module BNFC.Backend.Agda.Template where

import BNFC.CF
import BNFC.Options.GlobalOptions
import BNFC.Prelude

import BNFC.Backend.Agda.Options
import BNFC.Backend.Agda.State
import BNFC.Backend.CommonInterface.Backend
import BNFC.Backend.Haskell.Template (cf2template)
import BNFC.Backend.Haskell.Utilities.Utils

import Control.Monad.State

import qualified Data.Map as Map

import System.FilePath ( takeBaseName )

agdaTemplate :: LBNF -> State AgdaBackendState Result
agdaTemplate lbnf = do
  st <- get
  let
    cfName      = takeBaseName $ optInput $ globalOpt st
    rules       = filterRules $ hsAstRules st
    tokensNames = fst <$> tokens st
    inDirectory = inDir $ agdaOpts st
    nSpace      = nameSpace $ agdaOpts st
    funct       = functor $ agdaOpts st
    template    = cf2template rules tokensNames cfName inDirectory nSpace funct
  return [(mkFilePath inDirectory nSpace cfName "Skel" "hs", template)]

  where

      filterRules :: [(Type, [(Label, ([Type], (Integer, ARHS)))])]
                  -> [(Type, [(Label, ([Type], (Integer, ARHS)))])]
      filterRules rules =
        filter
        (\(_,l) -> not (null l))
        ((\(f,s) -> (f, filterLabelsAST fNames s)) <$> rules)

      -- Functions names.
      fNames :: [String]
      fNames = toList <$> Map.keys (_lbnfFunctions lbnf)