# keys.py (or inline in your main)
def xgp_key(item) -> str:
    # Prefer stable Microsoft Store productId if present; fallback to normalized title.
    pid = (item.get("productId") or "").strip()
    if pid:
        return f"item:xgp:{pid}"
    title = (item.get("title") or "").strip().lower()
    return f"item:xgp:title:{title}"

def egs_key(item) -> str:
    # Use title + start window (your fetcher usually knows the free-week start)
    title = (item.get("title") or "").strip()
    start = (item.get("start") or "").strip()  # ISO or YYYY-MM-DD
    return f"item:egs:{title}|{start}"

def psplus_key(item) -> str:
    # Use official PS Blog URL + the published month (or your computed date)
    url = (item.get("url") or "").strip()
    date = (item.get("date") or "").strip()
    return f"item:psplus:{url}|{date}"