package storage

import (
	"net"

	"github.com/bradfitz/gomemcache/memcache"
)

type Memcache struct {
	db *memcache.Client
}

type serverSelector struct {
	addrs []string
}

func (ss *serverSelector) PickServer(key string) (net.Addr, error) {
	return &netAddr{
		network: "tcp",
		addr:    ss.addrs[0],
	}, nil
}

func (ss *serverSelector) Each(each func(net.Addr) error) error {
	for _, addr := range ss.addrs {
		if err := each(&netAddr{
			network: "tcp",
			addr:    addr,
		}); err != nil {
			return err
		}
	}
	return nil
}

type netAddr struct {
	network string
	addr    string
}

func (a *netAddr) Network() string {
	return a.network
}

func (a *netAddr) String() string {
	return a.addr
}

func NewMemcache(addr string, addrs ...string) (*Memcache, error) {
	ss := &serverSelector{
		addrs: append(addrs, addr),
	}
	if err := ss.Each(func(addr net.Addr) error {
		conn, err := net.Dial("tcp", addr.String())
		if err != nil {
			return err
		}
		return conn.Close()
	}); err != nil {
		return nil, err
	}
	db := memcache.NewFromSelector(ss)
	return &Memcache{db: db}, nil
}

func (mc *Memcache) Get(key string) ([]byte, error) {
	v, err := mc.db.Get(key)
	return v.Value, err
}

func (mc *Memcache) Set(key string, value []byte) error {
	return mc.db.Set(&memcache.Item{
		Key:   key,
		Value: value,
	})
}

func (mc *Memcache) Close() error {
	return mc.db.FlushAll()
}