{-# LANGUAGE TypeSynonymInstances #-}

module HsDev.Inspect (
	analyzeModule,
	inspectFile, fileInspection,
	projectDirs, projectSources,
	inspectProject
	) where

import Control.Arrow
import Control.Applicative
import Control.DeepSeq
import qualified Control.Exception as E
import Control.Monad
import Control.Monad.Error
import Data.List (intercalate, find)
import Data.Map (Map)
import Data.Maybe (fromMaybe, mapMaybe, catMaybes)
import Data.Time.Clock.POSIX (utcTimeToPOSIXSeconds)
import Data.Traversable (traverse, sequenceA)
import qualified Data.Map as M
import qualified Language.Haskell.Exts as H
import qualified Language.Haskell.Exts.Extension as H
import qualified Documentation.Haddock as Doc
import qualified System.Directory as Dir
import System.IO
import System.FilePath

import qualified Name (Name, getOccString, occNameString)
import qualified Module (moduleNameString)
import qualified SrcLoc as Loc
import qualified HsDecls
import qualified HsBinds

import HsDev.Symbols
import HsDev.Project
import HsDev.Tools.Base
import HsDev.Tools.HDocs (hdocsProcess)
import HsDev.Util

-- | Analize source contents
analyzeModule :: [String] -> Maybe FilePath -> String -> Either String Module
analyzeModule exts file source = case H.parseFileContentsWithMode pmode source' of
		H.ParseFailed loc reason -> Left $ "Parse failed at " ++ show loc ++ ": " ++ reason
		H.ParseOk (H.Module _ (H.ModuleName mname) _ _ _ imports declarations) -> Right $ Module {
			moduleName = mname,
			moduleDocs =  Nothing,
			moduleLocation = OtherModuleSource Nothing,
			moduleExports = [],
			moduleImports = map getImport imports,
			moduleDeclarations = M.fromList $ map (declarationName &&& id) $ getDecls declarations }
	where
		pmode :: H.ParseMode
		pmode = H.defaultParseMode {
			H.parseFilename = fromMaybe (H.parseFilename H.defaultParseMode) file,
			H.baseLanguage = H.Haskell2010,
			H.extensions = map H.parseExtension exts }

		-- Replace all tabs to spaces to make SrcLoc valid, otherwise it treats tab as 8 spaces
		source' = map untab source
		untab '\t' = ' '
		untab ch = ch

getImport :: H.ImportDecl -> Import
getImport d = Import (mname (H.importModule d)) (H.importQualified d) (fmap mname $ H.importAs d) (Just $ toPosition $ H.importLoc d) where
	mname (H.ModuleName n) = n

getDecls :: [H.Decl] -> [Declaration]
getDecls decls = map addLocals infos ++ filter noInfo defs where
	infos = concatMap getDecl decls
	addLocals :: Declaration -> Declaration
	addLocals decl = decl `where_` maybe [] locals def where
		def = find (\d -> declarationName d == declarationName decl) defs
	defs = concatMap getDef decls
	noInfo :: Declaration -> Bool
	noInfo d = declarationName d `notElem` names
	names = map declarationName infos

getBinds :: H.Binds -> [Declaration]
getBinds (H.BDecls decls) = getDecls decls
getBinds _ = []

getDecl :: H.Decl -> [Declaration]
getDecl decl = case decl of
	H.TypeSig loc names typeSignature -> map
		(\n -> setPosition loc (Declaration (identOfName n) Nothing Nothing (Function (Just $ oneLinePrint typeSignature) [])))
		names
	H.TypeDecl loc n args _ -> [setPosition loc $ Declaration (identOfName n) Nothing Nothing (Type $ TypeInfo Nothing (map oneLinePrint args) Nothing)]
	H.DataDecl loc dataOrNew ctx n args _ _ -> [setPosition loc $ Declaration (identOfName n) Nothing Nothing (ctor dataOrNew $ TypeInfo (makeCtx ctx) (map oneLinePrint args) Nothing)]
	H.GDataDecl loc dataOrNew ctx n args _ _ _ -> [setPosition loc $ Declaration (identOfName n) Nothing Nothing (ctor dataOrNew $ TypeInfo (makeCtx ctx) (map oneLinePrint args) Nothing)]
	H.ClassDecl loc ctx n args _ _ -> [setPosition loc $ Declaration (identOfName n) Nothing Nothing (Class $ TypeInfo (makeCtx ctx) (map oneLinePrint args) Nothing)]
	_ -> []
	where
		ctor :: H.DataOrNew -> TypeInfo -> DeclarationInfo
		ctor H.DataType = Data
		ctor H.NewType = NewType

		makeCtx [] = Nothing
		makeCtx ctx = Just $ intercalate ", " $ map oneLinePrint ctx

		oneLinePrint :: H.Pretty a => a -> String
		oneLinePrint = H.prettyPrintStyleMode (H.style { H.mode = H.OneLineMode }) H.defaultMode

getDef :: H.Decl -> [Declaration]
getDef (H.FunBind []) = []
getDef (H.FunBind matches@(H.Match loc n _ _ _ _ : _)) = [setPosition loc $ Declaration (identOfName n) Nothing Nothing fun] where
	fun = Function Nothing $ concatMap (getBinds . matchBinds) matches
	matchBinds (H.Match _ _ _ _ _ binds) = binds
getDef (H.PatBind loc pat _ _ binds) = map (\name -> setPosition loc (Declaration (identOfName name) Nothing Nothing (Function Nothing $ getBinds binds))) (names pat) where
	names :: H.Pat -> [H.Name]
	names (H.PVar n) = [n]
	names (H.PNeg n) = names n
	names (H.PNPlusK n _) = [n]
	names (H.PInfixApp l _ r) = names l ++ names r
	names (H.PApp _ ns) = concatMap names ns
	names (H.PTuple _ ns) = concatMap names ns
	names (H.PList ns) = concatMap names ns
	names (H.PParen n) = names n
	names (H.PRec _ pf) = concatMap fieldNames pf
	names (H.PAsPat n ns) = n : names ns
	names H.PWildCard = []
	names (H.PIrrPat n) = names n
	names (H.PatTypeSig _ n _) = names n
	names (H.PViewPat _ n) = names n
	names (H.PBangPat n) = names n
	names _ = []

	fieldNames :: H.PatField -> [H.Name]
	fieldNames (H.PFieldPat _ n) = names n
	fieldNames (H.PFieldPun n) = [n]
	fieldNames H.PFieldWildcard = []
getDef _ = []

identOfName :: H.Name -> String
identOfName name = case name of
	H.Ident s -> s
	H.Symbol s -> s

toPosition :: H.SrcLoc -> Position
toPosition (H.SrcLoc _ l c) = Position l c

setPosition :: H.SrcLoc -> Declaration -> Declaration
setPosition loc d = d { declarationPosition = Just (toPosition loc) }

-- | Get Map from declaration name to its documentation
documentationMap :: Doc.Interface -> Map String String
documentationMap iface = M.fromList $ concatMap toDoc $ Doc.ifaceExportItems iface where
	toDoc :: Doc.ExportItem Name.Name -> [(String, String)]
	toDoc (Doc.ExportDecl decl docs _ _ _ _) = maybe [] (zip (extractNames decl) . repeat) $ extractDocs docs
	toDoc _ = []

	extractNames :: HsDecls.LHsDecl Name.Name -> [String]
	extractNames (Loc.L _ d) = case d of
		HsDecls.TyClD ty -> [locatedName $ HsDecls.tcdLName ty]
		HsDecls.SigD sig -> case sig of
			HsBinds.TypeSig names _ -> map locatedName names
			HsBinds.GenericSig names _ -> map locatedName names
			_ -> []
		_ -> []

	extractDocs :: Doc.DocForDecl Name.Name -> Maybe String
	extractDocs (mbDoc, _) = fmap printDoc $ Doc.documentationDoc mbDoc where
		printDoc :: Doc.Doc Name.Name -> String
		printDoc Doc.DocEmpty = ""
		printDoc (Doc.DocAppend l r) = printDoc l ++ printDoc r
		printDoc (Doc.DocString s) = s
		printDoc (Doc.DocParagraph p) = printDoc p
		printDoc (Doc.DocIdentifier i) = Name.getOccString i
		printDoc (Doc.DocIdentifierUnchecked (m, i)) = Module.moduleNameString m ++ "." ++ Name.occNameString i
		printDoc (Doc.DocModule m) = m
		printDoc (Doc.DocWarning w) = printDoc w
		printDoc (Doc.DocEmphasis e) = printDoc e
		printDoc (Doc.DocMonospaced m) = printDoc m
		printDoc (Doc.DocUnorderedList lst) = concatMap printDoc lst -- Is this right?
		printDoc (Doc.DocOrderedList lst) = concatMap printDoc lst -- And this
		printDoc (Doc.DocDefList defs) = concatMap (\(l, r) -> printDoc l ++ " = " ++ printDoc r) defs -- ?
		printDoc (Doc.DocCodeBlock code) = printDoc code
		printDoc (Doc.DocPic pic) = show pic
		printDoc (Doc.DocAName a) = a
		printDoc (Doc.DocExamples exs) = unlines $ map showExample exs where
			showExample (Doc.Example expr results) = expr ++ " => " ++ intercalate ", " results
		printDoc (Doc.DocHyperlink link) = fromMaybe (Doc.hyperlinkUrl link) (Doc.hyperlinkLabel link)
		printDoc (Doc.DocProperty prop) = prop
		-- Catch all unsupported ones
		-- printDoc _ = "[unsupported-by-extractDocs]" -- TODO

	locatedName :: Loc.Located Name.Name -> String
	locatedName (Loc.L _ nm) = Name.getOccString nm

-- | Adds documentation to declaration
addDoc :: Map String String -> Declaration -> Declaration
addDoc docsMap decl = decl { declarationDocs = M.lookup (declarationName decl) docsMap }

-- | Adds documentation to all declarations in module
addDocs :: Map String String -> Module -> Module
addDocs docsMap m = m { moduleDeclarations = M.map (addDoc docsMap) (moduleDeclarations m) }

-- | Inspect file
inspectFile :: [String] -> FilePath -> ErrorT String IO InspectedModule
inspectFile opts file = do
	let
		noReturn :: E.SomeException -> IO [Doc.Interface]
		noReturn _ = return []
	proj <- liftIO $ locateProject file
	absFilename <- liftIO $ Dir.canonicalizePath file
	inspect (FileModule absFilename proj) (fileInspection absFilename opts) $ do
		docsMap <- liftIO $ hdocsProcess absFilename opts
		--docsMap <- liftIO $ fmap (fmap documentationMap . lookup absFilename) $ do
		--	is <- E.catch (Doc.createInterfaces ([Doc.Flag_Verbosity "0", Doc.Flag_NoWarnings] ++ map Doc.Flag_OptGhc opts) [absFilename]) noReturn
		--	forM is $ \i -> do
		--		mfile <- Dir.canonicalizePath $ Doc.ifaceOrigFilename i
		--		return (mfile, i)
		forced <- ErrorT $ E.handle onError $ do
			analyzed <- liftM (analyzeModule exts (Just absFilename)) $ readFileUtf8 absFilename
			force analyzed `deepseq` return analyzed
			--E.evaluate $ force analyzed
		return $ setLoc absFilename proj . maybe id addDocs docsMap $ forced
	where
		setLoc f p m = m { moduleLocation = FileModule f p }
		onError :: E.ErrorCall -> IO (Either String Module)
		onError = return . Left . show

		exts = mapMaybe flagExtension opts

-- | File inspection data
fileInspection :: FilePath -> [String] -> ErrorT String IO Inspection
fileInspection f opts = do
	tm <- liftIO $ Dir.getModificationTime f
	return $ InspectionAt (utcTimeToPOSIXSeconds tm) opts

-- | Enumerate project dirs
projectDirs :: Project -> ErrorT String IO [Extensions FilePath]
projectDirs p = do
	p' <- loadProject p
	return $ map (fmap (projectPath p' </>)) $ maybe [] sourceDirs $ projectDescription p'

-- | Enumerate project source files
projectSources :: Project -> ErrorT String IO [Extensions FilePath]
projectSources p = do
	dirs <- projectDirs p
	let
		enumHs = liftM (filter haskellSource) . traverseDirectory
	liftIO $ liftM concat $ mapM (liftM sequenceA . traverse (liftIO . enumHs)) dirs

-- | Inspect project
inspectProject :: [String] -> Project -> ErrorT String IO (Project, [InspectedModule])
inspectProject opts p = do
	p' <- loadProject p
	srcs <- projectSources p'
	modules <- mapM inspectFile' srcs
	return (p', catMaybes modules)
	where
		inspectFile' exts = liftM return (inspectFile (opts ++ extensionsOpts (extensions exts)) (entity exts)) <|> return Nothing

-- | Read file in UTF8
readFileUtf8 :: FilePath -> IO String
readFileUtf8 f = withFile f ReadMode $ \h -> do
	hSetEncoding h utf8
	cts <- hGetContents h
	length cts `seq` return cts