module Rakka.Attachment
    ( Attachment(..)
    )
    where

import           Control.Arrow
import           Control.Arrow.ArrowList
import           System.IO.Unsafe
import           Text.XML.HXT.Arrow.ReadDocument
import           Text.XML.HXT.Arrow.WriteDocument
import           Text.XML.HXT.Arrow.XmlArrow
import           Text.XML.HXT.Arrow.XmlIOStateArrow
import           Text.XML.HXT.DOM.TypeDefs
import           Text.XML.HXT.DOM.XmlKeywords


class Attachment t where
    serializeToXmlTree     :: (ArrowChoice a, ArrowXml a) => a t XmlTree
    deserializeFromXmlTree :: (ArrowChoice a, ArrowXml a) => a XmlTree t

    serializeToString :: t -> String
    serializeToString attachment
        = unsafePerformIO $
          do [xmlStr] <- runX ( setErrorMsgHandler False fail
                                >>>
                                constA attachment
                                >>>
                                serializeToXmlTree
                                >>>
                                writeDocumentToString [ (a_indent, v_1) ]
                              )
             return xmlStr

    deserializeFromString :: String -> t
    deserializeFromString source
        = unsafePerformIO $
          do [ret] <- runX ( setErrorMsgHandler False fail
                             >>>
                             readString [ (a_validate         , v_0)
                                        , (a_check_namespaces , v_1)
                                        , (a_remove_whitespace, v_0)
                                        ] source
                             >>>
                             deserializeFromXmlTree
                           )
             return ret