MainViewModel.4.swift

authError = forecast
    .map { result -> AuthErrorModelRepresentable? in
        switch result.lastResult {
        case .none, .success:
            return nil
        case .failure(let reason):
            switch reason {
            case .downloadError(let reason):
                switch reason {
                case .download(let reason):
                    switch reason {
                    case .unauthorized:
                        return AuthErrorFromMain()
                    case .networkError, .invalidResponseType, .noData, .unexpectedStatusCode:
                        return nil
                    }
                case .parsing:
                    return nil
                }
            case .temperatureInvalid:
                return nil
            }
        }
    }
    .filter { $0 != nil }.map { $0! }