{-# LANGUAGE DataKinds #-}

module Main where

import Html
import qualified Html.Attribute as A
import qualified Small          as S
import qualified Medium         as M
import qualified Big            as B

import Weigh
import Control.DeepSeq
import Data.Proxy
import Data.Int

import System.IO.Temp
import GHC
import GHC.Paths (libdir)
import DynFlags
import Control.Monad

allocs :: Int64 -> Weight -> Maybe String
allocs n w
  | n' > n = Just $ "More" ++ answer
  | n' < n = Just $ "Less" ++ answer
  | otherwise = Nothing
  where n' = weightAllocatedBytes w
        answer = " allocated bytes than " ++ commas n ++ ": " ++ commas n'

allocsError :: Int -> Int -> Weight -> Maybe String
allocsError n i w
  | n' > (n+1) = Just $ "More" ++ answer
  | n' < (n-1) = Just $ "Less" ++ answer
  | otherwise = Nothing
  where n' = round (fromIntegral (weightAllocatedBytes w) / (10^i) :: Rational) :: Int
        answer = " allocated bytes than "
              ++ pretty (show n)
              ++ ": "
              ++ pretty (show n')
        pretty (a:as) = a : '.' : as ++ " e" ++ show (length as+i)
        pretty _      = ""

f :: NFData b => String -> Int64 -> (a -> b) -> a -> Weigh ()
f s n g x = validateFunc s g x (allocs n)

main :: IO ()
main = withSystemTempDirectory "compile" $ \tmp -> mainWith $ do

  -- nixpkgs: 1b27260
  -- ghc: 8.4.1

  f "()"                             144 renderByteString ()
  f "Int"                            216 renderByteString (123456789 :: Int)
  f "Word"                           216 renderByteString (123456789 :: Word)
  f "Char"                           232 renderByteString 'a'
  f "Integer"                        248 renderByteString (123456789 :: Integer)
  f "Proxy"                          280 renderByteString (Proxy :: Proxy "a")
  f "oneElement Proxy"               280 (renderByteString . S.oneElement) (Proxy :: Proxy "b")
  f "oneElement ()"                  280 (renderByteString . S.oneElement) ()
  f "oneAttribute ()"                280 (renderByteString . A.class_) ()
  f "oneAttribute Proxy"             280 (renderByteString . A.class_) (Proxy :: Proxy "c")
  f "listElement"                    352 (renderByteString . S.listElement) ()
  f "Double"                         360 renderByteString (123456789 :: Double)
  f "oneElement"                     368 (renderByteString . S.oneElement) ""
  f "nestedElement"                  368 (renderByteString . S.nestedElement) ""
  f "listOfAttributes"               352 (\x -> renderByteString [A.class_ x, A.class_ x]) ()
  f "Float"                          400 renderByteString (123456789 :: Float)
  f "oneAttribute"                   408 (renderByteString . A.class_) ""
  f "parallelElement"                520 (renderByteString . S.parallelElement) ""
  f "parallelAttribute"              584 (\x -> renderByteString $ A.class_ x # A.id_ x) ""
  f "elementWithAttribute"           584 (\x -> renderByteString $ div_A (A.class_ x) x) ""
  f "listOfListOf"                   632 (\x -> renderByteString $ div_ [i_ [span_ x]]) ()
  f "helloWorld"                    1232 (renderByteString . M.helloWorld) ()
  f "page"                          1512 (renderByteString . M.page) ()
  f "table"                         1664 (renderByteString . M.table) (2,2)
  f "AttrShort"                     2608 (renderByteString . M.attrShort) ()
  f "pageA"                         2960 (renderByteString . M.pageA) ()
  f "AttrLong"                      3352 (renderByteString . M.attrLong) ()
  f "Big table"                    19968 (renderByteString . M.table) (15,15)
  f "Big page"                     25064 (renderByteString . B.page) ()

  validateAction "Compile Library"   (compile tmp) "Html"           (allocsError 1021 6)
  validateAction "Compile Small.hs"  (compile tmp) "Small"          (allocsError 1061 6)
  validateAction "Compile Medium.hs" (compile tmp) "Medium"         (allocsError 1790 6)
  validateAction "Compile Big.hs"    (compile tmp) "Big"            (allocsError 2470 6)
  validateAction "Compile Alloc.hs"  (compile tmp) "bench/Alloc.hs" (allocsError 2531 6)
  validateAction "Compile Perf.hs"   (compile tmp) "bench/Perf.hs"  (allocsError 4809 6)

compile :: String -> String -> IO ()
compile out m =
  void . defaultErrorHandler defaultFatalMessager defaultFlushOut . runGhc (Just libdir) $ do
    dflags <- getSessionDynFlags
    void $ setSessionDynFlags (dflags {optLevel = 2, importPaths = ["src", "bench"], hiDir = Just out, objectDir = Just out, outputFile = Just (out ++ "/out")})
    target <- guessTarget m Nothing
    setTargets [target]
    load LoadAllTargets