#!/usr/bin/env python3
"""Download KISA/KNVD advisory HTML pages for offline analysis."""

from __future__ import annotations

import argparse
import datetime as dt
import sys
import xml.etree.ElementTree as ET
from pathlib import Path
from urllib.error import HTTPError, URLError
from urllib.parse import parse_qs, urlsplit
from urllib.request import Request, urlopen

FEED_URL = "https://knvd.krcert.or.kr/rss/securityInfo.do"
USER_AGENT = "Mozilla/5.0 (compatible; StellaOpsOffline/1.0)"


def fetch(url: str) -> bytes:
    req = Request(url, headers={"User-Agent": USER_AGENT})
    with urlopen(req, timeout=15) as resp:
        return resp.read()


def iter_idxs(feed_xml: bytes) -> list[tuple[str, str]]:
    root = ET.fromstring(feed_xml)
    items = []
    for item in root.findall(".//item"):
        title = (item.findtext("title") or "").strip()
        link = item.findtext("link") or ""
        idx = parse_qs(urlsplit(link).query).get("IDX", [None])[0]
        if idx:
            items.append((idx, title))
    return items


def capture(idx: str, title: str, out_dir: Path) -> Path:
    url = f"https://knvd.krcert.or.kr/detailDos.do?IDX={idx}"
    html = fetch(url)
    target = out_dir / f"{idx}.html"
    target.write_bytes(html)
    print(f"saved {target} ({title})")
    return target


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("--out", type=Path, default=Path("seed-data/kisa/html"))
    parser.add_argument("--limit", type=int, default=10, help="Maximum advisories to download")
    args = parser.parse_args()

    args.out.mkdir(parents=True, exist_ok=True)

    print(f"[{dt.datetime.utcnow():%Y-%m-%d %H:%M:%S}Z] fetching RSS feed…")
    try:
        feed = fetch(FEED_URL)
    except (URLError, HTTPError) as exc:
        print("RSS fetch failed:", exc, file=sys.stderr)
        return 1

    items = iter_idxs(feed)[: args.limit]
    if not items:
        print("No advisories found in feed", file=sys.stderr)
        return 1

    for idx, title in items:
        try:
            capture(idx, title, args.out)
        except (URLError, HTTPError) as exc:
            print(f"failed {idx}: {exc}", file=sys.stderr)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())