{- This module was generated from data in the Kate syntax highlighting file go.xml, version 1.00,
   by  Miquel Sabaté (mikisabate@gmail.com) -}

module Text.Highlighting.Kate.Syntax.Go ( highlight, parseExpression, syntaxName, syntaxExtensions ) where
import Text.Highlighting.Kate.Definitions
import Text.Highlighting.Kate.Common
import qualified Text.Highlighting.Kate.Syntax.Alert
import Text.ParserCombinators.Parsec
import Control.Monad (when)
import Data.Map (fromList)
import Data.Maybe (fromMaybe, maybeToList)

import qualified Data.Set as Set
-- | Full name of language.
syntaxName :: String
syntaxName = "Go"

-- | Filename extensions for this language.
syntaxExtensions :: String
syntaxExtensions = "*.go"

-- | Highlight source code using this syntax definition.
highlight :: String -> Either String [SourceLine]
highlight input =
  case runParser parseSource startingState "source" input of
    Left err     -> Left $ show err
    Right result -> Right result

-- | Parse an expression using appropriate local context.
parseExpression :: GenParser Char SyntaxState LabeledSource
parseExpression = do
  st <- getState
  let oldLang = synStLanguage st
  setState $ st { synStLanguage = "Go" }
  context <- currentContext <|> (pushContext "normal" >> currentContext)
  result <- parseRules context
  updateState $ \st -> st { synStLanguage = oldLang }
  return result

parseSource = do 
  lineContents <- lookAhead wholeLine
  updateState $ \st -> st { synStCurrentLine = lineContents }
  result <- manyTill parseSourceLine eof
  return $ map normalizeHighlighting result

startingState = SyntaxState {synStContexts = fromList [("Go",["normal"])], synStLanguage = "Go", synStCurrentLine = "", synStCharsParsedInLine = 0, synStPrevChar = '\n', synStCaseSensitive = True, synStKeywordCaseSensitive = True, synStCaptures = []}

parseSourceLine = manyTill parseExpressionInternal pEndLine

pEndLine = do
  lookAhead $ newline <|> (eof >> return '\n')
  context <- currentContext
  case context of
    "normal" -> return () >> pHandleEndLine
    "Commentar 1" -> (popContext) >> pEndLine
    "Commentar 2" -> return () >> pHandleEndLine
    "Package" -> (popContext) >> pEndLine
    "String" -> (popContext) >> pEndLine
    _ -> pHandleEndLine

withAttribute attr txt = do
  when (null txt) $ fail "Parser matched no text"
  let labs = attr : maybeToList (lookup attr styles)
  st <- getState
  let oldCharsParsed = synStCharsParsedInLine st
  let prevchar = if null txt then '\n' else last txt
  updateState $ \st -> st { synStCharsParsedInLine = oldCharsParsed + length txt, synStPrevChar = prevchar } 
  return (labs, txt)

styles = [("Keyword","kw"),("Special","ot"),("Type","dt"),("Builtin","ot"),("String Char","ch"),("String","st"),("Comment","co"),("Char","ch")]

parseExpressionInternal = do
  context <- currentContext
  parseRules context <|> (pDefault >>= withAttribute (fromMaybe "" $ lookup context defaultAttributes))

list_keywords = Set.fromList $ words $ "break case chan const continue default defer else fallthrough for func go goto if import interface map range return select struct switch type var"
list_types = Set.fromList $ words $ "bool byte complex64 complex128 float float32 float64 int int8 int16 int32 int64 string uint uint8 uint16 uint32 uint64"
list_builtin = Set.fromList $ words $ "cap len make new panic recover"
list_special = Set.fromList $ words $ "false nil true"


defaultAttributes = [("normal","Normal Text"),("Commentar 1","Comment"),("Commentar 2","Comment"),("Package","Package"),("String","String")]

parseRules "normal" = 
  do (attr, result) <- (((pKeyword " \n\t.():!+,-<=>%&*/;?[]^{|}~\\" list_keywords >>= withAttribute "Keyword"))
                        <|>
                        ((pKeyword " \n\t.():!+,-<=>%&*/;?[]^{|}~\\" list_special >>= withAttribute "Special"))
                        <|>
                        ((pKeyword " \n\t.():!+,-<=>%&*/;?[]^{|}~\\" list_types >>= withAttribute "Type"))
                        <|>
                        ((pKeyword " \n\t.():!+,-<=>%&*/;?[]^{|}~\\" list_builtin >>= withAttribute "Builtin"))
                        <|>
                        ((pString False "package" >>= withAttribute "Package") >>~ pushContext "Package")
                        <|>
                        ((pDetectChar False '{' >>= withAttribute "Symbol"))
                        <|>
                        ((pDetectChar False '}' >>= withAttribute "Symbol"))
                        <|>
                        ((pDetect2Chars False '/' '/' >>= withAttribute "Comment") >>~ pushContext "Commentar 1")
                        <|>
                        ((pDetect2Chars False '/' '*' >>= withAttribute "Comment") >>~ pushContext "Commentar 2")
                        <|>
                        ((pHlCChar >>= withAttribute "Char"))
                        <|>
                        ((pDetectChar False '"' >>= withAttribute "String") >>~ pushContext "String"))
     return (attr, result)

parseRules "Commentar 1" = 
  do (attr, result) <- (((pLineContinue >>= withAttribute "Comment"))
                        <|>
                        ((pDetectSpaces >>= withAttribute "Comment"))
                        <|>
                        ((Text.Highlighting.Kate.Syntax.Alert.parseExpression))
                        <|>
                        ((pDetectIdentifier >>= withAttribute "Comment")))
     return (attr, result)

parseRules "Commentar 2" = 
  do (attr, result) <- (((pDetectSpaces >>= withAttribute "Comment"))
                        <|>
                        ((pDetect2Chars False '*' '/' >>= withAttribute "Comment") >>~ (popContext))
                        <|>
                        ((Text.Highlighting.Kate.Syntax.Alert.parseExpression))
                        <|>
                        ((pDetectIdentifier >>= withAttribute "Comment")))
     return (attr, result)

parseRules "Package" = 
  pzero

parseRules "String" = 
  do (attr, result) <- (((pLineContinue >>= withAttribute "String"))
                        <|>
                        ((pHlCStringChar >>= withAttribute "String Char"))
                        <|>
                        ((pDetectChar False '"' >>= withAttribute "String") >>~ (popContext)))
     return (attr, result)

parseRules "" = parseRules "normal"

parseRules x = fail $ "Unknown context" ++ x