    {-
    (c) The University of Glasgow 2006
    (c) The GRASP/AQUA Project, Glasgow University, 1992-1998

    HsImpExp: Abstract syntax: imports, exports, interfaces
    -}

    {-# LANGUAGE DeriveDataTypeable #-}

    module HsImpExp where

    import Module           ( ModuleName )
    import HsDoc            ( HsDocString )
    import OccName          ( HasOccName(..), isTcOcc, isSymOcc )
    import BasicTypes       ( SourceText )

    import Outputable
    import FastString
    import SrcLoc

    import Data.Data

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Import and export declaration lists}
    *                                                                      *
    ************************************************************************

    One per \tr{import} declaration in a module.
    -}

    type LImportDecl name = Located (ImportDecl name)
            -- ^ When in a list this may have
            --
            --  - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnSemi'

            -- For details on above see note [Api annotations] in ApiAnnotation

    -- | A single Haskell @import@ declaration.
    data ImportDecl name
      = ImportDecl {
          ideclSourceSrc :: Maybe SourceText,
                                     -- Note [Pragma source text] in BasicTypes
          ideclName      :: Located ModuleName, -- ^ Module name.
          ideclPkgQual   :: Maybe FastString,  -- ^ Package qualifier.
          ideclSource    :: Bool,              -- ^ True <=> {-\# SOURCE \#-} import
          ideclSafe      :: Bool,               -- ^ True => safe import
          ideclQualified :: Bool,               -- ^ True => qualified
          ideclImplicit  :: Bool,               -- ^ True => implicit import (of Prelude)
          ideclAs        :: Maybe ModuleName,   -- ^ as Module
          ideclHiding    :: Maybe (Bool, Located [LIE name])
                                                -- ^ (True => hiding, names)
        }
         -- ^
         --  'ApiAnnotation.AnnKeywordId's
         --
         --  - 'ApiAnnotation.AnnImport'
         --
         --  - 'ApiAnnotation.AnnOpen', 'ApiAnnotation.AnnClose' for ideclSource
         --
         --  - 'ApiAnnotation.AnnSafe','ApiAnnotation.AnnQualified',
         --    'ApiAnnotation.AnnPackageName','ApiAnnotation.AnnAs',
         --    'ApiAnnotation.AnnVal'
         --
         --  - 'ApiAnnotation.AnnHiding','ApiAnnotation.AnnOpen',
         --    'ApiAnnotation.AnnClose' attached
         --     to location in ideclHiding

         -- For details on above see note [Api annotations] in ApiAnnotation
           deriving (Data, Typeable)

    simpleImportDecl :: ModuleName -> ImportDecl name
    simpleImportDecl mn = ImportDecl {
          ideclSourceSrc = Nothing,
          ideclName      = noLoc mn,
          ideclPkgQual   = Nothing,
          ideclSource    = False,
          ideclSafe      = False,
          ideclImplicit  = False,
          ideclQualified = False,
          ideclAs        = Nothing,
          ideclHiding    = Nothing
        }

    instance (OutputableBndr name, HasOccName name) => Outputable (ImportDecl name) where
        ppr (ImportDecl { ideclName = mod', ideclPkgQual = pkg
                        , ideclSource = from, ideclSafe = safe
                        , ideclQualified = qual, ideclImplicit = implicit
                        , ideclAs = as, ideclHiding = spec })
          = hang (hsep [ptext (sLit "import"), ppr_imp from, pp_implicit implicit, pp_safe safe,
                        pp_qual qual, pp_pkg pkg, ppr mod', pp_as as])
                 4 (pp_spec spec)
          where
            pp_implicit False = empty
            pp_implicit True = ptext (sLit ("(implicit)"))

            pp_pkg Nothing  = empty
            pp_pkg (Just p) = doubleQuotes (ftext p)

            pp_qual False   = empty
            pp_qual True    = ptext (sLit "qualified")

            pp_safe False   = empty
            pp_safe True    = ptext (sLit "safe")

            pp_as Nothing   = empty
            pp_as (Just a)  = ptext (sLit "as") <+> ppr a

            ppr_imp True  = ptext (sLit "{-# SOURCE #-}")
            ppr_imp False = empty

            pp_spec Nothing             = empty
            pp_spec (Just (False, (L _ ies))) = ppr_ies ies
            pp_spec (Just (True, (L _ ies))) = ptext (sLit "hiding") <+> ppr_ies ies

            ppr_ies []  = ptext (sLit "()")
            ppr_ies ies = char '(' <+> interpp'SP ies <+> char ')'

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Imported and exported entities}
    *                                                                      *
    ************************************************************************
    -}

    type LIE name = Located (IE name)
            -- ^ When in a list this may have
            --
            --  - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnComma'

            -- For details on above see note [Api annotations] in ApiAnnotation

    -- | Imported or exported entity.
    data IE name
      = IEVar       (Located name)
            -- ^ - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnPattern',
            --             'ApiAnnotation.AnnType'

            -- For details on above see note [Api annotations] in ApiAnnotation
      | IEThingAbs  (Located name)     -- ^ Class/Type (can't tell)
            --  - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnPattern',
            --             'ApiAnnotation.AnnType','ApiAnnotation.AnnVal'

            -- For details on above see note [Api annotations] in ApiAnnotation
      | IEThingAll  (Located name)     -- ^ Class/Type plus all methods/constructors
            --
            -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnOpen',
            --       'ApiAnnotation.AnnDotdot','ApiAnnotation.AnnClose',
            --                                 'ApiAnnotation.AnnType'

            -- For details on above see note [Api annotations] in ApiAnnotation

      | IEThingWith (Located name) [Located name]
                     -- ^ Class/Type plus some methods/constructors
            -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnOpen',
            --                                   'ApiAnnotation.AnnClose',
            --                                   'ApiAnnotation.AnnComma',
            --                                   'ApiAnnotation.AnnType'

            -- For details on above see note [Api annotations] in ApiAnnotation
      | IEModuleContents  (Located ModuleName) -- ^ (Export Only)
            --
            -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnModule'

            -- For details on above see note [Api annotations] in ApiAnnotation
      | IEGroup             Int HsDocString  -- ^ Doc section heading
      | IEDoc               HsDocString      -- ^ Some documentation
      | IEDocNamed          String           -- ^ Reference to named doc
      deriving (Eq, Data, Typeable)

    ieName :: IE name -> name
    ieName (IEVar (L _ n))         = n
    ieName (IEThingAbs  (L _ n))   = n
    ieName (IEThingWith (L _ n) _) = n
    ieName (IEThingAll  (L _ n))   = n
    ieName _ = panic "ieName failed pattern match!"

    ieNames :: IE a -> [a]
    ieNames (IEVar       (L _ n)   ) = [n]
    ieNames (IEThingAbs  (L _ n)   ) = [n]
    ieNames (IEThingAll  (L _ n)   ) = [n]
    ieNames (IEThingWith (L _ n) ns) = n : map unLoc ns
    ieNames (IEModuleContents _    ) = []
    ieNames (IEGroup          _ _  ) = []
    ieNames (IEDoc            _    ) = []
    ieNames (IEDocNamed       _    ) = []

    pprImpExp :: (HasOccName name, OutputableBndr name) => name -> SDoc
    pprImpExp name = type_pref <+> pprPrefixOcc name
        where
        occ = occName name
        type_pref | isTcOcc occ && isSymOcc occ = ptext (sLit "type")
                  | otherwise                   = empty

    instance (HasOccName name, OutputableBndr name) => Outputable (IE name) where
        ppr (IEVar          var)    = pprPrefixOcc (unLoc var)
        ppr (IEThingAbs     thing)  = pprImpExp (unLoc thing)
        ppr (IEThingAll      thing) = hcat [pprImpExp (unLoc thing), text "(..)"]
        ppr (IEThingWith thing withs)
            = pprImpExp (unLoc thing) <> parens (fsep (punctuate comma
                                                (map pprImpExp $ map unLoc withs)))
        ppr (IEModuleContents mod')
            = ptext (sLit "module") <+> ppr mod'
        ppr (IEGroup n _)           = text ("<IEGroup: " ++ (show n) ++ ">")
        ppr (IEDoc doc)             = ppr doc
        ppr (IEDocNamed string)     = text ("<IEDocNamed: " ++ string ++ ">")