import lxml.etree as etree

def inject(doc, add_ele, out_fufi=None):
    """inject an element into a document"""
    if(isinstance(doc, str)):
        ### allow for a file as the first argument
        parser = etree.XMLParser(remove_blank_text=True)
        doc = etree.parse(doc, parser)
    doc_root_ele = doc.getroot()
    doc_root_ele.append(add_ele)
    if out_fufi is not None:
        doc.write(out_fufi, pretty_print=True)
    return doc

def show(doc, do_verbose=False):
    string = etree.tostring(doc, pretty_print=True).decode()
    if do_verbose:
        print(string)
    return string

def dedup(doc, do_return=False):
    if(isinstance(doc, str)):
        ## allow for a file as the first argument
        parser = etree.XMLParser(remove_blank_text=True)
        doc = etree.parse(doc, parser)
    seen = {}
    has_it_changed = False
    for ele in doc.xpath('/*/*'):
        if 'id' not in ele.attrib:
            continue
        elid = ele.attrib['id']
        if elid not in seen:
            seen[elid] = 1
            continue
        ele.getparent().remove(ele)
        has_it_changed = True
    if not has_it_changed and not do_return:
        return None
    return doc