"""Narrow, sanitized company context discovery."""


def collect_company_context(reader):
    """Read only the catalog-approved company UF/regime projection; never CNPJ."""
    method = getattr(reader, "company_context_rows", None)
    if not callable(method):
        raise TypeError("reader must expose company_context_rows")
    rows = method()
    if not isinstance(rows, list) or not rows or any(not isinstance(row, dict) for row in rows):
        raise ValueError("company context is unavailable")
    ufs = {str(row.get("UF", "")).strip().upper() for row in rows}
    regimes = {str(row.get("REGIME", "")).strip() for row in rows}
    if len(ufs) != 1 or len(regimes) != 1 or not next(iter(ufs)) or not next(iter(regimes)):
        raise ValueError("company context is ambiguous")
    return {"uf": next(iter(ufs)), "regime": next(iter(regimes)), "cnpj": "REDACTED", "record_count": len(rows)}