import xml.dom.minidom
import base64
import string

def parse(fname):
    """This is the main interface."""
    doc = xml.dom.minidom.parse(fname)
    assert doc.documentElement.tagName == 'plist'
    return handle(doc.documentElement)
	    
def handle(elem):
    assert (elem.nodeType == elem.ELEMENT_NODE)
    if elem.tagName == 'dict':
	return dict(elem)
    elif elem.tagName == 'string':
	return string(elem)
    elif elem.tagName == 'array':
	return array(elem)
    elif elem.tagName == 'integer':
	return integer(elem)
    elif elem.tagName == 'data':
	return data(elem)
    elif elem.tagName == 'plist':
	return array(elem)
    # unhandled tag
    return None
    
def integer(elem):
    try:
	i = int(elem.firstChild.data)
    except ValueError:
	i = None
    
def string(elem):
    try:
	d = elem.firstChild.data
    except AttributeError:
	d = ''
    return d

def data(elem):
    try:
	d = base64.decodestring(elem.firstChild.data)
    except:
	d = elem.firstChild.data
    return d
    
def key(elem):
    return elem.firstChild.data
	
def array(elem):
    l = []
    for sub in filter(f, elem.childNodes):
	l.append(handle(sub))
    return l
    
def dict(elem):
    d = {}
        
    l = filter(f, elem.childNodes)
    i = 0
    while i < len(l):
	if l[i].tagName == 'key':
	    d[key(l[i])] = handle(l[i+1])
	i = i + 2
    return d
    
def f(n):
    "filter to get rid of non-element nodes"
    if n.nodeType == n.ELEMENT_NODE:
	return n
    return None