try:
  from xml.etree import cElementTree as etree
except ImportError:
  from xml.etree import ElementTree as etree

from . import xml2nrn

# module names derived from the namespace. Add new tags in proper namespace
from . import neuroml
from . import metadata
from . import morphml
from . import biophysics

class FileWrapper:
     def __init__(self, source):
         self.source = source
         self.lineno = 0
     def read(self, bytes):
         s = self.source.readline()
         self.lineno += 1
         return s

# for each '{namespace}element' call the corresponding module.func
def handle(x2n, fw, event, node):
  tag = node.tag.split('}')
  # hopefully a namespace token corresponding to an imported module name
  ns = tag[0].split('/')[-2]
  tag = ns+'.'+tag[1] #namespace.element should correspond to module.func
  f = None
  try:
    if event == 'start':
      f = eval(tag)
    elif event == 'end':
      f = eval(tag + '_end')
  except:
    pass
  if f:
    x2n.locator.lineno = fw.lineno
    try:
      f(x2n, node) # handle the element when it opens
    except:
      print(tag,' failed at ', x2n.locator.getLineNumber())
  elif event == 'start':
    print('ignore', node.tag) # no function to handle the element
    return 0
  return 1

def rdxml(fname, ho = None):
  f = FileWrapper(open(fname))
  x2n = xml2nrn.XML2Nrn()
  ig = None
  for event, elem in etree.iterparse(f, events=("start", "end")):
    if ig != elem:
      if handle(x2n, f, event, elem) == 0:
        ig = elem
  if (ho):
    ho.parsed(x2n)

if __name__ == '__main__':
  rdxml('temp.xml')
