func (ep *endpoint) networkIDFromKey(key []string) (types.UUID, error) {
	// endpoint Key structure : endpoint/network-id/endpoint-id
	// its an invalid key if the key doesnt have all the 3 key elements above
	if key == nil || len(key) < 3 || key[0] != datastore.EndpointKeyPrefix {
		return types.UUID(""), fmt.Errorf("invalid endpoint key : %v", key)
	}

	// network-id is placed at index=1. pls refer to endpoint.Key() method
	return types.UUID(key[1]), nil
}

func networkIDFromEndpointKey(key string, ep *endpoint) (types.UUID, error) {
	eKey, err := datastore.ParseKey(key)
	if err != nil {
		return types.UUID(""), err
	}
	return ep.networkIDFromKey(eKey)
}

func (ep *endpoint) updateParentHosts() error {
	ep.Lock()
	container := ep.container
	network := ep.network
	ep.Unlock()

	if container == nil {
		return ErrNoContainer{}
	}

	for _, update := range container.config.parentUpdates {
		network.Lock()
		pep, ok := network.endpoints[types.UUID(update.eid)]
		if !ok {
			network.Unlock()
			continue
		}
		network.Unlock()

		pep.Lock()
		pContainer := pep.container
		pep.Unlock()

		if pContainer != nil {
			if err := etchosts.Update(pContainer.config.hostsPath, update.ip, update.name); err != nil {
				return err
			}
		}
	}

	return nil
}

func (n *network) EndpointByID(id string) (Endpoint, error) {
	if id == "" {
		return nil, ErrInvalidID
	}
	n.Lock()
	defer n.Unlock()
	if e, ok := n.endpoints[types.UUID(id)]; ok {
		return e, nil
	}
	return nil, ErrNoSuchEndpoint
}

func (c *controller) NetworkByID(id string) (Network, error) {
	if id == "" {
		return nil, ErrInvalidID
	}
	c.Lock()
	defer c.Unlock()
	if n, ok := c.networks[types.UUID(id)]; ok {
		return n, nil
	}
	return nil, ErrNoSuchNetwork
}

// NewNetwork creates a new network of the specified network type. The options
// are network specific and modeled in a generic way.
func (c *controller) NewNetwork(networkType, name string, options ...NetworkOption) (Network, error) {
	if name == "" {
		return nil, ErrInvalidName(name)
	}
	// Check if a driver for the specified network type is available
	c.Lock()
	d, ok := c.drivers[networkType]
	c.Unlock()
	if !ok {
		var err error
		d, err = c.loadDriver(networkType)
		if err != nil {
			return nil, err
		}
	}

	// Check if a network already exists with the specified network name
	c.Lock()
	for _, n := range c.networks {
		if n.name == name {
			c.Unlock()
			return nil, NetworkNameError(name)
		}
	}
	c.Unlock()

	// Construct the network object
	network := &network{
		name:      name,
		id:        types.UUID(stringid.GenerateRandomID()),
		ctrlr:     c,
		driver:    d,
		endpoints: endpointTable{},
	}

	network.processOptions(options...)
	if err := c.addNetworkToStore(network); err != nil {
		return nil, err
	}
	// Create the network
	if err := d.CreateNetwork(network.id, network.generic); err != nil {
		return nil, err
	}

	// Store the network handler in controller
	c.Lock()
	c.networks[network.id] = network
	c.Unlock()

	return network, nil
}

func (d *driver) processEvent(u serf.UserEvent) {
	fmt.Printf("Received user event name:%s, payload:%s\n", u.Name,
		string(u.Payload))

	var dummy, action, vtepStr, nid, eid, ipStr, macStr string
	if _, err := fmt.Sscan(u.Name, &dummy, &vtepStr, &nid, &eid); err != nil {
		fmt.Printf("Failed to scan name string: %v\n", err)
	}

	if _, err := fmt.Sscan(string(u.Payload), &action,
		&ipStr, &macStr); err != nil {
		fmt.Printf("Failed to scan value string: %v\n", err)
	}

	fmt.Printf("Parsed data = %s/%s/%s/%s/%s\n", nid, eid, vtepStr, ipStr, macStr)

	mac, err := net.ParseMAC(macStr)
	if err != nil {
		fmt.Printf("Failed to parse mac: %v\n", err)
	}

	if d.serfInstance.LocalMember().Addr.String() == vtepStr {
		return
	}

	switch action {
	case "join":
		if err := d.peerAdd(types.UUID(nid), types.UUID(eid), net.ParseIP(ipStr), mac,
			net.ParseIP(vtepStr), true); err != nil {
			fmt.Printf("Peer add failed in the driver: %v\n", err)
		}
	case "leave":
		if err := d.peerDelete(types.UUID(nid), types.UUID(eid), net.ParseIP(ipStr), mac,
			net.ParseIP(vtepStr), true); err != nil {
			fmt.Printf("Peer delete failed in the driver: %v\n", err)
		}
	}
}

// TODO : Can be made much more generic with the help of reflection (but has some golang limitations)
func (n *network) UnmarshalJSON(b []byte) (err error) {
	var netMap map[string]interface{}
	if err := json.Unmarshal(b, &netMap); err != nil {
		return err
	}
	n.name = netMap["name"].(string)
	n.id = types.UUID(netMap["id"].(string))
	n.networkType = netMap["networkType"].(string)
	n.enableIPv6 = netMap["enableIPv6"].(bool)
	if netMap["generic"] != nil {
		n.generic = netMap["generic"].(map[string]interface{})
	}
	return nil
}

func (n *network) CreateEndpoint(name string, options ...EndpointOption) (Endpoint, error) {
	var err error
	if !config.IsValidName(name) {
		return nil, ErrInvalidName(name)
	}

	if _, err = n.EndpointByName(name); err == nil {
		return nil, types.ForbiddenErrorf("service endpoint with name %s already exists", name)
	}

	ep := &endpoint{name: name,
		iFaces:  []*endpointInterface{},
		generic: make(map[string]interface{})}
	ep.id = types.UUID(stringid.GenerateRandomID())
	ep.network = n
	ep.processOptions(options...)

	n.Lock()
	ctrlr := n.ctrlr
	n.Unlock()

	n.IncEndpointCnt()
	if err = ctrlr.updateNetworkToStore(n); err != nil {
		return nil, err
	}
	defer func() {
		if err != nil {
			n.DecEndpointCnt()
			if err = ctrlr.updateNetworkToStore(n); err != nil {
				log.Warnf("endpoint count cleanup failed when updating network for %s : %v", name, err)
			}
		}
	}()
	if err = n.addEndpoint(ep); err != nil {
		return nil, err
	}
	defer func() {
		if err != nil {
			if e := ep.Delete(); ep != nil {
				log.Warnf("cleaning up endpoint failed %s : %v", name, e)
			}
		}
	}()

	if err = ctrlr.updateEndpointToStore(ep); err != nil {
		return nil, err
	}

	return ep, nil
}

func (d *driver) processQuery(q *serf.Query) {
	fmt.Printf("Received query name:%s, payload:%s\n", q.Name,
		string(q.Payload))

	var nid, ipStr string
	if _, err := fmt.Sscan(string(q.Payload), &nid, &ipStr); err != nil {
		fmt.Printf("Failed to scan query payload string: %v\n", err)
	}

	peerMac, vtep, err := d.peerDbSearch(types.UUID(nid), net.ParseIP(ipStr))
	if err != nil {
		return
	}

	q.Respond([]byte(fmt.Sprintf("%s %s", peerMac.String(), vtep.String())))
}

func (n *network) CreateEndpoint(name string, options ...EndpointOption) (Endpoint, error) {
	if name == "" {
		return nil, ErrInvalidName
	}
	ep := &endpoint{name: name, iFaces: []*endpointInterface{}, generic: make(map[string]interface{})}
	ep.id = types.UUID(stringid.GenerateRandomID())
	ep.network = n
	ep.processOptions(options...)

	d := n.driver
	err := d.CreateEndpoint(n.id, ep.id, ep, ep.generic)
	if err != nil {
		return nil, err
	}

	n.Lock()
	n.endpoints[ep.id] = ep
	n.Unlock()
	return ep, nil
}

func (n *network) watchMiss(nlSock *nl.NetlinkSocket) {
	for {
		msgs, err := nlSock.Recieve()
		if err != nil {
			logrus.Errorf("Failed to receive from netlink: %v ", err)
			continue
		}

		for _, msg := range msgs {
			if msg.Header.Type != syscall.RTM_GETNEIGH && msg.Header.Type != syscall.RTM_NEWNEIGH {
				continue
			}

			neigh, err := netlink.NeighDeserialize(msg.Data)
			if err != nil {
				logrus.Errorf("Failed to deserialize netlink ndmsg: %v", err)
				continue
			}

			if neigh.IP.To16() != nil {
				continue
			}

			if neigh.State&(netlink.NUD_STALE|netlink.NUD_INCOMPLETE) == 0 {
				continue
			}

			mac, vtep, err := n.driver.resolvePeer(n.id, neigh.IP)
			if err != nil {
				logrus.Errorf("could not resolve peer %q: %v", neigh.IP, err)
				continue
			}

			if err := n.driver.peerAdd(n.id, types.UUID("dummy"), neigh.IP, mac, vtep, true); err != nil {
				logrus.Errorf("could not add neighbor entry for missed peer: %v", err)
			}
		}
	}
}

// NewNetwork creates a new network of the specified network type. The options
// are network specific and modeled in a generic way.
func (c *controller) NewNetwork(networkType, name string, options ...NetworkOption) (Network, error) {
	if !config.IsValidName(name) {
		return nil, ErrInvalidName(name)
	}
	// Check if a network already exists with the specified network name
	c.Lock()
	for _, n := range c.networks {
		if n.name == name {
			c.Unlock()
			return nil, NetworkNameError(name)
		}
	}
	c.Unlock()

	// Construct the network object
	network := &network{
		name:        name,
		networkType: networkType,
		id:          types.UUID(stringid.GenerateRandomID()),
		ctrlr:       c,
		endpoints:   endpointTable{},
	}

	network.processOptions(options...)

	if err := c.addNetwork(network); err != nil {
		return nil, err
	}

	if err := c.updateNetworkToStore(network); err != nil {
		log.Warnf("couldnt create network %s: %v", network.name, err)
		if e := network.Delete(); e != nil {
			log.Warnf("couldnt cleanup network %s: %v", network.name, err)
		}
		return nil, err
	}

	return network, nil
}

func (ep *endpoint) UnmarshalJSON(b []byte) (err error) {
	ep.Lock()
	defer ep.Unlock()

	var epMap map[string]interface{}
	if err := json.Unmarshal(b, &epMap); err != nil {
		return err
	}
	ep.name = epMap["name"].(string)
	ep.id = types.UUID(epMap["id"].(string))

	ib, _ := json.Marshal(epMap["ep_iface"])
	var ifaces []endpointInterface
	json.Unmarshal(ib, &ifaces)
	ep.iFaces = make([]*endpointInterface, 0)
	for _, iface := range ifaces {
		ep.iFaces = append(ep.iFaces, &iface)
	}

	tb, _ := json.Marshal(epMap["exposed_ports"])
	var tPorts []types.TransportPort
	json.Unmarshal(tb, &tPorts)
	ep.exposedPorts = tPorts

	epc, ok := epMap["container"]
	if ok {
		cb, _ := json.Marshal(epc)
		var cInfo containerInfo
		json.Unmarshal(cb, &cInfo)
		ep.container = &cInfo
	}

	if epMap["generic"] != nil {
		ep.generic = epMap["generic"].(map[string]interface{})
	}
	return nil
}

func (d *driver) link(network *bridgeNetwork, endpoint *bridgeEndpoint, options map[string]interface{}, enable bool) error {
	var (
		cc  *containerConfiguration
		err error
	)

	if enable {
		cc, err = parseContainerOptions(options)
		if err != nil {
			return err
		}
	} else {
		cc = endpoint.containerConfig
	}

	if cc == nil {
		return nil
	}

	if endpoint.config != nil && endpoint.config.ExposedPorts != nil {
		for _, p := range cc.ParentEndpoints {
			var parentEndpoint *bridgeEndpoint
			parentEndpoint, err = network.getEndpoint(types.UUID(p))
			if err != nil {
				return err
			}
			if parentEndpoint == nil {
				err = InvalidEndpointIDError(p)
				return err
			}

			l := newLink(parentEndpoint.addr.IP.String(),
				endpoint.addr.IP.String(),
				endpoint.config.ExposedPorts, network.config.BridgeName)
			if enable {
				err = l.Enable()
				if err != nil {
					return err
				}
				defer func() {
					if err != nil {
						l.Disable()
					}
				}()
			} else {
				l.Disable()
			}
		}
	}

	for _, c := range cc.ChildEndpoints {
		var childEndpoint *bridgeEndpoint
		childEndpoint, err = network.getEndpoint(types.UUID(c))
		if err != nil {
			return err
		}
		if childEndpoint == nil {
			err = InvalidEndpointIDError(c)
			return err
		}
		if childEndpoint.config == nil || childEndpoint.config.ExposedPorts == nil {
			continue
		}

		l := newLink(endpoint.addr.IP.String(),
			childEndpoint.addr.IP.String(),
			childEndpoint.config.ExposedPorts, network.config.BridgeName)
		if enable {
			err = l.Enable()
			if err != nil {
				return err
			}
			defer func() {
				if err != nil {
					l.Disable()
				}
			}()
		} else {
			l.Disable()
		}
	}

	if enable {
		endpoint.containerConfig = cc
	}

	return nil
}

func main() {
	if reexec.Init() {
		return
	}

	r := &router{}
	if err := overlay.Init(r); err != nil {
		fmt.Printf("Failed to initialize overlay driver: %v\n", err)
		os.Exit(1)
	}

	opt := make(map[string]interface{})
	if len(os.Args) > 1 {
		opt[netlabel.OverlayBindInterface] = os.Args[1]
	}
	if len(os.Args) > 2 {
		opt[netlabel.OverlayNeighborIP] = os.Args[2]
	}
	if len(os.Args) > 3 {
		opt[netlabel.KVProvider] = os.Args[3]
	}
	if len(os.Args) > 4 {
		opt[netlabel.KVProviderURL] = os.Args[4]
	}

	r.d.Config(opt)

	if err := r.d.CreateNetwork(types.UUID("testnetwork"),
		map[string]interface{}{}); err != nil {
		fmt.Printf("Failed to create network in the driver: %v\n", err)
		os.Exit(1)
	}

	ep := &endpoint{}
	if err := r.d.CreateEndpoint(types.UUID("testnetwork"), types.UUID("testep"),
		ep, map[string]interface{}{}); err != nil {
		fmt.Printf("Failed to create endpoint in the driver: %v\n", err)
		os.Exit(1)
	}

	if err := r.d.Join(types.UUID("testnetwork"), types.UUID("testep"),
		"", ep, map[string]interface{}{}); err != nil {
		fmt.Printf("Failed to join an endpoint in the driver: %v\n", err)
		os.Exit(1)
	}

	link, err := netlink.LinkByName(ep.name)
	if err != nil {
		fmt.Printf("Failed to find the container interface with name %s: %v\n",
			ep.name, err)
		os.Exit(1)
	}

	ipAddr := &netlink.Addr{IPNet: &ep.addr, Label: ""}
	if err := netlink.AddrAdd(link, ipAddr); err != nil {
		fmt.Printf("Failed to add address to the interface: %v\n", err)
		os.Exit(1)
	}

	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh, os.Interrupt, os.Kill)

	for {
		select {
		case <-sigCh:
			r.d.Leave(types.UUID("testnetwork"), types.UUID("testep"))
			overlay.Fini(r.d)
			os.Exit(0)
		}
	}
}