import feedparser
import pytz
from datetime import datetime
from typing import Optional
from bot.logger import get_logger

logger = get_logger("monitor")

CHANNEL_ID = "UCzHMxST9eZUo0XIaSyaTizA"
RSS_URL = f"https://www.youtube.com/feeds/videos.xml?channel_id={CHANNEL_ID}"
MMT = pytz.timezone("Asia/Yangon")


def fetch_latest_videos(seen_ids: set) -> list[dict]:
    """RSS Feed ကို parse လုပ်ပြီး အသစ်ဝင်လာသော video များကို return ပြန်သည်"""
    try:
        feed = feedparser.parse(RSS_URL)
        new_videos = []

        for entry in feed.entries:
            vid_id = entry.get("yt_videoid") or entry.get("id", "").split(":")[-1]
            if not vid_id or vid_id in seen_ids:
                continue

            published_str = entry.get("published", "")
            pub_dt = _parse_published(published_str)
            if pub_dt is None:
                continue

            video = {
                "video_id": vid_id,
                "title": entry.get("title", "No Title"),
                "url": f"https://www.youtube.com/watch?v={vid_id}",
                "published_time": pub_dt,          # UTC-aware datetime
                "published_mmt": pub_dt.astimezone(MMT),  # Myanmar time
            }
            new_videos.append(video)
            logger.info(f"New video detected: [{vid_id}] '{video['title']}' @ {video['published_mmt']}")

        return new_videos

    except Exception as e:
        logger.error(f"RSS fetch error: {e}")
        return []


def _parse_published(s: str) -> Optional[datetime]:
    """ISO 8601 string → UTC-aware datetime"""
    if not s:
        return None
    try:
        # feedparser က time_struct ပြန်ပေးတတ်သည်
        import time
        from email.utils import parsedate_to_datetime
        try:
            return parsedate_to_datetime(s)
        except Exception:
            pass
        # fallback: feedparser entry.published_parsed
        import calendar
        # handled outside; ဒီမှာ string form သာ process လုပ်
        dt = datetime.fromisoformat(s.replace("Z", "+00:00"))
        return dt
    except Exception as e:
        logger.warning(f"Cannot parse date '{s}': {e}")
        return None