#!/usr/bin/python
"""XML Enriched N-Triples Parser. Sean B. Palmer, 2003-06. GPL 2."""

import sys, urllib, cStringIO, xml.sax, xml.sax.handler
try: from uripath import join as urijoin
except ImportError: from urlparse import urljoin as urijoin

xent_ns = "@@"

class XENTParser(dict, xml.sax.handler.ContentHandler): 
   def __init__(self, sink, base=None): 
      self.stack = []
      self.sink = sink
      self.base = None
      self.next = 0
      self.s = ''

   def uri(self, u): 
      return '<%s>' % urijoin(self.base, u)

   def qname(self, q): 
      pfx, n = q.split(':')
      return self.uri(self[pfx][-1] + n)

   def term(self, t=None): 
      if self.s: 
         if `self.s`[1:].startswith("'"): t = `self.s`[2:-1]
         else: t = `self.s`[2:-1].replace("\\'", "'")
         self.s, t = '', '"%s"' % self.s.replace('"', '\\"')
      elif t.startswith('$'): t = '_:' + t[1:]
      elif t.startswith("'"): t = self.uri(t[1:])
      else: t = self.qname(t)

      self.triple[self.next] = t
      self.next += 1

      if self.next == 3 and self.stack[-1:] == ['properties']: 
         self.sink.triple(self.triple[0], self.triple[1], self.triple[2])
         del self.triple[1], self.triple[2]
         self.next = 1
      elif self.next == 3 and self.stack[-1:] == ['objects']: 
         self.sink.triple(self.triple[0], self.triple[1], self.triple[2])
         del self.triple[2]
         self.next = 2

   def startPrefixMapping(self, pfx, uri): 
      self.setdefault(pfx, []).append(uri)

   def endPrefixMapping(self, pfx): 
      self[pfx].pop()

   def startElementNS(self, name, qname, attrs): 
      if (name[0] == xent_ns): self.stack += [name[1]]
      if name == (xent_ns, 't'): 
         self.next = 0
         self.triple = {}
	
   def characters(self, chars): 
      if not (chars and (self.stack[-1:] == ['s'])): 
         for term in [t.strip() for t in chars.split(' ') if t.strip()]: 
            self.term(term)         
      else: self.s += chars
	
   def endElementNS(self, name, qname): 
      if name[0] == xent_ns: self.stack.pop()
      if name == (xent_ns, 's'): self.term()
      elif name == (xent_ns, 't') and len(self.triple) == 3: 
         self.sink.triple(self.triple[0], self.triple[1], self.triple[2])

class Sink(object): 
   def triple(self, s, p, o): 
      print ("%s %s %s ." % (s, p, o)).encode('utf-8')

def parseXENT(s, base=None, sink=None): 
   sink = sink or Sink()
   parser = xml.sax.make_parser()
   parser.setFeature(xml.sax.handler.feature_namespaces, 1)
   parser.setContentHandler(XENTParser(sink, base))
   parser.parse(cStringIO.StringIO(s))
   return sink

def parseURI(uri): 
   return parseXENT(urllib.urlopen(uri).read(), base=uri)

if __name__=="__main__": 
   if len(sys.argv) != 2: print __doc__
   else: parseURI(sys.argv[1])