package cache

import (
	"errors"
	"time"
)

func newInMemCache() Manager {
	return &inMemCache{make(map[string]inMemEntry)}
}

type inMemEntry struct {
	value      string
	expiration time.Time
}

type inMemCache struct {
	entries map[string]inMemEntry
}

func (i *inMemCache) Set(key, value string, expiration time.Duration) error {
	i.entries[key] = inMemEntry{
		value:      value,
		expiration: time.Now().Add(expiration),
	}
	return nil
}
func (i *inMemCache) Get(key string) (string, error) {
	if val, exists := i.entries[key]; exists {
		if val.expiration.Before(time.Now()) {
			delete(i.entries, key)
		} else {
			return val.value, nil
		}
	}
	return "", errors.New("no value for given key")
}
func (i *inMemCache) Remove(key string) {
	delete(i.entries, key)
}