# 2026-03-21 — pg-delete-old: удаляет строки старше N минут (default 60).
# Тестирует: DELETE с RETURNING, идемпотентность (повторный вызов = 0 удалений если нет старых).
import os, psycopg2, psycopg2.extras

def delete_old(event):
    older_than_min = max(int(event.get("older_than_min", 60)), 1)
    prefix_filter = event.get("prefix", "")

    conn = psycopg2.connect(
        host=os.environ["PGHOST"], port=int(os.environ.get("PGPORT", 5432)),
        dbname=os.environ["PGDATABASE"], user=os.environ["PGUSER"],
        password=os.environ["PGPASSWORD"], sslmode=os.environ.get("PGSSLMODE", "require"),
    )
    try:
        with conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor) as cur:
            if prefix_filter:
                cur.execute(
                    "DELETE FROM terraform_demo_table "
                    "WHERE created_at < now() - interval '1 minute' * %s "
                    "AND title LIKE %s RETURNING id, title",
                    (older_than_min, f"{prefix_filter}%"),
                )
            else:
                cur.execute(
                    "DELETE FROM terraform_demo_table "
                    "WHERE created_at < now() - interval '1 minute' * %s RETURNING id, title",
                    (older_than_min,),
                )
            deleted = [dict(r) for r in cur.fetchall()]
        conn.commit()
        return {"deleted": len(deleted), "older_than_min": older_than_min, "sample": deleted[:5]}
    finally:
        conn.close()