/*
Copyright 2022 The Karmada Authors.

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 native

import (
	"bytes"
	"fmt"

	appsv1 "k8s.io/api/apps/v1"
	autoscalingv2 "k8s.io/api/autoscaling/v2"
	batchv1 "k8s.io/api/batch/v1"
	corev1 "k8s.io/api/core/v1"
	networkingv1 "k8s.io/api/networking/v1"
	policyv1 "k8s.io/api/policy/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/klog/v2"

	"github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
	"github.com/karmada-io/karmada/pkg/util"
	"github.com/karmada-io/karmada/pkg/util/helper"
)

type reflectStatusInterpreter func(object *unstructured.Unstructured) (*runtime.RawExtension, error)

func getAllDefaultReflectStatusInterpreter() map[schema.GroupVersionKind]reflectStatusInterpreter {
	s := make(map[schema.GroupVersionKind]reflectStatusInterpreter)
	s[appsv1.SchemeGroupVersion.WithKind(util.DeploymentKind)] = reflectDeploymentStatus
	s[corev1.SchemeGroupVersion.WithKind(util.ServiceKind)] = reflectServiceStatus
	s[networkingv1.SchemeGroupVersion.WithKind(util.IngressKind)] = reflectIngressStatus
	s[batchv1.SchemeGroupVersion.WithKind(util.JobKind)] = reflectJobStatus
	s[appsv1.SchemeGroupVersion.WithKind(util.DaemonSetKind)] = reflectDaemonSetStatus
	s[appsv1.SchemeGroupVersion.WithKind(util.StatefulSetKind)] = reflectStatefulSetStatus
	s[policyv1.SchemeGroupVersion.WithKind(util.PodDisruptionBudgetKind)] = reflectPodDisruptionBudgetStatus
	s[autoscalingv2.SchemeGroupVersion.WithKind(util.HorizontalPodAutoscalerKind)] = reflectHorizontalPodAutoscalerStatus
	return s
}

func reflectDeploymentStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	deploymentStatus := &appsv1.DeploymentStatus{}
	if err = helper.ConvertToTypedObject(statusMap, deploymentStatus); err != nil {
		return nil, fmt.Errorf("failed to convert DeploymentStatus from map[string]interface{}: %v", err)
	}

	resourceTemplateGenerationInt := int64(0)
	resourceTemplateGenerationStr := util.GetAnnotationValue(object.GetAnnotations(), v1alpha2.ResourceTemplateGenerationAnnotationKey)
	err = runtime.Convert_string_To_int64(&resourceTemplateGenerationStr, &resourceTemplateGenerationInt, nil)
	if err != nil {
		klog.Errorf("Failed to parse Deployment(%s/%s) generation from annotation(%s:%s): %v", object.GetNamespace(), object.GetName(), v1alpha2.ResourceTemplateGenerationAnnotationKey, resourceTemplateGenerationStr, err)
		return nil, err
	}

	grabStatus := &WrappedDeploymentStatus{
		FederatedGeneration: FederatedGeneration{
			Generation:                 object.GetGeneration(),
			ResourceTemplateGeneration: resourceTemplateGenerationInt,
		},
		DeploymentStatus: appsv1.DeploymentStatus{
			Replicas:            deploymentStatus.Replicas,
			UpdatedReplicas:     deploymentStatus.UpdatedReplicas,
			ReadyReplicas:       deploymentStatus.ReadyReplicas,
			AvailableReplicas:   deploymentStatus.AvailableReplicas,
			UnavailableReplicas: deploymentStatus.UnavailableReplicas,
			ObservedGeneration:  deploymentStatus.ObservedGeneration,
		},
	}

	grabStatusRaw, err := helper.BuildStatusRawExtension(grabStatus)
	if err != nil {
		return nil, err
	}

	// if status is empty struct, it actually means status haven't been collected from member cluster.
	if bytes.Equal(grabStatusRaw.Raw, []byte("{}")) {
		return nil, nil
	}

	return grabStatusRaw, nil
}

func reflectServiceStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	serviceType, exist, err := unstructured.NestedString(object.Object, "spec", "type")
	if err != nil {
		klog.Errorf("Failed to get spec.type field from %s(%s/%s)", object.GetKind(), object.GetNamespace(), object.GetName())
	}
	if !exist {
		klog.Errorf("Failed to get spec.type from %s(%s/%s) which should have spec.type field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}
	if serviceType != string(corev1.ServiceTypeLoadBalancer) {
		return nil, nil
	}

	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	serviceStatus := &corev1.ServiceStatus{}
	err = helper.ConvertToTypedObject(statusMap, serviceStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert ServiceStatus from map[string]interface{}: %v", err)
	}

	grabStatus := corev1.ServiceStatus{
		LoadBalancer: serviceStatus.LoadBalancer,
	}
	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectIngressStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	return reflectWholeStatus(object)
}

func reflectJobStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	jobStatus := &batchv1.JobStatus{}
	err = helper.ConvertToTypedObject(statusMap, jobStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert JobStatus from map[string]interface{}: %v", err)
	}

	grabStatus := batchv1.JobStatus{
		Active:         jobStatus.Active,
		Succeeded:      jobStatus.Succeeded,
		Failed:         jobStatus.Failed,
		Conditions:     jobStatus.Conditions,
		StartTime:      jobStatus.StartTime,
		CompletionTime: jobStatus.CompletionTime,
	}
	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectDaemonSetStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	daemonSetStatus := &appsv1.DaemonSetStatus{}
	err = helper.ConvertToTypedObject(statusMap, daemonSetStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert DaemonSetStatus from map[string]interface{}: %v", err)
	}

	resourceTemplateGenerationInt := int64(0)
	resourceTemplateGenerationStr := util.GetAnnotationValue(object.GetAnnotations(), v1alpha2.ResourceTemplateGenerationAnnotationKey)
	err = runtime.Convert_string_To_int64(&resourceTemplateGenerationStr, &resourceTemplateGenerationInt, nil)
	if err != nil {
		klog.Errorf("Failed to parse DaemonSet(%s/%s) generation from annotation(%s:%s): %v", object.GetNamespace(), object.GetName(), v1alpha2.ResourceTemplateGenerationAnnotationKey, resourceTemplateGenerationStr, err)
		return nil, err
	}

	grabStatus := &WrappedDaemonSetStatus{
		FederatedGeneration: FederatedGeneration{
			Generation:                 object.GetGeneration(),
			ResourceTemplateGeneration: resourceTemplateGenerationInt,
		},
		DaemonSetStatus: appsv1.DaemonSetStatus{
			CurrentNumberScheduled: daemonSetStatus.CurrentNumberScheduled,
			DesiredNumberScheduled: daemonSetStatus.DesiredNumberScheduled,
			NumberAvailable:        daemonSetStatus.NumberAvailable,
			NumberMisscheduled:     daemonSetStatus.NumberMisscheduled,
			NumberReady:            daemonSetStatus.NumberReady,
			UpdatedNumberScheduled: daemonSetStatus.UpdatedNumberScheduled,
			NumberUnavailable:      daemonSetStatus.NumberUnavailable,
			ObservedGeneration:     daemonSetStatus.ObservedGeneration,
		},
	}

	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectStatefulSetStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	resourceTemplateGenerationInt := int64(0)
	resourceTemplateGenerationStr := util.GetAnnotationValue(object.GetAnnotations(), v1alpha2.ResourceTemplateGenerationAnnotationKey)
	err = runtime.Convert_string_To_int64(&resourceTemplateGenerationStr, &resourceTemplateGenerationInt, nil)
	if err != nil {
		klog.Errorf("Failed to parse StatefulSet(%s/%s) generation from annotation(%s:%s): %v", object.GetNamespace(), object.GetName(), v1alpha2.ResourceTemplateGenerationAnnotationKey, resourceTemplateGenerationStr, err)
		return nil, err
	}

	statefulSetStatus := &appsv1.StatefulSetStatus{}
	err = helper.ConvertToTypedObject(statusMap, statefulSetStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert StatefulSetStatus from map[string]interface{}: %v", err)
	}

	grabStatus := &WrappedStatefulSetStatus{
		FederatedGeneration: FederatedGeneration{
			Generation:                 object.GetGeneration(),
			ResourceTemplateGeneration: resourceTemplateGenerationInt,
		},
		StatefulSetStatus: appsv1.StatefulSetStatus{
			AvailableReplicas: statefulSetStatus.AvailableReplicas,
			CurrentReplicas:   statefulSetStatus.CurrentReplicas,
			ReadyReplicas:     statefulSetStatus.ReadyReplicas,
			Replicas:          statefulSetStatus.Replicas,
			UpdatedReplicas:   statefulSetStatus.UpdatedReplicas,
		},
	}
	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectPodDisruptionBudgetStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	pdbStatus := &policyv1.PodDisruptionBudgetStatus{}
	err = helper.ConvertToTypedObject(statusMap, pdbStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert PodDisruptionBudget from map[string]interface{}: %v", err)
	}

	grabStatus := policyv1.PodDisruptionBudgetStatus{
		DisruptionsAllowed: pdbStatus.DisruptionsAllowed,
		ExpectedPods:       pdbStatus.ExpectedPods,
		DesiredHealthy:     pdbStatus.DesiredHealthy,
		CurrentHealthy:     pdbStatus.CurrentHealthy,
		DisruptedPods:      pdbStatus.DisruptedPods,
	}
	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectHorizontalPodAutoscalerStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if !exist {
		klog.Errorf("Failed to grab status from %s(%s/%s) which should have status field.",
			object.GetKind(), object.GetNamespace(), object.GetName())
		return nil, nil
	}

	hpaStatus := &autoscalingv2.HorizontalPodAutoscalerStatus{}
	err = helper.ConvertToTypedObject(statusMap, hpaStatus)
	if err != nil {
		return nil, fmt.Errorf("failed to convert HorizontalPodAutoscaler from map[string]interface{}: %v", err)
	}

	grabStatus := autoscalingv2.HorizontalPodAutoscalerStatus{
		CurrentReplicas: hpaStatus.CurrentReplicas,
		DesiredReplicas: hpaStatus.DesiredReplicas,
	}
	return helper.BuildStatusRawExtension(grabStatus)
}

func reflectWholeStatus(object *unstructured.Unstructured) (*runtime.RawExtension, error) {
	statusMap, exist, err := unstructured.NestedMap(object.Object, "status")
	if err != nil {
		klog.Errorf("Failed to get status field from %s(%s/%s), error: %v",
			object.GetKind(), object.GetNamespace(), object.GetName(), err)
		return nil, err
	}
	if exist {
		return helper.BuildStatusRawExtension(statusMap)
	}
	return nil, nil
}