let token_url: String = format!(
"https://login.microsoftonline.com/{}/oauth2/token",
conf.tenant_id
);

let client_secret: Option<ClientSecret> = match &conf.client_secret {
    Some(secret) => Some(ClientSecret::new(secret.clone())),
    _ => None,
};

let client =
BasicClient::new(
	ClientId::new(conf.client_id.clone()),
	client_secret,
	AuthUrl::new("http://authorize/".to_string()).map_err(|err| {
		error::login(
			Some(err),
			"could not parse authorization url. it is likely invalid",
		)
	})?,
	Some(TokenUrl::new(token_url).map_err(|err| {
		error::login(Some(err), "could not parse token url. it is likely invalid")
	})?),
);

let token_result = client
.exchange_client_credentials()
.add_scopes(conf.scopes.clone())
.request(http_client)
.map_err(|err| {
	error::login(
		Some(err),
		"failed to authenticate. could not obtain valid access and refresh tokens",
	)
})?;