $ U.generate n (* 3)
    zs = unPoly $ xs `op` ys
{-# INLINE doBinOp #-}

doEval :: Int -> Int
doEval n = eval xs n
  where
    xs = toPoly $ U.generate n (* 2)

doDeriv :: Int -> Int
doDeriv n = U.sum zs
  where
    xs = toPoly $ U.generate n (* 2)
    zs = unPoly $ deriv xs

doIntegral :: Int -> Double
doIntegral n = U.sum zs
  where
    xs = toPoly $ U.generate n ((* 2) . fromIntegral)
    zs = unPoly $ integral xs

gen1 :: Ring a => Int -> a
gen1 k = S.fromIntegral (truncate (pi * fromIntegral k :: Double) `mod` (k + 1))

gen2 :: Ring a => Int -> a
gen2 k = S.fromIntegral (truncate (exp 1.0 * fromIntegral k :: Double) `mod` (k + 1))

doQuotRem :: Int -> Double
doQuotRem n = U.sum (unPoly qs) + U.sum (unPoly rs)
  where
    xs = toPoly $ U.generate (2 * n) gen1
    ys = toPoly $ U.generate n       gen2
    (qs, rs) = xs `quotRem` ys

doGcd :: (Eq a, Ring a, GcdDomain a) => Int -> a
doGcd n = V.foldl' plus zero gs
  where
    xs = S.toPoly $ V.generate n gen1
    ys = S.toPoly $ V.generate n gen2
    gs = unPoly $ xs `gcd` ys