package appmode

import (
	"errors"
	"fmt"
	"os"
)

const (
	envKey = "APP_MODE"

	Development = "development"
	Production  = "production"
)

var (
	ErrUnsupported = errors.New("unsupported app mode")
)

func Parse() (string, error) {
	appModeStr, ok := os.LookupEnv(envKey)
	if !ok {
		return Development, nil
	}

	switch appModeStr {
	case Development:
		return Development, nil
	case Production:
		return Production, nil
	default:
		return "", fmt.Errorf("%w: %s", ErrUnsupported, appModeStr)
	}
}