module Thriftier.CPPFile where

import Control.Lens
import Text.Printf
import Data.List
import Text.Regex
import System.FilePath.Posix
import Data.String.Utils
import Data.Maybe

import Thriftier.HandlerStub
import Thriftier.Util
import Thriftier.ModulePath
import Thriftier.OutputRoot
import Thriftier.InterfaceRoot

data CPPFile = CPPFile
  { _cppfileModuleL :: Module 
  , _cppfileIncludesL :: [String]
  , _cppfileDefinitionL :: String
  }
makeFields ''CPPFile

getHandlerName :: CPPFile -> String
getHandlerName file = last $ splitDirectories $ file ^. moduleL ^. valueL 

{-cppRelativePath :: CPPFile -> ModuleCPP-}
{-cppRelativePath file = -}
  {-addExtension (file ^. modulePathL ^. valueL) ".cpp"-}

{-hppRelativePath :: CPPFile -> FilePath-}
{-hppRelativePath file = -}
  {-addExtension (file ^. modulePathL ^. valueL) ".hpp"-}

mkCPPFile :: HandlerStub -> ModuleParent -> CPPFile
mkCPPFile stub moduleParent = CPPFile 
  (mkModule moduleParent (handlerName stub))
  (stub ^. includesL) 
  (stub ^. bodyL)

fromSkeleton :: OutputRoot -> ModuleCPP -> IO CPPFile
fromSkeleton outputRoot skeletonModuleCPP = do
  skeletonCode <- readFile $ joinPath 
    [ outputRoot ^. valueL
    , skeletonModuleCPP ^. valueL
    ]
  {-putStrLn skeletonCode-}
  {-putStrLn skeletonPath-}
  {-putStrLn $ takeDirectory skeletonPath-}
  {-putStrLn $ takeDirectory $ normalise skeletonPath-}
  return $ mkCPPFile
    (mkHandlerStub skeletonCode)
    (mkParentFromModuleCPP skeletonModuleCPP)

toDefinitionSyntax :: String -> String -> String
toDefinitionSyntax handlerName body =
  let
    Just innerClass = matchRegex
      (mkRegex "public:\n((.|\n)+)\n};")
      body
    aligned = map (drop 2) . lines $ head innerClass
    qualifyName line = 
      case matchRegex
        (mkRegex "([a-zA-Z0-9]+)\\(.+\\{")
        line of
        Nothing -> line
        Just [name] -> replace
          (name ++ "(")
          (handlerName ++ "::" ++ name ++ "(")
          line

  in 
    unlines $ map qualifyName aligned
    {-subRegex-}
      {-(mkRegex "([a-zA-Z]+).+\\{")-}
      {-aligned-}
      {-(handlerName ++ "::\1")-}

renderAsCPP :: CPPFile -> String
renderAsCPP file = unlines $ 
  [printf "#include \"%s\"" $ (mkModuleHPP (file ^. moduleL)) ^. valueL] ++ 
  [""] ++ 
  file ^. includesL ++
  [""] ++ 
  [toDefinitionSyntax (getHandlerName file) (file ^. definitionL)]

declarations :: CPPFile -> [String]
declarations file =
  let
    getDeclaration line = matchRegex
      (mkRegex "^  ([ a-zA-Z0-9]+\\(.*\\)) \\{$")
      line
    maybeMatches = map getDeclaration $ lines $ file ^. definitionL
    declarations' = concat $ catMaybes maybeMatches
  in
    map (++ ";") declarations' 

renderAsHPP :: CPPFile -> String
renderAsHPP file = 
  let 
    guard = mkString "_" "_" "_" $ splitDirectories $ file ^. moduleL ^. valueL 
    outerDeclaration = (init $ takeWhile (/= '{') $ file ^. definitionL) ++ " {"
    declaration = unlines $
      [outerDeclaration] ++
      [" public:"] ++
      (intersperse "" $ map ("  " ++) $ declarations file) ++
      ["};"]
  in unlines $
    [printf "#ifndef %s" guard] ++
    [printf "#define %s" guard] ++
    [""] ++
    file ^. includesL ++
    [""] ++
    [declaration] ++
    [""] ++
    [printf "#endif // %s" guard]