"""RSS / Atom fetcher(基于 feedparser)。"""
from __future__ import annotations

from datetime import datetime, timezone
from email.utils import parsedate_to_datetime

import feedparser
from dateutil import parser as dtp

from app.services.fetchers.base import BaseFetcher, FetchedItem


class RSSFetcher(BaseFetcher):
    async def fetch(self) -> list[FetchedItem]:
        raw = await self._http_get()
        # feedparser 在不同 Python 下处理 bytes/str
        try:
            text = raw.decode("utf-8")
        except UnicodeDecodeError:
            text = raw.decode("utf-8", errors="replace")
        feed = feedparser.parse(text)
        if feed.bozo and not feed.entries:
            # 整篇解析失败
            raise RuntimeError(f"RSS parse failed: {feed.bozo_exception}")
        items: list[FetchedItem] = []
        for e in feed.entries:
            url = e.get("link") or e.get("id")
            if not url:
                continue
            title = (e.get("title") or "").strip()
            if not title:
                continue

            body_html = None
            body_text = ""
            if e.get("content"):
                # 选最长 content
                contents = sorted(e["content"], key=lambda c: -len(c.get("value", "")))
                body_html = contents[0].get("value")
            if not body_html:
                body_html = e.get("summary")
            if body_html:
                from bs4 import BeautifulSoup

                soup = BeautifulSoup(body_html, "lxml")
                # 去 script/style
                for tag in soup(["script", "style", "noscript"]):
                    tag.decompose()
                body_text = soup.get_text(separator="\n", strip=True)

            published_at = _parse_dt(e.get("published") or e.get("updated") or e.get("created"))
            author = e.get("author")
            image_url = None
            if e.get("media_content"):
                try:
                    image_url = e["media_content"][0].get("url")
                except (IndexError, KeyError, TypeError):
                    pass
            if not image_url and e.get("media_thumbnail"):
                try:
                    image_url = e["media_thumbnail"][0].get("url")
                except (IndexError, KeyError, TypeError):
                    pass
            if not image_url and e.get("enclosures"):
                for enc in e["enclosures"]:
                    if enc.get("type", "").startswith("image/"):
                        image_url = enc.get("href") or enc.get("url")
                        break

            items.append(
                FetchedItem(
                    url=url,
                    title=title,
                    body_html=body_html,
                    body_text=body_text,
                    published_at=published_at,
                    lang=e.get("language") or feed.feed.get("language"),
                    author=author,
                    image_url=image_url,
                    guid=e.get("id") or e.get("guid"),
                )
            )
        return items


def _parse_dt(s: str | None) -> datetime | None:
    if not s:
        return None
    try:
        dt = dtp.parse(s)
    except (ValueError, TypeError, dtp.ParserError):
        try:
            dt = parsedate_to_datetime(s)
        except Exception:
            return None
    if dt is None:
        return None
    if dt.tzinfo is None:
        dt = dt.replace(tzinfo=timezone.utc)
    return dt.astimezone(timezone.utc)