auth

type ProviderOptions struct {
	// Timeout specifies the timeout for requests.
	// If not set, or set to a value that is less than 1 millisecond,
	// use the default timeout that depends on the concrete implementation of
	// authorization provider.
	Timeout time.Duration

	// ExpiryWindow specifies a duration of time that determines how far ahead
	// of access token expiry the provider is allowed to renew the access token.
	// If not set, or set to a value that is less than 1 millisecond,
	// use the default expiry window that depends on the concrete implementation
	// of authorization provider.
	// If set to a duration that is greater than the access token's lifetime,
	// the provider does not renew cached tokens.
	ExpiryWindow time.Duration

	// Logger specifies a logger for the provider.
	// If not set, use logger.DefaultLogger by default.
	Logger *logger.Logger

	// HTTPClient specifies an HTTP client for the provider.
	// If not set, use httputil.DefaultHTTPClient by default.
	HTTPClient *httputil.HTTPClient
}

type Request interface {
	// Request-dependent value.
	// The authorization provider is supposed to be able to interpret the value.
	Value() string
}

type Token struct {
	// The access token issued by the authorization server.
	AccessToken string `json:"access_token"`

	// Token type.
	// If not set, this is "Bearer" by default.
	Type string `json:"token_type,omitempty"`

	// The duration of time the access token is granted for.
	// A zero value of ExpiresIn means the access token does not expire.
	ExpiresIn time.Duration `json:"expires_in,omitempty"`

	// The time when the access token expires.
	// A zero value of Expiry means the access token does not expire.
	Expiry time.Time `json:"expiry,omitempty"`
}