content: {-
     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.
  -}
  
  {-# LANGUAGE GADTs #-}
  {-# LANGUAGE FlexibleContexts #-}
  
  module Camfort.Specification.Stencils.Synthesis
    ( formatSpec
    , formatSpecNoComment
    , offsetToIx
    ) where
  
  import           Camfort.Analysis.Annotations
  import           Camfort.Specification.Stencils.Syntax
  import           Data.List hiding (span)
  import qualified Language.Fortran.AST as F
  import qualified Language.Fortran.Analysis as FA
  import           Language.Fortran.Util.Position
  import qualified Language.Fortran.Util.Position as FU
  import           Prelude hiding (span)
  
  -- Format inferred specifications
  formatSpec :: F.MetaInfo -> Int -> Char
   -> (FU.SrcSpan, Either [([Variable], Specification)] (String,Variable))
   -> String
  formatSpec mi indent marker (_, Right (evalInfo, name)) =
    buildCommentText mi indent $
         marker : " "
      ++ evalInfo
      ++ (if name /= "" then " :: " ++ name else "") ++ "\n"
  
  formatSpec _ _ _ (_, Left []) = ""
  formatSpec mi indent marker (_, Left specs) =
    intercalate "\n" $ map commentText specs
      where
        commentText s = buildCommentText mi indent (marker : " " ++ doSpec s)
        commaSep                 = intercalate ", "
        doSpec (arrayVar, spec)  =
               show (fixSpec spec) ++ " :: " ++ commaSep arrayVar
        fixSpec s                = s
  
  
  -- | Format inferred specifications, but do not format as a comment.
  formatSpecNoComment ::
    (FU.SrcSpan, Either [([Variable], Specification)] (String,Variable))
    -> String
  formatSpecNoComment (span, Right (evalInfo, name)) =
    show span ++ "    " ++ evalInfo ++ (if name /= "" then " :: " ++ name else "") ++ "\n"
  formatSpecNoComment (_, Left []) = ""
  formatSpecNoComment (span, Left specs) =
    intercalate "\n" . map (\s -> show span ++ "    " ++ doSpec s) $ specs
      where
        commaSep                 = intercalate ", "
        doSpec (arrayVar, spec)  =
               show (fixSpec spec) ++ " :: " ++ commaSep arrayVar
        fixSpec s                = s
  
  
  ------------------------
  -- Make indexing expression for variable 'v' from an offset.
  -- essentially inverse to `ixToOffset` in StencilSpecification
  offsetToIx :: F.Name -> Int -> F.Index (FA.Analysis A)
  offsetToIx v o
    | o == absoluteRep
                = F.IxSingle a s Nothing (F.ExpValue a s (F.ValInteger "0" Nothing))
    | o == 0    = F.IxSingle a s Nothing (F.ExpValue a s (F.ValVariable v))
    | o  > 0    = F.IxSingle a s Nothing (F.ExpBinary a s F.Addition
                                   (F.ExpValue a s (F.ValVariable v))
                                   (F.ExpValue a s (F.ValInteger (show o) Nothing)))
    | otherwise = F.IxSingle a s Nothing (F.ExpBinary a s F.Subtraction
                                   (F.ExpValue a s (F.ValVariable v))
                                   (F.ExpValue a s (F.ValInteger (show (abs o)) Nothing)))
    where
      a = (head $ FA.initAnalysis [unitAnnotation]) { FA.insLabel = Just 0 }
      s = SrcSpan (Position 0 0 0 "" Nothing) (Position 0 0 0 "" Nothing)
  
  