discovery

type Callback func(Instancer)

type Client interface {
	Context() context.Context
	Instancer(serviceName string) (Instancer, error)
}

type HealthStatus int

type Instance struct {
	ID       string
	Service  string
	Address  string
	Port     int
	Tags     []string
	Meta     map[string]string
	Health   HealthStatus
	RawEntry interface{}
}

type InstanceMatcher matcher.ChainableMatcher

type Instancer interface {
	ServiceName() string
	Service() *Service
	Instances(InstanceMatcher) ([]*Instance, error)
	Start(ctx context.Context)
	Stop()
	RegisterCallback(id interface{}, cb Callback)
	DeregisterCallback(id interface{})
}

type Service struct {
	Name       string
	Insts      []*Instance
	Time       time.Time
	Err        error
	FirstErrAt time.Time
}

type ServiceCache interface {
	// Get returns service with given service name. return nil if not exist
	Get(name string) *Service
	// Set stores given service with name, returns non-nil if the service is already exists
	Set(name string, svc *Service) *Service
	// SetWithTTL stores given service with name and TTL, returns non-nil if the service is already exists
	// if ttl is zero or negative value, it's equivalent to Set
	SetWithTTL(name string, svc *Service, ttl time.Duration) *Service
	Has(name string) bool
	Entries() map[string]*Service
}

type ServiceRegistrar interface {
	Register(ctx context.Context, registration ServiceRegistration) error
	Deregister(ctx context.Context, registration ServiceRegistration) error
}

type ServiceRegistration interface {
	ID() string
	Name() string
	Address() string
	Port() int
	Tags() []string
	Meta() map[string]any

	SetID(id string)
	SetName(name string)
	SetAddress(addr string)
	SetPort(port int)
	AddTags(tags ...string)
	RemoveTags(tags ...string)
	SetMeta(key string, value any)
}

type ServiceRegistrationCustomizer interface {
	Customize(ctx context.Context, reg ServiceRegistration)
}

type ServiceRegistrationCustomizerFunc func(ctx context.Context, reg ServiceRegistration)