module Compiler.AST.FunctionDef where

import Common
import Control.Applicative
import Data.List as L
import Data.List.NonEmpty as NE
import Data.Maybe
import Data.Text as T

import Compiler.AST.Common
import Compiler.AST.FunctionStatement
import Compiler.AST.Parser.Common
import Compiler.Lexer
import Parser.Lib
import Test.Common

data FunctionDef
  = FunctionDef Identifier [Identifier] (NonEmpty FunctionStatementWithLoc)
  deriving (Show, Eq)

instance HasAstParser FunctionDef where
  astParser = nameParser "Function Definition" $ do
    surroundWs_ (parseKeyword KwProc)
    fnName <- surroundWs parseIdentifier
    args <- parseItemListInParen parseIdentifier
    stms <- mandatory (some (surroundWs (astParser @FunctionStatementWithLoc)))
    mandatory $ surroundWs_ $ parseKeyword KwEndProc
    pure $ FunctionDef fnName (fromMaybe [] (NE.toList <$> args)) (NE.fromList stms)

instance ToSource FunctionDef where
  toSourcePretty i (FunctionDef name args stms) =
    T.concat $
      [nlt, indent i, toSource KwProc, wst, toSource name, toSource DlParenOpen] <>
      (L.intersperse (toSource DlComma <> " ") (toSource <$> args)) <>
      [toSource DlParenClose] <> [nlt] <>
      [toSourcePretty (i+1) (NE.toList stms)] <> [nlt, indent i, toSource KwEndProc]

instance HasGen FunctionDef where
  getGen = FunctionDef <$> getGen <*> getGen <*> (nonEmptyGen getGen)