package config

import (
	configViper "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/internal/common/config"
	"github.com/spf13/viper"
)

// Config represents a group of named values structured
// by tree type.
//
// Sub-trees are named configuration sub-sections,
// leaves are named configuration values.
// Names are of string type.
type Config struct {
	v *viper.Viper

	configFile string
	configDir  string
	envPrefix  string

	defaultPath []string
	path        []string
}

const (
	// EnvPrefix is a prefix of ENV variables related
	// to storage node configuration.
	EnvPrefix = "FROSTFS"
)

// New creates a new Config instance.
//
// If file option is provided,
// configuration values are read from it.
// Otherwise, Config is a degenerate tree.
func New(configFile, configDir, envPrefix string) *Config {
	v, err := configViper.CreateViper(
		configViper.WithConfigFile(configFile),
		configViper.WithConfigDir(configDir),
		configViper.WithEnvPrefix(envPrefix))
	if err != nil {
		panic(err)
	}

	return &Config{
		v:          v,
		configFile: configFile,
		configDir:  configDir,
		envPrefix:  envPrefix,
	}
}

// Reload reads configuration path if it was provided to New.
func (x *Config) Reload() error {
	return configViper.ReloadViper(
		configViper.WithViper(x.v), configViper.WithConfigFile(x.configFile),
		configViper.WithConfigDir(x.configDir),
		configViper.WithEnvPrefix(x.envPrefix))
}