package helper

import (
	"os"
	"time"
)

// Returns env with default fallback value.
//
// Params:
//
//	key - enviroment var name
//	fallback - default value
func GetEnv(key, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	return fallback
}

type CacheItem struct {
	value      any
	expiration time.Time
}

type Cache struct {
	data  map[string]CacheItem
	ttl   time.Duration
	fetch func(key string) (any, error)
}

func NewCache(ttl time.Duration, fetchFunc func(key string) (any, error)) *Cache {
	return &Cache{
		data:  make(map[string]CacheItem),
		ttl:   ttl,
		fetch: fetchFunc,
	}
}

func (c *Cache) Get(key string) (any, error) {
	if item, found := c.data[key]; found {
		if time.Now().Before(item.expiration) {
			return item.value, nil
		}
	}

	value, err := c.fetch(key)
	if err != nil {
		return nil, err
	}
	c.data[key] = CacheItem{value: value, expiration: time.Now().Add(c.ttl)}
	return value, nil
}