#!/usr/bin/python
# Parse an XML file produced by the Overpass API with the geometry="center"
# print option. Produces a file where the way is replaced with a single
# node, placed at the way center.

import sys
import xml.etree.ElementTree

xml_file = sys.argv[1]
tag_type = sys.argv[2]

def escape(s):
    return s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace("\"", "&quot;")

print u'<?xml version="1.0" encoding="UTF-8"?>'.encode('utf-8')
print u'<osm version="0.6" generator="Python script way2node">'.encode('utf-8')
e = xml.etree.ElementTree.parse(xml_file).getroot()
for way in e.findall(u'way'):
    way_id     = int(way.get(u"id"))
    center     = way.find(u"center")
    tag_k_type = way.find(u"tag[@k='%s']" % (tag_type,))
    tag_k_name = way.find(u"tag[@k='name']")
    #print center.items()
    #print tag_k_type.items()
    #print tag_k_name.items()
    if center != None and tag_k_type != None:
        if tag_k_name != None:
            name = tag_k_name.get('v')
        else:
            name = tag_k_type.get('v')
        print (u'<node id="%d" lat="%.8f" lon="%.8f" version="1">' % (way_id, float(center.get('lat')), float(center.get('lon')))).encode('utf-8')
        print (u'  <tag k="%s" v="%s"/>' % (escape(tag_type), escape(tag_k_type.get('v')))).encode('utf-8')
        print (u'  <tag k="name" v="%s"/>' % (escape(name),)).encode('utf-8')
        print u'</node>'.encode('utf-8')
print u'</osm>'