module Gidl.Backend.Tower.Server where


import Data.Monoid
import Data.List (intercalate)

import Gidl.Interface
import Gidl.Schema
import Gidl.Backend.Ivory.Types
import Gidl.Backend.Ivory.Schema (ifModuleName)
import Ivory.Artifact
import Text.PrettyPrint.Mainland

umbrellaModule :: [String] -> Interface -> Artifact
umbrellaModule modulepath i =
  artifactPath (intercalate "/" modulepath) $
  artifactText (ifModuleName i ++ ".hs") $
  prettyLazyText 80 $
  stack
    [ text "module" <+> mname
    , indent 2 $ encloseStack lparen (rparen <+> text "where") comma
        [ text "module" <+> im "Producer"
        , text "module" <+> im "Consumer"
        , text "module" <+> im "Server"
        ]
    , text "import" <+> im "Producer"
    , text "import" <+> im "Consumer"
    , text "import" <+> im "Server"
    ]
  where
  modAt path = mconcat (punctuate dot (map text path))
  mname = modAt (modulepath ++ [ifModuleName i])
  im m = modAt (modulepath ++ [ifModuleName i, m])

serverModule :: [String] -> Interface -> Artifact
serverModule modulepath i =
  artifactPath (intercalate "/" (modulepath ++ [ifModuleName i])) $
  artifactText "Server.hs" $
  prettyLazyText 80 $
  stack
    [ text "{-# LANGUAGE DataKinds #-}"
    , text "{-# LANGUAGE RankNTypes #-}"
    , text "{-# LANGUAGE ScopedTypeVariables #-}"
    , text "{-# LANGUAGE KindSignatures #-}"
    , text "{-# LANGUAGE RecordWildCards #-}"
    , text "{-# OPTIONS_GHC -fno-warn-unused-imports #-}"
    , text "{-# OPTIONS_GHC -fno-warn-unused-matches #-}"
    , empty
    , text "module"
      <+> im "Server"
      <+> text "where"
    , empty
    , stack imports
    , empty
    , attrsDataType i
    , empty
    , attrsTowerConstructor i
    , empty
    , attrsInitializer i
    , empty
    , streamsDataType i
    , empty
    , streamsTowerConstructor i
    , empty
    , interfaceServer i
    ]
  where
  rootpath = reverse . drop 2 . reverse
  modAt path = mconcat (punctuate dot (map text path))
  im mname = modAt (modulepath ++ [ifModuleName i, mname])

  imports =
    [ text "import" <+> modAt (rootpath modulepath ++ ["Tower", "Attr"])
    , text "import" <+> im "Producer"
    , text "import" <+> im "Consumer"
    , text "import Ivory.Language"
    , text "import Ivory.Tower"
    ]


attrsDataType :: Interface -> Doc
attrsDataType i = text "data" <+> constructor <+> text "(p :: Area * -> *) ="
               </> indent 2 constructor
               </> indent 4 body
  where
  constructor = text (ifModuleName i) <> text "Attrs"
  body = encloseStack lbrace rbrace comma
    [ text n <+> colon <> colon <+> text "p"
                 <+> parens (text (typeIvoryType t))
    | (aname, AttrMethod _ t)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]

attrsTowerConstructor :: Interface -> Doc
attrsTowerConstructor i = typesig </> decl </> indent 2 body </> indent 2 ret
  where
  constructor = text (ifModuleName i) <> text "Attrs"
  typesig = text "tower" <> constructor <+> colon <> colon
    <+> constructor <+> text "Init"
    <+> text "->"
    <+> text "Tower e" <+> parens (constructor <+> text "Attr")
  decl = text "tower" <> constructor <+> text "ivals = do"
  body = stack
    [ text n <> text "_p <- towerAttr"
       <+> dquotes (text aname)
       <+> parens (text n <+> text "ivals")
    | (aname, AttrMethod _ _)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]
  ret = text "return" <+> constructor <+> encloseStack lbrace rbrace comma
    [ text n <+> equals <+> text n <> text "_p"
    | (aname, AttrMethod _ _)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]

attrsInitializer :: Interface -> Doc
attrsInitializer i = typesig </> decl </> indent 2 body
  where
  constructor = text (ifModuleName i) <> text "Attrs"
  typesig = text "init" <> constructor <+> colon <> colon
            <+> constructor <+> text "Init"
  decl = text "init" <> constructor <+> equals <+> constructor
  body = encloseStack lbrace rbrace comma
    [ text n <+> equals <+> text "izero"
    | (aname, AttrMethod _ _)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]

streamsDataType :: Interface -> Doc
streamsDataType i = text "data" <+> constructor <+> text "(p :: Area * -> *) ="
               </> indent 2 constructor
               </> indent 4 body
  where
  constructor = text (ifModuleName i) <> text "Streams"
  body = encloseStack lbrace rbrace comma
    [ text n <+> colon <> colon <+> text "p"
                 <+> parens (text (typeIvoryType t))
    | (aname, StreamMethod _ t)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]

streamsTowerConstructor :: Interface -> Doc
streamsTowerConstructor i = typesig </> decl </> indent 2 body </> indent 2 ret
  where
  constructor = text (ifModuleName i) <> text "Streams"
  typesig = text "tower" <> constructor <+> colon <> colon
    <+> text "Tower e"
    <+> parens (constructor <+> text "ChanInput" <> comma
                <+> constructor <+> text "ChanOutput")
  decl = text "tower" <> constructor <+> text "= do"
  body = stack
    [ text n <> text "_c <- channel"
    | (aname, StreamMethod _ _)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ]
  ret = text "return" <+> encloseStack lparen rparen comma
    [ mkstream "fst", mkstream "snd"]
  mkstream acc = constructor </> indent 2 (encloseStack lbrace rbrace comma
    [ text n <+> equals <+> text acc <+> text n <> text "_c"
    | (aname, StreamMethod _ _)  <- interfaceMethods i
    , let n = userEnumValueName aname
    ])


interfaceServer :: Interface -> Doc
interfaceServer i =
  stack [typedef, decl, indent 2 body, indent 2 ret]
  where
  constructor postfix = text (ifModuleName i) <> text postfix
  fname =  text "tower" <> constructor "Server"
  typedef = fname <+> align (stack
      [ guardEmptySchema (consumerSchema i)
                         (text "::" <+> constructor "Consumer")
                         (text ":: -- no consumer schema")
      , guardEmptySchema (consumerSchema i) (text "->") (text "  ")
            <+> constructor "Attrs Attr"
      , text "->" <+> constructor "Streams ChanOutput"
      , text "->" <+> text "Tower e"
             <+> guardEmptySchema (producerSchema i)
                                  (constructor "Producer")
                                  (text "()")
      ])
  decl = fname <+> guardEmptySchema (consumerSchema i)
                                    (constructor "Consumer{..}")
                                    empty
               <+> constructor "Attrs{..}"
               <+> constructor "Streams{..}"
               <+> equals <+> text "do"
  body = stack [ methodBody (text (userEnumValueName n)) m
               | (n,m) <- interfaceMethods i ]
  ret = text "return" <+> guardEmptySchema (producerSchema i)
                                           (constructor "Producer{..}")
                                           (text "()")

  methodBody n (StreamMethod _ _) =
    text "let" <+> n <> text "Producer" <+> equals <+> n
  methodBody n (AttrMethod Read _) =
    n <> text "ValProducer" <+> text "<- readableAttrServer"
      <+> n <+> n <> text "GetConsumer"
  methodBody n (AttrMethod Write _) =
    text "writableAttrServer" <+> n <+> n <> text "SetConsumer"
  methodBody n (AttrMethod ReadWrite _) =
    n <> text "ValProducer" <+> text "<- readwritableAttrServer"
      <+> n <+> n <> text "GetConsumer" <+> n <> text "SetConsumer"


guardEmptySchema :: Schema -> Doc -> Doc -> Doc
guardEmptySchema (Schema _ []) _ d = d
guardEmptySchema (Schema _ _) d _ = d