const (
	// We can fix this, as versions will be on separate subjects and use account mapping to roll requests to new versions etc.
	QG = "svc"

	// ServiceApiPrefix is the root of all control subjects
	ServiceApiPrefix = "$SRV"

	ServiceErrorHeader = "Nats-Service-Error"
)

type Endpoint struct {
	Subject string `json:"subject"`
	Handler ServiceHandler
}

type InternalEndpoint struct {
	Name    string
	Handler nats.MsgHandler
}

type Service interface {
	ID() string
	Name() string
	Description() string
	Version() string
	Stats() ServiceStats
	Reset()
	Stop()
}

type ServiceAPIError struct {
	ErrorCode   int
	Description string
}

type ServiceConfig struct {
	Name          string        `json:"name"`
	Description   string        `json:"description"`
	Version       string        `json:"version"`
	Schema        ServiceSchema `json:"schema"`
	Endpoint      Endpoint      `json:"endpoint"`
	StatusHandler func(Endpoint) interface{}
}

type ServiceHandler func(svc Service, req *nats.Msg) error

type ServiceInfo struct {
	Name        string `json:"name"`
	ID          string `json:"id"`
	Description string `json:"description"`
	Version     string `json:"version"`
	Subject     string `json:"subject"`
}

type ServiceSchema struct {
	Request  string `json:"request"`
	Response string `json:"response"`
}

type ServiceStats struct {
	Name      string    `json:"name"`
	ID        string    `json:"id"`
	Version   string    `json:"version"`
	Started   time.Time `json:"started"`
	Endpoints []Stats   `json:"stats"`
}

type ServiceVerb int64

const (
	SrvPing ServiceVerb = iota
	SrvStatus
	SrvInfo
	SrvSchema
)

type Stats struct {
	Name           string        `json:"name"`
	NumRequests    int           `json:"num_requests"`
	NumErrors      int           `json:"num_errors"`
	TotalLatency   time.Duration `json:"total_latency"`
	AverageLatency time.Duration `json:"average_latency"`
	Data           interface{}   `json:"data"`
}