// Checks if the client set configurations for more than one network while creating a container
// Also checks if the IPAMConfig is valid
func (daemon *Daemon) verifyNetworkingConfig(nwConfig *networktypes.NetworkingConfig) error {
	if nwConfig == nil || len(nwConfig.EndpointsConfig) == 0 {
		return nil
	}
	if len(nwConfig.EndpointsConfig) == 1 {
		for _, v := range nwConfig.EndpointsConfig {
			if v != nil && v.IPAMConfig != nil {
				if v.IPAMConfig.IPv4Address != "" && net.ParseIP(v.IPAMConfig.IPv4Address).To4() == nil {
					return errors.NewBadRequestError(fmt.Errorf("invalid IPv4 address: %s", v.IPAMConfig.IPv4Address))
				}
				if v.IPAMConfig.IPv6Address != "" {
					n := net.ParseIP(v.IPAMConfig.IPv6Address)
					// if the address is an invalid network address (ParseIP == nil) or if it is
					// an IPv4 address (To4() != nil), then it is an invalid IPv6 address
					if n == nil || n.To4() != nil {
						return errors.NewBadRequestError(fmt.Errorf("invalid IPv6 address: %s", v.IPAMConfig.IPv6Address))
					}
				}
			}
		}
		return nil
	}
	l := make([]string, 0, len(nwConfig.EndpointsConfig))
	for k := range nwConfig.EndpointsConfig {
		l = append(l, k)
	}
	err := fmt.Errorf("Container cannot be connected to network endpoints: %s", strings.Join(l, ", "))
	return errors.NewBadRequestError(err)
}

// GetContainer looks for a container using the provided information, which could be
// one of the following inputs from the caller:
//  - A full container ID, which will exact match a container in daemon's list
//  - A container name, which will only exact match via the GetByName() function
//  - A partial container ID prefix (e.g. short ID) of any length that is
//    unique enough to only return a single container object
//  If none of these searches succeed, an error is returned
func (daemon *Daemon) GetContainer(prefixOrName string) (*container.Container, error) {
	if len(prefixOrName) == 0 {
		return nil, errors.NewBadRequestError(fmt.Errorf("No container name or ID supplied"))
	}

	if containerByID := daemon.containers.Get(prefixOrName); containerByID != nil {
		// prefix is an exact match to a full container ID
		return containerByID, nil
	}

	// GetByName will match only an exact name provided; we ignore errors
	if containerByName, _ := daemon.GetByName(prefixOrName); containerByName != nil {
		// prefix is an exact match to a full container Name
		return containerByName, nil
	}

	containerID, indexError := daemon.idIndex.Get(prefixOrName)
	if indexError != nil {
		// When truncindex defines an error type, use that instead
		if indexError == truncindex.ErrNotExist {
			err := fmt.Errorf("No such container: %s", prefixOrName)
			return nil, errors.NewRequestNotFoundError(err)
		}
		return nil, indexError
	}
	return daemon.containers.Get(containerID), nil
}

// Checks if the client set configurations for more than one network while creating a container
func (daemon *Daemon) verifyNetworkingConfig(nwConfig *networktypes.NetworkingConfig) error {
	if nwConfig == nil || len(nwConfig.EndpointsConfig) <= 1 {
		return nil
	}
	l := make([]string, 0, len(nwConfig.EndpointsConfig))
	for k := range nwConfig.EndpointsConfig {
		l = append(l, k)
	}
	err := fmt.Errorf("Container cannot be connected to network endpoints: %s", strings.Join(l, ", "))
	return errors.NewBadRequestError(err)
}

func (s *systemRouter) getEvents(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
	if err := httputils.ParseForm(r); err != nil {
		return err
	}

	since, err := eventTime(r.Form.Get("since"))
	if err != nil {
		return err
	}
	until, err := eventTime(r.Form.Get("until"))
	if err != nil {
		return err
	}

	var (
		timeout        <-chan time.Time
		onlyPastEvents bool
	)
	if !until.IsZero() {
		if until.Before(since) {
			return errors.NewBadRequestError(fmt.Errorf("`since` time (%s) cannot be after `until` time (%s)", r.Form.Get("since"), r.Form.Get("until")))
		}

		now := time.Now()

		onlyPastEvents = until.Before(now)

		if !onlyPastEvents {
			dur := until.Sub(now)
			timeout = time.NewTimer(dur).C
		}
	}

	ef, err := filters.FromParam(r.Form.Get("filters"))
	if err != nil {
		return err
	}

	w.Header().Set("Content-Type", "application/json")
	output := ioutils.NewWriteFlusher(w)
	defer output.Close()
	output.Flush()

	enc := json.NewEncoder(output)

	buffered, l := s.backend.SubscribeToEvents(since, until, ef)
	defer s.backend.UnsubscribeFromEvents(l)

	for _, ev := range buffered {
		if err := enc.Encode(ev); err != nil {
			return err
		}
	}

	if onlyPastEvents {
		return nil
	}

	for {
		select {
		case ev := <-l:
			jev, ok := ev.(events.Message)
			if !ok {
				logrus.Warnf("unexpected event message: %q", ev)
				continue
			}
			if err := enc.Encode(jev); err != nil {
				return err
			}
		case <-timeout:
			return nil
		case <-ctx.Done():
			logrus.Debug("Client context cancelled, stop sending events")
			return nil
		}
	}
}