func (s *providerRegistrySuite) TestRegisterEnvironProvidersMultipleCalls(c *gc.C) {
	ptypeFoo := storage.ProviderType("foo")
	ptypeBar := storage.ProviderType("bar")
	registry.RegisterEnvironStorageProviders("ec2", ptypeFoo)
	registry.RegisterEnvironStorageProviders("ec2", ptypeBar)
	registry.RegisterEnvironStorageProviders("ec2", ptypeBar)
	c.Assert(registry.IsProviderSupported("ec2", ptypeFoo), jc.IsTrue)
	c.Assert(registry.IsProviderSupported("ec2", ptypeBar), jc.IsTrue)
}

func (s *providerRegistrySuite) TestSupportedEnvironProviders(c *gc.C) {
	ptypeFoo := storage.ProviderType("foo")
	ptypeBar := storage.ProviderType("bar")
	registry.RegisterEnvironStorageProviders("ec2", ptypeFoo, ptypeBar)
	c.Assert(registry.IsProviderSupported("ec2", ptypeFoo), jc.IsTrue)
	c.Assert(registry.IsProviderSupported("ec2", ptypeBar), jc.IsTrue)
	c.Assert(registry.IsProviderSupported("ec2", storage.ProviderType("foobar")), jc.IsFalse)
	c.Assert(registry.IsProviderSupported("openstack", ptypeBar), jc.IsFalse)
}

func (s *poolSuite) TestCreate(c *gc.C) {
	created, err := s.poolManager.Create("testpool", storage.ProviderType("loop"), map[string]interface{}{"foo": "bar"})
	c.Assert(err, jc.ErrorIsNil)
	p, err := s.poolManager.Get("testpool")
	c.Assert(created, gc.DeepEquals, p)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(p.Attrs(), gc.DeepEquals, map[string]interface{}{"foo": "bar"})
	c.Assert(p.Name(), gc.Equals, "testpool")
	c.Assert(p.Provider(), gc.Equals, storage.ProviderType("loop"))
}

func (s *providerRegistrySuite) TestRegisterProviderDuplicate(c *gc.C) {
	defer func() {
		if v := recover(); v != nil {
			c.Assert(v, gc.ErrorMatches, `.*duplicate storage provider type "foo"`)
		}
	}()
	p1 := &mockProvider{}
	p2 := &mockProvider{}
	registry.RegisterProvider(storage.ProviderType("foo"), p1)
	registry.RegisterProvider(storage.ProviderType("foo"), p2)
	c.Errorf("panic expected")
}

func (s *providerRegistrySuite) TestUnregisterProvider(c *gc.C) {
	ptype := storage.ProviderType("foo")

	// No-op, since there's nothing registered yet.
	registry.RegisterProvider(ptype, nil)

	// Register and then unregister, ensure that the provider cannot
	// be accessed.
	registry.RegisterProvider(ptype, &mockProvider{})
	registry.RegisterProvider(ptype, nil)
	_, err := registry.StorageProvider(storage.ProviderType("foo"))
	c.Assert(err, gc.ErrorMatches, `storage provider "foo" not found`)
}

func poolStorageProvider(st *State, poolName string) (storage.ProviderType, storage.Provider, error) {
	registry, err := st.storageProviderRegistry()
	if err != nil {
		return "", nil, errors.Annotate(err, "getting storage provider registry")
	}
	poolManager := poolmanager.New(NewStateSettings(st), registry)
	pool, err := poolManager.Get(poolName)
	if errors.IsNotFound(err) {
		// If there's no pool called poolName, maybe a provider type
		// has been specified directly.
		providerType := storage.ProviderType(poolName)
		provider, err1 := registry.StorageProvider(providerType)
		if err1 != nil {
			// The name can't be resolved as a storage provider type,
			// so return the original "pool not found" error.
			return "", nil, errors.Trace(err)
		}
		return providerType, provider, nil
	} else if err != nil {
		return "", nil, errors.Trace(err)
	}
	providerType := pool.Provider()
	provider, err := registry.StorageProvider(providerType)
	if err != nil {
		return "", nil, errors.Trace(err)
	}
	return providerType, provider, nil
}

func constructStartInstanceParams(
	machine *apiprovisioner.Machine,
	instanceConfig *instancecfg.InstanceConfig,
	provisioningInfo *params.ProvisioningInfo,
	possibleTools coretools.List,
) (environs.StartInstanceParams, error) {

	volumes := make([]storage.VolumeParams, len(provisioningInfo.Volumes))
	for i, v := range provisioningInfo.Volumes {
		volumeTag, err := names.ParseVolumeTag(v.VolumeTag)
		if err != nil {
			return environs.StartInstanceParams{}, errors.Trace(err)
		}
		if v.Attachment == nil {
			return environs.StartInstanceParams{}, errors.Errorf("volume params missing attachment")
		}
		machineTag, err := names.ParseMachineTag(v.Attachment.MachineTag)
		if err != nil {
			return environs.StartInstanceParams{}, errors.Trace(err)
		}
		if machineTag != machine.Tag() {
			return environs.StartInstanceParams{}, errors.Errorf("volume attachment params has invalid machine tag")
		}
		if v.Attachment.InstanceId != "" {
			return environs.StartInstanceParams{}, errors.Errorf("volume attachment params specifies instance ID")
		}
		volumes[i] = storage.VolumeParams{
			volumeTag,
			v.Size,
			storage.ProviderType(v.Provider),
			v.Attributes,
			v.Tags,
			&storage.VolumeAttachmentParams{
				AttachmentParams: storage.AttachmentParams{
					Machine:  machineTag,
					ReadOnly: v.Attachment.ReadOnly,
				},
				Volume: volumeTag,
			},
		}
	}
	var subnetsToZones map[network.Id][]string
	if provisioningInfo.SubnetsToZones != nil {
		// Convert subnet provider ids from string to network.Id.
		subnetsToZones = make(map[network.Id][]string, len(provisioningInfo.SubnetsToZones))
		for providerId, zones := range provisioningInfo.SubnetsToZones {
			subnetsToZones[network.Id(providerId)] = zones
		}
	}

	return environs.StartInstanceParams{
		Constraints:       provisioningInfo.Constraints,
		Tools:             possibleTools,
		InstanceConfig:    instanceConfig,
		Placement:         provisioningInfo.Placement,
		DistributionGroup: machine.DistributionGroup,
		Volumes:           volumes,
		SubnetsToZones:    subnetsToZones,
	}, nil
}

// CreatePool creates a new pool with specified parameters.
func (a *API) CreatePool(p params.StoragePool) error {
	_, err := a.poolManager.Create(
		p.Name,
		storage.ProviderType(p.Provider),
		p.Attrs)
	return err
}

// machineVolumeParams retrieves VolumeParams for the volumes that should be
// provisioned with, and attached to, the machine. The client should ignore
// parameters that it does not know how to handle.
func (p *ProvisionerAPI) machineVolumeParams(m *state.Machine) ([]params.VolumeParams, error) {
	volumeAttachments, err := m.VolumeAttachments()
	if err != nil {
		return nil, err
	}
	if len(volumeAttachments) == 0 {
		return nil, nil
	}
	envConfig, err := p.st.EnvironConfig()
	if err != nil {
		return nil, err
	}
	poolManager := poolmanager.New(state.NewStateSettings(p.st))
	allVolumeParams := make([]params.VolumeParams, 0, len(volumeAttachments))
	for _, volumeAttachment := range volumeAttachments {
		volumeTag := volumeAttachment.Volume()
		volume, err := p.st.Volume(volumeTag)
		if err != nil {
			return nil, errors.Annotatef(err, "getting volume %q", volumeTag.Id())
		}
		storageInstance, err := storagecommon.MaybeAssignedStorageInstance(
			volume.StorageInstance, p.st.StorageInstance,
		)
		if err != nil {
			return nil, errors.Annotatef(err, "getting volume %q storage instance", volumeTag.Id())
		}
		volumeParams, err := storagecommon.VolumeParams(volume, storageInstance, envConfig, poolManager)
		if err != nil {
			return nil, errors.Annotatef(err, "getting volume %q parameters", volumeTag.Id())
		}
		provider, err := registry.StorageProvider(storage.ProviderType(volumeParams.Provider))
		if err != nil {
			return nil, errors.Annotate(err, "getting storage provider")
		}
		if provider.Dynamic() {
			// Leave dynamic storage to the storage provisioner.
			continue
		}
		volumeAttachmentParams, ok := volumeAttachment.Params()
		if !ok {
			// Attachment is already provisioned; this is an insane
			// state, so we should not proceed with the volume.
			return nil, errors.Errorf(
				"volume %s already attached to machine %s",
				volumeTag.Id(), m.Id(),
			)
		}
		// Not provisioned yet, so ask the cloud provisioner do it.
		volumeParams.Attachment = &params.VolumeAttachmentParams{
			volumeTag.String(),
			m.Tag().String(),
			"", // we're creating the volume, so it has no volume ID.
			"", // we're creating the machine, so it has no instance ID.
			volumeParams.Provider,
			volumeAttachmentParams.ReadOnly,
		}
		allVolumeParams = append(allVolumeParams, volumeParams)
	}
	return allVolumeParams, nil
}

func (s *providerRegistrySuite) TestRegisterProvider(c *gc.C) {
	p1 := &mockProvider{}
	ptype := storage.ProviderType("foo")
	registry.RegisterProvider(ptype, p1)
	p, err := registry.StorageProvider(ptype)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(p, gc.Equals, p1)
}

func (s *poolSuite) TestList(c *gc.C) {
	s.createSettings(c)
	pools, err := s.poolManager.List()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(pools, gc.HasLen, 1)
	c.Assert(pools[0].Attrs(), gc.DeepEquals, map[string]interface{}{"foo": "bar"})
	c.Assert(pools[0].Name(), gc.Equals, "testpool")
	c.Assert(pools[0].Provider(), gc.Equals, storage.ProviderType("loop"))
}

func (a *API) validateProviderCriteria(providers []string) error {
	for _, p := range providers {
		_, err := a.registry.StorageProvider(storage.ProviderType(p))
		if err != nil {
			return errors.Trace(err)
		}
	}
	return nil
}

func (s *defaultStoragePoolsSuite) TestDefaultStoragePools(c *gc.C) {
	p1, err := storage.NewConfig("pool1", storage.ProviderType("loop"), map[string]interface{}{"1": "2"})
	p2, err := storage.NewConfig("pool2", storage.ProviderType("tmpfs"), map[string]interface{}{"3": "4"})
	c.Assert(err, jc.ErrorIsNil)
	defaultPools := []*storage.Config{p1, p2}
	poolmanager.RegisterDefaultStoragePools(defaultPools)

	settings := state.NewStateSettings(s.State)
	err = poolmanager.AddDefaultStoragePools(settings)
	c.Assert(err, jc.ErrorIsNil)
	pm := poolmanager.New(settings)
	for _, pool := range defaultPools {
		p, err := pm.Get(pool.Name())
		c.Assert(err, jc.ErrorIsNil)
		c.Assert(p.Provider(), gc.Equals, pool.Provider())
		c.Assert(p.Attrs(), gc.DeepEquals, pool.Attrs())
	}
}

func (a *API) isValidProviderCriteria(providers []string) (bool, error) {
	envName, err := a.storage.EnvName()
	if err != nil {
		return false, errors.Annotate(err, "getting env name")
	}
	for _, p := range providers {
		if !registry.IsProviderSupported(envName, storage.ProviderType(p)) {
			return false, errors.NotSupportedf("%q for environment %q", p, envName)
		}
	}
	return true, nil
}

func (a *API) validateProviderCriteria(providers []string) error {
	envName, err := a.storage.ModelName()
	if err != nil {
		return errors.Annotate(err, "getting model name")
	}
	for _, p := range providers {
		if !registry.IsProviderSupported(envName, storage.ProviderType(p)) {
			return errors.NotSupportedf("%q", p)
		}
	}
	return nil
}

func (s *defaultStoragePoolsSuite) TestDefaultStoragePools(c *gc.C) {
	p1, err := storage.NewConfig("pool1", storage.ProviderType("whatever"), map[string]interface{}{"1": "2"})
	c.Assert(err, jc.ErrorIsNil)
	p2, err := storage.NewConfig("pool2", storage.ProviderType("whatever"), map[string]interface{}{"3": "4"})
	c.Assert(err, jc.ErrorIsNil)
	provider := &dummystorage.StorageProvider{
		DefaultPools_: []*storage.Config{p1, p2},
	}

	settings := poolmanager.MemSettings{make(map[string]map[string]interface{})}
	pm := poolmanager.New(settings, storage.StaticProviderRegistry{
		map[storage.ProviderType]storage.Provider{"whatever": provider},
	})

	err = poolmanager.AddDefaultStoragePools(provider, pm)
	c.Assert(err, jc.ErrorIsNil)

	c.Assert(settings.Settings, jc.DeepEquals, map[string]map[string]interface{}{
		"pool#pool1": map[string]interface{}{"1": "2", "name": "pool1", "type": "whatever"},
		"pool#pool2": map[string]interface{}{"3": "4", "name": "pool2", "type": "whatever"},
	})
}

func (s *withoutControllerSuite) registerStorageProviders(c *gc.C, names ...string) {
	types := make([]storage.ProviderType, len(names))
	for i, name := range names {
		types[i] = storage.ProviderType(name)
		if name == "dynamic" {
			s.registerDynamicStorageProvider(c)
		} else if name == "static" {
			s.registerStaticStorageProvider(c)
		} else {
			c.Fatalf("unknown storage provider type: %q, expected static or dynamic", name)
		}
	}
	registry.RegisterEnvironStorageProviders("dummy", types...)
}

// StoragePoolConfig returns the storage provider type and
// configuration for a named storage pool. If there is no
// such pool with the specified name, but it identifies a
// storage provider, then that type will be returned with a
// nil configuration.
func StoragePoolConfig(name string, poolManager poolmanager.PoolManager, registry storage.ProviderRegistry) (storage.ProviderType, *storage.Config, error) {
	pool, err := poolManager.Get(name)
	if errors.IsNotFound(err) {
		// If not a storage pool, then maybe a provider type.
		providerType := storage.ProviderType(name)
		if _, err1 := registry.StorageProvider(providerType); err1 != nil {
			return "", nil, errors.Trace(err)
		}
		return providerType, &storage.Config{}, nil
	} else if err != nil {
		return "", nil, errors.Annotatef(err, "getting pool %q", name)
	}
	return pool.Provider(), pool, nil
}

func (i *importer) storagePools() error {
	registry, err := i.st.storageProviderRegistry()
	if err != nil {
		return errors.Annotate(err, "getting provider registry")
	}
	pm := poolmanager.New(NewStateSettings(i.st), registry)

	for _, pool := range i.model.StoragePools() {
		_, err := pm.Create(pool.Name(), storage.ProviderType(pool.Provider()), pool.Attributes())
		if err != nil {
			return errors.Annotatef(err, "creating pool %q", pool.Name())
		}
	}
	return nil
}

// storageConfig returns the provider type and config attributes for the
// specified poolName. If no such pool exists, we check to see if poolName is
// actually a provider type, in which case config will be empty.
func storageConfig(st *state.State, poolName string) (storage.ProviderType, map[string]interface{}, error) {
	pm := poolmanager.New(state.NewStateSettings(st))
	p, err := pm.Get(poolName)
	// If not a storage pool, then maybe a provider type.
	if errors.IsNotFound(err) {
		providerType := storage.ProviderType(poolName)
		if _, err1 := registry.StorageProvider(providerType); err1 != nil {
			return "", nil, errors.Trace(err)
		}
		return providerType, nil, nil
	}
	if err != nil {
		return "", nil, errors.Trace(err)
	}
	return p.Provider(), p.Attrs(), nil
}