package daemon
 
 import (
 	"errors"

 	"fmt"
 	"net"

 	"strings"
 

 	"github.com/docker/docker/daemon/network"

 	"github.com/docker/libnetwork"
 )
 
 const (
 	// NetworkByID represents a constant to find a network by its ID
 	NetworkByID = iota + 1
 	// NetworkByName represents a constant to find a network by its Name
 	NetworkByName
 )
 

 // NetworkControllerEnabled checks if the networking stack is enabled.
 // This feature depends on OS primitives and it's dissabled in systems like Windows.
 func (daemon *Daemon) NetworkControllerEnabled() bool {
 	return daemon.netController != nil
 }
 

 // FindNetwork function finds a network for a given string that can represent network name or id
 func (daemon *Daemon) FindNetwork(idName string) (libnetwork.Network, error) {
 	// Find by Name
 	n, err := daemon.GetNetwork(idName, NetworkByName)
 	if _, ok := err.(libnetwork.ErrNoSuchNetwork); err != nil && !ok {
 		return nil, err
 	}
 
 	if n != nil {
 		return n, nil
 	}
 
 	// Find by id
 	n, err = daemon.GetNetwork(idName, NetworkByID)
 	if err != nil {
 		return nil, err
 	}
 
 	return n, nil
 }
 
 // GetNetwork function returns a network for a given string that represents the network and
 // a hint to indicate if the string is an Id or Name of the network
 func (daemon *Daemon) GetNetwork(idName string, by int) (libnetwork.Network, error) {
 	c := daemon.netController
 	switch by {
 	case NetworkByID:
 		list := daemon.GetNetworksByID(idName)
 
 		if len(list) == 0 {
 			return nil, libnetwork.ErrNoSuchNetwork(idName)
 		}
 
 		if len(list) > 1 {
 			return nil, libnetwork.ErrInvalidID(idName)
 		}
 
 		return list[0], nil
 	case NetworkByName:
 		if idName == "" {
 			idName = c.Config().Daemon.DefaultNetwork
 		}
 		return c.NetworkByName(idName)
 	}
 	return nil, errors.New("unexpected selector for GetNetwork")
 }
 
 // GetNetworksByID returns a list of networks whose ID partially matches zero or more networks
 func (daemon *Daemon) GetNetworksByID(partialID string) []libnetwork.Network {
 	c := daemon.netController
 	list := []libnetwork.Network{}
 	l := func(nw libnetwork.Network) bool {
 		if strings.HasPrefix(nw.ID(), partialID) {
 			list = append(list, nw)
 		}
 		return false
 	}
 	c.WalkNetworks(l)
 
 	return list
 }
 
 // CreateNetwork creates a network with the given name, driver and other optional parameters

 func (daemon *Daemon) CreateNetwork(name, driver string, ipam network.IPAM, options map[string]string) (libnetwork.Network, error) {

 	c := daemon.netController
 	if driver == "" {
 		driver = c.Config().Daemon.DefaultDriver
 	}
 

 	nwOptions := []libnetwork.NetworkOption{}
 
 	v4Conf, v6Conf, err := getIpamConfig(ipam.Config)
 	if err != nil {
 		return nil, err
 	}
 

 	nwOptions = append(nwOptions, libnetwork.NetworkOptionIpam(ipam.Driver, "", v4Conf, v6Conf))

 	nwOptions = append(nwOptions, libnetwork.NetworkOptionDriverOpts(options))

 	return c.NewNetwork(driver, name, nwOptions...)
 }
 
 func getIpamConfig(data []network.IPAMConfig) ([]*libnetwork.IpamConf, []*libnetwork.IpamConf, error) {
 	ipamV4Cfg := []*libnetwork.IpamConf{}
 	ipamV6Cfg := []*libnetwork.IpamConf{}
 	for _, d := range data {
 		iCfg := libnetwork.IpamConf{}
 		iCfg.PreferredPool = d.Subnet
 		iCfg.SubPool = d.IPRange
 		iCfg.Gateway = d.Gateway
 		iCfg.AuxAddresses = d.AuxAddress
 		ip, _, err := net.ParseCIDR(d.Subnet)
 		if err != nil {
 			return nil, nil, fmt.Errorf("Invalid subnet %s : %v", d.Subnet, err)
 		}
 		if ip.To4() != nil {
 			ipamV4Cfg = append(ipamV4Cfg, &iCfg)
 		} else {
 			ipamV6Cfg = append(ipamV6Cfg, &iCfg)
 		}
 	}
 	return ipamV4Cfg, ipamV6Cfg, nil

 }