// SPDX-License-Identifier: Apache-2.0
// Copyright 2026 The Cozystack Authors.

package main

import (
	"crypto/tls"
	"flag"
	"os"

	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
	// to ensure that exec-entrypoint and run can make use of them.
	_ "k8s.io/client-go/plugin/pkg/client/auth"

	"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"
	"sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"

	sgc "github.com/cozystack/cozystack/internal/securitygroupcontroller"
)

var (
	scheme   = runtime.NewScheme()
	setupLog = ctrl.Log.WithName("setup")
)

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

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var secureMetrics bool
	var enableHTTP2 bool
	var tlsOpts []func(*tls.Config)
	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metrics endpoint binds to. "+
		"Use :8443 for HTTPS or :8080 for HTTP, or leave as 0 to disable the metrics service.")
	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	flag.BoolVar(&secureMetrics, "metrics-secure", true,
		"If set, the metrics endpoint is served securely via HTTPS. Use --metrics-secure=false to use HTTP instead.")
	flag.BoolVar(&enableHTTP2, "enable-http2", false,
		"If set, HTTP/2 will be enabled for the metrics server")
	opts := zap.Options{
		Development: false,
	}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))

	// Disable HTTP/2 by default to avoid the Stream Cancellation and Rapid Reset
	// CVEs (GHSA-qppj-fm5r-hxr3, GHSA-4374-p667-p6c8).
	disableHTTP2 := func(c *tls.Config) {
		setupLog.Info("disabling http/2")
		c.NextProtos = []string{"http/1.1"}
	}
	if !enableHTTP2 {
		tlsOpts = append(tlsOpts, disableHTTP2)
	}

	metricsServerOptions := metricsserver.Options{
		BindAddress:   metricsAddr,
		SecureServing: secureMetrics,
		TLSOpts:       tlsOpts,
	}
	if secureMetrics {
		metricsServerOptions.FilterProvider = filters.WithAuthenticationAndAuthorization
	}

	// Configure rate limiting for the Kubernetes client.
	config := ctrl.GetConfigOrDie()
	config.QPS = 50.0
	config.Burst = 100

	mgr, err := ctrl.NewManager(config, ctrl.Options{
		Scheme:                 scheme,
		Metrics:                metricsServerOptions,
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "securitygroup-controller.sdn.cozystack.io",
		// Bound the informer caches to the only objects this controller acts on.
		Cache: cache.Options{ByObject: sgc.CacheByObject()},
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	if err := (&sgc.Reconciler{Client: mgr.GetClient()}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to setup controller", "controller", "SecurityGroupMembership")
		os.Exit(1)
	}

	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to set up health check")
		os.Exit(1)
	}
	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to set up ready check")
		os.Exit(1)
	}

	setupLog.Info("starting manager")
	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		setupLog.Error(err, "problem running manager")
		os.Exit(1)
	}
}