// CreateNetwork creates a network in the cluster
func (c *Cluster) CreateNetwork(request *types.NetworkCreate) (*types.NetworkCreateResponse, error) {
	var (
		parts  = strings.SplitN(request.Name, "/", 2)
		config = &cluster.ContainerConfig{}
	)

	if len(parts) == 2 {
		// a node was specified, create the container only on this node
		request.Name = parts[1]
		config = cluster.BuildContainerConfig(containertypes.Config{Env: []string{"constraint:node==" + parts[0]}}, containertypes.HostConfig{}, networktypes.NetworkingConfig{})
	}

	c.scheduler.Lock()
	nodes, err := c.scheduler.SelectNodesForContainer(c.listNodes(), config)
	c.scheduler.Unlock()
	if err != nil {
		return nil, err
	}
	if nodes == nil {
		return nil, errors.New("cannot find node to create network")
	}
	n := nodes[0]
	s, ok := c.agents[n.ID]
	if !ok {
		return nil, fmt.Errorf("Unable to create network on agent %q", n.ID)
	}
	resp, err := s.engine.CreateNetwork(request)
	c.refreshNetworks()
	return resp, err
}

// CreateNetwork creates a network in the cluster
func (c *Cluster) CreateNetwork(request *types.NetworkCreate) (response *types.NetworkCreateResponse, err error) {
	var (
		parts  = strings.SplitN(request.Name, "/", 2)
		config = &cluster.ContainerConfig{}
	)

	if len(parts) == 2 {
		// a node was specified, create the container only on this node
		request.Name = parts[1]
		config = cluster.BuildContainerConfig(containertypes.Config{Env: []string{"constraint:node==" + parts[0]}}, containertypes.HostConfig{}, networktypes.NetworkingConfig{})
	}

	nodes, err := c.scheduler.SelectNodesForContainer(c.listNodes(), config)
	if err != nil {
		return nil, err
	}
	if nodes != nil {
		resp, err := c.engines[nodes[0].ID].CreateNetwork(request)
		if err == nil {
			if network := c.engines[nodes[0].ID].Networks().Get(resp.ID); network != nil && network.Scope == "global" {
				for id, engine := range c.engines {
					if id != nodes[0].ID {
						engine.AddNetwork(network)
					}
				}
			}
		}
		return resp, err
	}
	return nil, nil
}

// POST /networks/create
func postNetworksCreate(c *context, w http.ResponseWriter, r *http.Request) {
	var request apitypes.NetworkCreate

	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
		httpError(w, err.Error(), http.StatusBadRequest)
		return
	}

	if request.Driver == "" {
		request.Driver = "overlay"
	}

	response, err := c.cluster.CreateNetwork(&request)
	if err != nil {
		httpError(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(response)
}