from __future__ import annotations

"""Backfill cluster embeddings into news-mcp's SQLite store.

This precomputes a cluster-level embedding for older rows so the optional
Ollama-first clustering path has data to work with before live traffic resumes.

Usage:
  ./.venv/bin/python scripts/backfill_news_embeddings.py --dry-run --limit 200
  ./.venv/bin/python scripts/backfill_news_embeddings.py --limit 1000
"""

import argparse
import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))

from news_mcp.config import DB_PATH, OLLAMA_BASE_URL, OLLAMA_EMBEDDING_MODEL, NEWS_EMBEDDINGS_ENABLED
from news_mcp.dedup.embedding_support import ollama_embed
from news_mcp.storage.sqlite_store import SQLiteClusterStore


def _cluster_text(cluster: dict) -> str:
    parts = [cluster.get("headline", ""), cluster.get("summary", "") or ""]
    return "\n".join(p for p in parts if p).strip()


def main() -> None:
    parser = argparse.ArgumentParser(description="Backfill embeddings for stored news clusters")
    parser.add_argument("--db", type=Path, default=DB_PATH)
    parser.add_argument("--limit", type=int, default=None, help="Optional maximum number of rows to process")
    parser.add_argument("--dry-run", action="store_true", help="Do not write back changes")
    args = parser.parse_args()

    if not NEWS_EMBEDDINGS_ENABLED:
        print("NEWS_EMBEDDINGS_ENABLED is false; nothing to backfill.")
        return

    store = SQLiteClusterStore(args.db)
    with store._conn() as conn:  # noqa: SLF001 - one-off maintenance script
        rows = conn.execute("SELECT cluster_id, topic, payload FROM clusters ORDER BY updated_at ASC").fetchall()

    if args.limit is not None:
        rows = rows[: args.limit]

    total = 0
    updated = 0
    skipped = 0

    print(f"starting embeddings backfill: clusters={len(rows)} dry_run={args.dry_run} model={OLLAMA_EMBEDDING_MODEL} url={OLLAMA_BASE_URL}")

    for cluster_id, topic, payload_json in rows:
        total += 1
        try:
            cluster = json.loads(payload_json)
        except Exception:
            skipped += 1
            continue

        if cluster.get("embedding"):
            continue

        emb = ollama_embed(_cluster_text(cluster))
        if not emb:
            skipped += 1
            continue

        cluster = dict(cluster)
        cluster["embedding"] = emb
        cluster["embedding_model"] = f"ollama:{OLLAMA_EMBEDDING_MODEL}"

        if not args.dry_run:
            store.upsert_clusters([cluster], topic=topic or cluster.get("topic", "other"))
        updated += 1

        if updated % 25 == 0:
            print(f"updated={updated} processed={total}")

    print({"total_scanned": total, "updated": updated, "skipped": skipped, "dry_run": args.dry_run})


if __name__ == "__main__":
    main()