// NewContainerManager creates the entity that knows how to create and manage
// LXD containers.
// TODO(jam): This needs to grow support for things like LXC's ImageURLGetter
// functionality.
func NewContainerManager(conf container.ManagerConfig) (container.Manager, error) {
	name := conf.PopValue(container.ConfigName)
	if name == "" {
		return nil, errors.Errorf("name is required")
	}

	conf.WarnAboutUnused()
	return &containerManager{name: name}, nil
}

// NewContainerManager creates the entity that knows how to create and manage
// LXD containers.
// TODO(jam): This needs to grow support for things like LXC's ImageURLGetter
// functionality.
func NewContainerManager(conf container.ManagerConfig) (container.Manager, error) {
	modelUUID := conf.PopValue(container.ConfigModelUUID)
	if modelUUID == "" {
		return nil, errors.Errorf("model UUID is required")
	}
	namespace, err := instance.NewNamespace(modelUUID)
	if err != nil {
		return nil, errors.Trace(err)
	}

	conf.WarnAboutUnused()
	return &containerManager{
		modelUUID: modelUUID,
		namespace: namespace,
	}, nil
}

// NewContainerManager returns a manager object that can start and
// stop lxc containers. The containers that are created are namespaced
// by the name parameter inside the given ManagerConfig.
func NewContainerManager(
	conf container.ManagerConfig,
	imageURLGetter container.ImageURLGetter,
	loopDeviceManager looputil.LoopDeviceManager,
) (container.Manager, error) {
	name := conf.PopValue(container.ConfigName)
	if name == "" {
		return nil, errors.Errorf("name is required")
	}
	logDir := conf.PopValue(container.ConfigLogDir)
	if logDir == "" {
		logDir = agent.DefaultLogDir
	}
	var useClone bool
	useCloneVal := conf.PopValue("use-clone")
	if useCloneVal != "" {
		// Explicitly ignore the error result from ParseBool.
		// If it fails to parse, the value is false, and this suits
		// us fine.
		useClone, _ = strconv.ParseBool(useCloneVal)
	} else {
		// If no lxc-clone value is explicitly set in config, then
		// see if the Ubuntu series we are running on supports it
		// and if it does, we will use clone.
		useClone = preferFastLXC(releaseVersion())
	}
	useAUFS, _ := strconv.ParseBool(conf.PopValue("use-aufs"))
	backingFS, err := containerDirFilesystem()
	if err != nil {
		// Especially in tests, or a bot, the lxc dir may not exist
		// causing the test to fail. Since we only really care if the
		// backingFS is 'btrfs' and we treat the rest the same, just
		// call it 'unknown'.
		backingFS = "unknown"
	}
	logger.Tracef("backing filesystem: %q", backingFS)
	conf.WarnAboutUnused()
	return &containerManager{
		name:              name,
		logdir:            logDir,
		createWithClone:   useClone,
		useAUFS:           useAUFS,
		backingFilesystem: backingFS,
		imageURLGetter:    imageURLGetter,
		loopDeviceManager: loopDeviceManager,
	}, nil
}

// NewContainerManager returns a manager object that can start and stop kvm
// containers. The containers that are created are namespaced by the name
// parameter.
func NewContainerManager(conf container.ManagerConfig) (container.Manager, error) {
	name := conf.PopValue(container.ConfigName)
	if name == "" {
		return nil, fmt.Errorf("name is required")
	}
	logDir := conf.PopValue(container.ConfigLogDir)
	if logDir == "" {
		logDir = agent.DefaultLogDir
	}
	conf.WarnAboutUnused()
	return &containerManager{name: name, logdir: logDir}, nil
}

// NewContainerManager returns a manager object that can start and stop kvm
// containers.
func NewContainerManager(conf container.ManagerConfig) (container.Manager, error) {
	modelUUID := conf.PopValue(container.ConfigModelUUID)
	if modelUUID == "" {
		return nil, errors.Errorf("model UUID is required")
	}
	namespace, err := instance.NewNamespace(modelUUID)
	if err != nil {
		return nil, errors.Trace(err)
	}
	logDir := conf.PopValue(container.ConfigLogDir)
	if logDir == "" {
		logDir = agent.DefaultPaths.LogDir
	}
	conf.WarnAboutUnused()
	return &containerManager{namespace: namespace, logdir: logDir}, nil
}