package config

import (
	"encoding/json"
	"io/ioutil"
	"local/storage"
	"os"
	"sync"
)

type Config struct {
	Interval Duration
	States   []State
	Storage  []string
	Once     bool

	lock sync.Mutex
	db   storage.DB
}

var live Config

func Refresh() error {
	configPath, ok := os.LookupEnv("CONFIG")
	if !ok {
		configPath = "./config.json"
	}
	b, err := ioutil.ReadFile(configPath)
	if err != nil {
		return err
	}
	var c Config
	if err := json.Unmarshal(b, &c); err != nil {
		return err
	}
	if live.db != nil {
		live.db.Close()
	}
	live = c
	return nil
}

func Get() *Config {
	return &live
}

func (c *Config) DB() storage.DB {
	if c.db == nil {
		c.lock.Lock()
		defer c.lock.Unlock()
		if c.db == nil {
			if len(c.Storage) == 0 {
				c.Storage = []string{storage.MAP.String()}
			}
			db, err := storage.New(storage.TypeFromString(c.Storage[0]), c.Storage[1:]...)
			if err != nil {
				panic(err)
			}
			c.db = db
		}
	}
	return c.db
}