from dataclasses import dataclass
from io import BufferedReader
from pathlib import Path
from typing import List
import lxml.etree
from datetime import datetime


class MediaWikiRevision:
    id: int
    parentid: int
    timestamp: str
    contributor: str
    comment: str
    model: str
    format: str
    text: str

    def __init__(
        self, id, parentid, timestamp, contributor, comment, model, format, text
    ):
        self.id = id
        self.parentid = parentid
        self.timestamp = datetime.fromisoformat(timestamp.replace("Z", "+00:00"))
        self.contributor = contributor
        self.comment = comment
        self.model = model
        self.format = format
        self.text = text


@dataclass
class MediaWikiPage:
    title: str
    id: int
    revisions: List[MediaWikiRevision]
    text: str


class MediaWikiDump:
    sitename: str
    baseurl: str
    engine: str
    pages: List[MediaWikiPage]

    def __init__(self, source: Path | str | BufferedReader) -> None:
        if not hasattr(source, "read"):
            source = open(source, "rb")

        root = lxml.etree.parse(source).getroot()
        ns = {"mw": "http://www.mediawiki.org/xml/export-0.11/"}
        siteinfo = root.find("./mw:siteinfo", ns)
        self.sitename = siteinfo.find("./mw:sitename", ns).text
        self.baseurl = siteinfo.find("./mw:base", ns).text
        self.engine = siteinfo.find("./mw:generator", ns).text

        self.pages = []
        ids = []
        for page in root.findall("./mw:page", ns):
            title = page.find("./mw:title", ns).text
            id = int(page.find("./mw:id", ns).text)
            if id in ids:
                continue
            revisions: List[MediaWikiRevision] = []
            for revision in page.findall("./mw:revision", ns):
                revid = int(revision.find("./mw:id", ns).text)
                parentid = int(revision.find("./mw:parentid", ns).text)
                timestamp = revision.find("./mw:timestamp", ns).text
                contributor = revision.find("./mw:contributor", ns).text
                comment = revision.find("./mw:comment", ns)
                comment = comment.text if comment is not None else ""
                model = revision.find("./mw:model", ns).text
                format = revision.find("./mw:format", ns).text
                text = revision.find("./mw:text", ns).text
                text = text if text is not None else ""
                revisions.append(
                    MediaWikiRevision(
                        revid,
                        parentid,
                        timestamp,
                        contributor,
                        comment,
                        model,
                        format,
                        text,
                    )
                )
            revisions.sort(key=lambda r: r.timestamp)
            revisions.reverse()
            text = revisions[0].text
            ids.append(id)
            self.pages.append(MediaWikiPage(title, id, revisions, text))
        pass