/*
Copyright 2025.

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 controller

import (
	"context"
	"fmt"

	"github.com/tidbcloud/infra-provider/pkg/deploy"
	"github.com/tidbcloud/infra-provider/pkg/k8s"
	cdcv1 "github.com/tidbcloud/ticdc-service/api/v1"
	"github.com/tidbcloud/ticdc-service/controllers/sink-endpoint/task"
	"github.com/tidbcloud/ticdc-service/pkg/cloud"
	"github.com/tidbcloud/ticdc-service/pkg/config"
	"github.com/tidbcloud/ticdc-service/pkg/regionalservice"
	corev1 "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	"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/controller/controllerutil"
	"sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/predicate"
)

// SinkEndpointReconciler reconciles a SinkEndpoint object
type SinkEndpointReconciler struct {
	EventRecorder record.EventRecorder
	client.Client
	Scheme *runtime.Scheme
	Cache  client.Reader
	Config *config.Config
}

// +kubebuilder:rbac:groups=cdc.tidbcloud.com,resources=sinkendpoints,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=cdc.tidbcloud.com,resources=sinkendpoints/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=cdc.tidbcloud.com,resources=sinkendpoints/finalizers,verbs=update

// Reconcile is part of the main kubernetes reconciliation loop which aims to
// move the current state of the cluster closer to the desired state.
//
// For more details, check Reconcile and its Result here:
// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.19.1/pkg/reconcile
func (r *SinkEndpointReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	logger := log.FromContext(ctx)
	logger.Info("Reconciling SinkEndpoint")

	endpoint := &cdcv1.SinkEndpoint{}
	if err := r.Cache.Get(ctx, req.NamespacedName, endpoint); err != nil {
		if apierrors.IsNotFound(err) {
			return ctrl.Result{}, nil
		}
		return ctrl.Result{}, fmt.Errorf("unable to get sink endpoint %s: %v", req.NamespacedName, err)
	}
	regionalCli := regionalservice.NewRegionalServiceClient(r.Config.RegionalServiceBaseURL)
	appbox, err := regionalCli.GetAPPBoxByID(ctx, endpoint.Spec.AppBoxID)
	if err != nil {
		return ctrl.Result{}, fmt.Errorf("fail to get appbox: %v", err)
	}
	var cloudProvider cloud.Provider
	switch p := r.Config.Provider; p {
	case config.ProviderAWS:
		cloudProvider = cloud.NewAWSProvider(appbox, r.Config)
	case config.ProviderGCP:
		cloudProvider, err = cloud.NewGcpProvider(appbox, r.Config)
		if err != nil {
			return ctrl.Result{}, fmt.Errorf("fail to build gcp Provider: %v", err)
		}
	case config.ProviderAzure:
		tid := r.Config.Azure.CrossplaneProviderTenantID
		cid := r.Config.Azure.CrossplaneProviderClientID
		cloudProvider, err = cloud.NewAzureProvider(ctx, tid, cid, regionalCli, r.Client, appbox)
		if err != nil {
			return ctrl.Result{}, fmt.Errorf("fail to build azure Provider: %v", err)
		}
	default:
		return ctrl.Result{}, fmt.Errorf("unsupported provider: %s", p)
	}
	c := &task.Context{
		Recorder:      r.EventRecorder,
		Logger:        logger,
		Env:           r.Config.Env,
		Local:         r.Client,
		SinkEndpoint:  endpoint,
		CloudProvider: cloudProvider,
		AppBox:        appbox,
	}
	tasks := []deploy.Task{
		task.NewGuardian(c),
		task.NewProviderConfigTask(c),
		task.NewEndpoint(c),
		task.NewDNS(c),
	}
	deployer := deploy.NewDeployer(tasks, nil, logger)
	deleted := !endpoint.DeletionTimestamp.IsZero()
	// finalizer is added to cdcv1.SinkEndpoint in Guardian task
	// but Guardian task can't detect other task destroy results
	// so we remove finalizer in the main controller
	var res ctrl.Result
	var errs error
	var retriableErrs error
	if deleted {
		results := deployer.Destroy(ctx)
		res, errs, retriableErrs = deploy.MinRequeue(results)
		if errs == nil && retriableErrs == nil {
			// all tasks destroy finished without error, so remove finalizer
			controllerutil.RemoveFinalizer(endpoint, task.Finalizer)
		}
		if err := r.Client.Update(ctx, endpoint); err != nil {
			r.EventRecorder.Event(endpoint, corev1.EventTypeWarning, "ReconcileFailed", err.Error())
			return res, err
		}
	} else {
		results := deployer.Deploy(ctx)
		res, errs, retriableErrs = deploy.MinRequeue(results)
		if errs != nil || retriableErrs != nil {
			log.FromContext(ctx).Info("deploy met error",
				"errs", errs, "retriableErrs", retriableErrs)
		} else {
			endpoint.Status.Phase = cdcv1.EndpointResourceStateAvailable
		}
		endpointStatus := endpoint.Status.DeepCopy()
		if err := r.Client.Update(ctx, endpoint); err != nil {
			r.EventRecorder.Event(endpoint, corev1.EventTypeWarning, "ReconcileFailed", err.Error())
			return res, err
		}
		endpoint.Status = *endpointStatus
		if err := r.Client.Status().Update(ctx, endpoint); err != nil {
			r.EventRecorder.Event(endpoint, corev1.EventTypeWarning, "ReconcileFailed", err.Error())
			return res, err
		}
	}
	if errs != nil {
		r.EventRecorder.Event(endpoint, corev1.EventTypeWarning, "ReconcileFailed", errs.Error())
		return res, errs
	} else if retriableErrs != nil {
		r.EventRecorder.Event(endpoint, corev1.EventTypeWarning, "ReconcileFailed", retriableErrs.Error())
		return res, retriableErrs
	} else {
		r.EventRecorder.Event(endpoint, corev1.EventTypeNormal, "ReconcileSuccess", "")
		return res, nil
	}
}

// SetupWithManager sets up the controller with the Manager.
func (r *SinkEndpointReconciler) SetupWithManager(mgr ctrl.Manager, preds ...predicate.Predicate) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&cdcv1.SinkEndpoint{}, builder.WithPredicates(preds...)).
		WithOptions(controller.Options{RateLimiter: k8s.RetryLimiter, MaxConcurrentReconciles: 5}).
		Named("sinkendpoint").
		Complete(r)
}