package smartconfig

import (
	"fmt"
	"os"
)

// EnvResolver resolves environment variables.
// Usage: ${ENV:VARIABLE_NAME}
type EnvResolver struct{}

// Resolve returns the value of the environment variable.
func (r *EnvResolver) Resolve(value string) (string, error) {
	result := os.Getenv(value)
	if result == "" {
		return "", fmt.Errorf("environment variable %s not found", value)
	}
	return result, nil
}