// Start implements Machine.
func (m *machine) Start(args StartArgs) error {
	params := NewURLParams()
	params.MaybeAdd("user_data", args.UserData)
	params.MaybeAdd("distro_series", args.DistroSeries)
	params.MaybeAdd("hwe_kernel", args.Kernel)
	params.MaybeAdd("comment", args.Comment)
	result, err := m.controller.post(m.resourceURI, "deploy", params.Values)
	if err != nil {
		if svrErr, ok := errors.Cause(err).(ServerError); ok {
			switch svrErr.StatusCode {
			case http.StatusNotFound, http.StatusConflict:
				return errors.Wrap(err, NewBadRequestError(svrErr.BodyMessage))
			case http.StatusForbidden:
				return errors.Wrap(err, NewPermissionError(svrErr.BodyMessage))
			case http.StatusServiceUnavailable:
				return errors.Wrap(err, NewCannotCompleteError(svrErr.BodyMessage))
			}
		}
		return NewUnexpectedError(err)
	}

	machine, err := readMachine(m.controller.apiVersion, result)
	if err != nil {
		return errors.Trace(err)
	}
	m.updateFrom(machine)
	return nil
}

func translateControllerError(store jujuclient.ClientStore, err error) error {
	if !errors.IsNotFound(err) {
		return err
	}
	controllers, err2 := store.AllControllers()
	if err2 != nil {
		return err2
	}
	if len(controllers) == 0 {
		return errors.Wrap(err, ErrNoControllersDefined)
	}
	return errors.Wrap(err, ErrNoCurrentController)
}

// Delete implements File.
func (f *file) Delete() error {
	err := f.controller.delete(f.resourceURI)
	if err != nil {
		if svrErr, ok := errors.Cause(err).(ServerError); ok {
			switch svrErr.StatusCode {
			case http.StatusNotFound:
				return errors.Wrap(err, NewNoMatchError(svrErr.BodyMessage))
			case http.StatusForbidden:
				return errors.Wrap(err, NewPermissionError(svrErr.BodyMessage))
			}
		}
		return NewUnexpectedError(err)
	}
	return nil
}

// validateModelUUID is the common validator for the various
// apiserver components that need to check for a valid model
// UUID.  An empty modelUUID means that the connection has come in at
// the root of the URL space and refers to the controller
// model.
//
// It returns the validated model UUID.
func validateModelUUID(args validateArgs) (string, error) {
	ssState := args.statePool.SystemState()
	if args.modelUUID == "" {
		// We allow the modelUUID to be empty so that:
		//    TODO: server a limited API at the root (empty modelUUID)
		//    just the user manager and model manager are able to accept
		//    requests that don't require a modelUUID, like add-model.
		if args.strict {
			return "", errors.Trace(common.UnknownModelError(args.modelUUID))
		}
		return ssState.ModelUUID(), nil
	}
	if args.modelUUID == ssState.ModelUUID() {
		return args.modelUUID, nil
	}
	if args.controllerModelOnly {
		return "", errors.Unauthorizedf("requested model %q is not the controller model", args.modelUUID)
	}
	if !names.IsValidModel(args.modelUUID) {
		return "", errors.Trace(common.UnknownModelError(args.modelUUID))
	}
	modelTag := names.NewModelTag(args.modelUUID)
	if _, err := ssState.GetModel(modelTag); err != nil {
		return "", errors.Wrap(err, common.UnknownModelError(args.modelUUID))
	}
	return args.modelUUID, nil
}

// validateModelUUID is the common validator for the various
// apiserver components that need to check for a valid model
// UUID.  An empty modelUUID means that the connection has come in at
// the root of the URL space and refers to the controller
// model.
//
// It returns the validated model UUID.
func validateModelUUID(args validateArgs) (string, error) {
	ssState := args.statePool.SystemState()
	if args.modelUUID == "" {
		// We allow the modelUUID to be empty for 2 cases
		// 1) Compatibility with older clients
		// 2) TODO: server a limited API at the root (empty modelUUID)
		//    with just the user manager and model manager
		//    if the connection comes over a sufficiently up to date
		//    login command.
		if args.strict {
			return "", errors.Trace(common.UnknownModelError(args.modelUUID))
		}
		logger.Debugf("validate model uuid: empty modelUUID")
		return ssState.ModelUUID(), nil
	}
	if args.modelUUID == ssState.ModelUUID() {
		logger.Debugf("validate model uuid: controller model - %s", args.modelUUID)
		return args.modelUUID, nil
	}
	if args.controllerModelOnly {
		return "", errors.Unauthorizedf("requested model %q is not the controller model", args.modelUUID)
	}
	if !names.IsValidModel(args.modelUUID) {
		return "", errors.Trace(common.UnknownModelError(args.modelUUID))
	}
	modelTag := names.NewModelTag(args.modelUUID)
	if _, err := ssState.GetModel(modelTag); err != nil {
		return "", errors.Wrap(err, common.UnknownModelError(args.modelUUID))
	}
	logger.Debugf("validate model uuid: %s", args.modelUUID)
	return args.modelUUID, nil
}

// Devices implements Controller.
func (c *controller) CreateDevice(args CreateDeviceArgs) (Device, error) {
	// There must be at least one mac address.
	if len(args.MACAddresses) == 0 {
		return nil, NewBadRequestError("at least one MAC address must be specified")
	}
	params := NewURLParams()
	params.MaybeAdd("hostname", args.Hostname)
	params.MaybeAdd("domain", args.Domain)
	params.MaybeAddMany("mac_addresses", args.MACAddresses)
	params.MaybeAdd("parent", args.Parent)
	result, err := c.post("devices", "", params.Values)
	if err != nil {
		if svrErr, ok := errors.Cause(err).(ServerError); ok {
			if svrErr.StatusCode == http.StatusBadRequest {
				return nil, errors.Wrap(err, NewBadRequestError(svrErr.BodyMessage))
			}
		}
		// Translate http errors.
		return nil, NewUnexpectedError(err)
	}

	device, err := readDevice(c.apiVersion, result)
	if err != nil {
		return nil, errors.Trace(err)
	}
	device.controller = c
	return device, nil
}

// AddUser adds a user.
func (api *UserManagerAPI) AddUser(args params.AddUsers) (params.AddUserResults, error) {
	result := params.AddUserResults{
		Results: make([]params.AddUserResult, len(args.Users)),
	}
	if err := api.check.ChangeAllowed(); err != nil {
		return result, errors.Trace(err)
	}

	if len(args.Users) == 0 {
		return result, nil
	}
	loggedInUser, err := api.getLoggedInUser()
	if err != nil {
		return result, errors.Wrap(err, common.ErrPerm)
	}
	// TODO(thumper): PERMISSIONS Change this permission check when we have
	// real permissions. For now, only the owner of the initial environment is
	// able to add users.
	if err := api.permissionCheck(loggedInUser); err != nil {
		return result, errors.Trace(err)
	}
	for i, arg := range args.Users {
		user, err := api.state.AddUser(arg.Username, arg.DisplayName, arg.Password, loggedInUser.Id())
		if err != nil {
			err = errors.Annotate(err, "failed to create user")
			result.Results[i].Error = common.ServerError(err)
		} else {
			result.Results[i].Tag = user.Tag().String()
		}
	}
	return result, nil
}

func versionInitSystem(ser string) (string, error) {
	seriesos, err := series.GetOSFromSeries(ser)
	if err != nil {
		notFound := errors.NotFoundf("init system for series %q", ser)
		return "", errors.Wrap(err, notFound)
	}

	switch seriesos {
	case os.Windows:
		return InitSystemWindows, nil
	case os.Ubuntu:
		switch ser {
		case "precise", "quantal", "raring", "saucy", "trusty", "utopic":
			return InitSystemUpstart, nil
		default:
			// vivid and later
			if featureflag.Enabled(feature.LegacyUpstart) {
				return InitSystemUpstart, nil
			}
			return InitSystemSystemd, nil
		}
	case os.CentOS:
		return InitSystemSystemd, nil
	}
	return "", errors.NotFoundf("unknown os %q (from series %q), init system", seriesos, ser)
}

func createContainer(
	lxcContainer golxc.Container,
	directory string,
	networkConfig *container.NetworkConfig,
	extraCreateArgs, templateParams []string,
	caCert []byte,
) error {
	// Generate initial lxc.conf with networking settings.
	netConfig := generateNetworkConfig(networkConfig)
	configPath := filepath.Join(directory, "lxc.conf")
	if err := ioutil.WriteFile(configPath, []byte(netConfig), 0644); err != nil {
		return errors.Annotatef(err, "failed to write container config %q", configPath)
	}
	logger.Tracef("wrote initial config %q for container %q", configPath, lxcContainer.Name())

	var err error
	var execEnv []string = nil
	var closer func()
	if caCert != nil {
		execEnv, closer, err = wgetEnvironment(caCert)
		if err != nil {
			return errors.Annotatef(err, "failed to get environment for wget execution")
		}
		defer closer()
	}

	// Create the container.
	logger.Debugf("creating lxc container %q", lxcContainer.Name())
	logger.Debugf("lxc-create template params: %v", templateParams)
	if err := lxcContainer.Create(configPath, defaultTemplate, extraCreateArgs, templateParams, execEnv); err != nil {
		return errors.Wrap(err, instance.NewRetryableCreationError("lxc container creation failed: "+lxcContainer.Name()))
	}
	return nil
}

func (*functionSuite) TestWrapOfNil(c *gc.C) {
	detailed := errors.New("detailed")
	err := errors.Wrap(nil, detailed) //err nilWrapTest
	c.Assert(err.Error(), gc.Equals, "detailed")
	c.Assert(errors.Cause(err), gc.Equals, detailed)
	c.Assert(errors.Details(err), jc.Contains, tagToLocation["nilWrapTest"].String())
}

// Call will repeatedly execute the Func until either the function returns no
// error, the retry count is exceeded or the stop channel is closed.
func Call(args CallArgs) error {
	err := args.Validate()
	if err != nil {
		return errors.Trace(err)
	}
	for i := 1; args.Attempts < 0 || i <= args.Attempts; i++ {
		err = args.Func()
		if err == nil {
			return nil
		}
		if args.IsFatalError != nil && args.IsFatalError(err) {
			return errors.Trace(err)
		}
		if args.NotifyFunc != nil {
			args.NotifyFunc(err, i)
		}
		if i == args.Attempts && args.Attempts > 0 {
			break // don't wait before returning the error
		}
		// Wait for the delay, and retry
		select {
		case <-args.Clock.After(args.Delay):
		case <-args.Stop:
			return RetryStopped
		}

		args.Delay = ScaleDuration(args.Delay, args.MaxDelay, args.BackoffFactor)
	}
	return errors.Wrap(err, &AttemptsExceeded{err})
}

// validateEnvironUUID is the common validator for the various
// apiserver components that need to check for a valid environment
// UUID.  An empty envUUID means that the connection has come in at
// the root of the URL space and refers to the state server
// environment.
//
// It returns the validated environment UUID.
func validateEnvironUUID(args validateArgs) (string, error) {
	ssState := args.statePool.SystemState()
	if args.envUUID == "" {
		// We allow the environUUID to be empty for 2 cases
		// 1) Compatibility with older clients
		// 2) TODO: server a limited API at the root (empty envUUID)
		//    with just the user manager and environment manager
		//    if the connection comes over a sufficiently up to date
		//    login command.
		if args.strict {
			return "", errors.Trace(common.UnknownEnvironmentError(args.envUUID))
		}
		logger.Debugf("validate env uuid: empty envUUID")
		return ssState.EnvironUUID(), nil
	}
	if args.envUUID == ssState.EnvironUUID() {
		logger.Debugf("validate env uuid: state server environment - %s", args.envUUID)
		return args.envUUID, nil
	}
	if args.stateServerEnvOnly {
		return "", errors.Unauthorizedf("requested environment %q is not the state server environment", args.envUUID)
	}
	if !names.IsValidEnvironment(args.envUUID) {
		return "", errors.Trace(common.UnknownEnvironmentError(args.envUUID))
	}
	envTag := names.NewEnvironTag(args.envUUID)
	if _, err := ssState.GetEnvironment(envTag); err != nil {
		return "", errors.Wrap(err, common.UnknownEnvironmentError(args.envUUID))
	}
	logger.Debugf("validate env uuid: %s", args.envUUID)
	return args.envUUID, nil
}

// finalizeAction passes back the final status of an Action hook to state.
// It wraps any errors which occurred in normal behavior of the Action run;
// only errors passed in unhandledErr will be returned.
func (ctx *HookContext) finalizeAction(err, unhandledErr error) error {
	// TODO (binary132): synchronize with gsamfira's reboot logic
	message := ctx.actionData.ResultsMessage
	results := ctx.actionData.ResultsMap
	tag := ctx.actionData.Tag
	status := params.ActionCompleted
	if ctx.actionData.Failed {
		status = params.ActionFailed
	}

	// If we had an action error, we'll simply encapsulate it in the response
	// and discard the error state.  Actions should not error the uniter.
	if err != nil {
		message = err.Error()
		if IsMissingHookError(err) {
			message = fmt.Sprintf("action not implemented on unit %q", ctx.unitName)
		}
		status = params.ActionFailed
	}

	callErr := ctx.state.ActionFinish(tag, status, results, message)
	if callErr != nil {
		unhandledErr = errors.Wrap(unhandledErr, callErr)
	}
	return unhandledErr
}

// checkCreds validates the entities credentials in the current environment.
// If the entity is a user, and lookForEnvUser is true, an env user must exist
// for the environment.  In the case of a user logging in to the server, but
// not an environment, there is no env user needed.  While we have the env
// user, if we do have it, update the last login time.
func checkCreds(st *state.State, req params.LoginRequest, lookForEnvUser bool) (state.Entity, *time.Time, error) {
	tag, err := names.ParseTag(req.AuthTag)
	if err != nil {
		return nil, nil, err
	}
	entity, err := st.FindEntity(tag)
	if errors.IsNotFound(err) {
		// We return the same error when an entity does not exist as for a bad
		// password, so that we don't allow unauthenticated users to find
		// information about existing entities.
		logger.Debugf("entity %q not found", tag)
		return nil, nil, common.ErrBadCreds
	}
	if err != nil {
		return nil, nil, errors.Trace(err)
	}

	authenticator, err := authentication.FindEntityAuthenticator(entity)
	if err != nil {
		return nil, nil, err
	}

	if err = authenticator.Authenticate(entity, req.Credentials, req.Nonce); err != nil {
		logger.Debugf("bad credentials")
		return nil, nil, err
	}

	// For user logins, update the last login time.
	// NOTE: this code path is only for local users. When we support remote
	// user logins with bearer tokens, we will need to make sure that we also
	// update the last connection times for the environment users there.
	var lastLogin *time.Time
	if user, ok := entity.(*state.User); ok {
		userLastLogin, err := user.LastLogin()
		if err != nil && !state.IsNeverLoggedInError(err) {
			return nil, nil, errors.Trace(err)
		}
		if lookForEnvUser {
			envUser, err := st.EnvironmentUser(user.UserTag())
			if err != nil {
				return nil, nil, errors.Wrap(err, common.ErrBadCreds)
			}
			// The last connection for the environment takes precedence over
			// the local user last login time.
			userLastLogin, err = envUser.LastConnection()
			if err != nil && !state.IsNeverConnectedError(err) {
				return nil, nil, errors.Trace(err)
			}
			envUser.UpdateLastConnection()
		}
		// Only update the user's last login time if it is a successful
		// login, meaning that if we are logging into an environment, make
		// sure that there is an environment user in that environment for
		// this user.
		user.UpdateLastLogin()
		lastLogin = &userLastLogin
	}

	return entity, lastLogin, nil
}

// Next implements plan.Plan Next interface.
func (r *SelectFinalPlan) Next(ctx context.Context) (row *plan.Row, err error) {
	// push a new rowStackItem into RowStack
	pushRowStack(ctx, r.SelectList.ResultFields, r.SelectList.FromFields)

	row, err = r.Src.Next(ctx)

	// pop the rowStackItem
	if errPop := popRowStack(ctx); errPop != nil {
		return nil, errors.Wrap(err, errPop)
	}

	if row == nil || err != nil {
		return nil, errors.Trace(err)
	}

	// we should not output hidden fields to client.
	row.Data = row.Data[:r.HiddenFieldOffset]
	for i, o := range row.Data {
		switch v := o.(type) {
		case bool:
			// Convert bool field to int
			if v {
				row.Data[i] = uint8(1)
			} else {
				row.Data[i] = uint8(0)
			}
		}
	}
	if !r.infered {
		setResultFieldInfo(r.ResultFields[0:r.HiddenFieldOffset], row.Data)
		r.infered = true
	}
	return
}

func (s *ProvisionerSuite) TestProvisionerSucceedStartInstanceWithInjectedWrappedRetryableCreationError(c *gc.C) {
	// Set the retry delay to 0, and retry count to 1 to keep tests short
	s.PatchValue(provisioner.RetryStrategyDelay, 0*time.Second)
	s.PatchValue(provisioner.RetryStrategyCount, 1)

	// create the error injection channel
	errorInjectionChannel := make(chan error, 1)
	c.Assert(errorInjectionChannel, gc.NotNil)

	p := s.newEnvironProvisioner(c)
	defer stop(c, p)

	// patch the dummy provider error injection channel
	cleanup := dummy.PatchTransientErrorInjectionChannel(errorInjectionChannel)
	defer cleanup()

	// send the error message once
	// - instance creation should succeed
	retryableError := errors.Wrap(errors.New(""), instance.NewRetryableCreationError("container failed to start and was destroyed"))
	errorInjectionChannel <- retryableError

	m, err := s.addMachine()
	c.Assert(err, jc.ErrorIsNil)
	s.checkStartInstanceNoSecureConnection(c, m)
}

func (s *syncer) Complete() error {
	err := s.bulker.Submit()
	if err != nil {
		return errors.Wrap(err, canal.ErrHandleInterrupted)
	}
	return nil
}

func (*functionSuite) TestCause(c *gc.C) {
	c.Assert(errors.Cause(nil), gc.IsNil)
	c.Assert(errors.Cause(someErr), gc.Equals, someErr)

	fmtErr := fmt.Errorf("simple")
	c.Assert(errors.Cause(fmtErr), gc.Equals, fmtErr)

	err := errors.Wrap(someErr, fmtErr)
	c.Assert(errors.Cause(err), gc.Equals, fmtErr)

	err = errors.Annotate(err, "annotated")
	c.Assert(errors.Cause(err), gc.Equals, fmtErr)

	err = errors.Maskf(err, "maksed")
	c.Assert(errors.Cause(err), gc.Equals, err)

	// Look for a file that we know isn't there.
	dir := c.MkDir()
	_, err = os.Stat(filepath.Join(dir, "not-there"))
	c.Assert(os.IsNotExist(err), jc.IsTrue)

	err = errors.Annotatef(err, "wrap it")
	// Now the error itself isn't a 'IsNotExist'.
	c.Assert(os.IsNotExist(err), jc.IsFalse)
	// However if we use the Check method, it is.
	c.Assert(os.IsNotExist(errors.Cause(err)), jc.IsTrue)
}

func (api *UserManagerAPI) enableUserImpl(args params.Entities, action string, method func(*state.User) error) (params.ErrorResults, error) {
	result := params.ErrorResults{
		Results: make([]params.ErrorResult, len(args.Entities)),
	}
	if len(args.Entities) == 0 {
		return result, nil
	}
	loggedInUser, err := api.getLoggedInUser()
	if err != nil {
		return result, errors.Wrap(err, common.ErrPerm)
	}
	// TODO(thumper): PERMISSIONS Change this permission check when we have
	// real permissions. For now, only the owner of the initial environment is
	// able to add users.
	if err := api.permissionCheck(loggedInUser); err != nil {
		return result, errors.Trace(err)
	}

	for i, arg := range args.Entities {
		user, err := api.getUser(arg.Tag)
		if err != nil {
			result.Results[i].Error = common.ServerError(err)
			continue
		}
		err = method(user)
		if err != nil {
			result.Results[i].Error = common.ServerError(errors.Errorf("failed to %s user: %s", action, err))
		}
	}
	return result, nil
}

// SendMetrics will send any unsent metrics
// over the MetricSender interface in batches
// no larger than batchSize.
func SendMetrics(st *state.State, sender MetricSender, batchSize int) error {
	metricsManager, err := st.MetricsManager()
	if err != nil {
		return errors.Trace(err)
	}
	sent := 0
	for {
		metrics, err := st.MetricsToSend(batchSize)
		if err != nil {
			return errors.Trace(err)
		}
		lenM := len(metrics)
		if lenM == 0 {
			if sent == 0 {
				logger.Infof("nothing to send")
			} else {
				logger.Infof("done sending")
			}
			break
		}
		wireData := make([]*wireformat.MetricBatch, lenM)
		for i, m := range metrics {
			wireData[i] = ToWire(m)
		}
		response, err := sender.Send(wireData)
		if err != nil {
			logger.Errorf("%+v", err)
			if incErr := metricsManager.IncrementConsecutiveErrors(); incErr != nil {
				logger.Errorf("failed to increment error count %v", incErr)
				return errors.Trace(errors.Wrap(err, incErr))
			}
			return errors.Trace(err)
		}
		if response != nil {
			// TODO (mattyw) We are currently ignoring errors during response handling.
			handleResponse(metricsManager, st, *response)
			// TODO(fwereade): 2016-03-17 lp:1558657
			if err := metricsManager.SetLastSuccessfulSend(time.Now()); err != nil {
				err = errors.Annotate(err, "failed to set successful send time")
				logger.Warningf("%v", err)
				return errors.Trace(err)
			}
		}
		sent += lenM
	}

	unsent, err := st.CountOfUnsentMetrics()
	if err != nil {
		return errors.Trace(err)
	}
	sentStored, err := st.CountOfSentMetrics()
	if err != nil {
		return errors.Trace(err)
	}
	logger.Infof("metrics collection summary: sent:%d unsent:%d (%d sent metrics stored)", sent, unsent, sentStored)

	return nil
}