import sys, string, cPickle, traceback, os.path
from pydot import *

# ---------------
def layoutDot(D):
# ---------------
	"""Performs a JGraph layout on this Dot object.
		@type D: Dot / Graph
		@rtype: Dot / Graph
	"""
	# Make a bare adjacency-list with same topology as Dot
	G = Dot2G(D)
	sizes = Dot2Sizes(D)
	filename = tempfile.mktemp()
	f = file(filename, 'w')
	cPickle.dump(G, f)
	cPickle.dump(sizes, f)
	f.close()

	# Call the Jython portion, which talks to JGraph
	part2dir = os.path.dirname(traceback.extract_stack()[-1][0])
	part2file = os.path.join(part2dir, 'JGLayout2.py')
	os.spawnlp(os.P_WAIT, 'jython', 'jython', part2file, filename)
	try:
		f = file(filename, 'r')
		coords = cPickle.load(f)
		f.close()
	except:
		print 'Jython portion of layout did not finish properly. Aborting.'
		return D

	# Transfer coordinates from coord-list to dot object
	bb = coords['_bb']
	del coords['_bb']
	D.set('bb', '%d,%d,%d,%d' % bb)
	for name, numbers in coords.items():
		if isinstance(numbers, tuple):	# node
			node = D.get_node(name)
			if not node: continue
			node.set('pos', '%d,%d' % (numbers[0], numbers[1])) 
			node.set('width', '%f' % (float(numbers[2]) / 72.0))
			node.set('height', '%f' % (float(numbers[3]) / 72.0))
		elif isinstance(numbers, list):	# edge points
			src, tgt = name.split(' -> ')
			edge = D.get_edge(src, tgt)
			if not edge: continue
			posstrs = ['e,%d,%d' % numbers[-1], ' ']
			del numbers[-1]
			for pos in numbers:
				posstrs.extend(['%d,%d' % pos, ' '])
			del posstrs[-1]	# no final space
			posstr = ''.join(posstrs)
			edge.set('pos', posstr)

	return D


# -----------
def Dot2G(D):
# -----------
	"""Returns a simple adjency-list mapping that corresponds to
		the topology of this Dot object.
		@type D: Dot / Graph
		@rtype: {string: [string...]}
	"""
	G = {}
	for node in D.get_node_list():
		name = node.get_name()
		G[name] = []
	for edge in D.get_edge_list():
		src, dst = edge.get_source(), edge.get_destination()
		G[src].append(dst)
	return G


# ---------------
def Dot2Sizes(D):
# ---------------
	"""Gets you a mapping from node-names to (width, height) pairs.
		@type D: Dot / Graph
		@rtype: {string: (int, int)}
	"""
	sizes = {}
	for node in D.get_node_list():
		name = node.get_name()
		sizes[name] = map(int, (string.atof(node.width)*72, string.atof(node.height)*72))
	return sizes