/*
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 controller

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	zitadelv1alpha1 "gitea.corredorconect.com/software-engineering/zitadel-resources-operator/api/v1alpha1"
	"gitea.corredorconect.com/software-engineering/zitadel-resources-operator/pkg/builder"
	condition "gitea.corredorconect.com/software-engineering/zitadel-resources-operator/pkg/condition"
	"gitea.corredorconect.com/software-engineering/zitadel-resources-operator/pkg/controller/core"
	clientv2 "github.com/zitadel/zitadel-go/v3/pkg/client"
	"github.com/zitadel/zitadel-go/v3/pkg/client/zitadel/application/v2"
	"github.com/zitadel/zitadel-go/v3/pkg/client/zitadel/filter/v2"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/util/workqueue"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	ctrlClient "sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

// APIAppReconciler reconciles a APIApp object
type APIAppReconciler struct {
	client.Client
	RefResolver     *zitadelv1alpha1.RefResolver
	ConditionReady  *condition.Ready
	RequeueInterval time.Duration
	Builder         *builder.Builder
}

func NewAPIAppReconciler(client client.Client, refResolver *zitadelv1alpha1.RefResolver, builder *builder.Builder, conditionReady *condition.Ready,
	requeueInterval time.Duration) *APIAppReconciler {
	return &APIAppReconciler{
		Client:          client,
		RefResolver:     refResolver,
		ConditionReady:  conditionReady,
		RequeueInterval: requeueInterval,
		Builder:         builder,
	}
}

//+kubebuilder:rbac:groups=zitadel.github.com,resources=apiapps,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=zitadel.github.com,resources=apiapps/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=zitadel.github.com,resources=apiapps/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.
func (r *APIAppReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	var APIApp zitadelv1alpha1.APIApp
	if err := r.Get(ctx, req.NamespacedName, &APIApp); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}
	wr := newWrappedAPIAppReconciler(r.Client, r.RefResolver, r.Builder, &APIApp)
	wf := newWrappedAPIAppFinalizer(r.Client, &APIApp, r.RefResolver)
	tf := core.NewCoreFinalizer(r.Client, wf)
	tr := core.NewCoreReconciler(r.Client, r.ConditionReady, wr, tf, r.RequeueInterval)

	result, err := tr.Reconcile(ctx, &APIApp)
	if err != nil {
		return result, fmt.Errorf("error reconciling in APIAppReconciler: %v", err)
	}
	return result, nil
}

type wrappedAPIAppReconciler struct {
	client.Client
	refResolver *zitadelv1alpha1.RefResolver
	APIApp      *zitadelv1alpha1.APIApp
	Builder     *builder.Builder
}

func newWrappedAPIAppReconciler(client client.Client, refResolver *zitadelv1alpha1.RefResolver, builder *builder.Builder,
	APIApp *zitadelv1alpha1.APIApp) core.WrappedCoreReconciler {
	return &wrappedAPIAppReconciler{
		Client:      client,
		refResolver: refResolver,
		APIApp:      APIApp,
		Builder:     builder,
	}
}

type apiAppReconcilePhase struct {
	Name      string
	Reconcile func(context.Context, *clientv2.Client) error
}

func (wr *wrappedAPIAppReconciler) Reconcile(ctx context.Context, ztdClient *clientv2.Client) error {
	phases := []apiAppReconcilePhase{
		{
			Name:      "apiapp",
			Reconcile: wr.reconcileApp,
		},
		{
			Name:      "keys",
			Reconcile: wr.reconcileKeys,
		},
	}
	for _, p := range phases {
		err := p.Reconcile(ctx, ztdClient)
		if err != nil {
			return err
		}
	}
	return nil
}

func (wr *wrappedAPIAppReconciler) reconcileApp(ctx context.Context, ztdClient *clientv2.Client) error {
	projectRef, err := wr.APIApp.Project(ctx, wr.refResolver)
	if err != nil {
		return err
	}
	if projectRef.ID == "" {
		return fmt.Errorf("Project has not been created yet...")
	}

	var appid *string
	var clientid *string
	appList, err := ztdClient.ApplicationServiceV2().ListApplications(ctx,
		&application.ListApplicationsRequest{
			Filters: []*application.ApplicationSearchFilter{
				{
					Filter: &application.ApplicationSearchFilter_NameFilter{
						NameFilter: &application.ApplicationNameFilter{
							Name:   wr.APIApp.Spec.APIAppName,
							Method: filter.TextFilterMethod_TEXT_FILTER_METHOD_EQUALS,
						},
					},
				},
				{
					Filter: &application.ApplicationSearchFilter_ProjectIdFilter{
						ProjectIdFilter: &application.ProjectIDFilter{
							ProjectId: projectRef.ID,
						},
					},
				},
			},
		},
	)
	if err != nil {
		return fmt.Errorf("Error listing APIApps: %v", err)
	}

	if len(appList.Applications) > 0 {
		appid = &appList.Applications[0].ApplicationId
		clientid = &appList.Applications[0].GetApiConfiguration().ClientId
	}

	if appid == nil {
		resp, err := ztdClient.ApplicationServiceV2().CreateApplication(ctx,
			&application.CreateApplicationRequest{
				Name:      wr.APIApp.Spec.APIAppName,
				ProjectId: projectRef.ID,
				ApplicationType: &application.CreateApplicationRequest_ApiConfiguration{
					ApiConfiguration: &application.CreateAPIApplicationRequest{
						AuthMethodType: application.APIAuthMethodType(application.APIAuthMethodType_value[wr.APIApp.Spec.AuthMethodType]),
					},
				},
			},
		)
		if err != nil {
			return fmt.Errorf("error creating APIApp in Zitadel: %v", err)
		}
		key := types.NamespacedName{
			Name:      wr.APIApp.ClientSecretName(),
			Namespace: wr.APIApp.Namespace,
		}
		secretData := map[string][]byte{
			"clientSecret": []byte(resp.GetApiConfiguration().ClientSecret),
			"appId":        []byte(resp.ApplicationId),
			"clientId":     []byte(resp.GetApiConfiguration().ClientId),
			"projectId":    []byte(projectRef.ID),
		}
		secret, err := wr.Builder.BuildSecret(builder.SecretOpts{Immutable: false, Key: key, Data: secretData}, wr.APIApp)
		if err != nil {
			return fmt.Errorf("error building Secret: %v", err)
		}
		if err := wr.Create(ctx, secret); err != nil {
			return fmt.Errorf("error creating Client-secret Secret: %v", err)
		}
		appid = &resp.ApplicationId
		clientid = &resp.GetApiConfiguration().ClientId
	} else {
		_, err := ztdClient.ApplicationServiceV2().UpdateApplication(ctx,
			&application.UpdateApplicationRequest{
				Name:          wr.APIApp.Spec.APIAppName,
				ProjectId:     projectRef.ID,
				ApplicationId: *appid,
				ApplicationType: &application.UpdateApplicationRequest_ApiConfiguration{
					ApiConfiguration: &application.UpdateAPIApplicationConfigurationRequest{
						AuthMethodType: application.APIAuthMethodType(application.APIAuthMethodType_value[wr.APIApp.Spec.AuthMethodType]),
					},
				},
			},
		)
		if err != nil {
			return fmt.Errorf("error updating APIApp in Zitadel: %v", err)
		}
	}
	patch := ctrlClient.MergeFrom(wr.APIApp.DeepCopy())
	wr.APIApp.Status.AppId = appid
	wr.APIApp.Status.ClientId = clientid
	return wr.Client.Status().Patch(ctx, wr.APIApp, patch)
}

type Key struct {
	Type     string `json:"type"`
	KeyID    string `json:"keyId"`
	Key      string `json:"key"`
	AppID    string `json:"appId"`
	ClientID string `json:"clientId"`
}

func (wr *wrappedAPIAppReconciler) reconcileKeys(ctx context.Context, ztdClient *clientv2.Client) error {
	if wr.APIApp.Spec.AuthMethodType == "API_AUTH_METHOD_TYPE_PRIVATE_KEY_JWT" {
		projectRef, err := wr.APIApp.Project(ctx, wr.refResolver)
		if err != nil {
			return err
		}
		if wr.APIApp.Status.AppId == nil {
			return fmt.Errorf("APIApp has not been created yet...")
		}

		if wr.APIApp.Status.KeyId != nil {
			keyList, err := ztdClient.ApplicationServiceV2().ListApplicationKeys(ctx, &application.ListApplicationKeysRequest{
				Filters: []*application.ApplicationKeySearchFilter{
					{
						Filter: &application.ApplicationKeySearchFilter_ApplicationIdFilter{
							ApplicationIdFilter: &application.ApplicationKeyApplicationIDFilter{
								ApplicationId: *wr.APIApp.Status.AppId,
							},
						},
					},
					{
						Filter: &application.ApplicationKeySearchFilter_ProjectIdFilter{
							ProjectIdFilter: &application.ApplicationKeyProjectIDFilter{
								ProjectId: projectRef.ID,
							},
						},
					},
				},
			})
			if err != nil {
				return fmt.Errorf("Error listing application keys: %v", err)
			}

			for _, key := range keyList.Keys {
				if key.KeyId == *wr.APIApp.Status.KeyId {
					return nil
				}
			}
		}

		resp, err := ztdClient.ApplicationServiceV2().CreateApplicationKey(ctx, &application.CreateApplicationKeyRequest{
			ApplicationId: *wr.APIApp.Status.AppId,
			ProjectId:     projectRef.ID,
		})

		if err != nil {
			return fmt.Errorf("Error adding Key to app: %v", err)
		}

		key := types.NamespacedName{
			Name:      wr.APIApp.PrivateKeySecretName(),
			Namespace: wr.APIApp.Namespace,
		}
		var jsonKey Key
		if err = json.Unmarshal(resp.KeyDetails, &jsonKey); err != nil {
			return fmt.Errorf("Could not unmarshal key details: %v", err)
		}
		secretData := map[string][]byte{
			"clientId": []byte(jsonKey.ClientID),
			"type":     []byte(jsonKey.Type),
			"keyId":    []byte(jsonKey.KeyID),
			"appId":    []byte(jsonKey.AppID),
			"key":      []byte(jsonKey.Key),
		}
		secret, err := wr.Builder.BuildSecret(builder.SecretOpts{Immutable: false, Key: key, Data: secretData}, wr.APIApp)
		if err != nil {
			return fmt.Errorf("error building Secret: %v", err)
		}
		if err := wr.Create(ctx, secret); err != nil {
			return fmt.Errorf("error creating private-key Secret: %v", err)
		}
		patch := ctrlClient.MergeFrom(wr.APIApp.DeepCopy())
		wr.APIApp.Status.KeyId = &resp.KeyId
		return wr.Client.Status().Patch(ctx, wr.APIApp, patch)
	}
	return nil
}

func (wr *wrappedAPIAppReconciler) PatchStatus(ctx context.Context, patcher condition.Patcher) error {
	patch := client.MergeFrom(wr.APIApp.DeepCopy())
	patcher(&wr.APIApp.Status)

	if err := wr.Client.Status().Patch(ctx, wr.APIApp, patch); err != nil {
		return fmt.Errorf("error patching APIApp status: %v", err)
	}
	return nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *APIAppReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&zitadelv1alpha1.APIApp{}).
		Owns(&corev1.Secret{}).
		WithOptions(controller.Options{RateLimiter: workqueue.NewTypedItemExponentialFailureRateLimiter[reconcile.Request](time.Millisecond*500, time.Minute*3)}).
		Complete(r)
}