// updateRcWithRetries retries updating the given rc on conflict with the following steps:
// 1. Get latest resource
// 2. applyUpdate
// 3. Update the resource
func updateRcWithRetries(rcClient coreclient.ReplicationControllersGetter, namespace string, rc *api.ReplicationController, applyUpdate updateRcFunc) (*api.ReplicationController, error) {
	// Deep copy the rc in case we failed on Get during retry loop
	obj, err := api.Scheme.Copy(rc)
	if err != nil {
		return nil, fmt.Errorf("failed to deep copy rc before updating it: %v", err)
	}
	oldRc := obj.(*api.ReplicationController)
	err = retry.RetryOnConflict(retry.DefaultBackoff, func() (e error) {
		// Apply the update, then attempt to push it to the apiserver.
		applyUpdate(rc)
		if rc, e = rcClient.ReplicationControllers(namespace).Update(rc); e == nil {
			// rc contains the latest controller post update
			return
		}
		updateErr := e
		// Update the controller with the latest resource version, if the update failed we
		// can't trust rc so use oldRc.Name.
		if rc, e = rcClient.ReplicationControllers(namespace).Get(oldRc.Name); e != nil {
			// The Get failed: Value in rc cannot be trusted.
			rc = oldRc
		}
		// Only return the error from update
		return updateErr
	})
	// If the error is non-nil the returned controller cannot be trusted, if it is nil, the returned
	// controller contains the applied update.
	return rc, err
}

func LoadExistingNextReplicationController(c coreclient.ReplicationControllersGetter, namespace, newName string) (*api.ReplicationController, error) {
	if len(newName) == 0 {
		return nil, nil
	}
	newRc, err := c.ReplicationControllers(namespace).Get(newName)
	if err != nil && errors.IsNotFound(err) {
		return nil, nil
	}
	return newRc, err
}

func CreateNewControllerFromCurrentController(rcClient coreclient.ReplicationControllersGetter, codec runtime.Codec, cfg *NewControllerConfig) (*api.ReplicationController, error) {
	containerIndex := 0
	// load the old RC into the "new" RC
	newRc, err := rcClient.ReplicationControllers(cfg.Namespace).Get(cfg.OldName)
	if err != nil {
		return nil, err
	}

	if len(cfg.Container) != 0 {
		containerFound := false

		for i, c := range newRc.Spec.Template.Spec.Containers {
			if c.Name == cfg.Container {
				containerIndex = i
				containerFound = true
				break
			}
		}

		if !containerFound {
			return nil, fmt.Errorf("container %s not found in pod", cfg.Container)
		}
	}

	if len(newRc.Spec.Template.Spec.Containers) > 1 && len(cfg.Container) == 0 {
		return nil, goerrors.New("Must specify container to update when updating a multi-container pod")
	}

	if len(newRc.Spec.Template.Spec.Containers) == 0 {
		return nil, goerrors.New(fmt.Sprintf("Pod has no containers! (%v)", newRc))
	}
	newRc.Spec.Template.Spec.Containers[containerIndex].Image = cfg.Image
	if len(cfg.PullPolicy) != 0 {
		newRc.Spec.Template.Spec.Containers[containerIndex].ImagePullPolicy = cfg.PullPolicy
	}

	newHash, err := api.HashObject(newRc, codec)
	if err != nil {
		return nil, err
	}

	if len(cfg.NewName) == 0 {
		cfg.NewName = fmt.Sprintf("%s-%s", newRc.Name, newHash)
	}
	newRc.Name = cfg.NewName

	newRc.Spec.Selector[cfg.DeploymentKey] = newHash
	newRc.Spec.Template.Labels[cfg.DeploymentKey] = newHash
	// Clear resource version after hashing so that identical updates get different hashes.
	newRc.ResourceVersion = ""
	return newRc, nil
}

func FindSourceController(r coreclient.ReplicationControllersGetter, namespace, name string) (*api.ReplicationController, error) {
	list, err := r.ReplicationControllers(namespace).List(api.ListOptions{})
	if err != nil {
		return nil, err
	}
	for ix := range list.Items {
		rc := &list.Items[ix]
		if rc.Annotations != nil && strings.HasPrefix(rc.Annotations[sourceIdAnnotation], name) {
			return rc, nil
		}
	}
	return nil, fmt.Errorf("couldn't find a replication controller with source id == %s/%s", namespace, name)
}

// ControllerHasDesiredReplicas returns a condition that will be true if and only if
// the desired replica count for a controller's ReplicaSelector equals the Replicas count.
func ControllerHasDesiredReplicas(rcClient coreclient.ReplicationControllersGetter, controller *api.ReplicationController) wait.ConditionFunc {

	// If we're given a controller where the status lags the spec, it either means that the controller is stale,
	// or that the rc manager hasn't noticed the update yet. Polling status.Replicas is not safe in the latter case.
	desiredGeneration := controller.Generation

	return func() (bool, error) {
		ctrl, err := rcClient.ReplicationControllers(controller.Namespace).Get(controller.Name)
		if err != nil {
			return false, err
		}
		// There's a chance a concurrent update modifies the Spec.Replicas causing this check to pass,
		// or, after this check has passed, a modification causes the rc manager to create more pods.
		// This will not be an issue once we've implemented graceful delete for rcs, but till then
		// concurrent stop operations on the same rc might have unintended side effects.
		return ctrl.Status.ObservedGeneration >= desiredGeneration && ctrl.Status.Replicas == ctrl.Spec.Replicas, nil
	}
}

// decodeFromLatestDeployment will try to return the decoded version of the current deploymentconfig
// found in the annotations of its latest deployment. If there is no previous deploymentconfig (ie.
// latestVersion == 0), the returned deploymentconfig will be the same.
func decodeFromLatestDeployment(config *deployapi.DeploymentConfig, rn kcoreclient.ReplicationControllersGetter, decoder runtime.Decoder) (*deployapi.DeploymentConfig, error) {
	if config.Status.LatestVersion == 0 {
		return config, nil
	}

	latestDeploymentName := deployutil.LatestDeploymentNameForConfig(config)
	deployment, err := rn.ReplicationControllers(config.Namespace).Get(latestDeploymentName)
	if err != nil {
		// If there's no deployment for the latest config, we have no basis of
		// comparison. It's the responsibility of the deployment config controller
		// to make the deployment for the config, so return early.
		return nil, err
	}
	decoded, err := deployutil.DecodeDeploymentConfig(deployment, decoder)
	if err != nil {
		return nil, errors.NewInternalError(err)
	}
	return decoded, nil
}

func Rename(c coreclient.ReplicationControllersGetter, rc *api.ReplicationController, newName string) error {
	oldName := rc.Name
	rc.Name = newName
	rc.ResourceVersion = ""
	// First delete the oldName RC and orphan its pods.
	trueVar := true
	err := c.ReplicationControllers(rc.Namespace).Delete(oldName, &api.DeleteOptions{OrphanDependents: &trueVar})
	if err != nil && !errors.IsNotFound(err) {
		return err
	}
	err = wait.Poll(5*time.Second, 60*time.Second, func() (bool, error) {
		_, err := c.ReplicationControllers(rc.Namespace).Get(oldName)
		if err == nil {
			return false, nil
		} else if errors.IsNotFound(err) {
			return true, nil
		} else {
			return false, err
		}
	})
	if err != nil {
		return err
	}
	// Then create the same RC with the new name.
	_, err = c.ReplicationControllers(rc.Namespace).Create(rc)
	if err != nil {
		return err
	}
	return nil
}