/*
 * SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dynamo

import (
	"context"
	"encoding/json"
	"fmt"
	"maps"
	"regexp"
	"sort"
	"strings"

	istioNetworking "istio.io/api/networking/v1beta1"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/intstr"
	"k8s.io/utils/ptr"

	configv1alpha1 "github.com/ai-dynamo/dynamo/deploy/operator/api/config/v1alpha1"
	"github.com/ai-dynamo/dynamo/deploy/operator/api/v1alpha1"
	"github.com/ai-dynamo/dynamo/deploy/operator/internal/checkpoint"
	commonconsts "github.com/ai-dynamo/dynamo/deploy/operator/internal/consts"
	"github.com/ai-dynamo/dynamo/deploy/operator/internal/controller_common"
	"github.com/ai-dynamo/dynamo/deploy/operator/internal/discovery"
	grovev1alpha1 "github.com/ai-dynamo/grove/operator/api/core/v1alpha1"
	"github.com/imdario/mergo"
	networkingv1beta1 "istio.io/client-go/pkg/apis/networking/v1beta1"
	corev1 "k8s.io/api/core/v1"
	networkingv1 "k8s.io/api/networking/v1"
	ctrlclient "sigs.k8s.io/controller-runtime/pkg/client"
)

// RestartState holds the restart state for DGD services.
type RestartState struct {
	// Timestamp is the restart timestamp to apply as the annotation value.
	// Format: RFC3339
	Timestamp string
	// ServicesToAnnotate is the set of service names that should have the restart annotation.
	ServicesToAnnotate map[string]bool
}

// ShouldAnnotateService returns true if the given service should have a restart annotation.
func (s *RestartState) ShouldAnnotateService(serviceName string) bool {
	if s == nil || s.ServicesToAnnotate == nil {
		return false
	}
	return s.ServicesToAnnotate[serviceName]
}

// DetermineRestartState computes the restart state for DGD services.
func DetermineRestartState(dgd *v1alpha1.DynamoGraphDeployment, restartStatus *v1alpha1.RestartStatus) *RestartState {
	if restartStatus == nil {
		return nil
	}

	if dgd.Spec.Restart == nil || dgd.Spec.Restart.ID == "" {
		// Check if there's a completed restart we need to preserve
		if restartStatus.ObservedID != "" {
			return &RestartState{
				Timestamp:          restartStatus.ObservedID,
				ServicesToAnnotate: getAllServiceNames(dgd),
			}
		}
		return nil
	}

	specID := dgd.Spec.Restart.ID

	isNewRestart := restartStatus.ObservedID == "" ||
		dgd.Spec.Restart.ID != restartStatus.ObservedID

	if !isNewRestart && restartStatus.Phase == v1alpha1.RestartPhaseSuperseded {
		// Superseded: don't push any new annotations. Existing annotations
		// are preserved via the existingRestartAnnotations fallback path.
		return nil
	}

	if !isNewRestart && restartStatus.Phase == v1alpha1.RestartPhaseCompleted {
		return &RestartState{
			Timestamp:          specID,
			ServicesToAnnotate: getAllServiceNames(dgd),
		}
	}

	if IsParallelRestart(dgd) {
		return &RestartState{
			Timestamp:          specID,
			ServicesToAnnotate: getAllServiceNames(dgd),
		}
	}

	// Sequential restart (default or specified)
	return &RestartState{
		Timestamp:          specID,
		ServicesToAnnotate: getServicesToAnnotateForSequentialRestart(dgd, restartStatus),
	}
}

// getAllServiceNames returns a map of all service names in the DGD.
func getAllServiceNames(dgd *v1alpha1.DynamoGraphDeployment) map[string]bool {
	services := make(map[string]bool, len(dgd.Spec.Services))
	for serviceName := range dgd.Spec.Services {
		services[serviceName] = true
	}
	return services
}

// IsParallelRestart returns true if the restart strategy is parallel.
func IsParallelRestart(dgd *v1alpha1.DynamoGraphDeployment) bool {
	if dgd.Spec.Restart == nil || dgd.Spec.Restart.Strategy == nil {
		return false // Default is sequential
	}
	return dgd.Spec.Restart.Strategy.Type == v1alpha1.RestartStrategyTypeParallel
}

// getServicesToAnnotateForSequentialRestart determines which services should be annotated
// for a sequential restart in progress.
func getServicesToAnnotateForSequentialRestart(dgd *v1alpha1.DynamoGraphDeployment, status *v1alpha1.RestartStatus) map[string]bool {
	services := make(map[string]bool)

	order := GetRestartOrder(dgd)
	if len(order) == 0 {
		return services
	}

	// New restart or Pending phase - only first service needs to be annotated
	if status == nil ||
		status.Phase == v1alpha1.RestartPhasePending ||
		len(status.InProgress) == 0 {
		services[order[0]] = true
		return services
	}

	// Find the max index among in-progress services
	inProgress := make(map[string]bool)
	for _, svc := range status.InProgress {
		inProgress[svc] = true
	}

	maxIndex := -1
	for i, svc := range order {
		if inProgress[svc] {
			if i > maxIndex {
				maxIndex = i
			}
		}
	}

	// Add all services up to and including maxIndex
	// Services before the in-progress one have completed and need their annotation preserved
	if maxIndex >= 0 {
		for i := 0; i <= maxIndex; i++ {
			services[order[i]] = true
		}
	}

	return services
}

// GetRestartOrder returns the order of services for sequential restart.
// If not specified, returns a deterministic alphabetical order.
func GetRestartOrder(dgd *v1alpha1.DynamoGraphDeployment) []string {
	if dgd.Spec.Restart != nil && dgd.Spec.Restart.Strategy != nil && len(dgd.Spec.Restart.Strategy.Order) > 0 {
		return dgd.Spec.Restart.Strategy.Order
	}

	order := make([]string, 0, len(dgd.Spec.Services))
	for serviceName := range dgd.Spec.Services {
		order = append(order, serviceName)
	}
	sort.Strings(order)
	return order
}

// ServiceConfig represents the YAML configuration structure for a service
type DynamoConfig struct {
	Enabled       bool   `yaml:"enabled"`
	Namespace     string `yaml:"namespace"`
	Name          string `yaml:"name"`
	ComponentType string `yaml:"component_type,omitempty"`
}

type Traffic struct {
	Timeout int `yaml:"timeout"`
}

type Autoscaling struct {
	MinReplicas int `yaml:"min_replicas"`
	MaxReplicas int `yaml:"max_replicas"`
}

type Config struct {
	Dynamo       *DynamoConfig          `yaml:"dynamo,omitempty"`
	Resources    *Resources             `yaml:"resources,omitempty"`
	Traffic      *Traffic               `yaml:"traffic,omitempty"`
	Autoscaling  *Autoscaling           `yaml:"autoscaling,omitempty"`
	HttpExposed  bool                   `yaml:"http_exposed,omitempty"`
	ApiEndpoints []string               `yaml:"api_endpoints,omitempty"`
	Workers      *int32                 `yaml:"workers,omitempty"`
	TotalGpus    *int32                 `yaml:"total_gpus,omitempty"`
	ExtraPodSpec *v1alpha1.ExtraPodSpec `yaml:"extraPodSpec,omitempty"`
}

type ServiceConfig struct {
	Name         string              `yaml:"name"`
	Dependencies []map[string]string `yaml:"dependencies,omitempty"`
	Config       Config              `yaml:"config"`
}

type Resources struct {
	CPU    *string           `yaml:"cpu,omitempty" json:"cpu,omitempty"`
	Memory *string           `yaml:"memory,omitempty" json:"memory,omitempty"`
	GPU    *string           `yaml:"gpu,omitempty" json:"gpu,omitempty"`
	Custom map[string]string `yaml:"custom,omitempty" json:"custom,omitempty"`
}

type DynDeploymentConfig = map[string]*DynDeploymentServiceConfig

// ServiceConfig represents the configuration for a specific service
type DynDeploymentServiceConfig struct {
	ServiceArgs *ServiceArgs `json:"ServiceArgs,omitempty"`
}

// ServiceArgs represents the arguments that can be passed to any service
type ServiceArgs struct {
	Workers   *int32     `json:"workers,omitempty"`
	Resources *Resources `json:"resources,omitempty"`
}

func (s ServiceConfig) GetNamespace() *string {
	if s.Config.Dynamo == nil || s.Config.Dynamo.Namespace == "" {
		return nil
	}
	return &s.Config.Dynamo.Namespace
}

func ParseDynDeploymentConfig(ctx context.Context, jsonContent []byte) (DynDeploymentConfig, error) {
	var config DynDeploymentConfig
	err := json.Unmarshal(jsonContent, &config)
	return config, err
}

func (r RollingUpdateContext) InProgress() bool {
	return len(r.OldWorkerReplicas) > 0
}

// RollingUpdateContext provides information about an in-progress rolling update.
type RollingUpdateContext struct {
	// NewWorkerHash is the short hash (8 chars) for the new worker spec, used for DCD naming
	NewWorkerHash string
	// OldWorkerReplicas maps service name to the desired replica count for old workers.
	// Used by the controller to patch old worker DCDs directly.
	// Calculated as: max(0, desiredReplicas - newReadyReplicas)
	OldWorkerReplicas map[string]int32
	// NewWorkerReplicas maps service name to the desired replica count for new workers.
	// Calculated as: min(desiredReplicas, newReadyReplicas + 1) to gradually scale up.
	NewWorkerReplicas map[string]int32
}

// GenerateDynamoComponentsDeployments generates a map of DynamoComponentDeployments from a DynamoGraphConfig.
// The map key is a unique identifier for each DCD (serviceName).
func GenerateDynamoComponentsDeployments(
	ctx context.Context,
	parentDGD *v1alpha1.DynamoGraphDeployment,
	defaultIngressSpec *v1alpha1.IngressSpec,
	restartState *RestartState,
	existingRestartAnnotations map[string]string,
	rollingUpdateCtx RollingUpdateContext,
) (map[string]*v1alpha1.DynamoComponentDeployment, error) {
	deployments := make(map[string]*v1alpha1.DynamoComponentDeployment)

	// Generate DCDs for each service
	for componentName, component := range parentDGD.Spec.Services {
		dynamoNamespace := parentDGD.GetDynamoNamespaceForService(component)
		dcd, err := generateSingleDCD(ctx, parentDGD, componentName, component, dynamoNamespace, defaultIngressSpec, restartState, existingRestartAnnotations, rollingUpdateCtx)
		if err != nil {
			return nil, err
		}
		deployments[componentName] = dcd
	}

	return deployments, nil
}

func GetDynamoNamespace(object metav1.Object, service *v1alpha1.DynamoComponentDeploymentSharedSpec) string {
	return v1alpha1.ComputeDynamoNamespace(service.GlobalDynamoNamespace, object.GetNamespace(), object.GetName())
}

// generateSingleDCD creates a DynamoComponentDeployment for a single service.
func generateSingleDCD(
	ctx context.Context,
	parentDGD *v1alpha1.DynamoGraphDeployment,
	componentName string,
	component *v1alpha1.DynamoComponentDeploymentSharedSpec,
	dynamoNamespace string,
	defaultIngressSpec *v1alpha1.IngressSpec,
	restartState *RestartState,
	existingRestartAnnotations map[string]string,
	rollingUpdateCtx RollingUpdateContext,
) (*v1alpha1.DynamoComponentDeployment, error) {
	deployment := &v1alpha1.DynamoComponentDeployment{}
	deployment.Spec.DynamoComponentDeploymentSharedSpec = *component
	deployment.Name = GetDCDResourceName(parentDGD, componentName, rollingUpdateCtx.NewWorkerHash)
	deployment.Spec.BackendFramework = parentDGD.Spec.BackendFramework
	deployment.Namespace = parentDGD.Namespace
	deployment.Spec.ServiceName = componentName
	deployment.Spec.DynamoNamespace = &dynamoNamespace

	labels := make(map[string]string)
	maps.Copy(labels, component.Labels)
	labels[commonconsts.KubeLabelDynamoComponent] = componentName
	labels[commonconsts.KubeLabelDynamoNamespace] = dynamoNamespace
	labels[commonconsts.KubeLabelDynamoGraphDeploymentName] = parentDGD.Name
	deployment.Spec.Labels = labels
	deployment.Labels = labels

	// only label worker DCDs with their hash for cleanup during rolling updates
	if IsWorkerComponent(component.ComponentType) {
		labels[commonconsts.KubeLabelDynamoWorkerHash] = rollingUpdateCtx.NewWorkerHash
	}

	propagateDGDAnnotations(parentDGD.GetAnnotations(), &deployment.Spec.DynamoComponentDeploymentSharedSpec)
	propagateDGDSpecMetadata(parentDGD.Spec.Annotations, parentDGD.Spec.Labels, &deployment.Spec.DynamoComponentDeploymentSharedSpec)

	// Apply restart annotation if this service should be restarted.
	if restartState.ShouldAnnotateService(componentName) {
		if deployment.Spec.Annotations == nil {
			deployment.Spec.Annotations = make(map[string]string)
		}
		deployment.Spec.Annotations[commonconsts.RestartAnnotation] = restartState.Timestamp
	} else if existingRestartAnnotations != nil {
		if existingRestartAt, ok := existingRestartAnnotations[componentName]; ok && existingRestartAt != "" {
			if deployment.Spec.Annotations == nil {
				deployment.Spec.Annotations = make(map[string]string)
			}
			deployment.Spec.Annotations[commonconsts.RestartAnnotation] = existingRestartAt
		}
	}

	if component.ComponentType == commonconsts.ComponentTypePlanner {
		if deployment.Spec.ExtraPodSpec == nil {
			deployment.Spec.ExtraPodSpec = &v1alpha1.ExtraPodSpec{}
		}
		if deployment.Spec.ExtraPodSpec.PodSpec == nil {
			deployment.Spec.ExtraPodSpec.PodSpec = &corev1.PodSpec{}
		}
		deployment.Spec.ExtraPodSpec.PodSpec.ServiceAccountName = commonconsts.PlannerServiceAccountName
	}

	if deployment.IsFrontendComponent() && defaultIngressSpec != nil && deployment.Spec.Ingress == nil {
		deployment.Spec.Ingress = defaultIngressSpec
	}

	if len(parentDGD.Spec.Envs) > 0 {
		deployment.Spec.Envs = MergeEnvs(parentDGD.Spec.Envs, deployment.Spec.Envs)
	}

	if err := updateDynDeploymentConfig(deployment, commonconsts.DynamoServicePort); err != nil {
		return nil, err
	}
	if err := overrideWithDynDeploymentConfig(ctx, deployment); err != nil {
		return nil, err
	}

	// during a rolling update, the replica count is determined by the rollingUpdateCtx instead of the component spec
	if rollingUpdateCtx.InProgress() && IsWorkerComponent(component.ComponentType) && rollingUpdateCtx.NewWorkerReplicas[componentName] != 0 {
		deployment.Spec.Replicas = ptr.To(rollingUpdateCtx.NewWorkerReplicas[componentName])
	} else if component.Replicas != nil {
		deployment.Spec.Replicas = component.Replicas
	}

	return deployment, nil
}

// updateDynDeploymentConfig updates the runtime config object for the given dynamoDeploymentComponent
// It updates the port for the given service (if it is the main component)
func updateDynDeploymentConfig(dynamoDeploymentComponent *v1alpha1.DynamoComponentDeployment, newPort int) error {
	if dynamoDeploymentComponent.IsFrontendComponent() {
		dynamoDeploymentConfig := dynamoDeploymentComponent.GetDynamoDeploymentConfig()
		if dynamoDeploymentConfig != nil {
			var config map[string]any
			if err := json.Unmarshal(dynamoDeploymentConfig, &config); err != nil {
				return fmt.Errorf("failed to unmarshal %v: %w", commonconsts.DynamoDeploymentConfigEnvVar, err)
			}
			// Safely navigate and update the config
			if serviceConfig, ok := config[dynamoDeploymentComponent.Spec.ServiceName].(map[string]any); ok {
				serviceConfig["port"] = newPort
			}
			// Marshal back to JSON string
			updated, err := json.Marshal(config)
			if err != nil {
				return fmt.Errorf("failed to marshal updated config: %w", err)
			}
			dynamoDeploymentComponent.SetDynamoDeploymentConfig(updated)
		}
	}
	return nil
}

func overrideWithDynDeploymentConfig(ctx context.Context, dynamoDeploymentComponent *v1alpha1.DynamoComponentDeployment) error {
	dynamoDeploymentConfig := dynamoDeploymentComponent.GetDynamoDeploymentConfig()
	if dynamoDeploymentConfig == nil {
		return nil
	}
	dynDeploymentConfig, err := ParseDynDeploymentConfig(ctx, dynamoDeploymentConfig)
	if err != nil {
		return fmt.Errorf("failed to parse %v: %w", commonconsts.DynamoDeploymentConfigEnvVar, err)
	}
	componentDynConfig := dynDeploymentConfig[dynamoDeploymentComponent.Spec.ServiceName]
	if componentDynConfig != nil {
		if componentDynConfig.ServiceArgs != nil && componentDynConfig.ServiceArgs.Workers != nil {
			dynamoDeploymentComponent.Spec.Replicas = componentDynConfig.ServiceArgs.Workers
		}
		if componentDynConfig.ServiceArgs != nil && componentDynConfig.ServiceArgs.Resources != nil {
			requests := &v1alpha1.ResourceItem{}
			limits := &v1alpha1.ResourceItem{}
			if dynamoDeploymentComponent.Spec.Resources == nil {
				dynamoDeploymentComponent.Spec.Resources = &v1alpha1.Resources{
					Requests: requests,
					Limits:   limits,
				}
			} else {
				if dynamoDeploymentComponent.Spec.Resources.Requests != nil {
					requests = dynamoDeploymentComponent.Spec.Resources.Requests
				} else {
					dynamoDeploymentComponent.Spec.Resources.Requests = requests
				}
				if dynamoDeploymentComponent.Spec.Resources.Limits != nil {
					limits = dynamoDeploymentComponent.Spec.Resources.Limits
				} else {
					dynamoDeploymentComponent.Spec.Resources.Limits = limits
				}
			}
			if componentDynConfig.ServiceArgs.Resources.GPU != nil {
				requests.GPU = *componentDynConfig.ServiceArgs.Resources.GPU
				limits.GPU = *componentDynConfig.ServiceArgs.Resources.GPU
			}
			if componentDynConfig.ServiceArgs.Resources.CPU != nil {
				requests.CPU = *componentDynConfig.ServiceArgs.Resources.CPU
				limits.CPU = *componentDynConfig.ServiceArgs.Resources.CPU
			}
			if componentDynConfig.ServiceArgs.Resources.Memory != nil {
				requests.Memory = *componentDynConfig.ServiceArgs.Resources.Memory
				limits.Memory = *componentDynConfig.ServiceArgs.Resources.Memory
			}
			if componentDynConfig.ServiceArgs.Resources.Custom != nil {
				requests.Custom = componentDynConfig.ServiceArgs.Resources.Custom
				limits.Custom = componentDynConfig.ServiceArgs.Resources.Custom
			}
		}
	}
	return nil
}

func MergeEnvs(common, specific []corev1.EnvVar) []corev1.EnvVar {
	envMap := make(map[string]corev1.EnvVar)

	// Add all common environment variables.
	for _, env := range common {
		envMap[env.Name] = env
	}

	// Override or add with service-specific environment variables.
	for _, env := range specific {
		envMap[env.Name] = env
	}

	// Convert the map back to a slice.
	merged := make([]corev1.EnvVar, 0, len(envMap))
	for _, env := range envMap {
		merged = append(merged, env)
	}
	sort.Slice(merged, func(i, j int) bool {
		return merged[i].Name < merged[j].Name
	})
	return merged
}

// GetDCDResourceName returns the Kubernetes resource name for a DynamoComponentDeployment.
// If using for a non DCD resource (i.e. Ingress or VirtualService), use the empty string for the workerSuffix.
// For DCD Resources, Worker components include the workerSuffix; for non-workers, workerSuffix is ignored
func GetDCDResourceName(dgd *v1alpha1.DynamoGraphDeployment, serviceName string, workerSuffix string) string {
	baseName := fmt.Sprintf("%s-%s", dgd.Name, strings.ToLower(serviceName))
	if spec := dgd.Spec.Services[serviceName]; spec != nil && IsWorkerComponent(spec.ComponentType) && workerSuffix != "" {
		return baseName + "-" + workerSuffix
	}
	return baseName
}

type SecretsRetriever interface {
	GetSecrets(namespace, registry string) ([]string, error)
}

func resolveImagePullSecrets(retriever SecretsRetriever, namespace, image string) []corev1.LocalObjectReference {
	names, err := retriever.GetSecrets(namespace, image)
	if err != nil {
		return nil
	}
	refs := make([]corev1.LocalObjectReference, 0, len(names))
	for _, name := range names {
		refs = append(refs, corev1.LocalObjectReference{Name: name})
	}
	return refs
}

// applyCliqueStartupDependencies configures StartsAfter dependencies for cliques in a PodCliqueSet
// based on the backend framework and multinode deployment patterns.
//
// Rules:
// - For VLLM and SGLang: worker cliques start after leader clique
// - For TRTLLM: leader clique starts after worker cliques
// - Only applies to multinode deployments (numberOfNodes > 1)
// - Sets the PodCliqueSet StartupType to Explicit if any dependencies are configured
func applyCliqueStartupDependencies(
	gangSet *grovev1alpha1.PodCliqueSet,
	roles []ServiceRole,
	backendFramework BackendFramework,
	numberOfNodes int32,
) {
	// enabled for TRTLLM multinode deployments only
	// TODO: reactivate for all backends when we have a better way to handle the readiness probe for the leader.
	enabled := backendFramework == BackendFrameworkTRTLLM && numberOfNodes > 1

	if !enabled {
		return // No dependencies for single-node deployments
	}

	// Build maps of leader and worker clique names
	var leaderCliqueName string
	var workerCliqueNames []string

	for _, r := range roles {
		cliqueName := strings.ToLower(r.Name)
		switch r.Role {
		case RoleLeader:
			leaderCliqueName = cliqueName
		case RoleWorker:
			workerCliqueNames = append(workerCliqueNames, cliqueName)
		}
	}

	// Apply dependencies to cliques
	hasDependencies := false
	for _, clique := range gangSet.Spec.Template.Cliques {
		// Find the corresponding role for this clique
		var cliqueRole Role
		for _, r := range roles {
			if strings.ToLower(r.Name) == clique.Name {
				cliqueRole = r.Role
				break
			}
		}

		// Determine dependencies for this clique
		startsAfter := getCliqueStartupDependencies(cliqueRole, backendFramework, leaderCliqueName, workerCliqueNames)
		if len(startsAfter) > 0 {
			clique.Spec.StartsAfter = startsAfter
			hasDependencies = true
		}
	}

	// Set explicit startup type if we have any dependencies
	if hasDependencies {
		explicitStartupType := grovev1alpha1.CliqueStartupTypeExplicit
		gangSet.Spec.Template.StartupType = &explicitStartupType
	}
}

// getCliqueStartupDependencies determines the StartsAfter dependencies for a clique
// based on its role, backend framework, and available leader/worker clique names.
//
// Rules:
// - For VLLM and SGLang: worker cliques start after leader clique
// - For TRTLLM: leader clique starts after worker cliques
// - For other backends or single-node deployments: no dependencies
func getCliqueStartupDependencies(
	role Role,
	backendFramework BackendFramework,
	leaderCliqueName string,
	workerCliqueNames []string,
) []string {
	switch backendFramework {
	case BackendFrameworkVLLM, BackendFrameworkSGLang:
		// For vllm and sglang: worker cliques start after leader clique
		if role == RoleWorker && leaderCliqueName != "" {
			return []string{leaderCliqueName}
		}
	case BackendFrameworkTRTLLM:
		// For trtllm: leader clique starts after worker cliques
		if role == RoleLeader && len(workerCliqueNames) > 0 {
			return workerCliqueNames
		}
	}

	// No dependencies for other cases
	return nil
}

// ComponentServiceParams contains all the fields needed to generate a Kubernetes
// Service for a Dynamo component, independent of whether the caller is the DGD
// (Grove) or DCD controller.
type ComponentServiceParams struct {
	ServiceName     string
	Namespace       string
	ComponentType   string
	DynamoNamespace string
	ComponentName   string // original user-provided name, used in selector
	Labels          map[string]string
	Annotations     map[string]string
	IsK8sDiscovery  bool
}

func GenerateComponentService(params ComponentServiceParams) (*corev1.Service, error) {
	var servicePort corev1.ServicePort
	switch params.ComponentType {
	case commonconsts.ComponentTypeFrontend:
		servicePort = corev1.ServicePort{
			Name:       commonconsts.DynamoServicePortName,
			Port:       commonconsts.DynamoServicePort,
			TargetPort: intstr.FromString(commonconsts.DynamoContainerPortName),
			Protocol:   corev1.ProtocolTCP,
		}
	case commonconsts.ComponentTypeEPP:
		servicePort = corev1.ServicePort{
			Name:        commonconsts.EPPGRPCPortName,
			Port:        commonconsts.EPPGRPCPort,
			TargetPort:  intstr.FromInt(commonconsts.EPPGRPCPort),
			Protocol:    corev1.ProtocolTCP,
			AppProtocol: ptr.To("http2"),
		}
	default:
		servicePort = corev1.ServicePort{
			Name:       commonconsts.DynamoSystemPortName,
			Port:       commonconsts.DynamoSystemPort,
			TargetPort: intstr.FromString(commonconsts.DynamoSystemPortName),
			Protocol:   corev1.ProtocolTCP,
		}
	}

	labels := make(map[string]string)
	for k, v := range params.Labels {
		labels[k] = v
	}
	if params.IsK8sDiscovery {
		labels[commonconsts.KubeLabelDynamoDiscoveryBackend] = "kubernetes"
		labels[commonconsts.KubeLabelDynamoDiscoveryEnabled] = commonconsts.KubeLabelValueTrue
	}

	selector := map[string]string{
		commonconsts.KubeLabelDynamoComponentType: params.ComponentType,
		commonconsts.KubeLabelDynamoNamespace:     params.DynamoNamespace,
		commonconsts.KubeLabelDynamoComponent:     params.ComponentName,
	}

	annotations := make(map[string]string)
	for k, v := range params.Annotations {
		annotations[k] = v
	}

	service := &corev1.Service{
		ObjectMeta: metav1.ObjectMeta{
			// Service names must be DNS-1035 labels (no dots). Replace dots with
			// hyphens so model names like "Qwen3-0.6B" don't cause rejections.
			Name:        strings.ReplaceAll(params.ServiceName, ".", "-"),
			Namespace:   params.Namespace,
			Labels:      labels,
			Annotations: annotations,
		},
		Spec: corev1.ServiceSpec{
			Selector: selector,
			Ports:    []corev1.ServicePort{servicePort},
		},
	}
	return service, nil
}

func GenerateComponentIngress(ctx context.Context, componentName, componentNamespace string, ingressSpec v1alpha1.IngressSpec) *networkingv1.Ingress {
	resourceName := componentName
	ingress := &networkingv1.Ingress{
		ObjectMeta: metav1.ObjectMeta{
			Name:      resourceName,
			Namespace: componentNamespace,
		},
	}
	host := getIngressHost(ingressSpec)
	ingress.Spec = networkingv1.IngressSpec{
		IngressClassName: ingressSpec.IngressControllerClassName,
		Rules: []networkingv1.IngressRule{
			{
				Host: host,
				IngressRuleValue: networkingv1.IngressRuleValue{
					HTTP: &networkingv1.HTTPIngressRuleValue{
						Paths: []networkingv1.HTTPIngressPath{
							{
								Path:     "/",
								PathType: &[]networkingv1.PathType{networkingv1.PathTypePrefix}[0],
								Backend: networkingv1.IngressBackend{
									Service: &networkingv1.IngressServiceBackend{
										Name: resourceName,
										Port: networkingv1.ServiceBackendPort{
											Number: commonconsts.DynamoServicePort,
										},
									},
								},
							},
						},
					},
				},
			},
		},
	}
	if ingressSpec.TLS != nil {
		ingress.Spec.TLS = []networkingv1.IngressTLS{
			{
				Hosts:      []string{host},
				SecretName: ingressSpec.TLS.SecretName,
			},
		}
	}
	return ingress
}

func getIngressHost(ingressSpec v1alpha1.IngressSpec) string {
	host := ingressSpec.Host
	if ingressSpec.HostPrefix != nil {
		host = *ingressSpec.HostPrefix + host
	}
	ingressSuffix := commonconsts.DefaultIngressSuffix
	if ingressSpec.HostSuffix != nil {
		ingressSuffix = *ingressSpec.HostSuffix
	}
	return fmt.Sprintf("%s.%s", host, ingressSuffix)
}

func GenerateComponentVirtualService(ctx context.Context, componentName, componentNamespace string, ingressSpec v1alpha1.IngressSpec) *networkingv1beta1.VirtualService {
	vs := &networkingv1beta1.VirtualService{
		ObjectMeta: metav1.ObjectMeta{
			Name:      componentName,
			Namespace: componentNamespace,
		},
	}
	if ingressSpec.IsVirtualServiceEnabled() {
		vs.Spec = istioNetworking.VirtualService{
			Hosts: []string{
				getIngressHost(ingressSpec),
			},
			Gateways: []string{*ingressSpec.VirtualServiceGateway},
			Http: []*istioNetworking.HTTPRoute{
				{
					Match: []*istioNetworking.HTTPMatchRequest{
						{
							Uri: &istioNetworking.StringMatch{
								MatchType: &istioNetworking.StringMatch_Prefix{Prefix: "/"},
							},
						},
					},
					Route: []*istioNetworking.HTTPRouteDestination{
						{
							Destination: &istioNetworking.Destination{
								Host: componentName,
								Port: &istioNetworking.PortSelector{
									Number: commonconsts.DynamoServicePort,
								},
							},
						},
					},
				},
			},
		}
	}
	return vs
}

func GenerateDefaultIngressSpec(dynamoDeployment *v1alpha1.DynamoGraphDeployment, ingressConfig configv1alpha1.IngressConfiguration) v1alpha1.IngressSpec {
	res := v1alpha1.IngressSpec{
		Enabled:           ingressConfig.VirtualServiceGateway != "" || ingressConfig.ControllerClassName != "",
		Host:              dynamoDeployment.Name,
		UseVirtualService: ingressConfig.VirtualServiceGateway != "",
	}
	if ingressConfig.ControllerClassName != "" {
		res.IngressControllerClassName = &ingressConfig.ControllerClassName
	}
	if ingressConfig.ControllerTLSSecretName != "" {
		res.TLS = &v1alpha1.IngressTLSSpec{
			SecretName: ingressConfig.ControllerTLSSecretName,
		}
	}
	if ingressConfig.HostSuffix != "" {
		res.HostSuffix = &ingressConfig.HostSuffix
	}
	if ingressConfig.VirtualServiceGateway != "" {
		res.VirtualServiceGateway = &ingressConfig.VirtualServiceGateway
	}
	return res
}

// Define Role enum for leader/worker/main
// Use this type everywhere instead of string for role

type Role string

const (
	RoleLeader     Role = "leader"
	RoleWorker     Role = "worker"
	RoleMain       Role = "main"
	RoleCheckpoint Role = "checkpoint"
)

// Update ServiceRole struct for expandRolesForService

type ServiceRole struct {
	Name     string
	Role     Role
	Replicas int32
}

// Update expandRolesForService to use Role
func expandRolesForService(serviceName string, serviceReplicas *int32, numberOfNodes int32) []ServiceRole {
	var roles []ServiceRole
	if numberOfNodes > 1 {
		roles = append(roles, ServiceRole{Name: serviceName + "-" + commonconsts.GroveRoleSuffixLeader, Role: RoleLeader, Replicas: 1})
		roles = append(roles, ServiceRole{Name: serviceName + "-" + commonconsts.GroveRoleSuffixWorker, Role: RoleWorker, Replicas: numberOfNodes - 1})
	} else {
		replicas := int32(1)
		if serviceReplicas != nil {
			replicas = *serviceReplicas
		}
		roles = append(roles, ServiceRole{Name: serviceName, Role: RoleMain, Replicas: replicas})
	}
	return roles
}

// Define BackendFramework enum for sglang, vllm, trtllm

type BackendFramework string

const (
	BackendFrameworkSGLang BackendFramework = "sglang"
	BackendFrameworkVLLM   BackendFramework = "vllm"
	BackendFrameworkTRTLLM BackendFramework = "trtllm"
	BackendFrameworkNoop   BackendFramework = "noop"
)

// ParseBackendFramework converts a string to BackendFramework type.
// Returns an error if the framework string is not recognized.
func ParseBackendFramework(framework string) (BackendFramework, error) {
	bf := BackendFramework(framework)
	switch bf {
	case BackendFrameworkVLLM, BackendFrameworkSGLang, BackendFrameworkTRTLLM, BackendFrameworkNoop:
		return bf, nil
	default:
		return "", fmt.Errorf("unsupported backend framework: %s (valid values: vllm, sglang, trtllm)", framework)
	}
}

// Backend interface for modular backend logic
// Each backend (SGLang, VLLM, etc.) implements this interface
type Backend interface {
	UpdateContainer(container *corev1.Container, numberOfNodes int32, role Role, component *v1alpha1.DynamoComponentDeploymentSharedSpec, serviceName string, multinodeDeployer MultinodeDeployer)
	UpdatePodSpec(podSpec *corev1.PodSpec, numberOfNodes int32, role Role, component *v1alpha1.DynamoComponentDeploymentSharedSpec, serviceName string, multinodeDeployer MultinodeDeployer)
}

// NoopBackend does no processing - used for non-worker components like frontend, planner, router
type NoopBackend struct{}

func (b *NoopBackend) UpdateContainer(container *corev1.Container, numberOfNodes int32, role Role, component *v1alpha1.DynamoComponentDeploymentSharedSpec, serviceName string, multinodeDeployer MultinodeDeployer) {
	// No-op: frontend, planner, router, etc. don't need backend-specific processing
}

func (b *NoopBackend) UpdatePodSpec(podSpec *corev1.PodSpec, numberOfNodes int32, role Role, component *v1alpha1.DynamoComponentDeploymentSharedSpec, serviceName string, multinodeDeployer MultinodeDeployer) {
	// No-op: frontend, planner, router, etc. don't need backend-specific processing
}

type MultinodeDeployer interface {
	GetLeaderHostname(serviceName string) string
	GetHostNames(serviceName string, numberOfNodes int32) []string
	GetNodeRank() (string, bool) // returns (rank, needsShellInterpretation)
	NeedsDNSWait() bool          // returns true if DNS wait is needed to launch multinode components
}

// BackendFactory creates backend instances based on the framework type
func BackendFactory(backendFramework BackendFramework, operatorConfig *configv1alpha1.OperatorConfiguration, parentGraphDeploymentName string) Backend {
	switch backendFramework {
	case BackendFrameworkSGLang:
		return &SGLangBackend{}
	case BackendFrameworkVLLM:
		return &VLLMBackend{ParentGraphDeploymentName: parentGraphDeploymentName}
	case BackendFrameworkTRTLLM:
		return &TRTLLMBackend{
			MpiRunSecretName: operatorConfig.MPI.SSHSecretName,
		}
	case BackendFrameworkNoop:
		return &NoopBackend{}
	default:
		return nil
	}
}

func MultinodeDeployerFactory(multinodeDeploymentType commonconsts.MultinodeDeploymentType) MultinodeDeployer {
	switch multinodeDeploymentType {
	case commonconsts.MultinodeDeploymentTypeGrove:
		return &GroveMultinodeDeployer{}
	case commonconsts.MultinodeDeploymentTypeLWS:
		return &LWSMultinodeDeployer{}
	default:
		return nil
	}
}

// IsWorkerComponent checks if a component is a worker that needs backend framework detection
func IsWorkerComponent(componentType string) bool {
	return componentType == commonconsts.ComponentTypeWorker ||
		componentType == commonconsts.ComponentTypePrefill ||
		componentType == commonconsts.ComponentTypeDecode
}

// AddStandardEnvVars adds the standard environment variables that are common to
// both checkpoint jobs and generated worker pods.
func AddStandardEnvVars(container *corev1.Container, operatorConfig *configv1alpha1.OperatorConfiguration) {
	standardEnvVars := []corev1.EnvVar{}
	if operatorConfig.Infrastructure.NATSAddress != "" {
		standardEnvVars = append(standardEnvVars, corev1.EnvVar{
			Name:  "NATS_SERVER",
			Value: operatorConfig.Infrastructure.NATSAddress,
		})
	}

	if operatorConfig.Infrastructure.ETCDAddress != "" {
		standardEnvVars = append(standardEnvVars, corev1.EnvVar{
			Name:  "ETCD_ENDPOINTS",
			Value: operatorConfig.Infrastructure.ETCDAddress,
		})
	}

	if operatorConfig.Infrastructure.ModelExpressURL != "" {
		standardEnvVars = append(standardEnvVars, corev1.EnvVar{
			Name:  "MODEL_EXPRESS_URL",
			Value: operatorConfig.Infrastructure.ModelExpressURL,
		})
	}
	if operatorConfig.Infrastructure.PrometheusEndpoint != "" {
		standardEnvVars = append(standardEnvVars, corev1.EnvVar{
			Name:  "PROMETHEUS_ENDPOINT",
			Value: operatorConfig.Infrastructure.PrometheusEndpoint,
		})
	}
	// merge the env vars to allow users to override the standard env vars
	container.Env = MergeEnvs(standardEnvVars, container.Env)
}

// applyDefaultSecurityContext sets secure defaults for pod security context.
// Currently only sets fsGroup to solve volume permission issues.
// Does NOT set runAsUser/runAsGroup/runAsNonRoot to maintain backward compatibility
// with images that may expect to run as root.
// User-provided security context values (via extraPodSpec) will override these defaults.
func applyDefaultSecurityContext(podSpec *corev1.PodSpec) {
	// Initialize SecurityContext if not present
	if podSpec.SecurityContext == nil {
		podSpec.SecurityContext = &corev1.PodSecurityContext{}
	}

	// Only set fsGroup by default
	// This fixes volume permission issues without forcing a specific UID/GID
	// which maintains compatibility with both root and non-root images
	if podSpec.SecurityContext.FSGroup == nil {
		podSpec.SecurityContext.FSGroup = ptr.To(int64(commonconsts.DefaultSecurityContextFSGroup))
	}
}

// GenerateBasePodSpec creates a basic PodSpec with common logic shared between controller and grove
// Includes standard environment variables (DYNAMO_PORT, NATS_SERVER, ETCD_ENDPOINTS)
// Deployment-specific environment merging should be handled by the caller
//
//nolint:gocyclo
func GenerateBasePodSpec(
	component *v1alpha1.DynamoComponentDeploymentSharedSpec,
	backendFramework BackendFramework,
	secretsRetriever SecretsRetriever,
	parentGraphDeploymentName string,
	namespace string,
	role Role,
	numberOfNodes int32,
	operatorConfig *configv1alpha1.OperatorConfiguration,
	multinodeDeploymentType commonconsts.MultinodeDeploymentType,
	serviceName string,
	checkpointInfo *checkpoint.CheckpointInfo, // Optional checkpoint info (resolved by ResolveCheckpointForService)
) (*corev1.PodSpec, error) {
	// Start with base container generated per component type
	componentContext := generateComponentContext(component, parentGraphDeploymentName, namespace, numberOfNodes, controller_common.GetDiscoveryBackend(operatorConfig.Discovery.Backend, component.Annotations))
	componentDefaults := ComponentDefaultsFactory(component.ComponentType)
	container, err := componentDefaults.GetBaseContainer(componentContext)
	if err != nil {
		return nil, fmt.Errorf("failed to get base container: %w", err)
	}

	if component.ExtraPodSpec != nil && component.ExtraPodSpec.MainContainer != nil {
		main := component.ExtraPodSpec.MainContainer.DeepCopy()
		if main != nil {
			// merge the extraPodSpec from the parent deployment with the extraPodSpec from the service
			containerEnvs := container.Env
			err = mergo.Merge(&container, *main, mergo.WithOverride)
			if err != nil {
				return nil, fmt.Errorf("failed to merge extraPodSpec: %w", err)
			}

			// main container fields that require special handling
			container.Env = MergeEnvs(containerEnvs, container.Env)
			// Note: startup probe does not have its own top level field so it must be passed in extraPodSpec.MainContainer
			// We want to overwrite entirely if provided rather than merge
			if main.StartupProbe != nil {
				container.StartupProbe = main.StartupProbe
			}
		}
	}
	container.Env = MergeEnvs(container.Env, component.Envs)

	// Merge probes entirely if they are passed (no partial merge)
	if component.LivenessProbe != nil {
		container.LivenessProbe = component.LivenessProbe.DeepCopy()
	}
	if component.ReadinessProbe != nil {
		container.ReadinessProbe = component.ReadinessProbe.DeepCopy()
	}

	overrideResources, err := controller_common.GetResourcesConfig(component.Resources)
	if err != nil {
		return nil, fmt.Errorf("failed to get resources config: %w", err)
	}
	// Requests
	if overrideResources != nil && len(overrideResources.Requests) > 0 {
		if container.Resources.Requests == nil {
			container.Resources.Requests = corev1.ResourceList{}
		}
		maps.Copy(container.Resources.Requests, overrideResources.Requests)
	}

	// Limits
	if overrideResources != nil && len(overrideResources.Limits) > 0 {
		if container.Resources.Limits == nil {
			container.Resources.Limits = corev1.ResourceList{}
		}
		maps.Copy(container.Resources.Limits, overrideResources.Limits)
	}

	// Claims
	if overrideResources != nil && len(overrideResources.Claims) > 0 {
		if container.Resources.Claims == nil {
			container.Resources.Claims = []corev1.ResourceClaim{}
		}
		container.Resources.Claims = append(container.Resources.Claims, overrideResources.Claims...)
	}

	shouldDisableImagePullSecret := component.Annotations[commonconsts.KubeAnnotationDisableImagePullSecretDiscovery] == commonconsts.KubeLabelValueTrue

	imagePullSecrets := []corev1.LocalObjectReference{}
	if !shouldDisableImagePullSecret && secretsRetriever != nil && component.ExtraPodSpec != nil && component.ExtraPodSpec.MainContainer != nil && component.ExtraPodSpec.MainContainer.Image != "" {
		imagePullSecrets = resolveImagePullSecrets(secretsRetriever, namespace, component.ExtraPodSpec.MainContainer.Image)
	}
	if component.EnvFromSecret != nil {
		container.EnvFrom = append(container.EnvFrom, corev1.EnvFromSource{
			SecretRef: &corev1.SecretEnvSource{
				LocalObjectReference: corev1.LocalObjectReference{Name: *component.EnvFromSecret},
			},
		})
	}

	AddStandardEnvVars(&container, operatorConfig)

	volumes := make([]corev1.Volume, 0, len(component.VolumeMounts)+1) // +1 for shared memory volume

	for _, volumeMount := range component.VolumeMounts {
		if volumeMount.Name == "" {
			return nil, fmt.Errorf("volumeMount.name is required when volumeMounts is set")
		}

		// Determine mount point
		mountPoint := volumeMount.MountPoint
		if volumeMount.UseAsCompilationCache && mountPoint == "" {
			// Use backend-specific default for compilation cache
			defaultMountPoint := getDefaultCompilationCacheMountPoint(backendFramework)
			if defaultMountPoint == "" {
				return nil, fmt.Errorf("volumeMount with useAsCompilationCache=true requires an explicit mountPoint for backend framework %s (no default available)", backendFramework)
			}
			mountPoint = defaultMountPoint
		} else if !volumeMount.UseAsCompilationCache && mountPoint == "" {
			return nil, fmt.Errorf("volumeMount.mountPoint is required when useAsCompilationCache is false")
		}

		volumes = append(volumes, corev1.Volume{
			Name: volumeMount.Name,
			VolumeSource: corev1.VolumeSource{
				PersistentVolumeClaim: &corev1.PersistentVolumeClaimVolumeSource{
					ClaimName: volumeMount.Name,
				},
			},
		})

		container.VolumeMounts = append(container.VolumeMounts, corev1.VolumeMount{
			Name:      volumeMount.Name,
			MountPath: mountPoint,
		})
	}
	// Apply backend-specific container modifications
	multinodeDeployer := MultinodeDeployerFactory(multinodeDeploymentType)
	if multinodeDeployer == nil {
		return nil, fmt.Errorf("unsupported multinode deployment type: %s", multinodeDeploymentType)
	}
	backend := BackendFactory(backendFramework, operatorConfig, parentGraphDeploymentName)
	if backend == nil {
		return nil, fmt.Errorf("unsupported backend framework: %s", backendFramework)
	}
	backend.UpdateContainer(&container, numberOfNodes, role, component, serviceName, multinodeDeployer)

	// get base podspec from component
	podSpec, err := componentDefaults.GetBasePodSpec(componentContext)
	if err != nil {
		return nil, fmt.Errorf("failed to get base podspec: %w", err)
	}

	// Check if user provided their own security context before merging
	userProvidedSecurityContext := component.ExtraPodSpec != nil &&
		component.ExtraPodSpec.PodSpec != nil &&
		component.ExtraPodSpec.PodSpec.SecurityContext != nil

	if component.ExtraPodSpec != nil && component.ExtraPodSpec.PodSpec != nil {
		// merge extraPodSpec PodSpec with base podspec
		err := mergo.Merge(&podSpec, component.ExtraPodSpec.PodSpec.DeepCopy(), mergo.WithOverride)
		if err != nil {
			return nil, fmt.Errorf("failed to merge extraPodSpec: %w", err)
		}
	}

	// Apply default security context ONLY if user didn't provide any security context
	// If user provides ANY securityContext (even partial), they get full control with no defaults injected
	// This allows users to intentionally set fields to nil (e.g., to run as root)
	if !userProvidedSecurityContext {
		applyDefaultSecurityContext(&podSpec)
	}

	if controller_common.IsK8sDiscoveryEnabled(operatorConfig.Discovery.Backend, component.Annotations) {
		if podSpec.ServiceAccountName == "" {
			podSpec.ServiceAccountName = discovery.GetK8sDiscoveryServiceAccountName(parentGraphDeploymentName)
		}
	}

	podSpec.Volumes = append(podSpec.Volumes, volumes...)
	ApplySharedMemoryVolumeAndMount(&podSpec, &container, component.SharedMemory)
	podSpec.Containers = append(podSpec.Containers, container)
	podSpec.ImagePullSecrets = controller_common.AppendUniqueImagePullSecrets(podSpec.ImagePullSecrets, imagePullSecrets)

	backend.UpdatePodSpec(&podSpec, numberOfNodes, role, component, serviceName, multinodeDeployer)

	// Inject auto-generated frontend sidecar if configured
	if component.FrontendSidecar != nil {
		sidecar, err := generateFrontendSidecar(component.FrontendSidecar, componentContext, operatorConfig)
		if err != nil {
			return nil, fmt.Errorf("failed to generate frontend sidecar: %w", err)
		}
		podSpec.Containers = append(podSpec.Containers, sidecar)

		if !shouldDisableImagePullSecret && secretsRetriever != nil {
			podSpec.ImagePullSecrets = controller_common.AppendUniqueImagePullSecrets(
				podSpec.ImagePullSecrets,
				resolveImagePullSecrets(secretsRetriever, namespace, component.FrontendSidecar.Image),
			)
		}
	}

	return &podSpec, nil
}

func setMetricsLabels(labels map[string]string, dynamoGraphDeployment *v1alpha1.DynamoGraphDeployment) {
	// Convert user-provided metrics annotation into controller-managed label
	// By default (no annotation), metrics are enabled
	if metricsAnnotationValue, ok := dynamoGraphDeployment.Annotations[commonconsts.KubeAnnotationEnableMetrics]; ok && metricsAnnotationValue == commonconsts.KubeLabelValueFalse {
		// Explicitly disabled, don't add the label
		return
	}
	// Any other value (including empty) enables metrics
	labels[commonconsts.KubeLabelMetricsEnabled] = commonconsts.KubeLabelValueTrue
}

func generateComponentContext(component *v1alpha1.DynamoComponentDeploymentSharedSpec, parentGraphDeploymentName string, namespace string, numberOfNodes int32, discoveryBackend configv1alpha1.DiscoveryBackend) ComponentContext {
	dynamoNamespace := v1alpha1.ComputeDynamoNamespace(component.GlobalDynamoNamespace, namespace, parentGraphDeploymentName)
	var workerHashSuffix string
	if IsWorkerComponent(component.ComponentType) && component.Labels[commonconsts.KubeLabelDynamoWorkerHash] != "" {
		workerHashSuffix = component.Labels[commonconsts.KubeLabelDynamoWorkerHash]
	}

	componentContext := ComponentContext{
		numberOfNodes:                  numberOfNodes,
		ComponentType:                  component.ComponentType,
		ParentGraphDeploymentName:      parentGraphDeploymentName,
		ParentGraphDeploymentNamespace: namespace,
		DiscoveryBackend:               discoveryBackend,
		DynamoNamespace:                dynamoNamespace,
		EPPConfig:                      component.EPPConfig,
		WorkerHashSuffix:               workerHashSuffix,
	}
	return componentContext
}

// generateFrontendSidecar builds a fully configured frontend sidecar container
// using the same FrontendDefaults logic as standalone frontend services.
// This eliminates the need for users to manually specify Dynamo env vars, probes,
// and ports when running the frontend as a sidecar (e.g., GAIE deployments).
func generateFrontendSidecar(
	spec *v1alpha1.FrontendSidecarSpec,
	parentContext ComponentContext,
	operatorConfig *configv1alpha1.OperatorConfiguration,
) (corev1.Container, error) {
	frontendContext := ComponentContext{
		numberOfNodes:                  1,
		ComponentType:                  commonconsts.ComponentTypeFrontend,
		ParentGraphDeploymentName:      parentContext.ParentGraphDeploymentName,
		ParentGraphDeploymentNamespace: parentContext.ParentGraphDeploymentNamespace,
		DiscoveryBackend:               parentContext.DiscoveryBackend,
		DynamoNamespace:                parentContext.DynamoNamespace,
	}

	frontendDefaults := NewFrontendDefaults()
	container, err := frontendDefaults.GetBaseContainer(frontendContext)
	if err != nil {
		return corev1.Container{}, fmt.Errorf("failed to get frontend base container: %w", err)
	}

	container.Name = commonconsts.FrontendSidecarContainerName
	container.Image = spec.Image

	if len(spec.Args) > 0 {
		container.Args = spec.Args
	}

	if spec.EnvFromSecret != nil {
		container.EnvFrom = append(container.EnvFrom, corev1.EnvFromSource{
			SecretRef: &corev1.SecretEnvSource{
				LocalObjectReference: corev1.LocalObjectReference{Name: *spec.EnvFromSecret},
			},
		})
	}

	if len(spec.Envs) > 0 {
		container.Env = MergeEnvs(container.Env, spec.Envs)
	}

	AddStandardEnvVars(&container, operatorConfig)

	return container, nil
}

// GeneratePodSpecForComponent creates a PodSpec for Grove deployments (simplified wrapper)
func GeneratePodSpecForComponent(
	component *v1alpha1.DynamoComponentDeploymentSharedSpec,
	backendFramework BackendFramework,
	secretsRetriever SecretsRetriever,
	dynamoDeployment *v1alpha1.DynamoGraphDeployment,
	role Role,
	numberOfNodes int32,
	operatorConfig *configv1alpha1.OperatorConfiguration,
	multinodeDeploymentType commonconsts.MultinodeDeploymentType,
	serviceName string,
	checkpointInfo *checkpoint.CheckpointInfo, // Optional checkpoint info
) (*corev1.PodSpec, error) {
	if len(dynamoDeployment.Spec.Envs) > 0 {
		component.Envs = MergeEnvs(dynamoDeployment.Spec.Envs, component.Envs)
	}

	propagateDGDAnnotations(dynamoDeployment.GetAnnotations(), component)
	propagateDGDSpecMetadata(dynamoDeployment.Spec.Annotations, dynamoDeployment.Spec.Labels, component)

	podSpec, err := GenerateBasePodSpec(component, backendFramework, secretsRetriever, dynamoDeployment.Name, dynamoDeployment.Namespace, role, numberOfNodes, operatorConfig, multinodeDeploymentType, serviceName, checkpointInfo)
	if err != nil {
		return nil, err
	}
	return podSpec, nil
}

// dgdPropagatedAnnotationKeys lists DGD metadata annotations that are propagated
// to component-level annotations (for both the DCD/controller and Grove paths).
// Service-level annotations take precedence (are never overwritten).
var dgdPropagatedAnnotationKeys = []string{
	commonconsts.KubeAnnotationEnableMetrics,
	commonconsts.KubeAnnotationDynamoDiscoveryBackend,
	commonconsts.KubeAnnotationDynamoOperatorOriginVersion,
	commonconsts.KubeAnnotationVLLMDistributedExecutorBackend,
}

// propagateDGDAnnotations copies DGD-level annotations into the component
// annotations so that downstream logic can read them uniformly.
// Service-level annotations take precedence (are never overwritten).
func propagateDGDAnnotations(dgdAnnotations map[string]string, component *v1alpha1.DynamoComponentDeploymentSharedSpec) {
	for _, key := range dgdPropagatedAnnotationKeys {
		if val, exists := dgdAnnotations[key]; exists {
			if component.Annotations == nil {
				component.Annotations = make(map[string]string)
			}
			if _, serviceHas := component.Annotations[key]; !serviceHas {
				component.Annotations[key] = val
			}
		}
	}
}

// propagateDGDSpecMetadata merges DGD spec-level annotations and labels into
// the component as a low-priority base. Service-level values take precedence.
func propagateDGDSpecMetadata(annotations, labels map[string]string, component *v1alpha1.DynamoComponentDeploymentSharedSpec) {
	for k, v := range annotations {
		if component.Annotations == nil {
			component.Annotations = make(map[string]string)
		}
		if _, exists := component.Annotations[k]; !exists {
			component.Annotations[k] = v
		}
	}
	for k, v := range labels {
		if component.Labels == nil {
			component.Labels = make(map[string]string)
		}
		if _, exists := component.Labels[k]; !exists {
			component.Labels[k] = v
		}
	}
}

// GenerateGrovePodCliqueSet generates a Grove PodCliqueSet for the given deployment, supporting both single-node and multinode cases.
func GenerateGrovePodCliqueSet(
	ctx context.Context,
	dynamoDeployment *v1alpha1.DynamoGraphDeployment,
	operatorConfig *configv1alpha1.OperatorConfiguration,
	runtimeConfig *controller_common.RuntimeConfig,
	kubeClient ctrlclient.Reader,
	secretsRetriever SecretsRetriever,
	restartState *RestartState,
	existingRestartAnnotations map[string]string,
	checkpointInfoByService map[string]*checkpoint.CheckpointInfo, // Optional checkpoint info per service
) (*grovev1alpha1.PodCliqueSet, error) {
	gangSet := &grovev1alpha1.PodCliqueSet{}
	gangSet.Name = dynamoDeployment.Name
	gangSet.Namespace = dynamoDeployment.Namespace
	gangSet.Labels = maps.Clone(dynamoDeployment.Spec.Labels)
	gangSet.Annotations = maps.Clone(dynamoDeployment.Spec.Annotations)
	gangSet.Spec.Replicas = 1
	gangSet.Spec.Template.HeadlessServiceConfig = &grovev1alpha1.HeadlessServiceConfig{
		PublishNotReadyAddresses: true,
	}
	gangSet.Spec.Template.StartupType = ptr.To(grovev1alpha1.CliqueStartupTypeAnyOrder)
	if operatorConfig.Orchestrators.Grove.TerminationDelay.Duration > 0 {
		gangSet.Spec.Template.TerminationDelay = &operatorConfig.Orchestrators.Grove.TerminationDelay
	}

	// Inject deployment-level topology constraint (PCS template).
	// specToGroveTopologyConstraint returns nil when input is nil, so this is a no-op without TAS.
	gangSet.Spec.Template.TopologyConstraint = specToGroveTopologyConstraint(dynamoDeployment.Spec.TopologyConstraint)

	// Validate kai-scheduler queue once if kai-scheduler is enabled
	var validatedQueueName string
	if runtimeConfig.GroveEnabled && runtimeConfig.KaiSchedulerEnabled {
		var err error
		validatedQueueName, err = DetermineKaiSchedulerQueue(ctx, dynamoDeployment.Annotations)
		if err != nil {
			return nil, fmt.Errorf("failed to determine kai-scheduler queue: %w", err)
		}
	}

	discoveryBackend := controller_common.GetDiscoveryBackend(operatorConfig.Discovery.Backend, dynamoDeployment.Annotations)

	var scalingGroups []grovev1alpha1.PodCliqueScalingGroupConfig
	for serviceName, component := range dynamoDeployment.Spec.Services {
		dynamoNamespace := GetDynamoNamespace(dynamoDeployment, component)
		component.DynamoNamespace = &dynamoNamespace
		// Determine backend framework using hybrid approach
		backendFramework, err := getBackendFrameworkFromComponent(component, dynamoDeployment)
		if err != nil {
			return nil, fmt.Errorf("failed to determine backend framework for service %s: %w", serviceName, err)
		}

		if discoveryBackend != "" {
			if component.Annotations == nil {
				component.Annotations = make(map[string]string)
			}
			component.Annotations[commonconsts.KubeAnnotationDynamoDiscoveryBackend] = string(discoveryBackend)
		}

		// Get checkpoint info for this service if available
		var checkpointInfo *checkpoint.CheckpointInfo
		if checkpointInfoByService != nil {
			checkpointInfo = checkpointInfoByService[serviceName]
		}

		numberOfNodes := component.GetNumberOfNodes()
		isMultinode := numberOfNodes > 1
		roles := expandRolesForService(serviceName, component.Replicas, numberOfNodes)
		var cliqueNames []string

		for _, r := range roles {
			podSpec, err := GeneratePodSpecForComponent(
				component,
				backendFramework,
				secretsRetriever,
				dynamoDeployment,
				r.Role,
				numberOfNodes,
				operatorConfig,
				commonconsts.MultinodeDeploymentTypeGrove,
				serviceName,
				checkpointInfo,
			)
			if err != nil {
				return nil, fmt.Errorf("failed to generate podSpec for role %s: %w", r.Name, err)
			}
			if operatorConfig.Checkpoint.Enabled {
				if err := checkpoint.InjectCheckpointIntoPodSpec(
					ctx,
					kubeClient,
					dynamoDeployment.Namespace,
					podSpec,
					checkpointInfo,
				); err != nil {
					return nil, fmt.Errorf("failed to inject checkpoint config for role %s: %w", r.Name, err)
				}
			}

			minAvailable := int32(1)
			if isMultinode {
				minAvailable = r.Replicas
			}

			clique := &grovev1alpha1.PodCliqueTemplateSpec{
				Name: strings.ToLower(r.Name),
				Spec: grovev1alpha1.PodCliqueSpec{
					RoleName:     strings.ToLower(r.Name),
					Replicas:     r.Replicas,
					MinAvailable: ptr.To(minAvailable),
					PodSpec:      *podSpec,
				},
			}

			// For single-node services, set topology constraint directly on the clique.
			// For multinode services, the constraint goes on the PCSG instead;
			// child cliques inherit from PCSG and should NOT have explicit constraints.
			if !isMultinode {
				clique.TopologyConstraint = toGroveTopologyConstraint(component.TopologyConstraint)
			}
			labels, err := generateLabels(component, dynamoDeployment, serviceName)
			if err != nil {
				return nil, fmt.Errorf("failed to generate labels: %w", err)
			}
			clique.Labels = labels
			annotations, err := generateAnnotations(component)
			if err != nil {
				return nil, fmt.Errorf("failed to generate annotations: %w", err)
			}
			checkpoint.ApplyRestorePodMetadata(labels, annotations, checkpointInfo)

			// Apply restart annotation if this service should be restarted.
			// For services not in the current restart order, preserve their existing annotation
			// to avoid triggering unwanted rollouts when a new restart begins.
			if restartState.ShouldAnnotateService(serviceName) {
				if annotations == nil {
					annotations = make(map[string]string)
				}
				annotations[commonconsts.RestartAnnotation] = restartState.Timestamp
			} else if existingRestartAnnotations != nil {
				if existingTimestamp, ok := existingRestartAnnotations[serviceName]; ok {
					if annotations == nil {
						annotations = make(map[string]string)
					}
					annotations[commonconsts.RestartAnnotation] = existingTimestamp
				}
			}
			clique.Annotations = annotations

			// Inject kai-scheduler settings if enabled
			injectKaiSchedulerIfEnabled(clique, runtimeConfig, validatedQueueName)

			gangSet.Spec.Template.Cliques = append(gangSet.Spec.Template.Cliques, clique)
			cliqueNames = append(cliqueNames, strings.ToLower(r.Name))
		}

		// Apply startup dependencies for this service
		applyCliqueStartupDependencies(gangSet, roles, backendFramework, numberOfNodes)

		if isMultinode {
			scalingGroups = append(scalingGroups, grovev1alpha1.PodCliqueScalingGroupConfig{
				Name:               strings.ToLower(serviceName),
				CliqueNames:        cliqueNames,
				Replicas:           component.Replicas,
				MinAvailable:       ptr.To(int32(1)),
				TopologyConstraint: toGroveTopologyConstraint(component.TopologyConstraint),
			})
		}
	}
	if len(scalingGroups) > 0 {
		gangSet.Spec.Template.PodCliqueScalingGroupConfigs = scalingGroups
	}

	return gangSet, nil
}

func generateLabels(
	component *v1alpha1.DynamoComponentDeploymentSharedSpec,
	dynamoDeployment *v1alpha1.DynamoGraphDeployment,
	componentName string,
) (map[string]string, error) {
	labels := make(map[string]string)
	labels[commonconsts.KubeLabelDynamoSelector] = GetDCDResourceName(dynamoDeployment, componentName, "")
	labels[commonconsts.KubeLabelDynamoGraphDeploymentName] = dynamoDeployment.Name
	labels[commonconsts.KubeLabelDynamoComponent] = componentName
	if component.DynamoNamespace != nil {
		labels[commonconsts.KubeLabelDynamoNamespace] = *component.DynamoNamespace
	}
	if component.ComponentType != "" {
		labels[commonconsts.KubeLabelDynamoComponentType] = component.ComponentType
	}
	if component.SubComponentType != "" {
		labels[commonconsts.KubeLabelDynamoSubComponentType] = component.SubComponentType
	}
	// Add base model label if modelRef is specified
	AddBaseModelLabel(labels, component.ModelRef)
	// Merge user-supplied labels first so they cannot overwrite checkpoint labels.
	setMetricsLabels(labels, dynamoDeployment)
	if component.Labels != nil {
		if err := mergo.Merge(&labels, component.Labels, mergo.WithOverride); err != nil {
			return nil, fmt.Errorf("failed to merge labels: %w", err)
		}
	}
	if component.ExtraPodMetadata != nil {
		if err := mergo.Merge(&labels, component.ExtraPodMetadata.Labels, mergo.WithOverride); err != nil {
			return nil, fmt.Errorf("failed to merge extraPodMetadata labels: %w", err)
		}
	}
	labels[commonconsts.KubeLabelDynamoGraphDeploymentName] = dynamoDeployment.Name
	if component.ComponentType != "" {
		labels[commonconsts.KubeLabelDynamoComponentType] = component.ComponentType
	}
	if component.DynamoNamespace != nil {
		labels[commonconsts.KubeLabelDynamoNamespace] = *component.DynamoNamespace
	}
	if workerHash := component.Labels[commonconsts.KubeLabelDynamoWorkerHash]; workerHash != "" {
		labels[commonconsts.KubeLabelDynamoWorkerHash] = workerHash
	}
	return labels, nil
}

func generateAnnotations(component *v1alpha1.DynamoComponentDeploymentSharedSpec) (map[string]string, error) {
	annotations := make(map[string]string)
	if component.Annotations != nil {
		err := mergo.Merge(&annotations, component.Annotations, mergo.WithOverride)
		if err != nil {
			return nil, fmt.Errorf("failed to merge annotations: %w", err)
		}
	}
	if component.ExtraPodMetadata != nil {
		err := mergo.Merge(&annotations, component.ExtraPodMetadata.Annotations, mergo.WithOverride)
		if err != nil {
			return nil, fmt.Errorf("failed to merge extraPodMetadata annotations: %w", err)
		}
	}
	return annotations, nil
}

// detectBackendFrameworkFromArgs detects the backend framework from command/args
func detectBackendFrameworkFromArgs(command []string, args []string) (BackendFramework, error) {
	// Combine command and args to search through all parts
	allParts := append(command, args...)
	fullCommand := strings.Join(allParts, " ")

	// Pattern to match python -m dynamo.{backend}.something
	patterns := map[BackendFramework]*regexp.Regexp{
		BackendFrameworkVLLM:   regexp.MustCompile(`python[0-9.]*\s+[^|&;]*-m\s+[^|&;]*dynamo\.vllm[^|&;]*`),
		BackendFrameworkSGLang: regexp.MustCompile(`python[0-9.]*\s+[^|&;]*-m\s+[^|&;]*dynamo\.sglang[^|&;]*`),
		BackendFrameworkTRTLLM: regexp.MustCompile(`python[0-9.]*\s+[^|&;]*-m\s+[^|&;]*dynamo\.trtllm[^|&;]*`),
	}

	var detected []BackendFramework
	for framework, pattern := range patterns {
		if pattern.MatchString(fullCommand) {
			detected = append(detected, framework)
		}
	}

	if len(detected) == 0 {
		return BackendFrameworkNoop, nil
	}

	if len(detected) > 1 {
		return "", fmt.Errorf("multiple backend frameworks detected from command: %v in %q", detected, fullCommand)
	}

	return detected[0], nil
}

// determineBackendFramework is the core logic for hybrid backend framework detection
// Takes extracted parameters and applies the detection logic
func determineBackendFramework(
	componentType string,
	command []string,
	args []string,
	explicitBackendFramework string,
) (BackendFramework, error) {
	// Check if this is a worker component - if not, use noop backend
	if !IsWorkerComponent(componentType) {
		return BackendFrameworkNoop, nil
	}

	// Worker component - apply backend framework detection
	var detectedFramework BackendFramework
	var detectionError error

	// Try to detect from command/args
	if len(command) > 0 || len(args) > 0 {
		detected, err := detectBackendFrameworkFromArgs(command, args)
		if err == nil {
			detectedFramework = detected
		} else {
			detectionError = err
		}
	}

	// Get explicit framework
	var explicitFramework BackendFramework
	if explicitBackendFramework != "" {
		explicitFramework = BackendFramework(explicitBackendFramework)
	}

	// Validate consistency if both detected and explicit exist
	if detectedFramework != "" && detectedFramework != BackendFrameworkNoop && explicitFramework != "" && detectedFramework != explicitFramework {
		return "", fmt.Errorf("backend framework mismatch: detected %q from command but explicitly configured as %q",
			detectedFramework, explicitFramework)
	}

	// Return in order of preference: detected > explicit > error
	if detectedFramework != "" && detectedFramework != BackendFrameworkNoop {
		return detectedFramework, nil
	}

	if explicitFramework != "" {
		return explicitFramework, nil
	}

	// If we couldn't detect and no explicit config, return error
	if detectionError != nil {
		return "", fmt.Errorf("could not determine backend framework: %w", detectionError)
	}

	// No command/args to detect from and no explicit config
	return BackendFrameworkNoop, nil
}

// getBackendFrameworkFromComponent attempts to determine backend framework using hybrid approach:
// 1. Check if component is a worker - if not, return noop
// 2. For workers: try to detect from command/args, fall back to explicit config
// 3. Return error if worker has neither detection nor explicit config
// Also validates consistency between detected and explicit if both exist
func getBackendFrameworkFromComponent(
	component *v1alpha1.DynamoComponentDeploymentSharedSpec,
	dynamoDeployment *v1alpha1.DynamoGraphDeployment,
) (BackendFramework, error) {
	// Extract command/args from component
	var command, args []string
	if component.ExtraPodSpec != nil && component.ExtraPodSpec.MainContainer != nil {
		command = component.ExtraPodSpec.MainContainer.Command
		args = component.ExtraPodSpec.MainContainer.Args
	}

	// Extract explicit backend framework from deployment
	explicitBackendFramework := dynamoDeployment.Spec.BackendFramework

	return determineBackendFramework(
		component.ComponentType,
		command,
		args,
		explicitBackendFramework,
	)
}

// ConvertDynamoComponentDeploymentToSpec converts a DynamoComponentDeployment to our component spec interface
// This is a helper for the controller to use our backend logic
func ConvertDynamoComponentDeploymentToSpec(dynComponent *v1alpha1.DynamoComponentDeployment) *v1alpha1.DynamoComponentDeploymentSharedSpec {
	return dynComponent.Spec.DynamoComponentDeploymentSharedSpec.DeepCopy()
}

// GetBackendFrameworkFromDynamoComponent determines backend framework for a DynamoComponentDeployment
func GetBackendFrameworkFromDynamoComponent(dynComponent *v1alpha1.DynamoComponentDeployment) (BackendFramework, error) {
	// Extract command/args from component
	var command, args []string
	if dynComponent.Spec.ExtraPodSpec != nil && dynComponent.Spec.ExtraPodSpec.MainContainer != nil {
		command = dynComponent.Spec.ExtraPodSpec.MainContainer.Command
		args = dynComponent.Spec.ExtraPodSpec.MainContainer.Args
	}

	// Extract explicit backend framework
	explicitBackendFramework := dynComponent.Spec.BackendFramework

	return determineBackendFramework(
		dynComponent.Spec.ComponentType,
		command,
		args,
		explicitBackendFramework,
	)
}

// GenerateBasePodSpecForController generates a PodSpec using backend logic for controller usage
// This preserves the base pod generation while allowing controller-specific enhancements
func GenerateBasePodSpecForController(
	dynComponent *v1alpha1.DynamoComponentDeployment,
	secretsRetriever SecretsRetriever,
	operatorConfig *configv1alpha1.OperatorConfiguration,
	role Role,
	multinodeDeploymentType commonconsts.MultinodeDeploymentType,
	checkpointInfo *checkpoint.CheckpointInfo, // Optional checkpoint info (resolved by caller)
) (*corev1.PodSpec, error) {
	// Convert to our interface
	componentSpec := ConvertDynamoComponentDeploymentToSpec(dynComponent)

	numberOfNodes := componentSpec.GetNumberOfNodes()

	// Determine backend framework using hybrid approach
	backendFramework, err := GetBackendFrameworkFromDynamoComponent(dynComponent)
	if err != nil {
		return nil, fmt.Errorf("failed to determine backend framework: %w", err)
	}

	// Generate base PodSpec with standard env vars using merged component envs
	serviceName := dynComponent.Spec.ServiceName
	if serviceName == "" {
		serviceName = dynComponent.Name
	}
	podSpec, err := GenerateBasePodSpec(
		componentSpec,
		backendFramework,
		secretsRetriever,
		dynComponent.GetParentGraphDeploymentName(),
		dynComponent.Namespace,
		role,
		numberOfNodes,
		operatorConfig,
		multinodeDeploymentType,
		serviceName,
		checkpointInfo,
	)
	if err != nil {
		return nil, err
	}

	return podSpec, nil
}

// getDefaultCompilationCacheMountPoint returns the default mount point for compilation cache based on backend framework
func getDefaultCompilationCacheMountPoint(backendFramework BackendFramework) string {
	switch backendFramework {
	case BackendFrameworkVLLM:
		return commonconsts.DefaultVLLMCacheMountPoint
	case BackendFrameworkSGLang, BackendFrameworkTRTLLM:
		// SGLang and TensorRT-LLM don't currently support compilation caches
		// Return empty string as these should not be used
		return ""
	default:
		// For unknown backends, don't assume compilation cache support
		return ""
	}
}
