package fn

import (
	"os"

	"sigs.k8s.io/kustomize/kyaml/fn/framework/command"
)

const (
	standaloneEnv = "EDGE_KPT_FN_STANDALONE"
)

// Standalone reads the environment to determine if this function
// should be standalone or not: https://pkg.go.dev/sigs.k8s.io/kustomize/kyaml@v0.10.19/fn/framework/command#Build
//
// checks for environment variable EDGE_KPT_FN_STANDALONE:
//
// - if it is present (with any value, or empty value), standalone mode is enabled
//
// - if it isnt present, standalone mode is disabled
func Standalone() command.CLIMode {
	_, set := os.LookupEnv(standaloneEnv)
	if set {
		return command.StandaloneEnabled
	}

	return command.StandaloneDisabled
}

// EnableStandalone allows enabling standalone mode in Edge Kpt functions
// programmatically.
//
// It is a thin wrapper around the internal constant for the standalone mode
// environment variable name.
func EnableStandalone() {
	os.Setenv(standaloneEnv, "true")
}