package cache

import (
	"encoding/json"
	"github.com/bradfitz/gomemcache/memcache"
	"time"
)

type MemcacheSettings struct {
	Servers []string
}

type MemcacheCache struct {
	backend *memcache.Client
}

func NewMemcacheCache(s MemcacheSettings) (CacheInterface, error) {
	c := memcache.New(s.Servers...)

	return &MemcacheCache{
		backend: c,
	}, nil
}

func (mc *MemcacheCache) Has(key string) bool {
	_, err := mc.backend.Get(key)

	return err != nil
}

func (mc *MemcacheCache) Get(key string) ([]byte, error) {
	item, err := mc.backend.Get(key)

	if err != nil {
		return nil, err
	}

	return item.Value, nil
}

func (mc *MemcacheCache) Set(key string, val interface{}, ttl time.Duration) error {
	var v []byte

	if b, ok := val.([]byte); ok {
		v = b
	} else if s, ok := val.(string); ok {
		b = []byte(s)
	} else {
		b, err := json.Marshal(val)

		if err != nil {
			return err
		}

		v = b
	}

	return mc.backend.Set(&memcache.Item{Key: key, Value: v, Expiration: int32(ttl.Seconds())})
}

func (mc *MemcacheCache) Del(key string) error {
	return mc.backend.Delete(key)
}