/*
Copyright 2024.

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 v1beta1

import (
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/intstr"

	configv1beta1 "github.com/projectsveltos/addon-controller/api/v1beta1"
	libsveltosv1beta1 "github.com/projectsveltos/libsveltos/api/v1beta1"
)

const (
	// EventTriggerFinalizer allows Reconcilers to clean up resources associated with
	// EventTrigger before removing it from the apiserver.
	EventTriggerFinalizer = "eventtrigger.finalizer.projectsveltos.io"

	EventTriggerKind = "EventTrigger"

	FeatureEventTrigger = "EventTrigger"

	// InstantiateAnnotation is the annotation that must be set on a referenced
	// ConfigMap/Secret when the content is a template and needs variable substitution
	// using event/cluster data
	InstantiateAnnotation = "projectsveltos.io/instantiate"
)

type CloudEventAction string

const (
	// CloudEventActionCreate indicates that eventTrigger should create profiles (and
	// so kubernetes resources) in response to the CloudEvent.
	CloudEventActionCreate = CloudEventAction("Create")

	// CloudEventActionDelete indicates that eventTrigger should  should delete profiles
	// (and so Kubernetes resources) in response to the CloudEvent.
	CloudEventActionDelete = CloudEventAction("Delete")
)

type GeneratorReference struct {
	// Namespace of the referenced resource.
	// Namespace can be left empty. In such a case, namespace will
	// be implicit set to cluster's namespace.
	// +optional
	Namespace string `json:"namespace,omitempty"`

	// Name of the referenced resource.
	// Name can be expressed as a template and instantiate using
	// - `.Cluster.metadata.namespace`: namespace of the managed cluster
	// - `.Cluster.metadata.name`: name of the managed cluster
	// - `.Cluster.kind`: kind of the managed cluster object
	// +kubebuilder:validation:MinLength=1
	Name string `json:"name"`

	// InstantiatedResourceNameFormat defines a template used to generate the name
	// of the resource created in the management cluster. The template can reference:
	// - `.Cluster.metadata.namespace`: namespace of the managed cluster
	// - `.Cluster.metadata.name`: name of the managed cluster
	// - `.Cluster.kind`: kind of the managed cluster object
	// +kubebuilder:validation:MinLength=1
	InstantiatedResourceNameFormat string `json:"nameFormat"`
}

// EventTriggerSpec defines the desired state of EventTrigger
type EventTriggerSpec struct {
	// SourceClusterSelector identifies clusters to associate to.
	// This represents the set of clusters where Sveltos will watch for
	// events defined by referenced EventSource
	SourceClusterSelector libsveltosv1beta1.Selector `json:"sourceClusterSelector"`

	// SetRefs identifies referenced ClusterSets. Name of the referenced ClusterSets.
	// +optional
	ClusterSetRefs []string `json:"clusterSetRefs,omitempty"`

	// Multiple resources in a managed cluster can be a match for referenced
	// EventSource. OneForEvent indicates whether a ClusterProfile for all
	// resource (OneForEvent = false) or one per resource (OneForEvent = true)
	// needs to be creted.
	//+kubebuilder:validation:XValidation:rule="self == oldSelf",message="Value is immutable"
	// +optional
	OneForEvent bool `json:"oneForEvent,omitempty"`

	// EventSourceName is the name of the referenced EventSource.
	// Resources contained in the referenced ConfigMaps/Secrets and HelmCharts
	// will be customized using information from resources matching the EventSource
	// in the managed cluster.
	// Name can be expressed as a template and instantiate using:
	// - cluster namespace: .Cluster.metadata.namespace
	// - cluster name: .Cluster.metadata.name
	// - cluster type: .Cluster.kind
	// +kubebuilder:validation:MinLength=1
	EventSourceName string `json:"eventSourceName"`

	// DestinationClusterSelector identifies the cluster where add-ons will be deployed.
	// By default, this is nil and add-ons will be deployed in the very same cluster the
	// event happened.
	// If DestinationClusterSelector is set though, when an event happens in any of the
	// cluster identified by SourceClusterSelector, add-ons will be deployed in each of
	// the cluster indentified by DestinationClusterSelector.
	// +optional
	DestinationClusterSelector libsveltosv1beta1.Selector `json:"destinationClusterSelector,omitempty"`

	// The ConfigMapGenerator field references ConfigMaps containing templates.
	// These referenced ConfigMaps will be dynamically instantiated in the management cluster
	// based on event data.
	// +optional
	ConfigMapGenerator []GeneratorReference `json:"configMapGenerator,omitempty"`

	// The SecretGenerator field references Secrets containing templates.
	// These referenced Secret will be dynamically instantiated in the management cluster
	// based on event data.
	// +optional
	SecretGenerator []GeneratorReference `json:"secretGenerator,omitempty"`

	// SyncMode specifies how features are synced in a matching workload cluster.
	// - OneTime means, first time a workload cluster matches the ClusterProfile,
	// features will be deployed in such cluster. Any subsequent feature configuration
	// change won't be applied into the matching workload clusters;
	// - Continuous mode ensures that the first time a workload cluster matches a ClusterProfile,
	// the specified features are deployed. Subsequent changes to the feature configuration are also
	// automatically applied to all matching workload clusters.
	// _ SyncModeContinuousWithDriftDetection operates similarly to Continuous mode, but also monitors
	// matching managed clusters for configuration drift. If drift is detected, a reconciliation is
	// triggered to ensure the managed cluster's configuration aligns with the ClusterProfile.
	// - DryRun means no change will be propagated to any matching cluster. A report
	// instead will be generated summarizing what would happen in any matching cluster
	// because of the changes made to ClusterProfile while in DryRun mode.
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +kubebuilder:default:=Continuous
	// +optional
	SyncMode configv1beta1.SyncMode `json:"syncMode,omitempty"`

	// Tier controls the order of deployment for ClusterProfile or Profile resources targeting
	// the same cluster resources.
	// Imagine two configurations (ClusterProfiles or Profiles) trying to deploy the same resource (a Kubernetes
	// resource or an helm chart). By default, the first one to reach the cluster "wins" and deploys it.
	// Tier allows you to override this. When conflicts arise, the ClusterProfile or Profile with the **lowest**
	// Tier value takes priority and deploys the resource.
	// Higher Tier values represent lower priority. The default Tier value is 100.
	// Using Tiers provides finer control over resource deployment within your cluster, particularly useful
	// when multiple configurations manage the same resources.
	// +kubebuilder:default:=100
	// +kubebuilder:validation:Minimum=1
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	Tier int32 `json:"tier,omitempty"`

	// By default (when ContinueOnConflict is unset or set to false), Sveltos stops deployment after
	// encountering the first conflict (e.g., another ClusterProfile already deployed the resource).
	// If set to true, Sveltos will attempt to deploy remaining resources in the ClusterProfile even
	// if conflicts are detected for previous resources.
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +kubebuilder:default:=false
	// +optional
	ContinueOnConflict bool `json:"continueOnConflict,omitempty"`

	// The maximum number of clusters that can be updated concurrently.
	// Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%).
	// Defaults to 100%.
	// Example: when this is set to 30%, when list of add-ons/applications in ClusterProfile
	// changes, only 30% of matching clusters will be updated in parallel. Only when updates
	// in those cluster succeed, other matching clusters are updated.
	// +kubebuilder:validation:XIntOrString
	// +kubebuilder:validation:Pattern="^((100|[0-9]{1,2})%|[0-9]+)$"
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	MaxUpdate *intstr.IntOrString `json:"maxUpdate,omitempty"`

	// StopMatchingBehavior indicates what behavior should be when a Cluster stop matching
	// the ClusterProfile. By default all deployed Helm charts and Kubernetes resources will
	// be withdrawn from Cluster. Setting StopMatchingBehavior to LeavePolicies will instead
	// leave ClusterProfile deployed policies in the Cluster.
	// +kubebuilder:default:=WithdrawPolicies
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	StopMatchingBehavior configv1beta1.StopMatchingBehavior `json:"stopMatchingBehavior,omitempty"`

	// Reloader indicates whether Deployment/StatefulSet/DaemonSet instances deployed
	// by Sveltos and part of this ClusterProfile need to be restarted via rolling upgrade
	// when a ConfigMap/Secret instance mounted as volume is modified.
	// When set to true, when any mounted ConfigMap/Secret is modified, Sveltos automatically
	// starts a rolling upgrade for Deployment/StatefulSet/DaemonSet instances mounting it.
	// +kubebuilder:default:=false
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	Reloader bool `json:"reloader,omitempty"`

	// TemplateResourceRefs is a list of resource to collect from the management cluster.
	// Those resources' values will be used to instantiate templates contained in referenced
	// PolicyRefs and Helm charts
	// +patchMergeKey=identifier
	// +patchStrategy=merge,retainKeys
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	TemplateResourceRefs []configv1beta1.TemplateResourceRef `json:"templateResourceRefs,omitempty"`

	// PolicyRefs references all the ConfigMaps/Secrets containing kubernetes resources
	// that need to be deployed in the matching clusters based on EventSource.
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	PolicyRefs []configv1beta1.PolicyRef `json:"policyRefs,omitempty"`

	// Helm charts to be deployed in the matching clusters based on EventSource.
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	HelmCharts []configv1beta1.HelmChart `json:"helmCharts,omitempty"`

	// Kustomization refs
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	KustomizationRefs []configv1beta1.KustomizationRef `json:"kustomizationRefs,omitempty"`

	// ValidateHealths is a slice of Lua functions to run against
	// the managed cluster to validate the state of those add-ons/applications
	// is healthy
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	ValidateHealths []configv1beta1.ValidateHealth `json:"validateHealths,omitempty"`

	// Define additional Kustomize inline Patches applied for all resources on this profile
	// Within the Patch Spec you can use templating
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	Patches []libsveltosv1beta1.Patch `json:"patches,omitempty"`

	// DriftExclusions is a list of configuration drift exclusions to be applied when syncMode is
	// set to ContinuousWithDriftDetection. Each exclusion specifies JSON6902 paths to ignore
	// when evaluating drift, optionally targeting specific resources and features.
	// This field will be directly transferred to the ClusterProfile Spec
	// generated in response to events.
	// +optional
	DriftExclusions []configv1beta1.DriftExclusion `json:"driftExclusions,omitempty"`

	// CloudEventAction determines the action to take based on the received CloudEvent.
	// CloudEvents with the same source and subject are considered related and represent
	// different states of the same entity. This field specifies whether to create or
	// delete the associated Kubernetes resources.
	// This can be expressed as a template and instantiated at run time using CloudEvent
	// +kubebuilder:default:=Create
	// +optional
	CloudEventAction CloudEventAction `json:"cloudEventAction,omitempty"`

	// ExtraLabels: These labels will be added by Sveltos to all Kubernetes resources deployed in
	// a managed cluster based on this ClusterProfile/Profile instance.
	// **Important:** If a resource deployed by Sveltos already has a label with a key present in
	// `ExtraLabels`, the value from `ExtraLabels` will override the existing value.
	// (Deprecated use Patches instead)
	// +optional
	ExtraLabels map[string]string `json:"extraLabels,omitempty"`

	// ExtraAnnotations: These annotations will be added by Sveltos to all Kubernetes resources
	// deployed in a managed cluster based on this ClusterProfile/Profile instance.
	// **Important:** If a resource deployed by Sveltos already has a annotation with a key present in
	// `ExtraAnnotations`, the value from `ExtraAnnotations` will override the existing value.
	// (Deprecated use Patches instead)
	// +optional
	ExtraAnnotations map[string]string `json:"extraAnnotations,omitempty"`
}

// EventTriggerStatus defines the observed state of EventTrigger
type EventTriggerStatus struct {
	// MatchingClusterRefs reference all the cluster-api Cluster currently matching
	// ClusterProfile SourceClusterSelector
	// +optional
	MatchingClusterRefs []corev1.ObjectReference `json:"matchingClusters,omitempty"`

	// DestinationMatchingClusterRefs reference all the cluster-api Cluster currently matching
	// ClusterProfile DestinationClusterSelector
	// +optional
	DestinationMatchingClusterRefs []corev1.ObjectReference `json:"destinationMatchingClusterRefs,omitempty"`

	// ClusterInfo represent the deployment status in each managed
	// cluster.
	// +optional
	ClusterInfo []libsveltosv1beta1.ClusterInfo `json:"clusterInfo,omitempty"`
}

//+kubebuilder:object:root=true
//+kubebuilder:resource:path=eventtriggers,scope=Cluster
//+kubebuilder:subresource:status
//+kubebuilder:storageversion

// EventTrigger is the Schema for the eventtriggers API
type EventTrigger struct {
	metav1.TypeMeta   `json:",inline"`
	metav1.ObjectMeta `json:"metadata,omitempty"`

	Spec   EventTriggerSpec   `json:"spec,omitempty"`
	Status EventTriggerStatus `json:"status,omitempty"`
}

//+kubebuilder:object:root=true

// EventTriggerList contains a list of EventTrigger
type EventTriggerList struct {
	metav1.TypeMeta `json:",inline"`
	metav1.ListMeta `json:"metadata,omitempty"`
	Items           []EventTrigger `json:"items"`
}

func init() {
	SchemeBuilder.Register(&EventTrigger{}, &EventTriggerList{})
}