client

type Client interface {
	Registry
	Discovery
}

type Config struct {

	// URL of the registry server.
	URL string

	// AuthToken is the bearer token to be used for authentication with the registry.
	// If left empty, no authentication is used.
	AuthToken string

	// HTTPClient can be used to customize the underlying HTTP client behavior,
	// such as enabling TLS, setting timeouts, etc.
	// If left nil, a default HTTP client will be used.
	HTTPClient *http.Client
}

type Discovery interface {

	// ListServices queries the registry for the list of services for which instances are currently registered.
	ListServices() ([]string, error)

	// ListInstances queries the registry for the list of service instances currently registered.
	// The given InstanceFilter can be used to filter the returned instances as well as the fields returned for each.
	ListInstances(filter InstanceFilter) ([]*ServiceInstance, error)

	// ListServiceInstances queries the registry for the list of service instances with status 'UP' currently
	// registered for the given service.
	ListServiceInstances(serviceName string) ([]*ServiceInstance, error)
}

type Error struct {
	Code      ErrorCode
	Message   string
	Cause     error
	RequestID string
}

type ErrorCode int

type InstanceFilter struct {

	// ServiceName is used to filter service instances based on their service name.
	// When set to a non-empty string, registered service instances will be returned
	// only if their service name matches the specified service name.
	ServiceName string

	// Status is used to filter service instances based on their status.
	// When set to a non-empty string, registered service instances will be returned
	// only if their status matches the specified status.
	// When left empty, only instances with status "UP" will be returned.
	// When set to "ALL", all instances will be returned, regardless of their status.
	Status string

	// Tags is used to filter service instances based on their tags.
	// When set to a non-empty array, registered service instances will be returned
	// only if they are tagged with each of the specified tags.
	Tags []string

	// Fields is used to filter the fields returned for each service instance.
	// When set to a non-empty array, returned service instances will have their corresponding fields set,
	// while other fields will remain at their zero-value.
	// When set to an empty or nil array, returned service instances will have all of their fields set.
	Fields []string
}

type Registry interface {

	// Register adds a service instance, described by the given ServiceInstance structure, to the registry.
	// The returned ServiceInstance is mostly similar to the given one, but includes additional
	// attributes set by the registry server, such as the service instance ID and TTL.
	Register(instance *ServiceInstance) (*ServiceInstance, error)

	// Deregister removes a registered service instance, identified by the given ID, from the registry.
	Deregister(id string) error

	// Renew sends a heartbeat for the service instance identified by the given ID.
	Renew(id string) error
}

type ServiceEndpoint struct {

	// Type is the endpoint's type. Valid values are "http", "tcp", or "user".
	Type string `json:"type"`

	// Value is the endpoint's value according to its type,
	// e.g. "172.135.10.1:8080" or "http://myapp.ng.bluemix.net/api/v1".
	Value string `json:"value"`
}

type ServiceInstance struct {

	// ID is the unique ID assigned to this service instance by Amalgam8 Service Registry.
	// This field is ignored for registration, and is mandatory for discovery.
	ID string `json:"id,omitempty"`

	// ServiceName is the name of the service being provided by this service instance.
	// This field is mandatory both for registration and discovery.
	ServiceName string `json:"service_name"`

	// Endpoint is the network endpoint of this service instance.
	// This field is mandatory both for registration and discovery.
	Endpoint ServiceEndpoint `json:"endpoint"`

	// Status is a string representing the status of the service instance.
	// Valid values are "STARTING", "UP", or "OUT_OF_SERVICE".
	// This field is optional both for registration and discovery.
	Status string `json:"status,omitempty"`

	// Tags is a set of arbitrary tags attached to this service instance.
	// This field is optional both for registration and discovery.
	Tags []string `json:"tags,omitempty"`

	// Metadata is a marshaled JSON value associated with this service instance, in encoded-form.
	// Any arbitrary JSON value is valid, including numbers, strings, arrays and objects.
	// This field is optional both for registration and discovery.
	Metadata json.RawMessage `json:"metadata,omitempty"`

	// TTL is the time-to-live associated with this service instance, specified in seconds.
	// This field is optional for registration, and is mandatory for discovery.
	TTL int `json:"ttl,omitempty"`

	// LastHeartbeat is the timestamp in which heartbeat has been last received for this service instance.
	// This field is ignored for registration, and is mandatory for discovery.
	LastHeartbeat time.Time `json:"last_heartbeat,omitempty"`
}