{-# LANGUAGE TupleSections #-}
{-
   Copyright 2016, Dominic Orchard, Andrew Rice, Mistral Contrastin, Matthew Danish

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
-}

module Camfort.Specification.Stencils
 (infer, check, synth) where

import           Camfort.Analysis
import           Camfort.Analysis.Annotations
import           Camfort.Specification.Stencils.Analysis (StencilsAnalysis)
import qualified Camfort.Specification.Stencils.Annotation as SA
import           Camfort.Specification.Stencils.CheckFrontend
import           Camfort.Specification.Stencils.InferenceFrontend
import           Control.DeepSeq
import           Data.Maybe (catMaybes)
import qualified Language.Fortran.AST as F
import qualified Language.Fortran.Analysis as FA
import qualified Language.Fortran.Analysis.BBlocks as FAB
import qualified Language.Fortran.Analysis.DataFlow as FAD
import qualified Language.Fortran.Analysis.Renaming as FAR

-- | Helper for retrieving analysed blocks.
getBlocks :: F.ProgramFile A -> F.ProgramFile SA.SA
getBlocks = FAD.analyseConstExps . FAB.analyseBBlocks . FAR.analyseRenames . FA.initAnalysis . fmap SA.mkStencilAnnotation

--------------------------------------------------
--         Stencil specification inference      --
--------------------------------------------------
-- Top-level of specification inference
infer :: Bool
      -> Char
      -> F.ProgramFile Annotation
      -> StencilsAnalysis StencilsReport
infer useEval marker pf =
  (force . StencilsReport . map (F.pfGetFilename pf,)) <$> stencilInference useEval marker (getBlocks pf)

--------------------------------------------------
--         Stencil specification synthesis      --
--------------------------------------------------

-- Top-level of specification synthesis
synth :: Char
      -> [F.ProgramFile A]
      -> StencilsAnalysis [F.ProgramFile A]
synth marker pfs = do
  syntheses <- unzip <$> traverse buildOutput pfs
  logInfo' pfs $ describe . normaliseMsg . fst $ syntheses
  pure . catMaybes $ snd syntheses
  where
    buildOutput :: F.ProgramFile A -> StencilsAnalysis ((String, String), Maybe (F.ProgramFile Annotation))
    buildOutput pf = do
      let f = F.pfGetFilename pf
      result <- synthWithCheck pf
      pure $ case result of
               Left err         -> ((mkMsg f err, ""), Nothing)
               Right (warn,pf') -> (("", mkMsg f warn), Just pf')
    synthWithCheck :: F.ProgramFile A -> StencilsAnalysis (Either String (String, F.ProgramFile Annotation))
    synthWithCheck pf = do
      let blocks = getBlocks pf
      checkRes <- stencilChecking blocks
      case checkFailure checkRes of
        Nothing  -> do
          res <- fst <$> stencilSynthesis marker blocks
          let inference = fmap SA.getBaseAnnotation res
          pure $ Right (maybe "" show (checkWarnings checkRes), inference)
        Just err -> pure . Left $ show err

    mkMsg _ "" = ""
    mkMsg f e  = "\nEncountered the following errors when checking\
                 \ stencil specs for '" ++ f ++ "'\n\n" ++ e

    normaliseMsg outs =
      let errors = fmap fst outs
          fullMsg = concatMap (uncurry (++)) outs
      in if any (/="") errors then fullMsg ++ errorTrailer else fullMsg
      where errorTrailer = "\nPlease resolve these errors, and then\
                           \ run synthesis again."


--------------------------------------------------
--         Stencil specification checking       --
--------------------------------------------------

check :: F.ProgramFile Annotation -> StencilsAnalysis CheckResult
check = fmap force . stencilChecking . getBlocks

-- Local variables:
-- mode: haskell
-- haskell-program-name: "cabal repl"
-- End: