package dns

import (
	"fmt"
	"time"

	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/klog/v2"

	"github.com/cert-manager/cert-manager/pkg/acme/webhook/apis/acme/v1alpha1"
	//"github.com/cert-manager/cert-manager/pkg/issuer/acme/dns/util"
	"github.com/stuurmcp/cert-manager-webhook-sthome/pkg/util"
)

var (
	DNS01Nameservers = []string{"10.0.0.15:53", "192.168.2.1:53", "1.1.1.1:53", "1.0.0.1:53"}
)

const (
	DNS01CheckAuthoritative = true
)

// LocalDNSProviderSolver implements the provider-specific logic needed to
// 'present' an ACME challenge TXT record for your own DNS provider.
// To do so, it must implement the `github.com/cert-manager/cert-manager/pkg/acme/webhook.Solver`
// interface.
type LocalDNSProviderSolver struct {
	client kubernetes.Interface
}

// Name is used as the name for this DNS solver when referencing it on the ACME
// Issuer resource.
// This should be unique **within the group name**, i.e. you can have two
// solvers configured with the same Name() **so long as they do not co-exist
// within a single webhook deployment**.
// For example, `cloudflare` may be used as the name of a solver.
func (loc *LocalDNSProviderSolver) Name() string {
	return ProviderName
}

// Present is responsible for actually presenting the DNS record with the
// DNS provider.
// This method should tolerate being called multiple times with the same value.
// cert-manager itself will later perform a self check to ensure that the
// solver has correctly configured the DNS provider.
func (loc *LocalDNSProviderSolver) Present(ch *v1alpha1.ChallengeRequest) error {
	//domainName := extractDomainName(ch.ResolvedZone)
	_, err := LoadConfig(ch.Config)
	if err != nil {
		return err
	}
	// TODO: convert shell script to golang
	//localip := GetOutboundIP(Dnsserver_net)
	success, err := Execute(
		Shell,
		//	"-c",
		AcmeAuthCmd,
		"set",
		ch.DNSName,
		ch.ResolvedFQDN,
		ch.Key,
		"-l",
		"\"\"", //localip,
		//"-v",
	)
	klog.Infof("Present: Execute set TXT returned success: %t\n", success)
	err2 := loc.Check(ch.DNSName, ch.Key)
	if err2 != nil {
		klog.Infof("Present: Check prop failed: %s", err2)
	}
	return err
}

// CleanUp should delete the relevant TXT record from the DNS provider console.
// If multiple TXT records exist with the same record name (e.g.
// _acme-challenge.example.com) then **only** the record with the same `key`
// value provided on the ChallengeRequest should be cleaned up.
// This is in order to facilitate multiple DNS validations for the same domain
// concurrently.
func (loc *LocalDNSProviderSolver) CleanUp(ch *v1alpha1.ChallengeRequest) error {
	//domainName := extractDomainName(ch.ResolvedZone)
	//localip := GetOutboundIP(Dnsserver_net)
	success, err := Execute(
		Shell,
		//	"-c",
		AcmeAuthCmd,
		"unset",
		ch.DNSName,
		ch.ResolvedFQDN,
		ch.Key,
		"-l",
		"\"\"", //localip,
		//"-v",
	)
	klog.Infof("Execute unset TXT returned success: %t\n", success)
	return err
}

// Initialize will be called when the webhook first starts.
// This method can be used to instantiate the webhook, i.e. initialising
// connections or warming up caches.
// Typically, the kubeClientConfig parameter is used to build a Kubernetes
// client that can be used to fetch resources from the Kubernetes API, e.g.
// Secret resources containing credentials used to authenticate with DNS
// provider accounts.
// The stopCh can be used to handle early termination of the webhook, in cases
// where a SIGTERM or similar signal is sent to the webhook process.
func (loc *LocalDNSProviderSolver) Initialize(kubeClientConfig *rest.Config, stopCh <-chan struct{}) error {
	cl, err := kubernetes.NewForConfig(kubeClientConfig)
	if err != nil {
		return fmt.Errorf("failed to get kubernetes client: %w", err)
	}
	loc.client = cl
	klog.InfoS("CZ: Successfully initialised kubernetes client!")
	return nil
}

// Check verifies that the DNS records for the ACME challenge have propagated.
func (s *LocalDNSProviderSolver) Check(DNSName string, Key string) error {
	ttl := 20

	fqdn, err := util.DNS01LookupFQDN(DNSName, false, DNS01Nameservers...)
	if err != nil {
		return err
	}
	klog.Info("waiting DNS record TTL to allow the DNS01 record to propagate for domain")
	time.Sleep(time.Second * time.Duration(ttl))

	//klog.Info("checking DNS propagation: ", "dns: ", DNSName, ", fqdn: ", fqdn, ", key: ", Key, ", nameservers: ", DNS01Nameservers)
	klog.Info("checking DNS prop: fqdn: ", fqdn)

	ok, err := util.PreCheckDNS(fqdn, Key, DNS01Nameservers, DNS01CheckAuthoritative)
	if err != nil {
		return err
	}
	if !ok {
		return fmt.Errorf("DNS record for %q not yet propagated", DNSName)
	}

	//	klog.Info("waiting DNS record TTL to allow the DNS01 record to propagate for domain")
	//	time.Sleep(time.Second * time.Duration(ttl))
	klog.Info("ACME DNS01 validation record propagated: ", "fqdn", fqdn)

	return nil
}

/*
func extractDomainName(zone string) string {
	authZone, err := util.FindZoneByFqdn(zone, util.RecursiveNameservers)
	if err != nil {
		klog.Errorf("could not get zone by fqdn %v", err)
		return zone
	}
	return util.UnFqdn(authZone)
}
*/