func (s *apiAddresserSuite) SetUpTest(c *gc.C) {
	s.fake = &fakeAddresses{
		hostPorts: [][]network.HostPort{
			network.NewHostPorts(1, "apiaddresses"),
			network.NewHostPorts(2, "apiaddresses"),
		},
	}
	s.addresser = common.NewAPIAddresser(s.fake, common.NewResources())
}

// NewProvisionerAPI creates a new server-side ProvisionerAPI facade.
func NewProvisionerAPI(st *state.State, resources *common.Resources, authorizer common.Authorizer) (*ProvisionerAPI, error) {
	if !authorizer.AuthMachineAgent() && !authorizer.AuthEnvironManager() {
		return nil, common.ErrPerm
	}
	getAuthFunc := func() (common.AuthFunc, error) {
		isEnvironManager := authorizer.AuthEnvironManager()
		isMachineAgent := authorizer.AuthMachineAgent()
		authEntityTag := authorizer.GetAuthTag()

		return func(tag names.Tag) bool {
			if isMachineAgent && tag == authEntityTag {
				// A machine agent can always access its own machine.
				return true
			}
			switch tag := tag.(type) {
			case names.MachineTag:
				parentId := state.ParentId(tag.Id())
				if parentId == "" {
					// All top-level machines are accessible by the
					// environment manager.
					return isEnvironManager
				}
				// All containers with the authenticated machine as a
				// parent are accessible by it.
				// TODO(dfc) sometimes authEntity tag is nil, which is fine because nil is
				// only equal to nil, but it suggests someone is passing an authorizer
				// with a nil tag.
				return isMachineAgent && names.NewMachineTag(parentId) == authEntityTag
			default:
				return false
			}
		}, nil
	}
	env, err := st.Environment()
	if err != nil {
		return nil, err
	}
	urlGetter := common.NewToolsURLGetter(env.UUID(), st)
	return &ProvisionerAPI{
		Remover:                common.NewRemover(st, false, getAuthFunc),
		StatusSetter:           common.NewStatusSetter(st, getAuthFunc),
		StatusGetter:           common.NewStatusGetter(st, getAuthFunc),
		DeadEnsurer:            common.NewDeadEnsurer(st, getAuthFunc),
		PasswordChanger:        common.NewPasswordChanger(st, getAuthFunc),
		LifeGetter:             common.NewLifeGetter(st, getAuthFunc),
		StateAddresser:         common.NewStateAddresser(st),
		APIAddresser:           common.NewAPIAddresser(st, resources),
		EnvironWatcher:         common.NewEnvironWatcher(st, resources, authorizer),
		EnvironMachinesWatcher: common.NewEnvironMachinesWatcher(st, resources, authorizer),
		InstanceIdGetter:       common.NewInstanceIdGetter(st, getAuthFunc),
		ToolsFinder:            common.NewToolsFinder(st, st, urlGetter),
		st:                     st,
		resources:              resources,
		authorizer:             authorizer,
		getAuthFunc:            getAuthFunc,
	}, nil
}

// NewDeployerAPI creates a new server-side DeployerAPI facade.
func NewDeployerAPI(
	st *state.State,
	resources facade.Resources,
	authorizer facade.Authorizer,
) (*DeployerAPI, error) {
	if !authorizer.AuthMachineAgent() {
		return nil, common.ErrPerm
	}
	getAuthFunc := func() (common.AuthFunc, error) {
		// Get all units of the machine and cache them.
		thisMachineTag := authorizer.GetAuthTag()
		units, err := getAllUnits(st, thisMachineTag)
		if err != nil {
			return nil, err
		}
		// Then we just check if the unit is already known.
		return func(tag names.Tag) bool {
			for _, unit := range units {
				// TODO (thumper): remove the names.Tag conversion when gccgo
				// implements concrete-type-to-interface comparison correctly.
				if names.Tag(names.NewUnitTag(unit)) == tag {
					return true
				}
			}
			return false
		}, nil
	}
	getCanWatch := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	return &DeployerAPI{
		Remover:         common.NewRemover(st, true, getAuthFunc),
		PasswordChanger: common.NewPasswordChanger(st, getAuthFunc),
		LifeGetter:      common.NewLifeGetter(st, getAuthFunc),
		StateAddresser:  common.NewStateAddresser(st),
		APIAddresser:    common.NewAPIAddresser(st, resources),
		UnitsWatcher:    common.NewUnitsWatcher(st, resources, getCanWatch),
		StatusSetter:    common.NewStatusSetter(st, getAuthFunc),
		st:              st,
		resources:       resources,
		authorizer:      authorizer,
	}, nil
}

// NewMachinerAPI creates a new instance of the Machiner API.
func NewMachinerAPI(st *state.State, resources *common.Resources, authorizer common.Authorizer) (*MachinerAPI, error) {
	if !authorizer.AuthMachineAgent() {
		return nil, common.ErrPerm
	}
	getCanModify := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	getCanRead := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	return &MachinerAPI{
		LifeGetter:         common.NewLifeGetter(st, getCanRead),
		StatusSetter:       common.NewStatusSetter(st, getCanModify),
		DeadEnsurer:        common.NewDeadEnsurer(st, getCanModify),
		AgentEntityWatcher: common.NewAgentEntityWatcher(st, resources, getCanRead),
		APIAddresser:       common.NewAPIAddresser(st, resources),
		st:                 st,
		auth:               authorizer,
		getCanModify:       getCanModify,
	}, nil
}

// NewUniterAPI creates a new instance of the Uniter API.
func NewUniterAPI(st *state.State, resources *common.Resources, authorizer common.Authorizer) (*UniterAPI, error) {
	if !authorizer.AuthUnitAgent() {
		return nil, common.ErrPerm
	}
	accessUnit := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	accessService := func() (common.AuthFunc, error) {
		switch tag := authorizer.GetAuthTag().(type) {
		case names.UnitTag:
			entity, err := st.Unit(tag.Id())
			if err != nil {
				return nil, errors.Trace(err)
			}
			serviceName := entity.ServiceName()
			serviceTag := names.NewServiceTag(serviceName)
			return func(tag names.Tag) bool {
				return tag == serviceTag
			}, nil
		default:
			return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
		}
	}
	accessUnitOrService := common.AuthEither(accessUnit, accessService)

	return &UniterAPI{
		LifeGetter:         common.NewLifeGetter(st, accessUnitOrService),
		StatusSetter:       common.NewStatusSetter(st, accessUnit),
		DeadEnsurer:        common.NewDeadEnsurer(st, accessUnit),
		AgentEntityWatcher: common.NewAgentEntityWatcher(st, resources, accessUnitOrService),
		APIAddresser:       common.NewAPIAddresser(st, resources),
		EnvironWatcher:     common.NewEnvironWatcher(st, resources, authorizer),

		st:            st,
		auth:          authorizer,
		resources:     resources,
		accessUnit:    accessUnit,
		accessService: accessService,
	}, nil
}

// NewUniterAPIV4 creates a new instance of the Uniter API, version 3.
func NewUniterAPIV4(st *state.State, resources facade.Resources, authorizer facade.Authorizer) (*UniterAPIV3, error) {
	if !authorizer.AuthUnitAgent() {
		return nil, common.ErrPerm
	}
	var unit *state.Unit
	var err error
	switch tag := authorizer.GetAuthTag().(type) {
	case names.UnitTag:
		unit, err = st.Unit(tag.Id())
		if err != nil {
			return nil, errors.Trace(err)
		}
	default:
		return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
	}
	accessUnit := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	accessService := func() (common.AuthFunc, error) {
		switch tag := authorizer.GetAuthTag().(type) {
		case names.UnitTag:
			entity, err := st.Unit(tag.Id())
			if err != nil {
				return nil, errors.Trace(err)
			}
			applicationName := entity.ApplicationName()
			applicationTag := names.NewApplicationTag(applicationName)
			return func(tag names.Tag) bool {
				return tag == applicationTag
			}, nil
		default:
			return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
		}
	}
	accessMachine := func() (common.AuthFunc, error) {
		switch tag := authorizer.GetAuthTag().(type) {
		case names.UnitTag:
			entity, err := st.Unit(tag.Id())
			if err != nil {
				return nil, errors.Trace(err)
			}
			machineId, err := entity.AssignedMachineId()
			if err != nil {
				return nil, errors.Trace(err)
			}
			machineTag := names.NewMachineTag(machineId)
			return func(tag names.Tag) bool {
				return tag == machineTag
			}, nil
		default:
			return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
		}
	}
	storageAPI, err := newStorageAPI(getStorageState(st), resources, accessUnit)
	if err != nil {
		return nil, err
	}
	msAPI, err := meterstatus.NewMeterStatusAPI(st, resources, authorizer)
	if err != nil {
		return nil, errors.Annotate(err, "could not create meter status API handler")
	}
	accessUnitOrService := common.AuthEither(accessUnit, accessService)
	return &UniterAPIV3{
		LifeGetter:                 common.NewLifeGetter(st, accessUnitOrService),
		DeadEnsurer:                common.NewDeadEnsurer(st, accessUnit),
		AgentEntityWatcher:         common.NewAgentEntityWatcher(st, resources, accessUnitOrService),
		APIAddresser:               common.NewAPIAddresser(st, resources),
		ModelWatcher:               common.NewModelWatcher(st, resources, authorizer),
		RebootRequester:            common.NewRebootRequester(st, accessMachine),
		LeadershipSettingsAccessor: leadershipSettingsAccessorFactory(st, resources, authorizer),
		MeterStatus:                msAPI,
		// TODO(fwereade): so *every* unit should be allowed to get/set its
		// own status *and* its service's? This is not a pleasing arrangement.
		StatusAPI: NewStatusAPI(st, accessUnitOrService),

		st:            st,
		auth:          authorizer,
		resources:     resources,
		accessUnit:    accessUnit,
		accessService: accessService,
		accessMachine: accessMachine,
		unit:          unit,
		StorageAPI:    *storageAPI,
	}, nil
}

// newUniterBaseAPI creates a new instance of the uniter base API.
func newUniterBaseAPI(st *state.State, resources *common.Resources, authorizer common.Authorizer) (*uniterBaseAPI, error) {
	if !authorizer.AuthUnitAgent() {
		return nil, common.ErrPerm
	}
	var unit *state.Unit
	var err error
	switch tag := authorizer.GetAuthTag().(type) {
	case names.UnitTag:
		unit, err = st.Unit(tag.Id())
		if err != nil {
			return nil, errors.Trace(err)
		}
	default:
		return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
	}
	accessUnit := func() (common.AuthFunc, error) {
		return authorizer.AuthOwner, nil
	}
	accessService := func() (common.AuthFunc, error) {
		switch tag := authorizer.GetAuthTag().(type) {
		case names.UnitTag:
			entity, err := st.Unit(tag.Id())
			if err != nil {
				return nil, errors.Trace(err)
			}
			serviceName := entity.ServiceName()
			serviceTag := names.NewServiceTag(serviceName)
			return func(tag names.Tag) bool {
				return tag == serviceTag
			}, nil
		default:
			return nil, errors.Errorf("expected names.UnitTag, got %T", tag)
		}
	}
	accessMachine := func() (common.AuthFunc, error) {
		machineId, err := unit.AssignedMachineId()
		if err != nil {
			return nil, errors.Trace(err)
		}
		machine, err := st.Machine(machineId)
		if err != nil {
			return nil, errors.Trace(err)
		}
		return func(tag names.Tag) bool {
			return tag == machine.Tag()
		}, nil
	}

	accessUnitOrService := common.AuthEither(accessUnit, accessService)
	return &uniterBaseAPI{
		LifeGetter:                 common.NewLifeGetter(st, accessUnitOrService),
		DeadEnsurer:                common.NewDeadEnsurer(st, accessUnit),
		AgentEntityWatcher:         common.NewAgentEntityWatcher(st, resources, accessUnitOrService),
		APIAddresser:               common.NewAPIAddresser(st, resources),
		EnvironWatcher:             common.NewEnvironWatcher(st, resources, authorizer),
		RebootRequester:            common.NewRebootRequester(st, accessMachine),
		LeadershipSettingsAccessor: leadershipSettingsAccessorFactory(st, resources, authorizer),

		// TODO(fwereade): so *every* unit should be allowed to get/set its
		// own status *and* its service's? This is not a pleasing arrangement.
		StatusAPI: NewStatusAPI(st, accessUnitOrService),

		st:            st,
		auth:          authorizer,
		resources:     resources,
		accessUnit:    accessUnit,
		accessService: accessService,
		unit:          unit,
	}, nil
}

func (s *apiAddresserSuite) SetUpTest(c *gc.C) {
	s.addresser = common.NewAPIAddresser(fakeAddresses{}, common.NewResources())
}