package xserver

import (
	"context"
	"fmt"
	"os"

	"github.com/go-logr/logr"
	kruntime "k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	ctrl "sigs.k8s.io/controller-runtime"

	"edge-infra.dev/pkg/k8s/runtime/controller"
	"edge-infra.dev/pkg/sds/display/constants"
	"edge-infra.dev/pkg/sds/display/displaymanager/manager"
	xorgmanager "edge-infra.dev/pkg/sds/display/displaymanager/manager/xorg"
)

const (
	hostnameEnvvar      = "HOSTNAME"
	healthzCheckAddress = ":8082"
)

var errHostnameEnvvarNotSet = fmt.Errorf("%s envvar is not set", hostnameEnvvar)

var scheme = kruntime.NewScheme()

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
}

func Run(ctx context.Context, opts ...controller.Option) error {
	log := ctrl.LoggerFrom(ctx).WithName(constants.XServerName)

	mgr, err := createManager(opts...)
	if err != nil {
		log.Error(err, "unable to create manager")
		return err
	}

	hostname := os.Getenv(hostnameEnvvar)
	if hostname == "" {
		log.Error(errHostnameEnvvarNotSet, "unable to find hostname")
		return errHostnameEnvvarNotSet
	}

	displayManager := xorgmanager.NewXorgDisplayManager(hostname, mgr.GetClient(), log)
	configChan := make(configChannel)

	if err := registerComponentsWithManager(mgr, displayManager, configChan, log); err != nil {
		log.Error(err, "unable to setup components with manager")
		return err
	}

	if err := mgr.Start(ctx); err != nil {
		log.Error(err, "xserver received an error")
		return err
	}

	return nil
}

func createManager(opts ...controller.Option) (ctrl.Manager, error) {
	mgrCfg, mgrOpts := controller.ProcessOptions(opts...)
	mgrOpts.Scheme = scheme
	mgrOpts.HealthProbeBindAddress = healthzCheckAddress
	return ctrl.NewManager(mgrCfg, mgrOpts)
}

func registerComponentsWithManager(mgr ctrl.Manager, displayManager manager.DisplayManager, configChan configChannel, log logr.Logger) error {
	r, err := NewXServerRunnable(displayManager, configChan, mgr.GetClient(), log)
	if err != nil {
		return err
	}
	if err := r.SetupWithManager(mgr); err != nil {
		return err
	}

	c := NewConfigController(displayManager.Hostname(), configChan, mgr.GetClient())
	return c.SetupWithManager(mgr)
}