{-# LANGUAGE DeriveFunctor #-}

-- |
-- Module      : Verismith.Tool.Internal
-- Description : Class of the simulator.
-- Copyright   : (c) 2018-2019, Yann Herklotz
-- License     : GPL-3
-- Maintainer  : yann [at] yannherklotz [dot] com
-- Stability   : experimental
-- Portability : POSIX
--
-- Class of the simulator and the synthesize tool.
module Verismith.Tool.Internal
  ( ResultSh,
    resultSh,
    Tool (..),
    Simulator (..),
    Synthesiser (..),
    Failed (..),
    renameSource,
    checkPresent,
    checkPresentModules,
    replace,
    replaceMods,
    rootPath,
    timeout,
    timeout_,
    bsToI,
    noPrint,
    logger,
    logCommand,
    logCommand_,
    execute,
    execute_,
    (<?>),
    annotate,
  )
where

import Control.Lens
import Control.Monad (forM, void)
import Control.Monad.Catch (throwM)
import Data.Bits (shiftL)
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import Data.Maybe (catMaybes)
import Data.Text (Text)
import qualified Data.Text as T
import Data.Time.Format (defaultTimeLocale, formatTime)
import Data.Time.LocalTime (getZonedTime)
import Shelly
import Shelly.Lifted (MonadSh, liftSh)
import System.FilePath.Posix (takeBaseName)
import Verismith.CounterEg (CounterEg)
import Verismith.Internal
import Verismith.Result
import Verismith.Verilog.AST
import Prelude hiding (FilePath)

-- | Tool class.
class Tool a where
  toText :: a -> Text

-- | Simulation type class.
class Tool a => Simulator a where
  runSim ::
    Show ann =>
    -- | Simulator instance
    a ->
    -- | Run information
    SourceInfo ann ->
    -- | Inputs to simulate
    [ByteString] ->
    -- | Returns the value of the hash at the output of the testbench.
    ResultSh ByteString
  runSimWithFile ::
    a ->
    FilePath ->
    [ByteString] ->
    ResultSh ByteString

data Failed
  = EmptyFail
  | EquivFail (Maybe CounterEg)
  | EquivError
  | SimFail ByteString
  | SynthFail
  | TimeoutError
  deriving (Eq)

instance Show Failed where
  show EmptyFail = "EmptyFail"
  show (EquivFail _) = "EquivFail"
  show EquivError = "EquivError"
  show (SimFail bs) = "SimFail " <> T.unpack (T.take 10 $ showBS bs)
  show SynthFail = "SynthFail"
  show TimeoutError = "TimeoutError"

instance Semigroup Failed where
  EmptyFail <> a = a
  b <> _ = b

instance Monoid Failed where
  mempty = EmptyFail

-- | Synthesiser type class.
class Tool a => Synthesiser a where
  runSynth ::
    Show ann =>
    -- | Synthesiser tool instance
    a ->
    -- | Run information
    SourceInfo ann ->
    -- | does not return any values
    ResultSh ()
  synthOutput :: a -> FilePath
  setSynthOutput :: a -> FilePath -> a

renameSource :: (Synthesiser a) => a -> SourceInfo ann -> SourceInfo ann
renameSource a src =
  src & infoSrc . _Wrapped . traverse . modId . _Wrapped %~ (<> toText a)

-- | Type synonym for a 'ResultT' that will be used throughout 'Verismith'. This
-- has instances for 'MonadSh' and 'MonadIO' if the 'Monad' it is parametrised
-- with also has those instances.
type ResultSh = ResultT Failed Sh

resultSh :: ResultSh a -> Sh a
resultSh s = do
  result <- runResultT s
  case result of
    Fail e -> throwM . RunFailed "" [] 1 $ showT e
    Pass s' -> return s'

checkPresent :: FilePath -> Text -> Sh (Maybe Text)
checkPresent fp t = do
  errExit False $ run_ "grep" [t, toTextIgnore fp]
  i <- lastExitCode
  if i == 0 then return $ Just t else return Nothing

-- | Checks what modules are present in the synthesised output, as some modules
-- may have been inlined. This could be improved if the parser worked properly.
checkPresentModules :: FilePath -> SourceInfo ann -> Sh [Text]
checkPresentModules fp (SourceInfo _ src) = do
  vals <-
    forM (src ^.. _Wrapped . traverse . modId . _Wrapped) $
      checkPresent fp
  return $ catMaybes vals

-- | Uses sed to replace a string in a text file.
replace :: FilePath -> Text -> Text -> Sh ()
replace fp t1 t2 = do
  errExit False . noPrint $
    run_
      "sed"
      ["-i", "s/" <> t1 <> "/" <> t2 <> "/g", toTextIgnore fp]

-- | This is used because rename only renames the definitions of modules of
-- course, so instead this just searches and replaces all the module names. This
-- should find all the instantiations and definitions. This could again be made
-- much simpler if the parser works.
replaceMods :: FilePath -> Text -> SourceInfo ann -> Sh ()
replaceMods fp t (SourceInfo _ src) =
  void
    . forM (src ^.. _Wrapped . traverse . modId . _Wrapped)
    $ (\a -> replace fp a (a <> t))

rootPath :: Sh FilePath
rootPath = do
  current <- pwd
  maybe current fromText <$> get_env "VERISMITH_ROOT"

timeout :: FilePath -> [Text] -> Sh Text
timeout = command1 "timeout" ["300"] . toTextIgnore
{-# INLINE timeout #-}

timeout_ :: FilePath -> [Text] -> Sh ()
timeout_ = command1_ "timeout" ["300"] . toTextIgnore
{-# INLINE timeout_ #-}

-- | Helper function to convert bytestrings to integers
bsToI :: ByteString -> Integer
bsToI = B.foldl' (\i b -> (i `shiftL` 8) + fromIntegral b) 0
{-# INLINE bsToI #-}

noPrint :: Sh a -> Sh a
noPrint = print_stdout False . print_stderr False
{-# INLINE noPrint #-}

logger :: Text -> Sh ()
logger t = do
  fn <- pwd
  currentTime <- liftIO getZonedTime
  echo $
    "Verismith "
      <> T.pack (formatTime defaultTimeLocale "%H:%M:%S " currentTime)
      <> bname fn
      <> " - "
      <> t
  where
    bname = T.pack . takeBaseName . T.unpack . toTextIgnore

logCommand :: FilePath -> Text -> Sh a -> Sh a
logCommand fp name =
  log_stderr_with (l "_stderr.log")
    . log_stdout_with (l ".log")
  where
    l s t = appendFile (file s) (T.unpack t) >> appendFile (file s) "\n"
    file s = T.unpack (toTextIgnore $ fp </> fromText name) <> s

logCommand_ :: FilePath -> Text -> Sh a -> Sh ()
logCommand_ fp name = void . logCommand fp name

execute ::
  (MonadSh m, Monad m) =>
  Failed ->
  FilePath ->
  Text ->
  FilePath ->
  [Text] ->
  ResultT Failed m Text
execute f dir name e cs = do
  (res, exitCode) <- liftSh $ do
    res <- errExit False . logCommand dir name $ timeout e cs
    (,) res <$> lastExitCode
  case exitCode of
    0 -> ResultT . return $ Pass res
    124 -> ResultT . return $ Fail TimeoutError
    _ -> ResultT . return $ Fail f

execute_ ::
  (MonadSh m, Monad m) =>
  Failed ->
  FilePath ->
  Text ->
  FilePath ->
  [Text] ->
  ResultT Failed m ()
execute_ a b c d = void . execute a b c d