----------------------------------------------------------------------
-- |
-- Module      : VisualizeTree
-- Maintainer  : AR
-- Stability   : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 
-- > CVS $Author:
-- > CVS $Revision: 
--
-- Print a graph of an abstract syntax tree in Graphviz DOT format
-- Based on BB's VisualizeGrammar
-- FIXME: change this to use GF.Visualization.Graphviz, 
--        instead of rolling its own.
-----------------------------------------------------------------------------

module PGF.VisualizeTree ( visualizeTrees
			) where

import PGF.CId (prCId)
import PGF.Data

visualizeTrees :: Bool -> [Tree] -> String
visualizeTrees digr = unlines . map (prGraph digr . tree2graph digr)

tree2graph :: Bool -> Tree -> [String]
tree2graph digr = prf [] where
  prf ps t = case t of
    Fun cid trees -> 
      let (nod,lab) = prn ps cid in
        (nod ++ " [label = " ++ lab ++ ", style = \"solid\", shape = \"plaintext\"] ;") : 
        [       pra (j:ps) nod t | (j,t) <- zip [0..] trees] ++
        concat [prf (j:ps) t     | (j,t) <- zip [0..] trees]
  prn ps cid = 
    let lab = "\"" ++ prCId cid ++ "\""
    in (show(show (ps :: [Int])),lab)
  pra i nod t@(Fun cid _) =  nod ++ arr ++ fst (prn i cid) ++ " [style = \"solid\"];"
  arr = if digr then " -> " else " -- "

prGraph digr ns = concat $ map (++"\n") $ [graph ++ "{\n"] ++ ns ++ ["}"] where
  graph = if digr then "digraph" else "graph"