import warnings

def check_scdf(obj, message=False):
    """
    Check a Single-Case DataFrame (SCD) for errors and warnings.

    Parameters:
    - obj: The object to check (e.g., a pandas DataFrame).
    - message (bool): If True, print a success message when no issues are found.

    Returns:
    - True if no errors or warnings, otherwise raises/prints as appropriate.
    """
    results = _check_scdf(obj)
    if results is True:
        if message:
            print("No errors or warnings.")
        return True
    if results.get("warnings"):
        for w in results["warnings"]:
            warnings.warn(w)
    if results.get("errors"):
        raise ValueError("\n".join(results["errors"]))
    return False

def _check_scdf(obj):
    """
    Placeholder for actual checks. Should return True if all is well,
    or a dict with 'warnings' and 'errors' lists.
    """
    # Example implementation (replace with real checks)
    warnings_list = []
    errors_list = []
    # Example: check if 'case' column exists
    if hasattr(obj, "columns"):
        if "case" not in obj.columns:
            errors_list.append("Missing 'case' column.")
        if "phase" not in obj.columns:
            errors_list.append("Missing 'phase' column.")
        if "values" not in obj.columns:
            warnings_list.append("Missing 'values' column (not critical).")
    else:
        errors_list.append("Input object is not a DataFrame-like object.")

    if errors_list or warnings_list:
        return {"warnings": warnings_list, "errors": errors_list}
    return True