#!/usr/bin/env python
"""
inkex.py
A helper module for creating Inkscape extensions
"""
import sys, getopt
import xml.dom.ext
import xml.dom.ext.reader.Sax2
import xml.xpath

def parseStyle(s):
	"""Create a dictionary from the value of an inline style attribute"""
	return dict([i.split(":") for i in s.split(";")])
def formatStyle(a):
	"""Format an inline style attribute from a dictionary"""
	return ";".join([":".join(i) for i in a.iteritems()])

def affect(effect_callback):
	"""Affect an SVG document with a callback effect"""
	#collect ids from the arguments
	#TODO: get other arguments?
	opts = getopt.getopt(sys.argv[1:],'',['id='])
	ids = [opt[1] for opt in opts[0] if opt[0]=='--id']

	#create xml parser
	reader = xml.dom.ext.reader.Sax2.Reader()
	#open SVG tempfile
	#TODO: optionailly read from STDIN
	stream = open(sys.argv[-1:][0],'r')
	#create DOM object
	doc = reader.fromStream(stream)
	stream.close()

	#collect nodes
	nodes = {}
	for id in ids:
		path = '//*[@id="%s"]' % id
		for node in xml.xpath.Evaluate(path,doc):
			nodes[id] = node

	#affect the document
	params = {
		'doc': doc,
		'selected': nodes 
	}
	effect_callback(params)

	#serialize DOM object into XML on stdout
	xml.dom.ext.Print(doc)