{-# LANGUAGE OverloadedStrings #-}
{- | Convert the view hierarchy to OPML

-}
module OPML(
	  opml
	) where 


import Prelude hiding (head, id, div)
import qualified Data.ByteString.Lazy as L 
import Data.Tree 
import Text.OPML.Syntax
import Text.OPML.Writer
import Types
import Text.XML.Light.Types

-- | Convert the view hierarchy into a textural description using the OPML format
opml :: Tree (String,View)  -> String
opml = serializeOPML . genOpml

genOpml :: Tree (String,View)  -> OPML 
genOpml t = nullOPML { opmlBody = [htmlTree t]}

htmlTree :: Tree (String,View) -> Outline
htmlTree (Node a []) = node a []
htmlTree (Node a children) =  node a (map htmlTree children)

node :: (String,View) -> [Outline] -> Outline 
node (name,v) childen = 
	let attr s k = Attr (blank_name {qName = s}) k
	    attrs = [attr "Width" (show $ width v),attr "Height" (show $ height v), attr "Layer" (layerType v)]
	in
	(nullOutline name) {opmlOutlineChildren = childen, opmlOutlineAttrs = reverse attrs}