namespace.go

package growthbook

import "encoding/json"

// Namespace specifies what part of a namespace an experiment
// includes. If two experiments are in the same namespace and their
// ranges don't overlap, they wil be mutually exclusive.
type Namespace struct {
	ID    string
	Start float64
	End   float64
}

// Determine whether a user's ID lies within a given namespace.
func (namespace *Namespace) inNamespace(userID string) bool {
	n := float64(hashFnv32a(userID+"__"+namespace.ID)%1000) / 1000
	return n >= namespace.Start && n < namespace.End
}

// ParseNamespace creates a Namespace value from raw JSON input.
func ParseNamespace(data []byte) *Namespace {
	array := []interface{}{}
	err := json.Unmarshal(data, &array)
	if err != nil {
		logError("Failed parsing JSON input", "Namespace")
		return nil
	}
	return BuildNamespace(array)
}

// BuildNamespace creates a Namespace value from a generic JSON value.
func BuildNamespace(val interface{}) *Namespace {
	array, ok := val.([]interface{})
	if !ok || len(array) != 3 {
		logError("Invalid JSON data type", "Namespace")
		return nil
	}
	id, ok1 := array[0].(string)
	start, ok2 := array[1].(float64)
	end, ok3 := array[2].(float64)
	if !ok1 || !ok2 || !ok3 {
		logError("Invalid JSON data type", "Namespace")
		return nil
	}
	return &Namespace{id, start, end}
}