package approver

import (
	"context"
	"errors"
	"net"
	"strings"

	pve "git.giftfish.de/ston1th/pve-go"

	//"k8s.io/client-go/kubernetes/typed/certificates/v1"
	"github.com/go-logr/logr"
	certificatesv1beta1 "k8s.io/api/certificates/v1beta1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/kubernetes/typed/certificates/v1beta1"
	"k8s.io/kubernetes/pkg/apis/certificates"
)

var ErrNoKubeletServingCSR = errors.New("CSR is no kubelet serving certificate")

func checkCSR(ctx context.Context, pveClient *pve.Client, request *certificatesv1beta1.CertificateSigningRequest) error {
	req, err := certificates.ParseCSR(request.Spec.Request)
	if err != nil {
		return err
	}
	usages := make([]string, len(request.Spec.Usages))
	for i, v := range request.Spec.Usages {
		usages[i] = string(v)
	}
	if !certificates.IsKubeletServingCSR(req, sets.NewString(usages...)) {
		return ErrNoKubeletServingCSR
	}
	hostname := strings.TrimPrefix(req.Subject.CommonName, "system:node:")
	ref, err := pveClient.Pool.FindServerByName(ctx, "", hostname)
	if err != nil {
		return err
	}
	if ref.Name != hostname {
		return errors.New("CSR hostname and PVE server name do not match")
	}
	ok := false
	for _, dns := range req.DNSNames {
		if dns == hostname {
			ok = true
		}
	}
	if len(req.DNSNames) == 0 {
		ok = true
	}
	if !ok {
		return errors.New("req.DNSNames does not contain hostname")
	}
	srv, err := pveClient.Server.GetByRef(ctx, ref)
	if err != nil {
		return err
	}
	ok = false
	for _, ip := range req.IPAddresses {
		for _, ipc := range srv.IPConfig {
			ipv4, _, err := net.ParseCIDR(ipc.IPv4CIDR)
			if err == nil {
				if ip.String() == ipv4.String() {
					ok = true
					break
				}
			}
			ipv6, _, err := net.ParseCIDR(ipc.IPv6CIDR)
			if err == nil {
				if ip.String() == ipv6.String() {
					ok = true
					break
				}
			}
		}
		if ok {
			break
		}
	}
	if len(req.IPAddresses) == 0 {
		ok = true
	}
	if !ok {
		return errors.New("req.IPAddresses does not contain a valid IP")
	}
	return nil
}

var conditionv1beta1 = certificatesv1beta1.CertificateSigningRequestCondition{
	Type:    certificatesv1beta1.CertificateApproved,
	Reason:  "AutoApproved",
	Message: "Auto approving kubelet client certificate in PVE Cluster",
}

func ApproveV1beta1(log logr.Logger, pveClient *pve.Client, client v1beta1.CertificateSigningRequestInterface, request *certificatesv1beta1.CertificateSigningRequest) error {
	if len(request.Status.Conditions) > 0 {
		return nil
	}
	ctx := context.Background()
	err := checkCSR(ctx, pveClient, request)
	if err == ErrNoKubeletServingCSR {
		return nil
	}
	if err != nil {
		return err
	}

	for {
		if len(request.Status.Conditions) > 0 {
			return nil
		}
		request.Status.Conditions = append(request.Status.Conditions, conditionv1beta1)
		// Submit the updated CSR.
		if _, err := client.UpdateApproval(ctx, request, metav1.UpdateOptions{}); err != nil {
			if strings.Contains(err.Error(), "the object has been modified") {
				// The CSR might have been updated by a third-party, retry until we
				// succeed.
				request, err = client.Get(ctx, request.ObjectMeta.Name, metav1.GetOptions{})
				if err != nil {
					return err
				}
				continue
			}
			return err
		}
		log.Info("csr approval successful", "name", request.ObjectMeta.Name)
		return nil
	}
}

//func ApproveV1(pveClient *pve.Client, client v1.CertificateSigningRequestInterface, request *certificates.CertificateSigningRequest) error {
//	if len(request.Status.Conditions) > 0 {
//		return nil
//	}
//	err := checkCSR(pveClient, request)
//	if err != nil {
//		return err
//	}
//
//	for {
//		if len(request.Status.Conditions) > 0 {
//			return nil
//		}
//		request.Status.Conditions = append(request.Status.Conditions, condition)
//		// Submit the updated CSR.
//		if _, err := client.UpdateApproval(request); err != nil {
//			if strings.Contains(err.Error(), "the object has been modified") {
//				// The CSR might have been updated by a third-party, retry until we
//				// succeed.
//				request, err = client.Get(request.ObjectMeta.Name)
//				if err != nil {
//					return err
//				}
//				continue
//			}
//			return err
//		}
//		return nil
//	}
//}