"""
News fetcher — correlates bills with news articles.
Triggered after LLM brief creation and on a 6-hour schedule for active bills.
"""
import logging
from datetime import date, datetime, timedelta, timezone

from sqlalchemy import and_

from app.database import get_sync_db
from app.models import Bill, BillBrief, NewsArticle
from app.services import news_service
from app.workers.celery_app import celery_app

logger = logging.getLogger(__name__)


def _save_articles(db, bill_id: str, articles: list[dict]) -> int:
    """Persist a list of article dicts for a bill, skipping duplicates. Returns saved count."""
    saved = 0
    for article in articles:
        url = article.get("url")
        if not url:
            continue
        existing = db.query(NewsArticle).filter_by(bill_id=bill_id, url=url).first()
        if existing:
            continue
        pub_at = None
        if article.get("published_at"):
            try:
                pub_at = datetime.fromisoformat(article["published_at"].replace("Z", "+00:00"))
            except Exception:
                pass
        db.add(NewsArticle(
            bill_id=bill_id,
            source=article.get("source", "")[:200],
            headline=article.get("headline", ""),
            url=url,
            published_at=pub_at,
            relevance_score=1.0,
        ))
        saved += 1
    return saved


@celery_app.task(bind=True, max_retries=2, name="app.workers.news_fetcher.fetch_news_for_bill")
def fetch_news_for_bill(self, bill_id: str):
    """Fetch news articles for a specific bill."""
    db = get_sync_db()
    try:
        bill = db.get(Bill, bill_id)
        if not bill:
            return {"status": "not_found"}

        query = news_service.build_news_query(
            bill_title=bill.title,
            short_title=bill.short_title,
            sponsor_name=None,
            bill_type=bill.bill_type,
            bill_number=bill.bill_number,
        )

        newsapi_articles = news_service.fetch_newsapi_articles(query)
        gnews_articles = news_service.fetch_gnews_articles(query)
        saved = _save_articles(db, bill_id, newsapi_articles + gnews_articles)
        db.commit()
        logger.info(f"Saved {saved} news articles for bill {bill_id}")
        return {"status": "ok", "saved": saved}

    except Exception as exc:
        db.rollback()
        logger.error(f"News fetch failed for {bill_id}: {exc}")
        raise self.retry(exc=exc, countdown=300)
    finally:
        db.close()


@celery_app.task(bind=True, max_retries=2, name="app.workers.news_fetcher.fetch_news_for_bill_batch")
def fetch_news_for_bill_batch(self, bill_ids: list):
    """
    Fetch news for a batch of bills in ONE NewsAPI call using OR query syntax
    (up to NEWSAPI_BATCH_SIZE bills per call).  Google News is fetched per-bill
    but served from the 2-hour Redis cache so the RSS is only hit once per query.
    """
    db = get_sync_db()
    try:
        bills = [db.get(Bill, bid) for bid in bill_ids]
        bills = [b for b in bills if b]
        if not bills:
            return {"status": "no_bills"}

        # Build (bill_id, query) pairs for the batch NewsAPI call
        bill_queries = [
            (
                bill.bill_id,
                news_service.build_news_query(
                    bill_title=bill.title,
                    short_title=bill.short_title,
                    sponsor_name=None,
                    bill_type=bill.bill_type,
                    bill_number=bill.bill_number,
                ),
            )
            for bill in bills
        ]

        # One NewsAPI call for the whole batch
        newsapi_batch = news_service.fetch_newsapi_articles_batch(bill_queries)

        total_saved = 0
        for bill in bills:
            query = next(q for bid, q in bill_queries if bid == bill.bill_id)
            newsapi_articles = newsapi_batch.get(bill.bill_id, [])
            # Google News is cached — fine to call per-bill (cache hit after first)
            gnews_articles = news_service.fetch_gnews_articles(query)
            total_saved += _save_articles(db, bill.bill_id, newsapi_articles + gnews_articles)

        db.commit()
        logger.info(f"Batch saved {total_saved} articles for {len(bills)} bills")
        return {"status": "ok", "bills": len(bills), "saved": total_saved}

    except Exception as exc:
        db.rollback()
        logger.error(f"Batch news fetch failed: {exc}")
        raise self.retry(exc=exc, countdown=300)
    finally:
        db.close()


@celery_app.task(bind=True, name="app.workers.news_fetcher.fetch_news_for_active_bills")
def fetch_news_for_active_bills(self):
    """
    Scheduled task: fetch news for bills with recent actions (last 7 days).
    Groups bills into batches of NEWSAPI_BATCH_SIZE to multiply effective quota.
    """
    db = get_sync_db()
    try:
        cutoff = date.today() - timedelta(days=7)
        active_bills = (
            db.query(Bill)
            .filter(Bill.latest_action_date >= cutoff)
            .order_by(Bill.latest_action_date.desc())
            .limit(80)
            .all()
        )

        bill_ids = [b.bill_id for b in active_bills]
        batch_size = news_service.NEWSAPI_BATCH_SIZE
        batches = [bill_ids[i:i + batch_size] for i in range(0, len(bill_ids), batch_size)]
        for batch in batches:
            fetch_news_for_bill_batch.delay(batch)

        logger.info(
            f"Queued {len(batches)} news batches for {len(active_bills)} active bills "
            f"({batch_size} bills/batch)"
        )
        return {"queued_batches": len(batches), "total_bills": len(active_bills)}
    finally:
        db.close()