def compareDTD(uris):
    attributesSet = {'Common':set(['class', 'id', 'style', 'title', 'xml:lang']),
                     'Events':set(['onclick', 'ondblclick', 'onkeydown', 'onkeypress', 'onkeyup', 'onmousedown', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup']),
                     'I18N':set(['dir', 'lang']),
                     'XML':set(['xml:space', 'xmlns', 'xmlns:xsi'])}

    
    from xml.parsers.xmlproc import xmldtd
    all_elements = {}
    all_attributes = {}
    print "<link rel='stylesheet' href='http://www.w3.org/2001/11/results.css' />"
    print "<table border='1'><thead><tr><th>Element</th><th>Attributes</th>"
    for uri in uris:
        # hackish way to get a shorter heading for DTDs
        # ideally, there would be a way to get a human readable name
        print "<th><a href='%s'>%s</a></th>" % (uri,uri[uri.rfind('/') + 1:])
        dtd = xmldtd.load_dtd(uri)
        elements = dtd.get_elements()
        for elem_name in elements :
            elem = dtd.get_elem(elem_name)
            attributes = set(elem.get_attr_list())
            if not all_elements.has_key(elem_name):
                all_elements[elem_name] = {}
            if not all_attributes.has_key(elem_name):
                all_attributes[elem_name] = set()
            all_elements[elem_name][uri] = attributes
            all_attributes[elem_name] = all_attributes[elem_name] | attributes
    print "</tr></thead><tbody>"
    
    for elem_name in sorted(all_elements.keys()):
        dtds = all_elements[elem_name]
        attributes = all_attributes[elem_name]
        att_list = list(attributes)
        att_list.sort()
        
        print "<tr><th>%s</th>" % elem_name
        elem_attributes_set = []
        if att_list:
            remaining_att = attributes
            print "<td>"
            sets = []
            for setname in sorted(attributesSet.keys()):
                setdata = attributesSet[setname]
                if setdata<=attributes:
                    sets.append("<a href='#%s' title='%s'>%s</a>" % (setname,', '.join(sorted(list(setdata))),setname))
                    remaining_att = remaining_att - setdata
                    elem_attributes_set.append(setname)
            print "%s</td>" % ', '.join(sets + sorted(list(remaining_att)))
        else:
            print "<td>None</td>" 
        for uri in uris:
            if dtds.has_key(uri):
                print "<td><span class='yes'>Element present</span><br />"
                remaining_att = attributes
                if len(attributes - all_elements[elem_name][uri]):
                    print "<span class='no'>without</span>: "
                    absentSets = []
                    for setname in elem_attributes_set:
                        if not (all_elements[elem_name][uri] & attributesSet[setname]):
                            absentSets.append(setname)
                            remaining_att = remaining_att - attributesSet[setname]
#                        elif not attributesSet[setname] <= all_elements[elem_name][uri]:
#                            print "<a href='#%s'>%s</a> " % (setname,setname)
#                            print "<span class='no'>without</span> "
#                            print ",".join(list(attributesSet[setname] - (all_elements[elem_name][uri] & attributesSet[setname])))
                            #remaining_att = remaining_att - attributesSet[setname]
                    diff = remaining_att - all_elements[elem_name][uri]
                    print  (', '.join(sorted(absentSets) + sorted(list(diff))))
                else:
                    print "<span class='yes'>with all attributes</span>"
                print "</td>"
            else:
                print "<td class='no'>Element not present</td>"
        print "</tr>"
    print "</tbody></table>"
    print "<dl>"
    for setname in sorted(attributesSet.keys()):
        print "<dt><a name='%s' id='%s'>%s</a></dt>" % (setname,setname,setname)
        print "<dd>%s</dd>" % ", ".join(sorted(list(attributesSet[setname])))
        
    print "</dl>"

if __name__ == '__main__':
    from optparse import OptionParser
    usage = "usage: %prog uri1 uri2 ..."
    parser = OptionParser(usage)
    import sys
    #parser.add_option("-o", "--output",
    #                  action="store", type="string", dest="filename",
    #                  help="write output to FILE", metavar="FILE", default=sys.stdout)
    (options, args) = parser.parse_args()
    if len(args) < 2:
        parser.error("please specifty the URIs of the DTD you want to compare")
    compareDTD(args)