package appbox

import (
	"context"
	"fmt"
	"time"

	eksv1beta1 "github.com/crossplane-contrib/provider-aws/apis/eks/v1beta1"
	gkev1beta2 "github.com/crossplane-contrib/provider-gcp/apis/container/v1beta2"
	"github.com/go-logr/logr"
	"github.com/tidbcloud/infra-provider/pkg/cloud/aws"
	"github.com/tidbcloud/infra-provider/pkg/cloud/gcp"
	"github.com/tidbcloud/infra-provider/pkg/consts"
	"github.com/tidbcloud/infra-provider/pkg/deploy"
	"github.com/tidbcloud/infra-provider/pkg/k8s"
	"github.com/tidbcloud/infra-provider/pkg/namer"
	"github.com/tidbcloud/infra-provider/pkg/o11y/tracing"
	tracerutil "github.com/tidbcloud/infra-provider/pkg/tracer"
	"github.com/tidbcloud/infra-provider/regional-server/api/v1alpha1"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/common/utils"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/config"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/controllers"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/controllers/appbox/task"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/resourcemanager/appbox"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/resourcemanager/internet"
	"github.com/tidbcloud/infra-provider/regional-server/pkg/resourcemanager/vpc"
	agentcontrolapi "github.com/tidbcloud/observability/agent-control-server/pkg/agentcontrol/api"
	aksv1beta1 "github.com/upbound/provider-azure/apis/containerservice/v1beta1"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/trace"
	corev1 "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/tools/record"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/builder"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/predicate"
)

const (
	defaultRequeueTime = 2 * time.Second
)

var (
	requeue = ctrl.Result{Requeue: true, RequeueAfter: defaultRequeueTime}
	forget  = ctrl.Result{Requeue: false}
	tracer  = otel.Tracer("APPBoxReconciler")
)

type APPBoxReconciler struct {
	client.Client
	Log           logr.Logger
	Scheme        *runtime.Scheme
	Config        config.RootConfig
	TmplConfig    config.TemplatesConfig
	Manager       *controllers.Manager
	EventRecorder record.EventRecorder
	Provider      string
	APPBoxRW      appbox.APPBoxReaderWriter
	VPCR          vpc.VPCReader
	InternetR     internet.InternetReader

	AWSCli aws.Client
	GCPCli gcp.Client

	AgentControlAPI agentcontrolapi.AgentControlAPI
}

func NewAPPBoxReconciler(
	client client.Client,
	log logr.Logger, scheme *runtime.Scheme,
	config config.RootConfig,
	tmplConfig config.TemplatesConfig,
	manager *controllers.Manager,
	recorder record.EventRecorder,
	provider string,
	awsCli aws.Client,
	gcpCli gcp.Client,
	agentControlAPI agentcontrolapi.AgentControlAPI,
) *APPBoxReconciler {
	return &APPBoxReconciler{
		Client:          client,
		Log:             log,
		Scheme:          scheme,
		Config:          config,
		TmplConfig:      tmplConfig,
		Manager:         manager,
		EventRecorder:   recorder,
		Provider:        provider,
		APPBoxRW:        appbox.NewAPPBoxReaderWriter(client),
		VPCR:            vpc.NewVPCReader(client),
		InternetR:       internet.NewInternetReader(client),
		AWSCli:          awsCli,
		GCPCli:          gcpCli,
		AgentControlAPI: agentControlAPI,
	}
}

func (r *APPBoxReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	logger := r.Log.WithValues("APPBox", req.NamespacedName)
	ctx = log.IntoContext(ctx, logger)
	logger.Info("Start Reconciling APPBox")
	defer func() {
		logger.Info("Finish Reconcile")
	}()
	var appBox v1alpha1.APPBox
	if err := r.APPBoxRW.Get(ctx, req.NamespacedName, &appBox); err != nil {
		if apierrors.IsNotFound(err) {
			// APPBox not found, deregister from manager if it was registered
			r.Manager.Deregister(ctx, &appBox)
			return ctrl.Result{}, nil
		}
		return ctrl.Result{}, fmt.Errorf("unable to get APPBox : %v", err)
	}

	// Check if reconciliation is paused
	if utils.IsPaused(appBox.GetObjectMeta()) {
		logger.Info("reconciliation is paused through the pause annotation",
			"annotation", v1alpha1.AnnotationKeyReconciliationPaused,
			"appbox", req.NamespacedName.String(),
		)
		r.EventRecorder.Event(&appBox, "ReconciliationPaused", "reconciliation is paused through the pause annotation", v1alpha1.AnnotationKeyReconciliationPaused)
		return ctrl.Result{}, nil
	}

	var vpc v1alpha1.VPC
	if err := r.VPCR.Get(ctx, types.NamespacedName{Name: appBox.Spec.VPCRef.Name, Namespace: appBox.Spec.VPCRef.Namespace}, &vpc); err != nil {
		return requeue, fmt.Errorf("unable to get vpc %s: %w", appBox.Spec.VPCRef.Name, err)
	}

	addonTemplate, tmplExists := r.TmplConfig.GetAddonTemplate(appBox.Spec.KubernetesConfig.AddonTemplateID)
	if !tmplExists && r.Config.Provider == consts.ProviderTypeEKS {
		return forget, fmt.Errorf("addon template not found for templateId %s", appBox.Spec.KubernetesConfig.AddonTemplateID)
	}
	infraTemplate, tmplExists := r.TmplConfig.GetInfraTemplateWithVersion(appBox.Spec.KubernetesConfig.InfraTemplateID, appBox.Spec.KubernetesConfig.Version)
	if !tmplExists {
		return forget, fmt.Errorf("infra template not found for templateId %s and version %s", appBox.Spec.KubernetesConfig.InfraTemplateID, appBox.Spec.KubernetesConfig.Version)
	}
	dedicatedTemplate, tmplExists := r.TmplConfig.GetDedicatedTemplateWithVersion(appBox.Spec.KubernetesConfig.DedicatedTemplateID, appBox.Spec.KubernetesConfig.Version)
	if !tmplExists {
		return forget, fmt.Errorf("dedicated template not found for templateId %s and version %s", appBox.Spec.KubernetesConfig.DedicatedTemplateID, appBox.Spec.KubernetesConfig.Version)
	}
	dpTemplate, tmplExists := r.TmplConfig.GetDPTemplateWithVersion(appBox.Spec.KubernetesConfig.DPTemplateID, appBox.Spec.KubernetesConfig.Version)
	if !tmplExists {
		return forget, fmt.Errorf("data platform template not found for templateId %s and version %s", appBox.Spec.KubernetesConfig.DPTemplateID, appBox.Spec.KubernetesConfig.Version)
	}

	k8sExists, err := r.k8sIsExists(ctx, &appBox)
	if err != nil {
		return ctrl.Result{}, fmt.Errorf("failed to check k8s is ready: %v", err)
	}
	// if kubernetes cluster is ready and exists, register the appbox to the manager
	// if k8s is not exists, deregister the appbox from the manager
	if appBox.Status.Conditions.GetConditionEqualsTo(v1alpha1.APPBoxConditionK8SReady, metav1.ConditionTrue) && k8sExists {
		if err := r.Manager.Register(ctx, &appBox); err != nil {
			return ctrl.Result{}, fmt.Errorf("failed to register appbox: %v", err)
		}
	} else if !k8sExists {
		r.Manager.Deregister(ctx, &appBox)
	}

	c, err := (&task.Context{
		Local:               k8s.NewMutClientWithOwner(r.Client, appBox.DeepCopy(), namer.NewNamer()).Client(),
		Config:              r.Config,
		AddonTmplConfig:     addonTemplate,
		InfraTmplConfig:     infraTemplate,
		DedicatedTmplConfig: dedicatedTemplate,
		DPTmplConfig:        dpTemplate,
		VPC:                 vpc.DeepCopy(),
		APPBox:              &appBox,
		Logger:              r.Log,
		APPBoxRW:            r.APPBoxRW,
		VPCR:                r.VPCR,
		InternetR:           r.InternetR,
		AgentControlAPI:     r.AgentControlAPI,
	}).Default()
	if err != nil {
		return ctrl.Result{}, fmt.Errorf("failed to create a new context: %v", err)
	}

	getter, err := r.Manager.ClientGetter(ctx, req.NamespacedName)
	if err != nil {
		logger.Info("manager client not ready", "error", err)
	} else {
		c.Remote = getter
	}

	tasks := GetAPPBoxTasks(r, c)
	if appBox.DeletionTimestamp.IsZero() && isNotReadyAPPBox(&appBox) {
		tasks = r.setHookOnTasks(tasks, c)

		// TODO: refactor tracing
		var span trace.Span
		ctx, span = tracer.Start(tracing.ExtractTraceContext(ctx, &appBox), "APPBox Reconcile")
		span.SetAttributes(
			attribute.String("appbox", appBox.Name),
			attribute.String("namespace", appBox.Namespace),
			attribute.String("provider", appBox.Spec.Provider),
			attribute.String("region", appBox.Spec.Region),
			attribute.String("vpc", appBox.Spec.VPCRef.Name),
		)
		defer func() { tracerutil.EndSpan(span, err) }()
	}
	d := deploy.NewDeployer(tasks, nil, logger)

	var res ctrl.Result
	if appBox.DeletionTimestamp.IsZero() {
		res, err = updateCreate(ctx, c, d.Deploy(ctx))
	} else {
		res, err = updateDelete(ctx, c, d.Destroy(ctx))
	}
	if err == nil {
		r.EventRecorder.Event(&appBox, corev1.EventTypeNormal, "ReconcileSucceed", "")
	} else {
		r.EventRecorder.Event(&appBox, corev1.EventTypeWarning, "ReconcileFailed", err.Error())
	}

	// Final cleanup: deregister if no finalizers remain
	if len(appBox.Finalizers) == 0 {
		logger.Info("deregistering appbox from manager - no finalizers remaining",
			"appbox", req.NamespacedName)
		r.Manager.Deregister(ctx, &appBox)
	}

	return res, err
}

func (r *APPBoxReconciler) setHookOnTasks(tasks []deploy.Task, c *task.Context) []deploy.Task {
	hook := func(ctc context.Context, task deploy.Task) {
		name := task.Name()
		passTimeKey := utils.GenTaskFirstPastAnnotationKey(name)
		_, ok := c.APPBox.Annotations[passTimeKey]
		if ok {
			return
		}
		if c.APPBox.Annotations == nil {
			c.APPBox.Annotations = map[string]string{}
		}

		age := time.Since(c.APPBox.GetCreationTimestamp().Time)
		c.APPBox.Annotations[passTimeKey] = age.String()
		log.FromContext(ctc).Info("pass task when creating appbox", "task", name, "age", age.String())
	}

	for idx, task := range tasks {
		tasks[idx] = deploy.NewTaskWraper(task, hook, tracer)
	}
	return tasks
}

func isNotReadyAPPBox(appBox *v1alpha1.APPBox) bool {
	return appBox.Status.Phase != v1alpha1.APPBoxPhaseActive &&
		appBox.Status.Phase != v1alpha1.APPBoxPhaseReadyForDelete &&
		appBox.Status.Phase != v1alpha1.APPBoxPhaseDeleting
}

func (r *APPBoxReconciler) SetupWithManager(mgr ctrl.Manager, pds ...predicate.Predicate) error {
	if err := mgr.GetFieldIndexer().IndexField(context.Background(), &v1alpha1.APPBox{}, controllers.VPCNameField, func(o client.Object) []string {
		c := o.(*v1alpha1.APPBox)
		var res []string
		if c.Spec.VPCRef != nil {
			res = append(res, c.Spec.VPCRef.Name)
		}
		return res
	}); err != nil {
		return err
	}

	return ctrl.NewControllerManagedBy(mgr).
		Named("appbox").
		For(&v1alpha1.APPBox{}, builder.WithPredicates(pds...)).
		WithOptions(controller.Options{RateLimiter: k8s.RetryLimiter, MaxConcurrentReconciles: 5}).
		WithEventFilter(predicate.Or(
			predicate.GenerationChangedPredicate{},
			predicate.LabelChangedPredicate{},
			controllers.AnnotationChangedPredicate{})).
		Complete(r)
}

func (r *APPBoxReconciler) k8sIsExists(ctx context.Context, appBox *v1alpha1.APPBox) (bool, error) {
	logger := log.FromContext(ctx)
	appBoxKey := client.ObjectKeyFromObject(appBox)

	// Check if kubernetes cluster name is available
	if appBox.Status.KubernetesClusterName == "" {
		logger.V(1).Info("kubernetes cluster name not available",
			"appbox", appBoxKey)
		return false, nil
	}

	clusterKey := types.NamespacedName{
		Name: appBox.Status.KubernetesClusterName,
	}

	switch appBox.Spec.Provider {
	case consts.ProviderTypeEKS:
		var eks eksv1beta1.Cluster
		if err := r.Client.Get(ctx, clusterKey, &eks); err != nil {
			if apierrors.IsNotFound(err) {
				logger.V(1).Info("eks cluster not found",
					"appbox", appBoxKey,
					"cluster", clusterKey)
				return false, nil
			}
			return false, fmt.Errorf("failed to get eks cluster %s: %v", clusterKey, err)
		}
		return true, nil
	case consts.ProviderTypeGKE:
		var gke gkev1beta2.Cluster
		if err := r.Client.Get(ctx, clusterKey, &gke); err != nil {
			if apierrors.IsNotFound(err) {
				logger.V(1).Info("gke cluster not found",
					"appbox", appBoxKey,
					"cluster", clusterKey)
				return false, nil
			}
			return false, fmt.Errorf("failed to get gke cluster %s: %v", clusterKey, err)
		}
		return true, nil
	case consts.ProviderTypeAKS:
		var aks aksv1beta1.KubernetesCluster
		if err := r.Client.Get(ctx, clusterKey, &aks); err != nil {
			if apierrors.IsNotFound(err) {
				logger.V(1).Info("aks cluster not found",
					"appbox", appBoxKey,
					"cluster", clusterKey)
				return false, nil
			}
			return false, fmt.Errorf("failed to get aks cluster %s: %v", clusterKey, err)
		}
		return true, nil
	default:
		logger.V(1).Info("unknown provider type",
			"appbox", appBoxKey,
			"provider", appBox.Spec.Provider)
		return false, nil
	}
}