import bz2
import json
import sys
from xml.etree import cElementTree

PAGE_TAG = "page"
SITEINFO_TAG = "siteinfo"
XML_NAMESPACES = {"": "http://www.mediawiki.org/xml/export-0.11/"}


def doc_generator(f):
    namespaces = dict()
    for _, element in cElementTree.iterparse(f):
        _, tag = element.tag.split("}")
        if tag == PAGE_TAG:
            yield parse_page(element, namespaces)
            element.clear()
        if tag == SITEINFO_TAG:
            namespaces = parse_namespaces(element)


def get_doc_meta(doc_data, op_type="index"):
    return {op_type: {"_index": "wikipedia", "_id": doc_data["title"]}}


def to_json(f):
    with bz2.BZ2File(f, "r") as fp:
        for doc_data in doc_generator(fp):
            print(json.dumps(get_doc_meta(doc_data)))
            print(json.dumps(doc_data))


def parse_namespaces(element) -> dict:
    namespaces = dict()
    for namespace_element in element.findall("namespaces/namespace", XML_NAMESPACES):
        namespaces[namespace_element.get("key")] = namespace_element.text
    return namespaces


def parse_page(element, namespaces):
    page_data = {
        "title": element.find("title", XML_NAMESPACES).text,
    }

    redirect = element.find("redirect", XML_NAMESPACES)
    if redirect is not None:
        page_data["redirect"] = redirect.get("title")
    else:
        page_data["content"] = element.find("revision/text", XML_NAMESPACES).text

    namespace = namespaces[element.find("ns", XML_NAMESPACES).text]
    if namespace is not None:
        page_data["namespace"] = namespace

    return page_data


for file_name in sys.argv[1:]:
    to_json(file_name)